Oncological surgery

Question 1

a severe lack of differentiation is referred to as

Answer 1

anaplasia

Question 2

MCTs can feel like

Answer 2

lipomas.

Question 3

difference in mode of growth between benign and malignant

Answer 3

benign - expansion

malignant - invasion

Question 4

Obesity in canine puberty is a risk factor for

Answer 4

mammary gland tumors.

Question 5

explain Proto-oncogenes &
Tumor suppressor genes

Answer 5

proto-oncogenes have normal physiological purpose/function

oncogenes are permanently active

tumor suppressor genes have normal physiological purpose/function but can be deactivated in cancers

Question 6

The hallmarks of cancer (10)

Answer 6

1. self sufficient growth
2. limitless replicative potential
3. evasion of programmed cell death
4. reprogramming energy metabolism
5. insensitive to antigrowth signals
6. sustained angiogenesis
7. evade immune destruction
8. tissue invasion and metastasis
9. genome instability
10. tumor-promoting inflammation

Question 7

Cancer cells bypass senescecence by

Answer 7

activating telomerase enzymes to increase the length of telomeres.

Question 8

Explain cancer cell energy dysregulation: Warburg effect

Answer 8

The Warburg effect describes how cancer cells preferentially produce energy via aerobic glycolysis rather than oxidative phosphorylation, even when oxygen is plentiful.

Normal cells: Use glycolysis (in cytoplasm) for energy under low oxygen, then switch to oxidative phosphorylation (in mitochondria) when oxygen is available—this yields more ATP.

Cancer cells: Persist with glycolysis, converting glucose to lactate, despite sufficient oxygen. This is inefficient (low ATP yield) but faster and supports rapid growth.

Tumors with high glycolysis rates are more easily detected using imaging tools like PET scans (less common in routine vet practice but used in research and specialty clinics).

Question 9

Cancer stem cells are

Answer 9

a small subpopulation of cells within tumors with
capabilities of self-renewal, differentiation and hence tumorigenecity.

Like normal stem cells, they are able to give rise to all cell types found in a particular tumour and are thought to be involved in metastasis and
relapse after treatment.

Question 10

most common paraneoplastic syndrome

Answer 10

hypercalcemia (measure ionized Ca2+)

t-cell lymphoma, thymoma

Question 11

Paraneoplastic Syndromes:
* Gastrointestinal?
* Endocrinologic?
* Hematologic?
* Cutaneous?
* Neurologic?

Answer 11

• Gastrointestinal - cancer cachexia/anorexia, GI ulceration
• Endocrinologic - hypercalcemia, hypoglycemia, hyperestogenism, acromegaly
• Hematologic - hyperglobulinemia, anemia (min.28% PCV, if lower then something else is at play as well), erythrocytosis, leukocytosis, thrombocytopenia
• Cutaneous - alopecia, superficial necrolytic dermatitis, nodular dermatofibrosis, feline paraneoplastic alopecia, feline thymoma-associated exfoliative dermatitis
• Neurologic - myasthenia Gravis, peripheral neuropathy, hypertrophic osteopathy

Question 12

Pain meds for use in chronic cancer pain in dogs.

Answer 12

• Nonopioid analgesics (NSAIDs, paracetamol, steroids)
• Weak opioid drugs (butorphanol, codeine)
• Strong opioid drugs (morphine, buprenorphine, fentanyl patch)
• Adjuvant drugs (NMDA antagonists (amantadine), corticosteroids, tricyclic antidepressants, gabapentin (gaba min 10mg and up), Nerve Growth Factor (NGF) antibodies, tramadol)
• amitryptyline (alfaadrenergic antagonist)
• glucosamine & chondroitin (have analgesic effects too!)
• pamidronate for osteosarcomas (bisphosponate)

Question 13

Pain meds for use in chronic cancer pain in cats.

Answer 13

meloxicam
morphine
piroxicam
prednisolone
polysulfated glycosaminoglycans
robenacoxib
tepoxalin (NSAID)
Tolfenamic acid (NSAID)
tramadol
fentanyl patches

Question 14

Nutritional management of cancer patients.

Answer 14

Sugar is believed to contribute to cancer growth but this isn’t proven. Cancer will grow either way.

The best diet to feed a pet with cancer is one that
they like!

The diet should be nutritionally complete and
balanced!

