Oncology AI Flashcards
1
Q
What is the main disadvantage of incisional biopsies?
A
They provide visual access but harvest smaller samples than other methods.
2
Q
When is excisional biopsy indicated?
A
For lymph nodes, some intestinal masses, and most mammary tumors.
3
Q
What are some features of malignancy used to establish malignancy grade?
A
Degree of differentiation, mitotic index, degree of cellular or nuclear polymorphism, amount of necrosis, invasiveness, stromal reaction, nucleolar size and number, overall cellularity, lymphoid response
4
Q
How can the presumed clinical behavior of a tumor be assessed when there is no validated grading scheme?
A
On the basis of well, moderately, or poorly differentiated
5
Q
What are grading schemes often used for?
A
To give a prognosis and decide treatment intensity
6
Q
What is the role of histologic grade?
A
It is complementary to the TNM clinical stage
7
Q
What is the mechanism of action of toceranib against MCTs?
A
Antiangiogenic nature, results of VEGFR and PDGFR blockage
8
Q
Is tumour grade associated with response rate to toceranib?
A
No
9
Q
Is duration of response longer for grade II or grade III MCT treated with toceranib?
A
Grade II
10
Q
What are potential mechanisms for resistance to toceranib?
A
Development of new mutations in c-kit, significant overexpression of KIT, activation of other signaling pathways
11
Q
What was the response rate in the randomized trial of masitinib for dogs with inoperable MCTs?
A
15% for treatment group, 16% for placebo group
12
Q
Was there a significant difference in time to disease progression between masitinib and placebo group?
A
Yes, masitinib group had a significantly improved time to disease progression
13
Q
Did c-Kit mutation presence affect the time to disease progression in the masitinib group?
A
No
14
Q
What are the survival rates at 12 and 24 months for dogs treated with masitinib?
A
Higher survival rate at 12 and 24 months
15
Q
What is the treatment response rate of masitinib in non-resectable and metastatic MCT?
A
50%
16
Q
What is the most significant prognostic factor for survival in dogs treated with masitinib?
A
Response to masitinib
17
Q
What are the adverse reactions associated with masitinib treatment?
A
Diarrhoea, anorexia, vomiting, lethargy, lameness, weight loss, blood in stool
18
Q
What are the laboratory abnormalities associated with masitinib treatment?
A
Neutropenia, hypoalbuminaemia, thrombocytopenia, increased ALT, decreased hematocrit, increased creatinine, hyperbilirubinemia, urinary tract infection
19
Q
Is there evidence of TKIs effectiveness against feline MCTs?
A
No published studies on the activity of masitinib against feline MCTs
20
Q
What was the response rate of feline MCTs positive for c-kit mutation treated with imatinib?
A
Complete response: 2/9, Partial response: 6/9
21
Q
What is a possible alternative chemotherapy regime for feline MCTs?
A
Toceranib and prednisolone
22
Q
What is the dosage of toceranib for cats?
A
2.75mg/kg three times per week
23
Q
What was the clinical benefit seen in cats treated with toceranib?
A
86% for cutaneous cases, 76% for gastrointestinal cases
24
Q
What is the median duration of treatment for cats experiencing clinical benefit with toceranib?
A
36 weeks for cutaneous cases, 23 weeks for gastrointestinal cases
25
What is the most significant prognostic factor for survival in cats treated with toceranib?
Response to toceranib
26
Why should tablets or capsules of cyclophosphamide never be broken or opened?
Breaking or opening the tablets or capsules may lead to an inappropriate dose and exposure to cytotoxic drugs.
27
What precaution should be taken by veterinary surgeons or pet owners when administering cytotoxic drugs?
They must wear gloves when administering these drugs.
28
What is the recommended administration route for chemotherapy drugs in dogs and cats with malignant pleural or abdominal effusions?
Intracavitary administration, with the implantation of permanent thoracic or pleural catheters.
29
Which chemotherapy drugs have been successful in reducing malignant effusion in dogs?
Cisplatin, carboplatin, mitoxantrone, and fluorouracil.
30
What factors should be considered in monitoring and managing the adverse effects of chemotherapy?
Dose-related toxicity, organ system failure, genetic defects, and tissue-specific effects.
31
What is the common term for the toxic effects of chemotherapy on the bone marrow?
Myelosuppression.
32
What is the limiting factor of myelosuppression in pets undergoing cytotoxic therapy?
Neutropenia.
33
When does the nadir of neutrophils typically occur after the administration of chemotherapy?
Around 8 days post-administration, varying from 5 to 10 days depending on the drug.
34
What is the recommended interval for administering most chemotherapy drugs in veterinary oncology?
At least every one to two weeks, except for lomustine and carboplatin.
35
What should be performed when the neutrophil nadir is expected?
A full complete blood count, including platelet count.
36
When should the dose of a chemotherapy drug be reduced?
If nadirs below 1000 neutrophils per microliter are detected.
37
How much should the dose of a chemotherapy drug be reduced if the neutrophil count falls below 1000/μl?
By 15 - 20% for the next administration.
38
What is the general approach when the neutrophil count is below 2000/μl?
Delay chemotherapy treatment by 3 days to one week and consider other factors for treatment decision-making.
39
When should chemotherapy not be administered, regardless of the neutrophil count?
If the patient is clinically unwell (anorexia, diarrhea, vomiting) or has a fever.
40
What is the high-risk complication associated with neutrophil counts below 500/μl?
Sepsis.
41
What breakthrough was achieved in the treatment of canine melanoma?
A breakthrough was achieved with a DNA vaccine encoding the human tyrosinase.
42
What is the name of the DNA vaccine used for treating oral melanoma in dogs?
The DNA vaccine is commercialized under the name of Oncept.
43
Which regulatory authority has licensed Oncept for veterinary use?
Oncept is the only veterinary therapeutic tumour vaccine licensed by the US FDA.
44
How was the clinical efficacy of Oncept evaluated in a study?
The clinical efficacy of Oncept was evaluated in a pilot study with 9 dogs.
45
What was the administration method used for the DNA vaccine?
The DNA vaccine was administered i/m in a needle-free manner without electroporation.
46
What was the advantage of the administration method used for the DNA vaccine?
Unlike electroporation, no general anaesthesia was required for the administration of the DNA vaccine.
47
What was the frequency of administration for the DNA vaccine in early trials?
The DNA vaccine was administered four times weekly in early trials.
48
How was the frequency of administration for the DNA vaccine changed in recent trials?
In recent trials, the DNA vaccine was administered four biweekly injections followed by boosts every 6 months.
49
What type of response was observed in some patients after vaccination?
An antibody response against human tyrosinase was observed in some patients.
50
What correlation was observed between the antibody response and the clinical response?
A correlation between the antibody response and the clinical response was observed in the initial pilot study.
51
What is tyrosinase and why was the antibody response unexpected?
Tyrosinase is an intracellular protein, and it was unexpected to see a response from antibodies.
52
How were the survival times of vaccinated dogs compared to a control group?
A statistical survival analysis compared the survival times of vaccinated dogs to a historical control group.
53
What was the median survival time for vaccinated dogs in the study?
The median survival time was not reached for vaccinated dogs.
54
What percentage of vaccinated dogs were expected to live beyond 464 days?
75% of vaccinated dogs were expected to live beyond 464 days.
55
What is a weakness of the study comparing survival times to a control group?
The study used survival data from an article published in 1999, which may not be comparable to the present.
56
What additional study design is recommended to prove the clinical efficacy of Oncept?
A randomized, placebo-controlled study should be performed to prove the clinical efficacy of Oncept.
57
What did a recent study find in terms of survival time for vaccinated and non-vaccinated dogs?
No difference in survival time could be found between vaccinated and not vaccinated dogs.
58
How many dogs were included in the study with canine oral melanoma?
The study included 151 dogs with canine oral melanoma.
59
What is the recommended approach for cases of oral melanoma in terms of local control?
Complete removal of primary tumor and removal of metastatic lymph nodes is recommended for local control.
60
What are the four major categories of tumour antigens?
Differentiation antigens, cancer/testis antigens, mutational antigens, ubiquitous antigens
61
What are differentiation antigens?
Antigens overexpressed in a given type of cancer and often expressed in normal tissue.
62
What are examples of differentiation antigens?
