Oncology Flashcards
1
Q
define cancer
A
persistent, purposeless proliferation of host cells, often to detriment of host
2
Q
what are different behaviours cancers can show?
A
benign
highly malignant
metastasis
3
Q
list features of cancer
A
evading apoptosis self sufficiency in growth signals insensitive to anti-growth signals sustained angiogenesis limitless replicative potential tissue invasion and metastasis
4
Q
what is the cause of cancer?
A
alteration of genes
5
Q
what changes to genetics lead to cancer?
A
overactive oncogens which are tumour promoting
loss of tumour suppression genes
6
Q
how are cancers named?
A
tissue of origin
status- benign or malignant
7
Q
define metastasis
A
development of tumour away from primary tumour
8
Q
define benign
A
neoplasm that forms solid cohesive tumour without metastasis
9
Q
define malignant
A
neoplasm with capacity for local invasion and metastasis
10
Q
list clinical features of cancer
A
effect on host
response to treatment
reflection of tumour growth, grade and behaviour
11
Q
what is meant by tumour behaviour?
A
local behaviour
metastatic and PNS effects
12
Q
why are most cancers advanced before they are detected?
A
most of growth has taken place before this time
13
Q
when can tumours be detected?
A
1cm diameter
1g weight
10^9 cells
14
Q
define growth fraction
A
proportion of actively dividing cells which determines tumour growth
15
Q
define tumour
A
swelling inferred to be neoplastic
16
Q
why are tumours susceptible to treatment when in early stages?
A
tumour cells are rapidly dividing so sensitive to chemo and radiation
17
Q
what determines response to chemo and radiation?
A
growth fraction
18
Q
why is treatment likely to be toxic for treating detectable tumours?
A
growth fraction reaching plateau so tumour is less susceptible than rapidly dividing healthy tissues such as intestinal epithelium and bone marrow
19
Q
what makes tumours heterogenous?
A
cancer cells modify properties as they grow by small sequential mutations
20
Q
what determines tumour grade?
A
mitotic rate
cellular and nuclear characteristics
21
Q
how does rate of growth differ between benign and malignant tumours?
A
benign- slow
malignant- rapid
22
Q
describe how benign and malignant tumours grow in space
A
benign- expansive with well defined boundaries
malignant- invasive with poorly defined boundaries
23
Q
which type of tumour has often serious effects on adjacent tissues?
A
malignant
24
Q
what is the effect of surgery on benign and malignant tumours?
A
benign- curative with complete resection
malignant- curative if complete resection and no mets
25
which tumour type has potential to metastasise?
malignant
26
when can benign tumours be dangerous to the host?
if causes bleeds
| located in vital organ
27
which types of tumour can cause paraneoplastic effects?
benign and malignant
28
how do malignant tumours grow?
local invasion and may extend microscopically into surrounding tissues
29
list indicators of local invasion
diffuse and indistinct boundaries
fixation of tumour in one or more planes
thickening of adjacent tissue
spontaneous bleeding
30
what is meant by metastatic potential?
ability to spread to distant tissues
31
list ways of metastatic spread
blood
lymphatics
transcoelomic across pleural or peritoneal space
iatrogenic
32
what is the effect of metastasis via blood?
secondary tumours can form in any body cavity
33
how does cancer metastasise via lymphatics?
spreads to local then regional lymphnodes
34
what are examples of iatrogenic spread?
biopsies and seeding
35
where is the most common site for secondary tumours to develop?
lungs
36
name common places for secondary tumours to develop and why
```
liver
spleen
kidneys
bone
CNS
high blood flow
```
37
define paraneoplastic syndrome/PNS
signs from indirect effect of tumours production and release of biologically active substances
38
what is the impact of PNS?
may be first evidence of neoplastic disease
| may be life threatening before cancer kills patient
39
list the types of hematologic PNS and signs of these
anaemia- weakness, lethargy, tachypnoea
thrombocytopenia- bleeding
leukopenia- susceptible to infection
40
what is hyper viscosity syndrome?
PNS with increased blood cell numbers with sludging blood and poor circulation
41
list causes of hyper viscosity syndrome
primary polycythaemia
leukaemia
excess gamma globulins
secondary polycythaemia due to excess erythropoietin secretion
42
what are clinical signs of hyper viscosity syndrome?