Supplements are acceptable if the owners want but maybe not during chemothrapy in case of interactions.

Stimulate appetite - hand feed, warm the food, avoid
associating feeding time with drug administration.

Question 15

Appetite stimulants. (2)

Answer 15

mirtazapine
cyproheptadine

Question 16

What kind of tumors are there? (3)

Answer 16

• Epithelial - tumors that arise from epithelial tissue (carcinoma)
• Mesenchymal - tumors that come from connective tissue (sarcoma)
• Round cell - lymphoma, melanoma, mast cell tumor (has distinctive granules inside) etc.

If you know what kind of tumor you are dealing with than you know where to look for metastasis and how the tumor develops.

Metastases:
* mesenchymal predominantly via blood vessels
* epithelial and round cell tumors via lymphatics

round cells are round, epithelial cells are squarish, mesenchymal cells are spindle shaped

Question 17

Answer 17

neoplastic mast cell upper right

Question 18

For FNA: the firmer the tumor, the…

Answer 18

bigger the needle gauge you should use in order to pick up cells.

With FNA of you get cytology results (type of cell, criteria
of malignancy, changes in nucleus and cell).

Question 19

Histological grading includes

Answer 19

necrosis,
mitotic index,
invasivness and
the reaction of the surrounding stroma.

It directly correlates with survival, metastasis rate, disease free interval and local recurrence.

Question 20

Excisional Biopsy =

Answer 20

primary excision of entire tumor without prior knowledge of tumor character
– performed far more often than indicated
– advantage: only one surgical treatment (??)
– disadvantage: possibility of „under-“ or „overdosing“ (margins)

only indicated when „dose“ of surgical intervention is independent from type of tumor
– mammary tumors
– lung tumor: lung lobe resection
– solitary splenic tumor: splenectomy

Question 21

formalin only penetrates

Answer 21

1 cm in

you need to slice open large biopsy samples

tissue : formalin = 1:1
In winter add alcohol (anti-freeze)

Question 22

After surgical incision of cancer, when do you start chemo?

Answer 22

2 weeks after surgery

Question 23

TNM Staging refers to

Answer 23

• Tumor (T): size, extent, CT, MRI
• Node (lymph) (N): palpation is not indicative, you need FNA. Contrast is possible too!
• Distant Metastasis (M): use x-ray, ultrasound, CT

Grade comes from the histopath lab! Stage refers to the tumor in the body, grade refers to the cellular level characteristics.

Question 24

procedure where you inject contrast that identifies a cancerous tumor and related lymph node infiltration

Answer 24

contrast lymphangiography, with sentinel lymph node mapping.

Sentinel Lymph Node Mapping (SLN Mapping)
Purpose: Identifies the first lymph node (“sentinel node”) that drains a tumor area, where metastasis is likely to spread first.

How it’s done:
* Peritumoral injection of contrast agents (radioactive tracer, blue dye, or CT/MRI contrast).
* Advanced imaging (CT, MRI, or lymphoscintigraphy) tracks the lymph flow to the sentinel node.

Question 25

Describe Tumor resection

Answer 25

* As often as possible the tumor should be resected widely * Depending on the tumor type and size, 1-3 cm lateral margins are recommended * Tumors should be manipulated as little and as gently as possible - try to ligate the blood vessel first, manipulate MCT with great care!

Question 26

The only canine cancer that can be cured with chemotherapy

Answer 26

transmissible venereal tumor chemo is otherwise only palliative

Question 27

Chemotherapy precautions at home

Answer 27

Vomitus/feces – Normal urinations and defecations can be left in the environment – vomitus/feces/diarrhea in the household should be handled with gloves and disposed of into the toilet. Instruct owners concerning handling of tablets – keep away from children – advise pregnant owners to avoid any contact with urine, feces or vomitus.

Question 28

Chemotherapy tablets precautions:

Answer 28

* Do NOT break tablets containing cytostatics

Question 29

Chemotherapy should be used on the following types of cases: (4)

Answer 29

1. Systemic tumors (e.g. lymphoma) 2. Tumors with lymph node metastasis 3. Highly metastatic tumors 4. Tumors that respond well to chemo (e.g. TVT)

Question 30

M = G0 = G1= S = G2 =

Answer 30

M = mitosis G0 = temporarily or permanently non-dividing (G0-) cells G1= Cell grows in size and prepares for DNA replication. A major checkpoint for cancer control; mutations here (e.g., p53 dysfunction) often lead to unchecked growth. S = synthesis; DNA replication occurs. G2 = Cell prepares for mitosis. Checks for DNA replication errors and begins forming the mitotic spindle. Another checkpoint — cancer cells may bypass this if regulatory genes are mutated.