Prostate-specific antigen and tyrosinase.
63
What are cancer/testis antigens?
Antigens expressed in germ-line tissue and different types of cancers.
64
Why are cancer/testis antigens considered tumour specific?
Germ-line tissue lacks MHC expression, hence tolerance and autoimmunity are not major issues.
65
What are mutational antigens?
Antigens resulting from mutations and are strictly tumour specific.
66
What are the limitations of mutational antigens?
They are patient-specific or restricted to certain patients.
67
How can unknown mutational antigens be included in tumour vaccines?
By using whole, autologous tumour cell vaccines.
68
What are ubiquitous antigens?
Antigens expressed in many normal tissues and overexpressed in tumours.
69
What is the rationale behind the effectiveness of ubiquitous antigens without causing autoimmunity?
Overexpression in tumour cells can reach the threshold for T-cell recognition, breaking immune tolerance.
70
What is an example of a ubiquitous antigen?
Her2/neu
71
What are the three classes of antigens based on their origin?
Autologous, allogeneic, and xenogeneic antigens.
72
What are autologous antigens?
Antigens isolated from the patient's own tumour cells, representing personalized therapy.
73
How can autologous antigens be included in tumour vaccines?
By using tumour cell vaccines, dendritic cell vaccines, peptide vaccines, or DC tumour fusion vaccines.
74
What are allogeneic antigens?
Antigens from the same species as the patient, but from a different individual.
75
What are xenogeneic antigens?
Antigens derived from another species than the patient, breaking immune tolerance to self-antigens.
76
When does surgical resection become possible after neoadjuvant chemotherapy?
Surgical resection becomes possible after a few cycles of chemotherapy.
77
Should chemotherapy be used as a substitute for surgery or radiotherapy?
No, chemotherapy should not be used as a substitute for surgery or radiotherapy.
78
When can chemotherapy be used following surgery with incomplete margins?
Chemotherapy can be used following surgery with incomplete margins, usually for neoplasms not very responsive to chemotherapy and/or with low mitotic index.
79
Why should chemotherapy not be used in patients with severe organ dysfunction?
Chemotherapy should not be used in patients with severe organ dysfunction due to the increased risk of systemic toxicity.
80
What are the considerations for choice, combination, and dose calculation of cytotoxic drugs?
Drugs must have proven efficacy, different mechanisms of action, and no overlapping toxicities.
81
Why are combinations of drugs usually more effective than single agents?
Combinations of drugs have proven to be more effective than single agents, except for doxorubicin/carboplatin in osteosarcoma.
82
What is dose intensity?
Dose intensity is the amount of drug administered per unit time.
83
How can dose intensity be increased?
Dose intensity can be increased by increasing the dosage or shortening the time interval between drug administrations.
84
What is the aim of dosing myelosuppressive drugs?
The aim is to deliver doses that produce a neutrophil nadir of between 1.0 and 1.5 x 109/L.
85
What is the formula for calculating the body surface area (BSA) for dogs and cats?
For dogs: S=10.1 x weight (kg)0.66 / 104, For cats: S=10 x weight (kg)0.66 / 104
86
Why is dosage based on BSA imperfect for small dogs and cats?
Dosage based on BSA for many drugs is imperfect because small dogs and cats should be dosed at a lower rate than larger dogs.
87
What should be done for patients with fever or gastrointestinal symptoms?
Hospitalization and administration of intravenous fluids and antibiotics.
88
What should be done for patients who are not febrile?
Careful monitoring and administration of broad-spectrum antibiotics.
89
What treatment is usually sufficient for neutrophil counts from 500-1200/μl if the patient does not present clinical signs?
Administering broad-spectrum oral antibiotics orally for several days and monitoring until the next blood count.
90
How long does the neutrophil nadir rarely last for in most cases?
48-72 hours.
91
What is considered a normal neutrophil count below in certain breeds, especially sighthounds?
3000/μl.
92
What factors should be considered when deciding whether or not to treat?
Number of neutrophils, type of neoplasm, and clinical stage of the disease.
93
What is the potential adverse effect with the greatest impact on the quality of life of pets treated with chemotherapy?
Gastrointestinal (GI) toxicity.
94
How can gastrointestinal toxicity be managed?
Through prevention and a good preventive plan.
95
What factors should be assessed to determine the patient's risk of GI toxicity?
Prevalence of GI toxicity associated with the drug, breed of the patient, individual sensitivity, and whether the neoplasm being treated affects the gastrointestinal tract.
96
What should be prescribed when a drug with a high prevalence of GI toxicity is administered for the first time?
Symptomatic treatment (antiemetics or antidiarrhea agents).
97
What are the common clinical signs of gastrointestinal toxicity?
Lack of appetite, anorexia, nausea, vomiting, diarrhoea, abdominal pain, and constipation.
98
What can cytotoxic drugs cause in the gastric and intestinal epithelium?
Gastrointestinal toxicity due to high cell turnover, leading to vomiting and mucoid or haemorrhagic diarrhea.
99
What should be considered for unacceptable toxicity?
Reductions in the dose or changes to the chemotherapy protocol.
100
What can contribute to the severity of gastrointestinal toxicity?
Lack of symptomatic or preventive therapy.
101
What can some drugs induce?
Nausea and vomiting.
102
What is the proposed dose range of TKIs in dogs and cats?
10-15 mg/kg
103
How are TKIs mostly eliminated in dogs and cats?
Through feces (92%) with a small portion excreted in urine (7%)
104
Where can concentration of toceranib be detected in dogs after a single oral dose?
Bile, liver, lymph nodes, adrenals, colon, bone marrow, kidneys, lungs, spleen, pancreas, and skin
105
What are the most common adverse effects of TKIs in dogs and cats?
Gastrointestinal (GI) disorders
106
What are the second most common adverse effects of TKIs in dogs and cats?
Hematologic disorders (neutropenia and thrombocytopenia)
107
What are the third most common adverse effects of TKIs in dogs and cats?
Musculoskeletal disorders (muscle pain and lameness)
108
What is a confounding factor when reporting adverse effects in dogs with mast cell tumors?
The prevalence of GI signs in patients with this disease secondary to histamine release
109
What is the prevalence of grade III and IV adverse effects in dogs with non-mast cell neoplasia treated with toceranib?
Lower than in dogs with mast cell tumors
110
What are some less frequently described adverse effects of TKIs in dogs and cats?
Liver toxicity, vasculitis, edema, hypertension, hypopigmentation, alopecia, pancreatitis, pulmonary thromboembolism, nephrotic syndrome, hemolytic anemia, etc.
111
What adverse effects were observed in cats administered masitinib?
Proteinuria, neutropenia, gastrointestinal toxicity, and increases in creatinine
112
Why is early recognition of adverse effects important when using TKIs?
Due to the possible occurrence of a cumulative effect
113
How long can it take for the resolution of adverse effects after TKI discontinuation?
Weeks in some cases
114
What is the suggested monitoring plan for early detection of adverse effects?
Not mentioned in the given text
115
What is the known potential toxicity with the use of this drug in dogs?
10% of dogs had evidence of this side effect at some point during treatment.
116
Which drugs have been shown to be relatively safe in dogs with advanced tumors when used in a metronomic fashion?
Lomustine and chlorambucil.
117
Why did a significant number of dogs have to withdraw from receiving lomustine?
Due to toxicosis (GI, hepatic and renal).
118
Are there veterinary studies that examine the usefulness of these drugs to reduce angiogenesis, number of CEPs or Tregs?
No, there are currently no veterinary studies that examine the usefulness of these drugs.
119
Are there objective measures of outcomes and efficacy for metronomic therapy?
No, there are no objective measures of outcomes and efficacy.
120
What does sustained stable disease manifest as with metronomic chemotherapy?
Sustained stable disease may be the only manifestation of objective results with metronomic chemotherapy.
121
How long does it typically take for actual tumor shrinkage to occur with continuous therapy?
Actual tumor shrinkage, if it occurs, may manifest only after 1 to 2 months of continuous therapy, or more.
122
When may the benefits of metronomic dosing be maximized?
The benefits of metronomic dosing may be maximized at the lowest tumor burden, i.e., as adjuvant therapy.
123
What were the initial dosing recommendations for cyclophosphamide in metronomic therapy?