```
lethargy
tremors
thromboembolism
bleeding
ataxia
seizures
```
43
what causes hyperhistaminaemia PNS?
mast cell tumours often release histamine and vasoactive amines
44
what are local affects of hyperhistaminaemia?
oedematous swelling with erythema and pruritis
tendency for localised bleeding due to heparin release
delayed wound healing, dehiscence after surgery due to released proteases
45
what are systemic effects of hyperhistaminaemia?
anaphylactic shock
46
what is meant by immune mediated reactions due to PNS?
cross reactivity between cancer and healthy cells
47
what causes endocrine related PNS?
non-endocrine tumours release hormones or hormone like substances which have paraneoplastic effects
48
what causes hypercalcaemia PNS?
tumours release parathormone-like substance increasing total and ionised calcium concentration
49
what types of cancer most commonly causes PNS hypercalcaemia?
lymphoma
| myeloma and carcinoma with skeletal metastasis
50
what are clinical signs of hypercalcaemia?
```
PUPD
anorexia
vomiting
lethargy
depression
muscle weakness
bradycardia
renal effects and failure
```
51
how does hypoglycaemia PNS happen?
pancreatic insulinoma produces insulin
release of insulin like factor called leiomyoma
excess glucose consumption
52
what causes cancer cachexia PNS?
abnormal metabolism due to enhanced catabolism
| reduced food intake
53
what causes fever PNS?
pyrogens
| cytokines
54
what are the aims of cancer investigations?
make histological diagnosis of type and grade
determine stage of disease
investigate and treat tumour related or other complications
55
state investigations carried out for cancer diagnosis
```
history
physical exam
lab testing
imaging
biopsy for cytology and histopathology
```
56
what is the only way to accurately diagnose cancer?
microscopic exam of tissue or cells
57
how can you produce samples for cytology?
touch/impression preparations
fine needle aspirations
samples of effusion or body fluid in EDTA tube
58
define neoplasia
new growth, inferring abnormal growth
59
what are negatives of cytology samples for cancer diagnosis?
may not be definitive diagnosis
false negatives possible
can be hard to differentiate inflammation and neoplasia
60
what can be shown by large biopsies of tumours?
cellular features of malignancy
tumour architecture
invasion of adjacent tissues
evidence of metastasis
61
define incisional biopsy
small piece of tumour taken with some healthy tissue for comparison
62
define excisional biopsy
whole tumour including margins removed
63
how can you provide a representative sample of a tumour for biopsy?
avoid superficial ulceration, inflammation or necrosis
ensure adequate depth
include boundary between tumour and normal tissue
64
when are biopsies not done?
too dangerous location
| biopsy wont affect treatment
65
why is staging of tumours used?
determines feasibility of treatment and prognosis
66
what are the aims of tumour staging?
identify grade, local invasion and metastatic spread
67
what is assessed in tumour staging
tumour size and invasiveness
nodes- spread to local draining lymph nodes
metastasis
68
how is tumour assessed in staging?
T0- no evidence of primary tumour
| T1-4 depending on extent and size of primary tumour
69
how are lymph nodes assessed in staging?
N0- no regional lymph node involvement
| N1-4- involvement of regional lymph nodes, number and extent of spread
70
how is metastasis assessed in staging?
M0- no distant mets
M1- single distant met present
M2- multiple distant mets present
71
state how distant spread of tumours is assessed
```
history
physical exam
imaging- thorax, abdomen
FNA- lymph nodes, spleen, liver
bone marrow aspiration
observe lymph node metastasis and routes of drainage
```
72
what is the purpose of tumour staging?
used to decide treatment along with grade and behaviour of tumour
73
how are treatment options chosen?
informed based on nature of disease, treatment options, potential side effects, prognosis, cost
74
state the different aims for treating cancer
cure
remission
palliation
75
what is meant by cure?
all cells with capacity for tumour regeneration eradicated usually by excision
76
what is meant by remission?
all clinical evidence of cancer disappeared but occult cancer cells remain and relapse will happen at some point
77
what is the aims of palliation?
reduce pain
improve wellbeing
correct physiological malfunctions
78
what is meant by palliation?
treating patient without aim of curing patient, cancer still clinically identifiable
79
list the main treatment options for cancer
surgical excision
radiation
chemotherapy
80
what is the aim of surgical excision?
complete removal of tumour cells
81
when is surgical excision most effective?
solid tumours
82
what are lumpectomies used for?
truly benign tumours such as lipoma, fibroma, mammary tumour
83
describe wide local excisions
wider margins and 2 tissue planes deep of normal tissue excised to remove all of tumour and prevent regrowth
84
what types of tumours are wide local excisions used for?