Question 31

Sensitivity to chemo is low and high in?

Answer 31

lower in slowly growing tumors high in rapidly growing tumors

Question 32

Chemo drug dosing is in the form of

Answer 32

mg/m2! ## Footnote Tables can found that convert kg into m2, square meters.

Question 33

Median surival time =

Answer 33

Question 34

Chemotherapy drugs' most common side-effects: doxorubicin epirubicin vincristine chlorambucil cisplatin

Answer 34

Question 35

sterile hemorrhagic cystitis as a side effect of chemotherapy

Answer 35

side effect of most notably cyclophosphamide. This condition arises due to the accumulation of toxic metabolites, such as acrolein, in the urinary bladder, which causes sterile inflammation and hemorrhage of the bladder wall without evidence of infection. relatively uncommon Preventative strategies such as concurrent administration of diuretics or mesna, increased fluid intake, and frequent urination can help reduce the risk in at-risk patients. ## Footnote Mesna (2-mercaptoethane sulfonate sodium) is a uroprotective agent used in veterinary medicine to prevent sterile hemorrhagic cystitis associated with cyclophosphamide chemotherapy. It works by binding to and inactivating acrolein, the toxic metabolite responsible for bladder irritation.

Question 36

Tx for diarrhea as side effect of chemotherapy.

Answer 36

metronidazole loperamide butylscopolamine bland diet

Question 37

Prevent chemotherapy associated nausea and vomiting with 4 drugs:

Answer 37

ondansetron, metoclopramide, maropitant, butorphanol

Question 38

Explain Metronomic chemotherapy.

Answer 38

continuous or frequent administration of low doses of chemotherapeutic drugs with minimal or no drug-free breaks. Unlike traditional chemotherapy, which uses high doses at spaced intervals “Cancer is a chronic disease and should be treated like other chronic disease” Fidler and Ellis Metronomic: * Chemotherapy drugs given constantly at low doses to have minimum tumor burden and stable disease. * Is Cheaper * More comfortable (tablet form vs IV) * Antiangiogenic therapy

Question 39

Tyrosine Kinase inhibitors as chemotherapeutics in vet med

Answer 39

e.g. masitinib, toceranib Tyrosine kinase inhibitors (TKIs) are a class of targeted chemotherapeutic agents increasingly used in veterinary medicine, particularly in the treatment of canine mast cell tumors (MCTs) and other cancers driven by dysregulated tyrosine kinase signaling. In veterinary oncology, the most commonly used TKIs are toceranib phosphate (Palladia) and masitinib, both approved for use in dogs.

Question 40

Prednisolone and cancer

Answer 40

Anti-inflammatory -> cancer induces inflammation, pred can improve clinical signs. Prednisolone also stimulates appetite! Pred is end of life or pre-chemo. Works on lymphoma only short-term.

Question 41

Describe electrochemotherapy.

Answer 41

a novel cancer treatment modality used in veterinary medicine that combines the administration of chemotherapeutic drugs with the application of short, intense electrical pulses to enhance drug uptake by tumor cells. The most commonly used drug is bleomycin, which is poorly permeable across cell membranes on its own, but becomes significantly more effective when electric pulses temporarily increase cell membrane permeability—a process called electroporation. ECT is primarily used for treating **cutaneous and subcutaneous tumors** in dogs and cats, such as mast cell tumors, soft tissue sarcomas, and squamous cell carcinomas. The technique is minimally invasive, often performed under sedation or light anesthesia, and has been shown to improve local tumor control with limited systemic side effects.

Question 42

NSAID options for cats with cancer.

Answer 42

meloxicam piroxicam robenacoxib (Onsior)

Question 43

Most aggressive MCTs are located

Answer 43

on genitals and paws ## Footnote vinblastin is used for killing MCT cells. Masivet® is prescribed for the treatment of non-resectable (inoperable) high grade mast cell tumours.