Cyclophosphamide 15 mg/m2 daily (reduced to EOD in face of toxicity).
124
What is the recommended dosing of piroxicam in metronomic therapy?
Piroxicam 0.3mg/kg daily (or NSAID of choice).
125
What are the potential side effects of long-term metronomic chemotherapy?
Up to 30% prevalence of sterile hemorrhagic cystitis, therefore concurrent use of frusemide at 0.5mg/kg is recommended.
126
Can anti-angiogenic therapies and metronomic scheduling replace traditional cytotoxic schedules?
No, on their own, anti-angiogenic therapies and metronomic scheduling may not replace traditional cytotoxic schedules.
127
What do current research focus on in terms of metronomic chemotherapy?
Understanding its effects on angiogenesis, immunology, tumour microenvironment, cell specificity, and drug-resistance mechanisms.
128
Are metronomic chemotherapy protocols currently considered the standard of care?
No, they are still considered investigational and not the current standard of care.
129
Who should input be sought from when considering the approach?
All involved parties, including radiation and surgical oncologists.
130
What treatment is often used for tumors at high risk of metastasis?
Hypofractionated radiation and chemotherapy.
131
Name three tumors that may be treated with full-dose chemotherapy and radiation therapy.
Appendicular osteosarcoma, tonsillar squamous cell carcinoma (SCC), and oral melanoma.
132
What is the primary purpose of giving chemotherapy in conjunction with radiation therapy?
Systemic effect on presumed microscopic metastatic disease.
133
How does chemotherapy impact local tumor control?
It may impact local tumor control, but it is primarily given for its systemic effect.
134
What are potential complications of full-dose chemotherapy?
Bone marrow suppression and sepsis.
135
How can carboplatin concurrently given with radiation impact myelosuppression?
It can result in marked myelosuppression, including profound neutropenia.
136
What factors can influence the response of tumors to radiation therapy?
Species, histology, tumor location, histopathological grade, stage of disease, age of patient.
137
What response can be expected for SCC on the nasal planum of a cat?
Typically an excellent response.
138
How does the response of oral SCC in cats differ from that in dogs?
Oral SCC in cats is notoriously radio-resistant, while dogs may achieve long-term local control with radiation alone.
139
What characteristic is associated with the papillary variant of SCC in young dogs?
Local aggression and extensive osteolysis.
140
What are acute radiation side effects primarily caused by?
Rapidly proliferating cells in tissues.
141
How long do acute radiation side effects typically take to resolve?
Within 3 to 6 weeks.
142
Name one treatment option for skin reactions during radiation therapy.
Topical aloe vera based lotions or silver sulfadiazine cream.
143
Where do late radiation side effects primarily occur?
In tissues where cells do not undergo mitosis, such as nerves and bone.
144
What causes late radiation side effects?
Changes in connective tissues, stroma, and vasculature.
145
What can cause diarrhoea after chemotherapy administration?
Direct stimulation of the chemoreceptor trigger zone.
146
When does diarrhoea tend to occur after administration of chemotherapy?
3 to 5 days.
147
Which drugs can be used for symptomatic management of chemotherapy-induced diarrhoea?
Sulphasalazine, metronidazole, and loperamide.
148
What are some other causes of diarrhoea?
Dietary indiscretion and parasites.
149
What can vincristine cause in cats?
Ileus paralyticus.
150
What clinical signs are associated with vincristine-induced ileus paralyticus?
Lack of appetite, abdominal pain, and constipation.
151
What is the recommended treatment for vincristine-induced ileus paralyticus?
Reduce vincristine dose, replace with vinblastine, or discontinue treatment.
152
What is the most common clinical sign of gastrointestinal toxicity in cats?
Anorexia.
153
What can high dose cyclophosphamide administration lead to in cats?
Development of nausea.
154
What gastric protectants can be used for nausea or vomiting secondary to gastroenteritis?
Antacids, proton pump inhibitors (omeprazole), or H2 blockers (ranitidine or famotidine).
155
What is the purpose of sucralfate in gastrointestinal therapy?
To help the healing of the GI mucosa and prevent further damage.
156
What is a possible side effect of doxorubicin in dogs?
Cardiotoxicity and mast cell degranulation.
157
What is the cumulative dose that can lead to chronic doxorubicin-induced dilated cardiomyopathy?
>180 mg/m2.
158
What is a possible side effect of doxorubicin in cats?
Nephrotoxicity.
159
What can cause sterile haemorrhagic cystitis in dogs?
Cyclophosphamide.
160
What is the metabolite of cyclophosphamide that is irritant to the bladder lining?
Acrolein.
161
What is the efficacy of toceranib and masitinib in malignancies other than MCTs?
Information is scarce.
162
What are the types of neoplasms in which toceranib has been used as a treatment?
Canine solid neoplasias.
163
What is the expected benefit of toceranib treatment for dogs with solid neoplasms?
Good quality of life and partial response or stabilization of the disease.
164
What are the clinical benefits observed in dogs treated with toceranib?
Clinical benefit was observed in 74% of dogs with AGASACA, OSAs, thyroid carcinomas, head and neck carcinomas, and nasal carcinomas.
165
What other treatments did the dogs in the study receive along with toceranib?
NSAIDs or metronomic cyclophosphamide or both.
166
What was the median dose of toceranib for dogs experiencing clinical benefit?
2.8 mg/kg.
167
What was the duration of treatment for most dogs experiencing clinical benefit?
Four months or longer.
168
What safety study involved the combination of toceranib and piroxicam?
A study to document the safety of the combination.
169
What neoplasm showed a complete response with toceranib in a case report?
Canine lymphangiosarcoma.
170
What neoplasm showed a temporal complete remission with masitinib in a case report, but subsequently relapsed?
Canine neurofibrosarcoma.
171
What technique was used in a case report for primary tumor cell culture from a primary osteosarcoma in a dog?
Establishment of a primary tumor cell culture.
172
What is the relationship between the dose per fraction and the probability of late effects?
The higher the dose per fraction, the higher the probability of late effects.
173
Which animals are more likely to experience late effects after palliative radiation therapy?
Animals treated with a larger dose per fraction in palliative radiation therapy.
174
What are some possible treatments for late effects?
Surgery to remove cataracts, surgical debridement for bone necrosis, and bougienage or resection for strictures of hollow viscera.
175
Why are palliative/hypofractionated protocols not recommended for patients expected to live long?
Increased potential for late side effects is one of the reasons.
176
What is stereotactic radiosurgery?
The use of multiple, non-coplanar beams of radiation to deliver a single, high-radiation dose precisely to the target.
177
In which cases has helical tomotherapy been used?
Helical tomotherapy has been used in the treatment of brain tumors and canine appendicular osteosarcoma.
178
What is tomotherapy?
It is intensity-modulated radiation therapy that uses CT imaging for planning, delivery, and verification of treatment.
179
What is the role of surgery in the management of cancer?
Diagnosis (biopsy), resection for cure, palliation, and debulking.
180
What is the purpose of tumour biopsy?
To allow a diagnosis, prognosis, staging, and decision-making about therapeutic options.
181
When is biopsy performed for staging purposes?
Biopsy of primary lesions and potential metastases may be performed for staging purposes.
182
What type of gloves should veterinary surgeons and staff wear for chemotherapy?
Thick latex gloves specifically for chemotherapy or two pairs of latex gloves.
183
What is more important for the glove used in chemotherapy?
Thickness is more important than the material.
184
What additional protective clothing should personnel wear for chemotherapy?
Disposable impermeable gowns.
185
What precautions are recommended when closed systems are not used in chemotherapy?
Eye protection and particle-filtering masks.
186
What should be done to reduce environmental contamination in chemotherapy?
Purge the infusion equipment before adding drugs to the saline solution.
187
How should potentially contaminating material be disposed of in chemotherapy?
Place in bags or bins for bio-hazardous material.
188
Who can arrange for the disposal of material contaminated with cytotoxic drugs in chemotherapy?
Human hospital or approved companies.
189
Can the materials used in the preparation and administration of chemotherapy be reused?
No, they cannot be reused.
190
What precautions should be taken when handling waste from patients who received chemotherapy?
Disposable gown and gloves should be worn by personnel while cleaning excreta.