locally invasive tumours such as basal or squamous cell carcinoma, mast cell tumour
85
when can wide local excision be difficult?
insufficient normal tissue to close wound
| need excision of underlying bone
86
what is meant by compartmental excision?
removing all tissue compartment involved in tumour
87
when is compartmental excision done and why?
soft tissue tumours as they infiltrate tissues more widely
88
when does excisional surgery fail?
regrows due to incomplete resection of margins
cant remove all as involved in vital structures
already metastasised
is systemic
89
what is surgical debulking?
surgically removing as much of a incurable malignant neoplasm before using other therapy to treat
90
what needs considering when planning surgical excision?
margins
cutting deep and large
2 sets of instruments
91
what needs to be included on lab forms to send with tumours?
clinical history
margin concerns
orientate and identify samples
submit whole tumour
92
what are general post op considerations?
nutrition
analgesia
wound care
functionality
93
what is the problem of excess tension when closing wounds?
```
compromise circulation
ischemia if artery compromised
if veins or lymphatics compromised oedema
slow healing
wound breakdown
necrosis
distortion of anatomy
```
94
what patient factors can lead to wound breakdown?
```
concurrent disease
nutrition
chemotherapy
steroids
radiotherapy
```
95
what wound factors can lead to wound breakdown?
```
neoplasia
tissue handling
haemostasis
tension
motion around joint
sutures
infection
patient interference
```
96
if wounds breakdown how should they heal?
classed as dirty so heal by second intention
97
how can you prevent seromas following surgical excision?
reduce dead space
place drains
rest as motion creates fluid
98
how are seromas following excision treated?
leave alone
pressure bandage
drainage
99
how are infections post excision managed?
antibiotics after culture and sensitivity
drainage
heal via second intention
explore wound if needed
100
what is meant by radiation therapy?
ionising radiation to kill or control malignant cells
101
when is radiation therapy used and why?
when surgery is incomplete
| is the least toxic and most effective local treatment
102
state how radiation therapy is given to patients
brachytherapy
external beam radiation
teletherapy
103
what type of radiation is used in radiation therapy?
electrons which absorbed by tissue or easily shielded
| high energy x-rays which are highly penetrating and harmful
104
what is meant by brachytherapy?
radioactive substance emits gamma rays or beta particles close to tumour
105
how is brachytherapy administered?
surface of tumour
implanted in tumour
systemically but concentrated in tumour
106
how is radioiodine treatment used to treat thyroid cancer?
systemically administered and concentrated in tumour
| beta cells kill local cancer cells
107
how is external beam radiation therapy given?
external radiation source at distance from body with multiple doses over 4-6 weeks
108
what are side effects of external beam radiation?
```
skin reddening
vesiculation
desquamation
severe exfoliative dermatitis
localised hair loss
depigmentation
dermal fibrosis
osteonecrosis
neural necrosis
```
109
why is chemotherapy so dangerous?
highly toxic
110
what are chemo drugs most effective against and what are examples?
growing and dividing cells
cancer
bone marrow
GI tract
111
why are chemo drugs effective against dividing and growing cells?
acts on processes involved in cell growth and division such as DNA replication, mitotic spindle and metabolism
112
state factors affecting response to chemo
tumour growth rate and drug resistance
113
what is the main consideration when using chemo?
use highest possible dose with maximum fractional kill with minimal side effects
114
when is the best time to use chemo?
tumour burden lowest and growth fraction highest so in early stages or after debulking
115
how are chemo dose calculated?
function of body surface area
116
how often is chemo normally given?
3 week cycles
117
state cancers highly sensitive to chemo
lymphoma
myeloma
leukaemia
118
state cancers with moderate sensitivity to chemo
high grade sarcoma
| mast cell tumour
119
what cancers are poorly sensitive to chemo?
slow growing sarcoma
carcinoma
melanoma
120
why is combination chemotherapy preferred?
more effective
less side effects
less resistance
121
describe combination chemotherapy
combining different classes of chemo agents with different mechanisms of action
122
what is the cat and dog protocols for lymphoma
cats- COP
| dogs- CHOP
123
when is chemo used as first line therapy and why is it usually effective?
systemic disease- lymphoma, leukaemia, multiple myeloma
| high growth fraction
124
why is adjunctive chemotherapy used?
solid tumours rarely respond to chemo alone so used with surgery and radiation
125
why is chemo used along with surgery?
reduce mass to allow resection
| delay metastasis
126
what is meant by metronomic chemo?
palliative low doses of chemo daily targeting endothelium or tumour stroma
127
what is the purpose of metronomic chemo?
minimise toxicity
slow progression
anti-angiogenic- stops new vessels growing in tumour
128
what is meant by chemoembolization?
local direct delivery of chemo and embolization to treat inoperable solid tumours
129
how is chemoembolization done?
chemo injected to blood vessel supplying tumour
| synthetic material placed in blood vessel trapping chemo in tumour
130
what safety measures need to be in place when using chemo?