191
Who should not prepare or administer chemotherapy drugs or handle hospitalized patients?
Pregnant women.
192
Where should tablets be prepared and transferred for chemotherapy patients?
To an area with little movement of personnel and animals.
193
What is the advantage of tumour vaccination in cancer therapy?
Practically no or minor adverse effects and potential protection from relapses.
194
Why is research on tumour vaccination in pets also of interest for human medicine?
Successful vaccines in pets can often be translated to human medicine.
195
What are two therapeutic tumour vaccines that have gained approval?
Provenge for prostate cancer in men and Oncept for melanoma in dogs.
196
What is a weakness of tumour vaccination?
It takes a long time to develop an effective immune response which may be too late for aggressive tumours.
197
What is a concern with tumour vaccines?
Autoimmunity is a theoretical concern with tumour-associated vaccines.
198
What is the purpose of a break period in chemotherapy?
To allow normal tissues to recover before the next dose.
199
How long can a break period be in chemotherapy?
It can be as lengthy as 2-4 weeks depending on the chemotherapy agent.
200
Which chemotherapy agents are used for osteosarcoma?
Carboplatin
201
Which chemotherapy agents are used for haemangiosarcoma?
Doxorubicin or epirubicin
202
What is the term for continuous low-dose chemotherapy?
Metronomic chemotherapy
203
What are the advantages of metronomic chemotherapy?
Low-cost, high-convenience, and acceptable side effect profiles
204
What is the main assumption regarding the mechanism of metronomic chemotherapy?
Cytotoxic effect of the drugs on tumour cells
205
What is the goal of conventional chemotherapy regarding drug dose?
Raise the dose to the maximum tolerated level
206
What is angiogenesis?
The process of blood vessel growth within a tumour
207
Why do traditional chemotherapeutics have common side effect profiles?
They cause damage to rapidly dividing cell populations, including normal tissues
208
What is the problem with standard chemotherapy from an antiangiogenic perspective?
Regrowth and replacement of damaged tumour vasculature during the break period
209
What are the potential effects of chemotherapy on tumour blood vessels?
Direct cytotoxic effect and tipping the balance of angiogenic growth factors and inhibitors
210
What may be required for the expansion of tumour blood vessels?
Recruitment of bone marrow-derived endothelial progenitor cells
211
What is the term for the relative sparing of normal cells during chemotherapy?
Endothelial cell selectivity
212
What is spared during endothelial cell selectivity?
Normally susceptible cells
213
What is the recommended administration strategy for a high dose of medication?
Dividing the dose over 2 days or giving furosemide on the same day.
214
How long does it take for resolution of SHC?
Several weeks.
215
What should be ruled out and discontinued when treating SHC?
Infection and the drug.
216
What are some possible treatments for SHC?
Analgesia, oxybutinin, and intravesical DMSO.
217
What are the potential side effects of vincristine in cats?
Ileus paralyticus, constipation, abdominal pain, and anorexia.
218
What are the recommended treatments for vincristine side effects in cats?
Metoclopramide and ranitidine.
219
What are the rare side effects of vincristine?
Peripheral neuropathies and skin sloughs if injected perivascularly.
220
What percentage of dogs treated with lomustine may develop hepatotoxicity?
7%.
221
What is the recommended action for monitoring ALT when using lomustine?
Monitor ALT prior to dosing.
222
What treatment can be considered to protect the liver when using lomustine?
SAMe.
223
What are the potential side effects of cisplatin?
Nephrotoxicity and vomiting via the Chemoreceptor Trigger Zone.
224
Can cisplatin be used in cats?
No, it can cause fatal pulmonary edema in cats and should not be used.
225
What should be monitored prior to dosing with carboplatin?
Renal function (USG).
226
What are the potential side effects of receptor tyrosine kinase inhibitors?
Gastrointestinal effects, myelosuppression, proteinuria, muscle cramping, and hypertension.
227
What are some specific toxicities that cats may experience with certain drugs?
Cisplatin causes fatal pulmonary edema, and 5-fluoruracil causes extreme neurotoxicity.
228
Which dog breeds may have increased sensitivity to vinca alkaloids and doxorubicin?
Herding breeds, such as collies, Shetland Sheepdogs, Australian Shepherds, and long-haired whippets.
229
Why do some herding breeds have increased sensitivity to certain drugs?
Due to a mutation in the MDR1 gene, leading to impaired excretion.
230
What guidelines should be followed for handling cytotoxic chemotherapy drugs?
Cytotoxic drugs should be prepared and administered in closed systems or in a human hospital/pharmacy.
231
What are the potential side effects of exposure to cytotoxic drugs for personnel?
Headache, nausea, liver disease, and reproductive disorders.
232
What precautions should be taken to limit personnel's exposure to cytotoxic drugs?
Personnel should wear suitable protective clothing and follow safe handling practices.
233
What equipment is recommended for reconstituting cytotoxic drugs?
A class II vertical laminar flow cabinet or closed systems for chemotherapy administrations.
234
Did the addition of systemic therapy with chemotherapy or vaccine improve survival time?
No, it did not improve survival time.
235
What is the cost of the 4 doses of vaccine?
The cost is no less than 2,500-3,500£.
236
How many patients were used in the study with digital melanoma?
58 patients were used in the study.
237
What was the MST (median survival time) for patients in the study with digital melanoma?
The MST was 476 days.
238
What was the MST (median survival time) for the historical control group in the literature?
The MST was 365 days.
239
What did the authors consider as an important explanation for the lower efficacy of the vaccine?
The authors indicated a long interval between diagnosis and start of the vaccination as an important explanation.
240
What is implicated in the aetiology of canine MCTs?
The stem cell factor receptor, KIT, is implicated in the aetiology of canine MCTs.
241
What is KIT?
KIT is a surface growth factor receptor encoded by the proto-oncogene c-kit.
242
What activities are initiated by activated KIT?
Activated KIT initiates a signaling cascade that culminates in a wide array of biological activities including proliferation, migration, maturation, and survival of mast cells.
243
Is KIT expressed in both normal and neoplastic canine MCs?
Yes, KIT is expressed in both normal and neoplastic canine MCs.
244
What percentage of canine MCTs are affected by c-kit mutations?
About 15% to 40% of canine MCTs are affected by c-kit mutations.
245
Are mutations of c-kit identified in more than 60% of canine MCTs?
No, mutations of c-kit are not identified in more than 60% of canine MCTs.
246
What are tyrosine kinase inhibitors?
Tyrosine kinase inhibitors are drugs that can have anti-cancer activity and prevent the formation of blood vessels important for tumor growth.
247
Which two veterinary TKIs are available for use in canine mast cell tumors?
Toceranib phosphate (Palladia®) and masitinib (Masivet®) are available for use in canine mast cell tumors.
248
What other effects does toceranib have besides blocking KIT?
Toceranib also has effect over VEGFR, PDGFR, CSF-1, Flt-3, and probably Ret.
249
What effect has toceranib been demonstrated to have on T-regulatory cells in dogs?
Toceranib has been demonstrated to decrease the number and percentage of T-regulatory cells in peripheral blood of dogs with cancer.
250
What is the action of Toceranib on KIT in mast cell tumours?
Toceranib blocks KIT in inoperable mast cell tumours of grade II or III.
251
What is the antitumor activity of Toceranib based on?
Toceranib has a greater spectrum of RTKs it can block, including VEGFR and PDGFR, which results in important anti-angiogenic activity.
252
What is the dosage of Toceranib for dogs?
The dosage is 3.25 mg/kg every other day, but it can be reduced if adverse effects are observed.
253
How long does the concentration of Toceranib remain sustained in plasma?
The concentration remains sustained for more than 48 hours.
254
What is the clinical benefit of Toceranib at different dosages?
At 2mg/kg, the clinical benefit is 68%, while at 3.25 mg/kg, it is 60%.
255
What is the recommended administration regimen for Toceranib?
A common regimen is three days per week (e.g. Monday, Wednesday, Friday) and it can be combined with other drugs like NSAIDs or metronomic cyclophosphamide.
256
What is the dosage of Masitinib in dogs?
The recommended dosage is 12.5mg/kg daily.
257
What is the selectivity of Masitinib for specific RTKs?
Masitinib is designed to block KIT, PDGF, Lyn, Lck, and Fyn, providing selectivity in its action.
258
What potential benefit does Masitinib have in diseases other than MCT?
Masitinib may be beneficial in feline asthma or canine atopic dermatitis, and potentially in other neoplasms through its antiangiogenic and anti-inflammatory actions.
259
What is the dosage of Masitinib in cats?
There is no specific dosage described for cats, but an alternative regime of 2.75 mg/kg three days per week is used anecdotally.
260
What are the components of the baseline monitoring plan?
History, physical examination, CBC, serum biochemistry, urinalysis, and blood pressure.
261
When should the 2 weeks post start monitoring be performed?
Two weeks after the start of treatment.
262
What adverse effects are the 2 weeks post start monitoring aimed at detecting?
Gastrointestinal adverse effects and hematologic toxicity.
263
What conditions might predispose pets to development of toxicity with TKIs use?
Pets with cancer, especially those with mast cell tumors, which can cause GI ulceration and intestinal bleeding.
264
What is the recommended approach to minimize risk of GI toxicity in pets with altered GI mucosa?
Pre-treatment with symptomatic therapy for a few days before starting TKI therapy.
265
What is the recommended strategy if adverse GI effects appear during treatment?
Symptomatic therapy if effects are mild to moderate, and a 'holiday period' off TKIs if effects are moderate to severe.
266
Which medications are recommended for dogs with risk or evidence of GI bleeding?
Antacids such as H2 blockers or proton pump inhibitors, and sucralfate.
267
Which medications can be beneficial in patients with GI ulceration from mast cell degranulation?
Antihistaminics like diphenhydramine or chlorpheniramine.
268
What medications can be used for appetite loss, nausea, or vomiting?
Ondansetron or maropitant.
269
What is the recommended management approach for diarrhea in pets receiving toceranib?
The use of metronidazole or loperamide, with possible drug holiday and dose decrease.
270
What is the potential risk of concurrent use of NSAIDs with toceranib?
Exacerbation of GI toxicity.
271
How should NSAIDs be administered when using toceranib?
On alternate days when TKI is not given, with prophylactic GI protection.
272
Which combination of drugs did not show increased toxicity when used with toceranib?
Toceranib and piroxicam.
273
What is the effect of combination cyclophosphamide (metronomic dosage) with toceranib on GI toxicity?
It does not seem to increase GI toxicity or myelosuppression.
274
What is the mitotic index?
The percentage of cells in mitosis in a tissue.
275
What is the relationship between the mitotic index and the sensitivity of tissues to chemotherapy?
Tissues with a high mitotic index are more sensitive to chemotherapy.
276
Describe the growth pattern of tumors.
Tumor growth is Gompertzian, with initial rapid growth followed by a plateau phase.
277
When are cells most susceptible to chemotherapy?
Cells are most susceptible to chemotherapy when they are in the process of division.
278
What is the significance of the fraction of resting cells in the tumor population?
The fraction of resting cells (Go) in the tumor population determines the outcome of chemotherapy.
279
Which tissues are known to have a high mitotic index?
The epithelium of intestinal villi and bone marrow have a high mitotic index.
280
What is the effect of chemotherapy on cells?
Chemotherapy kills a percentage of cells rather than a constant number.
281
What type of tumors are more sensitive to chemotherapy?
Tumors with a high growth rate and high mitotic index are more sensitive to chemotherapy.
282
When is chemotherapy indicated as the primary therapy?
Chemotherapy is indicated as primary therapy for animals with systemic or metastatic neoplasms.
283
When is chemotherapy indicated as adjuvant therapy?
Chemotherapy is indicated as adjuvant therapy following surgery in tumors with high rates of metastasis.
284
What is a shape constant?
A shape constant is a constant derived from studies with small sample sizes.
285
Is the shape constant constant for different breeds of dogs?
No, the shape constant is not constant for different breeds of dogs.
286
Do studies show that the constant varies in cats?
Yes, studies have shown that the constant varies in cats.
287
What is the best practical solution for a veterinarian until further guidelines are available?
The best practical solution is to use a BSA conversion table and become familiar with drugs that require lower dosages for small pets.
288
What is the recommended dosage of doxorubicin for dogs weighing less than 15 kilos and cats?
The recommended dosage is 1 mg/kg instead of the standard dosage.
289
Why is chemotherapy less effective for large bulky solid tumors?
Chemotherapy is less effective for large tumors due to poor blood supply and lower delivery of drugs to cancer cells at cytotoxic levels.
290
What types of tumors are exceptions to the rule of chemotherapy effectiveness for large tumors?
Haemangiosarcomas, canine transmissible venereal tumor, lymphoma, mast cell tumors, multiple myeloma, malignant histiocytosis, and leukemias.
291
What factors affect the success of anti-cancer drug therapy?
Tumor type, penetration of drug into the tumor, and development of drug resistance.
292
What are some mechanisms of drug resistance in tumors?
Decreased drug uptake, increased removal of drug from cells, decreased drug activation, increased drug inactivation, increased or altered drug targets, alternative cell-signalling pathways, and increased DNA repair.
293
What is multi-drug resistance and how does it occur?
Multi-drug resistance is when tumor cells become cross-resistant to unrelated compounds. It occurs due to increased expression of the MDR1 gene and P-glycoprotein (Pgp) expression.
294
What is the recommended approach if resistance occurs during chemotherapy?
Switch to drugs that the tumor has not been exposed to before, preferably combinations of drugs with different mechanisms of action (rescue therapy).
295
When is adjuvant chemotherapy used?
Adjuvant chemotherapy is used following resection of a primary tumor with a significant risk of recurrence or metastasis.
296
When is the effectiveness of adjuvant chemotherapy greatest?
The effectiveness is greatest at the earliest stages of tumor growth.
297
What are some examples of drugs that inhibit proliferation and migration of endothelial cells?
Cyclophosphamide, methotrexate, vinblastine, paclitaxel
298
What is the balance that must be tipped in favor of angiogenic stimulation?
Balance between pro-angiogenic and antiangiogenic factors
299
What is one strategy for targeted antiangiogenic therapy?
Increasing levels of endogenous angiogenic inhibitors
300
What are Circulating Endothelial Progenitor Cells (CEPs) derived from?
Bone marrow
301
What happens to CEP levels when traditional chemotherapy is administered?
They fall markedly and abruptly
302
What type of immune cells are present in the tumor microenvironment?
B and T cells
303
What type of lymphocytes are involved in autoimmune disease prevention and tolerance?
Regulatory T-cells (Tregs)
304
What were the results of the human clinical trial using daily low-dose cyclophosphamide and methotrexate in women with advanced breast cancer?
Around a third of women responded or had disease stabilization
305
What protocol was used to treat canine splenic haemangiosarcoma?
Daily cyclophosphamide, oral etoposide, and piroxicam
306
What was the outcome of the adjuvant study using metronomic cyclophosphamide and piroxicam treatment for incompletely resected soft tissue sarcomas?
Significant prolongation of the disease-free interval
307
What is a potential concern regarding the use of cyclophosphamide?
Possibility of sterile hemorrhagic cystitis
308
What are the indications for biopsy?
A cytologic diagnosis has not been reached; Treatment or prognosis would be altered by knowing the tumour type; Owner's willingness to treat would be altered by knowledge of tumour type and prognosis.
309
What are the guidelines for tumor biopsy?
Biopsy site within likely surgical field; Minimal risk of local dissemination of tumor; Fresh instruments for multiple biopsies; Longitudinal incisions on limbs and tail; Avoid tissue difficult to resect or needed for surgical closure.
310
How can a diagnosis be improved during a biopsy?
Taking a large biopsy; Taking several samples from a single mass.
311
What are the steps for proper fixation of the tissue specimen?
Use 10% neutral buffered formalin; Use 1-part tissue to 10 parts of fixative; Less than 1cm thick tissue for penetration; Deep incisions for large masses.
312
What information can be gained from a biopsy?
Identification of benign vs malignant tumor; Determination of tumor grade; Assessment of margins (if excisional biopsy); Evaluation of potential metastasis sites.
313
What is surgery with curative intent?
The use of surgery as the sole method of treatment for an outright cure in a single procedure.
314
What are the advantages of surgery with curative intent?