```
PPE- gloves, mask, glasses, apron
sealed injection system
cleaning and disposal protocols
chemo room- fume cupboard for drawing up, surfaces covered, chemo waste bins
no use by pregnant women
```
131
what are nursing considerations for chemo patients?
excretions may have drugs or metabolites in
kennel states chemo is used
PPE when with patient
use cytotoxic waste bins
132
what measures should be in place for chemo patients at home?
```
wash hands after contact with pet
keep children and pets away
wash food and toys separately
wash bedding separately and run empty cycle after
latex gloves to clean up excretions
double bag all rubbish
clean then disinfect with bleach
```
133
what makes chemo have toxic effects?
affects dividing cells in normal tissue
134
how does chemo cause GI toxicity?
death and loss of intestinal epithelial cells
135
what are the signs of GI toxicity from chemo?
stomatitis, vomiting, diarrhoea usually 5-10 days after admin
136
how is GI toxicity from chemo treated?
IVFT
antiemetics
gastroprotectants for ulceration
parenteral antibiotics if haemorrhagic diarrhoea or immunosuppressed
137
what are the effects of chemo on patients coats?
cats- lose whiskers
| dogs- not major problem, can be in breeds such as poodle, shih tzu, bichon
138
define myelosuppression
decreased bone marrow activity resulting in fewer WBC, RBC and platelets
139
what needs to be done before cytotoxic drugs are given in case of myelosupression?
routine haematology
140
what happens if chemo patients experience myelosuppression?
treatment is delayed or reduced
141
what is the effect of myelosuppression?
neutropenia
thrombocytopenia
anaemia
142
what effects management of neutropenia as a result of myelosuppression?
absolute cell count
| clinical signs
143
what does neutropenia indicate when using chemotherapy?
maximum dose tolerated being reached
| better prognosis
144
what should you do if have reaction to chemo drugs?
```
stop admin
IVFT
soluble corticosteroids
epinephrine
antihistamines
```
145
describe chemo drugs being irritants and state an example
local inflammatory reactions at infusion site
| carboplatin
146
what is meant by chemo drugs being vesicants and state examples
severe irreversible tissue injury and necrosis
| vincristine, vinblastine, cisplatin
147
how can you reduce risk of extravasation of chemo drugs?
keep in sealed system
good patient restraint
give through clean stick IV
flush catheter before and after
148
what effect do chemo drugs have if extravasate or go on patient topically?
irritant
| vesicant
149
how is perivascular leakage of chemo drugs treated?
stop infusion
leave in catheter
aspirate drug through catheter then give intralesional saline to dilute
draw back blood and remove catheter
give IV hydrocortisone and antidote if available
cold compress
150
what causes sterile haemorrhagic cystitis?
metabolites of cyclophosphamide in urine irritate bladder causing cystitis and haematuria
151
how do you minimise risk of sterile haemorrhagic cystitis?
give drugs in morning so not retained in bladder
good fluid intake
frequent urination
monitor for blood and protein by urine dipstick after every admin
152
what acute cardiotoxicity can be caused by chemo and how is this reduced?
tachyarrhythmias
| infuse over 15 minutes
153
what chronic cardiotoxicity can be a result of chemo and what affects its prevalence?
irreversible cardiomyopathy
| dose dependent
154
what is the impact of hepatotoxicity as a result of chemo?
cumulative and irreversible effects
155
what should you do if increased liver enzymes indicating hepatotoxicity as a result of chemo?
delay or stop treatment
156
how can you prevent hepatotoxicity from chemo?
monitor biochemistry before each treatment
157
how does nephrotoxicity happen due to chemo?
platinum compounds cause necrosis of proximal tubular cells
158
how do you manage nephrotoxicity as a result of chemo?
monitor urea and creatinine
159
how can you reduce likelihood of nephrotoxicity as a result of chemo?
administer drugs slowly with IV diuresis