Immediate cure; Not carcinogenic; No local toxic effects; Better for large masses.
315
What are the disadvantages of surgery with curative intent?
Local cure only; Change in cosmetics; Change in function; Not immunosuppressive.
316
What are the principles of surgical excision?
Establish diagnosis by biopsy; Perform early in the course of disease; First surgery has best chance of success; Adequate margins in three dimensions; Don't compromise margins for closure; Remove incisional biopsy tracts with tumor.
317
Who is the module developer for Small Animal Medicine Distance Learning Module 10?
Dr Ana Lara
318
What are the learning objectives of this module?
Develop an understanding of radiotherapy, surgical oncology, chemotherapy, and other medical therapy options.
319
What is the role of radiation therapy in treating cancer in companion animals?
It is an important component of a multimodality approach in controlling and potentially curing cancer.
320
What are the potential acute and late side effects of radiation therapy?
The notes don't mention specific side effects.
321
What advances are being made in clinical veterinary radiation oncology?
Use of daily radiation therapy protocols, higher total doses of radiation, and computed tomography (CT) for imaging and treatment planning.
322
What types of radiation sources are used in external beam radiation therapy?
X-rays, gamma rays, and electrons.
323
What is the difference between orthovoltage and megavoltage radiation therapy equipment?
Orthovoltage is used on a limited basis while megavoltage delivers higher energy radiation.
324
What is teletherapy and how is it commonly used in the UK?
Teletherapy is radiation applied from a distance to the patient, similar to a massive x-ray machine, and it is the most common method used in the UK.
325
What is a linear accelerator and how does it treat tumours?
A linear accelerator uses X-rays or electron beams to treat both deep and superficial tumours.
326
What is the maximum photon energy range of a linear accelerator?
The photon energy can range from 4 to 25 MV.
327
What is the 'skin-sparing' effect in megavoltage radiotherapy units?
The maximum radiation dose is not deposited at the skin surface but at a depth of 0.5 cm below the skin.
328
What is the purpose of using a tissue-equivalent material over a surgical incision during radiation treatment?
To allow the radiation dose to build up and maximize deposition at the skin surface.
329
How are photons used in radiation treatment?
Photons are used to treat deeper-seated tumors or when more depth is required.
330
What are the two sets of jaws used for in a linear accelerator?
Collimating the photon beam and field shaping to form square or rectangular fields.
331
How is field modification achieved in radiation treatment?
Lead blocks or multileaf collimators (MLC) are used to create the desired field shape.
332
What is the typical source-to-skin distance in radiation treatment?
100 cm.
333
What is a cone used for in electron beam therapy?
A cone is attached to the head of the machine to collimate the electron beam.
334
Why are electron beams particularly useful for treating lesions over critical normal tissues?
Electron beams have a rapid dose fall-off in tissues, allowing safe delivery of radiation to tumors overlying critical structures.
335
How does ionizing radiation cause biological damage?
X-rays and gamma rays produce fast-moving charged particles that cause chemical and biological damage when absorbed in tissue.
336
What is the most critical target for radiation damage?
Deoxyribonucleic acid (DNA) is the most critical target for radiation damage.
337
What is the term used when cells die after irradiation when they attempt to divide at the next or a later mitosis?
Mitotic death or mitotic catastrophe.
338
Why do some solid tumors take a long time to shrink with radiotherapy?
Cells typically die after irradiation when they attempt to divide at the next or a later mitosis.
339
How do some cells die as a result of radiation therapy?
Some cells die by apoptosis (programmed cell death).
340
Why are lymphocytes particularly sensitive to radiation?
Lymphocytes undergo apoptosis quickly and are therefore exquisitely radiosensitive.
341
What is the role of oxygen in radiation therapy?
Oxygen is important because free radicals, which cause DNA damage, are primarily formed in the presence of oxygen.
342
What is the most effective targeted therapy for the dog's tumour?
An Src (non RTK tyrosine kinase) inhibitor
343
What is the clinical response in dogs with epitheliotropic cutaneous lymphoma treated with masitinib?
Documented clinical responses
344
What is the treatment option for dogs with chronic monocytic leukemia?
Tyrosine kinase inhibitors
345
What is the response rate of cats with FISS treated with toceranib?
No clinical response
346
What was the clinical benefit in feline patients with solid neoplasias treated with toceranib or masitinib?
Clinical benefit of 70%
347
What was the medium time to progression for cats with stable disease?
123 days
348
What was the medium survival time of cats with squamous cell carcinoma treated with toceranib?
96 days
349
What side effects are associated with tyrosine kinase inhibitors?
Anorexia, GI upsets, haematological dyscrasias, and renal disease
350
What is metronomic chemotherapy?
Chemotherapy administered on a continuous basis
351
What is the goal of traditional chemotherapy?
To administer as much drug as can be tolerated
352
What factors make metronomic chemotherapy protocols attractive to the veterinary world?
Low cost, oral administration, and low toxicity
353
What is the efficacy of metronomic chemotherapy?
Continuous drug exposure to susceptible cancer cells, anti-angiogenesis, and alterations in the immune response
354
What is the result of the reaction between a free radical and oxygen?
The production of an organic peroxide that is a non-restorable form of the target material.
355
In the absence of oxygen, what can potentially happen to ionized target molecules?
They can repair themselves and recover the ability to function normally.
356
Why are hypoxic cells more resistant to the effects of radiation?
Because they have the ability to potentially repair themselves and recover in the absence of oxygen.
357
How does fractionation of radiation therapy work?
The total radiation dose is divided and delivered as smaller doses known as fractions.
358
Why is it considered better to give small fractions daily for curative-intent therapy?
It allows less time between fractions for tumor cells to repair DNA damage and repopulate.
359
What happens to hypoxic cells during the course of radiotherapy?
Some of the initially resistant hypoxic cells become re-oxygenated, allowing greater radiation kill.
360
Why is giving more frequent treatments beneficial in radiation therapy?
It prevents the repair of damage and repopulation of tumor cells between fractions.
361
What are some factors that can affect the sensitivity of cells to radiotherapy?
The presence of oxygen, cell cycle phase, and redistribution of tumor cells.
362
What are some initial evaluations involved in radiation therapy?
Haematology, biochemical profile, urinalysis, and thoracic radiography.
363
How are regional and distant metastases evaluated in radiation therapy?
Through regional lymph node aspiration, thoracic radiographs, and abdominal ultrasonography.
364
Why is it important to perform aspiration cytology or biopsy of a regional lymph node?
To evaluate the expected biological behavior of the primary tumor, not just detectable lymphadenopathy.
365
What are the commonly used imaging tools for tumor imaging and localization?
Radiography and CT, but other tools include ultrasonography, nuclear scintigraphy, and MRI.
366
Which imaging tool is considered a critical component in radiation treatment planning?
Computed tomography (CT).
367
What are the possible complications of implanting permanent catheters for vascular access?
Stress in the hospital or having an aggressive nature
368
How long can permanent catheters for vascular access remain in the patient?
Up to 3 years
369
What are the functions of permanent vascular access catheters?
Taking blood samples and administering intravenous cytotoxic drugs
370
What is the recommended treatment for extravasation of vesicant chemotherapy drug?
Symptomatic treatment with anti-inflammatories, local antibiotics, bandages, and surgical debridement if necessary
371
What should be done if extravasation of a strictly intravenous chemotherapy drug occurs?
Stop the infusion immediately
372
What should be used to check the effective venous access after extravasation?
A certain volume of saline solution
373
What should be done if the catheter is outside the vein or a certain extravascular volume has been administered?
Do not remove the catheter and try to aspirate if possible
374
What is the recommended procedure for treating extravasation of vincristine/vinblastine?
Infiltrate the area with hyaluronidase, apply warm compresses, and apply anti-inflammatory ointment
375
What is the recommended procedure for treating extravasation of doxorubicin/epirubicin/actinomycin/mitoxantrone?
Apply cold compresses, administer dexrazoxane IV, apply DMSO topically, and apply anti-inflammatory ointment
376
What is a helpful solution for oral administration of chemotherapy drugs in small dogs or cats?
Reformulating drugs in capsules with fewer milligrams
377
What is the purpose of three-dimensional treatment planning?
To deliver maximum dose to the tumor while minimizing dose to normal structures.
378
What are the differences between definitive and palliative therapy?
Definitive therapy aims for long-term control, while palliative therapy focuses on pain relief and improving quality of life.
379
What side effects are more commonly seen with a full course of radiation therapy?
Acute side effects that temporarily decrease the quality of life for 3 to 6 weeks.
380
What types of tumors are often treated with radiation therapy alone?
Nasal tumors, brain tumors, and pituitary macroadenomas and macroadenocarcinomas.
381
What are the goals of palliative radiation therapy?
Alleviate pain, decrease obstructive masses, and alleviate debilitating signs of cancer.
382
What are the potential benefits of hypofractionated radiation therapy?
Less acute side effects and good long-term outcomes for certain neoplasias.
383
What is the difference between preoperative and postoperative radiation therapy?
Preoperative aims to kill microscopic extensions, postoperative treats residual microscopic disease.
384
Why are haemoclips used in radiation treatment field establishment?
They facilitate delineation of the region containing residual microscopic disease.
385
What complications can arise with preoperative radiation therapy?
Potential wound-healing problems.
386
When should adjuvant chemotherapy be used?
After local disease control for types of cancer with high prevalence of metastasis.
387
Name two types of cancer in dogs that may require adjuvant chemotherapy.
Osteosarcoma and hemangiosarcoma.
388
For neoplasia with low prevalence of metastasis, is adjuvant therapy indicated?
No, adjuvant therapy is not indicated.
389
What is the objective of neoadjuvant chemotherapy?
To reduce the size of the primary tumor and the side effects of other treatment.
390
What factors should be considered when choosing a chemotherapy regimen?
Patient-related factors, owner-related factors, and disease-related factors.
391
Give an example of a patient-related factor that influences treatment choice.
Presence of systemic diseases.
392
What should be discussed with the owner when choosing a chemotherapy protocol?
Willingness to treat, tolerance of adverse effects, availability, and cost of treatment.
393
What is the main objective of chemotherapy?
To cure the disease.
394
What is the objective of treatment when a cure is unlikely?
To maintain a good quality of life and achieve remission or stable disease.
395
How does early diagnosis affect prognosis and survival time?
Early diagnosis generally carries a better prognosis and longer survival time.
396
What are cytotoxic drugs and how do they work?
Cytotoxic drugs have anti-cancer activity and work through different mechanisms.
397
Name two alkylating agents used in chemotherapy.
Cyclophosphamide and Melphalan.
398
When do anti-metabolites act in the cell cycle?
They act in the S-phase of the cell cycle.
399
How do anti-tumor antibiotics inhibit DNA and RNA synthesis?
They use multiple mechanisms, including DNA breakage and inhibition of enzymes.
400
Which phase of the cell cycle do vinca alkaloids act in?
They act in the M phase of the cell cycle.
401
What do platinum-based drugs interfere with?
They interfere with DNA replication and RNA synthesis.
402
What does hydroxycarbamide inhibit?
Ribonucleoside diphosphate reductase.
403
What is the purpose of cytoreductive surgery?
Cytoreductive surgery is performed when complete excision is not possible to retain essential structures.
404
When is excision with narrow margins indicated?
Excision with narrow margins is indicated when complete excision is not possible but recurrence rate is low.
405
What is the conservative approach after cytoreductive surgery?
The conservative approach is a 'watch and see' approach or radiation therapy based on owner preference.
406
What is the aim of palliative surgery?
The aim of palliative surgery is to improve the patient's quality of life, not necessarily the length of life.
407
When is palliative surgery considered?
Palliative surgery is considered when complete excision or in the presence of metastasis is not possible.
408
Give an example of surgical palliation.
Removal of large ulcerating tumors causing systemic illness or amputation of bone tumors causing lameness with distant metastasis.
409
What does chemotherapy mean?
Chemotherapy is medical treatment using chemical substances, commonly associated with cytotoxic drugs for cancer treatment.
410
What percentage of dogs and cats are estimated to get cancer?
Approximately 25% of dogs and cats will suffer from cancer during their lifetime.
411
What is the main objective of chemotherapy treatment in pets with cancer?
The main objective is to treat the disease while maintaining or improving the quality of life.
412
Why is good communication with pet owners important during chemotherapy treatment?
Good communication ensures owners understand the prognosis, treatment aim, and possible adverse effects.
413
What are the four phases in the cell cycle?
The phases are G1, S, G2, and M, which include DNA synthesis and mitosis.
414
What types of tumors are suitable for margin indications?
Benign tumors with local infiltration capacity, malignant tumors with limited infiltration potential
415
What types of tumors are contraindicated for margin indications?
Malignant tumors with moderate to high potential for local infiltration
416
What is the purpose of radical local excision?
To remove the tumor along with margins extending into adjacent undisturbed fascial planes
417
When is radical local excision suitable?
For tumors with circumferential zones of compressed tissue due to rapid radial expansion
418
What is compartmental excision?
Removal of the tumor within an intact anatomic compartment surrounded by undisturbed fascial planes
419
For which tumors is muscle group excision suitable?
Small tumors involving muscle bellies without breached fascial planes
420
What is the purpose of amputation?
To remove the tumor along with the entire limb
421
When is amputation indicated?
For large tumors where compartmental or muscle group excision is not practical
422
What should be done to the resected tissue for histological examination?
It should always be submitted for histological examination
423
What does histological evaluation of resected tissues determine?
Histological type, grade, lymph node status, margins, and invasion
424
What is cytoreductive surgery?
Planned incomplete removal of a tumor to improve the efficacy of other therapies
425
When is cytoreductive surgery considered a failed excision?
When it follows a planned surgical excision for cure
426
How can complications such as haematoma, seroma, or wound infection be avoided?
Complications can be avoided by using gentle surgical technique, ensuring meticulous haemostasis, closing dead space, using surgical drains, and rational peri-operative antibiosis.
427
Why is it important to ligate the vascular supply to the tumour and its venous and lymphatic drainage?
It is important to ligate the vascular supply to prevent exfoliation or dissemination of cells and metastasis via haematogenous or lymphatic routes.
428
Which type of tumour is more likely to metastasize to regional lymph nodes: epithelial tumours or mesenchymal tumours?
Epithelial tumours are more likely to metastasize to regional lymph nodes.
429
When should the removal of regional lymph nodes draining the primary tumour be considered?
The removal of regional lymph nodes should be considered if there is a diagnosed malignant neoplasia or if the lymph node is known to be metastatic.
430
What impact does the removal of affected metastatic lymph nodes have on the outcome of neoplasms like anal gland adenocarcinomas, malignant melanomas, and mast cell tumours?
The removal of affected metastatic lymph nodes has a positive impact on the outcome of these neoplasms.
431
When should lymph nodes be removed if they are positive for tumour?
Lymph nodes should be removed if they are positive for tumour and not fixed to the surrounding tissues.
432
What factors should be considered when selecting the margins of excision for surgical removal of tumours?
The selection of appropriate margins depends on the established pattern of behaviour for that histological type and the grade of the tumour.
433
What are the common reasons for failure of definitive tumor excision?
Failure to plan the surgery and failure to stick to the plan.
434
Why is closure of the defect more difficult in cases where surgery has been performed previously?
There is less normal tissue.
435
What are the practical considerations for oncologic surgery?
Effect on cosmetics and function, pre-operative patient preparation, dissection technique, reduction of tumor cell contamination, avoidance of wound complications.
436
What should be explained to the client pre-operatively regarding the effect of surgery?
The effect on the animal's cosmetic appearance and the function of the body part.
437
What are the risk factors associated with an increased likelihood of wound infection in tumor-bearing patients?
Old age, poor nutritional status, obesity, hypoxemia, presence of remote sites of infection, poor blood supply to the surgical site, presence of systemic illness, and concurrent use of other medication.
438
What technique should be used to make the incision in the skin and hollow viscera?
A scalpel.
439
Why should blood vessels be isolated and ligated or cauterized prior to transection?
To prevent bleeding.
440
How should tissues be placed during dissection to facilitate the identification of fascial planes and tumor margins?
Under moderate tension.
441
What should be used to manipulate the tumor during surgery?
Only normal tissue, such as thumb forceps or stay sutures.
442
Why should gloves, instruments, and drapes be changed after excision?
To avoid adherence of tumor cells.
443
How does Bleomycin act?
Bleomycin causes single- and double-stranded DNA breaks, leading to inhibition of DNA and RNA synthesis.
444
What is the main toxic side effect of Bleomycin?
Bleomycin can cause pulmonary fibrosis.
445
What are the normal tissues in the body susceptible to cytotoxic drugs?
Bone marrow and gastrointestinal tract (GIT) are susceptible to toxicity from cytotoxic drugs.
446
What is the mechanism of action of L-Asparaginase?
L-Asparaginase depletes L-Asparagine, leading to inability of neoplastic lymphoid cells to synthesize protein and their death.
447
Which types of cells are targeted by corticosteroids?
Corticosteroids induce apoptosis in lymphoid cells and other round cells with steroid receptors.
448
What are the mechanisms of action of NSAIDs in cancer treatment?
NSAIDs inhibit COX-2, promote apoptosis, inhibit angiogenesis, and have anti-inflammatory and analgesic effects.
449
How should intravenous chemotherapy drugs be administered?
Intravenous administration should use small-gauge catheters or butterfly catheters and ensure correct positioning and fixation.
450
Which drugs are exceptions to intravenous administration and can be administered subcutaneously?
L-asparaginase, cytosine arabinoside, gemcitabine, and bleomycin can be administered subcutaneously.
451
What are the recommended practices for blood sample collection in chemotherapy patients?
Blood samples should be taken from the jugular vein to prevent damage to peripheral veins needed for administering chemotherapy.
452
Why is it important to alternate veins for administration of chemotherapy drugs?
Alternating veins allows for recovery from phlebitis caused by previous treatments.
453
What is computer-assisted radiation treatment planning based on?
CT scan
454
What does a CT scan help determine in radiation treatment planning?
Extent of disease
455
How does histopathology of the tumor help determine the usefulness of radiation therapy?
Tumor grading and expected prognosis
456
What are good candidates for radiation therapy?
Animals with radiosensitive tumors and localized disease
457
What are the potential treatment options for animals with distant metastases or radioresistant tumors?
Palliative radiotherapy or a combination of radiotherapy and cytoreductive surgery
458
What is the purpose of post-treatment evaluations after radiation therapy?
Evaluate tumor response and side effects in normal tissues
459
What is the unit of dose in radiation therapy?
Gray (Gy)
460
What is the standard radiation protocol for a full course of definitive radiation therapy?
2.25 to 3.2 Gy/fraction, 16 to 25 treatments, 48 to 63 Gy total dose
461
What does a palliative radiation protocol usually entail?
Larger dose per fraction and lower total dose, such as 8-9 Gy/fraction, 4 consecutive weeks, 32-36 Gy total dose
462
What can affect radiation protocols in terms of tumor type, stage, and site?
Variation from one facility to another
463
What is required for radiation therapy?
Anaesthesia
464
What types of treatments can be done with manual treatment planning?
Single treatment fields or bilateral, parallel-opposed fields
465
Which tumors typically require CT-based, computer-generated treatment planning?
Large head and neck tumors, caudal oral tumors, brain tumors, and abdominal/pelvic masses
466
What do three-dimensional radiation treatment planning systems provide?
Information on radiation dose to both tumor and normal tissues
467
How often can Cytarabine be added during treatment?
Cytarabine can be added every 3 weeks.
468
What maintenance protocol follows the COP protocol?
LP or LPV is the maintenance protocol that follows the COP protocol.
469
What is the initial dosage of L-asparaginase for complicated presentations?
The initial dosage of L-asparaginase for complicated presentations is 400 IU/kg SC.
470
What medication is given 24 hours after L-asparaginase in complicated presentations?
Vincristine is given 24 hours after L-asparaginase in complicated presentations.
471
How often is Vincristine administered in Week 1 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 1 of the Wisconsin-Madison protocol.
472
What is the dosage of L-Asparaginase in Week 1 of the Wisconsin-Madison protocol?
The dosage of L-Asparaginase is 400 IU/kg IM or SC in Week 1 of the Wisconsin-Madison protocol.
473
How often is Prednisolone administered in Week 1 of the Wisconsin-Madison protocol?
Prednisolone is administered every 24 hours in Week 1 of the Wisconsin-Madison protocol.
474
What medication is given in Week 2 of the Wisconsin-Madison protocol?
Cyclophosphamide is given in Week 2 of the Wisconsin-Madison protocol.
475
What is the dosage of Prednisolone in Week 2 of the Wisconsin-Madison protocol?
The dosage of Prednisolone is 1.5 mg/kg PO every 24 hours in Week 2 of the Wisconsin-Madison protocol.
476
How often is Vincristine administered in Week 3 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 3 of the Wisconsin-Madison protocol.
477
What is the dosage of Prednisolone in Week 3 of the Wisconsin-Madison protocol?
The dosage of Prednisolone is 1 mg/kg PO every 24 hours in Week 3 of the Wisconsin-Madison protocol.
478
What medication is given in Week 4 of the Wisconsin-Madison protocol?
Doxorubicin is given in Week 4 of the Wisconsin-Madison protocol.
479
What is the dosage of Prednisolone in Week 4 of the Wisconsin-Madison protocol?
The dosage of Prednisolone is 0.5 mg/kg PO every 24 hours in Week 4 of the Wisconsin-Madison protocol.
480
How often is Vincristine administered in Week 6 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 6 of the Wisconsin-Madison protocol.
481
What medication is given in Week 7 of the Wisconsin-Madison protocol?
Cyclophosphamide is given in Week 7 of the Wisconsin-Madison protocol.
482
How often is Vincristine administered in Week 8 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 8 of the Wisconsin-Madison protocol.
483
What medication is given in Week 9 of the Wisconsin-Madison protocol?
Doxorubicin is given in Week 9 of the Wisconsin-Madison protocol.
484
How often is Vincristine administered in Week 11 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 11 of the Wisconsin-Madison protocol.
485
What medication is given in Week 13 of the Wisconsin-Madison protocol?
Cyclophosphamide is given in Week 13 of the Wisconsin-Madison protocol.
486
How often is Vincristine administered in Week 15 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 15 of the Wisconsin-Madison protocol.
487
What medication is given in Week 17 of the Wisconsin-Madison protocol?
Doxorubicin is given in Week 17 of the Wisconsin-Madison protocol.
488
How often is Vincristine administered in Week 19 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 19 of the Wisconsin-Madison protocol.
489
What medication is given in Week 21 of the Wisconsin-Madison protocol?
Cyclophosphamide is given in Week 21 of the Wisconsin-Madison protocol.
490
How often is Vincristine administered in Week 23 of the Wisconsin-Madison protocol?
Vincristine is administered once during Week 23 of the Wisconsin-Madison protocol.
491
What medication is given in Week 25 of the Wisconsin-Madison protocol?
Doxorubicin is given in Week 25 of the Wisconsin-Madison protocol.
492
What is the recommended dose range for Vincristine?
The recommended dose range for Vincristine is 0.5-0.7 mg/m2.
493
What dose of Vincristine is typically used for feline protocols?
For feline protocols, the lower end of the dose, 0.5 mg/m2, is typically used.
494
What medication can be substituted for vincristine in cases of GI toxicity?
Vinblastine can be substituted for vincristine at a dosage of 1.8 mg/m2 IV.
495
What medications are included in the LPV maintenance protocol?
The LPV maintenance protocol includes Vincristine, Chlorambucil, and Prednisolone.
496
How often is Vincristine administered in the LPV maintenance protocol?
Vincristine is administered every 2 weeks in the LPV maintenance protocol.
497
What is the dosage of Chlorambucil in the LPV maintenance protocol?
The dosage of Chlorambucil is 20 mg/m2 PO every 2 weeks in the LPV maintenance protocol.
498
How often is Prednisolone administered in the LPV maintenance protocol?
Prednisolone is administered every 48 hours in the LPV maintenance protocol.
499
When is the LP maintenance protocol used?
The LP maintenance protocol is used for intermediate/high grade LSA, low grade alimentary LSA, chronic lymphocytic leukaemia, and feline multiple myeloma.
500
What medications are included in the LP maintenance protocol?
The LP maintenance protocol includes Chlorambucil and Prednisolone.
