Oncology Flashcards Preview

SAM II > Oncology > Flashcards

Flashcards in Oncology Deck (92)
Loading flashcards...
1
Q

Defining cancer to client

A

group of abnormal cells grow uncontrollably by disregarding normal rules of cell division

2
Q

What causes cancer?

A

Multifactorial
Genetic - DNA mutations result in deficits in the regulatory circuits of a cell; individual cell behaviour not autonomous
Environmental - diet, exposure, viruses, age

3
Q

Mechanisms of cancer - multistep carcinogenesis

A

Initiation - rapid - carcinogens induce DNA damage but not enough to induce neoplastic transformation
Promotion - original carcinogens or normal growth promoters/hormones cause reversible tissue and cellular changes
Progression - slow - progressing agents are able to irreversibly convert an initiated cell into a cell exhibiting malignancy

4
Q

6 hallmarks of cancer cell

A
  1. Evading apoptosis
  2. self-sufficiency in growth signals
  3. insensitivity to anti-growth signals
  4. tissue invasion and metastasis
  5. limitless replicative potential
  6. sustained angiogenesis
5
Q

Establishment of tissue diagnosis

A

diagnostic cytology - needle biopsy

6
Q

3 cell type origins of cancer

A
  1. round cell
  2. mesenchymal
  3. epithelial
7
Q

Round cell tumors

A

individualized round cells arranged in a mono layer

8
Q

5 Ddx of round cell tumors

A

Please Help Me Learn This

Plasmacytoma, Histiocytoma, Mast cell tumor, Lymphoma, TVT

9
Q

Mesenchymal tumors

A

spindle-shaped, arranged individually or in non cohesive aggregates
SARCOMAS

10
Q

Epithelial tumors

A

round, cuboidal, columnar or polygonal cells arranged in cohesive sheets or clusters
CARCINOMAS

11
Q

Characteristics of malignancy

A

homogenous vs. heterogenous
monomorphic vs pleomorphic
cellular/cytoplasmic cluster
nuclear criteria - anisokaryosis, multiple nucleoli, increased mitosis

12
Q

Advantages and Disadvantages of cytology

A
Advantages 
- low risk, low cost, non-invasive
- rapid turnover of results
- ability to evaluate morphologic appearance of individual cells
- HIGHLY SPECIFIC
Disadvantages
- low sensitivity
- poor sample quality
- small sample size
- inability to evaluate tissue architecture
13
Q

When will cytopathology fail you?

A

oral tumors (don’t exfoliate well), mammary tumors (most are carcinomas which have inflammation = false -), splenic tumors (often very bloody)

14
Q

In which tumors do cells spill out causing tumor cell growth along the needle tact when you take a cytopathology sample?

A
Urogenital neoplasms (carcinomas)
*remember he said you wouldn't do a FNA on a TCC because risk of seeding
15
Q

Clinical technique preferred for FNA

A
Needle off (coring)
- grasp mass, advance needle in mass and redirect several times to dislodge cells and drive them into hollow shaft of needle
16
Q

Cytology of liver, splenic, GI and bone tumors

A

Liver - <50% accuracy, interpret with caution
Splenic - non-aspiration techniques superior because produce samples of > cellularity and less blood contamination
GI - high specificity
Bone - ALP staining - very good, differentiates OSA from other sarcomas

17
Q

cytology of bone tumors with ALP staining

A

differentiates OSA from other sarcomas

18
Q

Staging vs. Grading

A

Staging
- answers Q is tumor localized, spread regionally or diffusely
- requires series of noninvasive testing
- based on WHO TNM (tumor, node, metastasis system)
Grading
- requires a block of tissue
- estimates inherent aggressiveness of tumor using systematic approaches
- allow definitive prognostication

19
Q

Regional LN cytology

A

Sentinel LN = LN cancer cell is most likely to spread to from primary tumor, not always nearest LN downstream
SLN - unique to each patient
- don’t assume normal sized LN are not metastatic
- 3 view thoracic metastasis check (rads) - can detect >7-9mm nodules
- CT detects greater # nodules and greater Dx confidence and accuracy
- abdominal US +/- image guided FNA
- cross sectional imaging (CT/MRI)

20
Q

Which organ is most common receptacle of blood born metastasis?

A

Liver

21
Q

Paraneoplastic syndrome

A

tumor associated alterations in body structure or function, occur distant to tumor, often first signs of malignancy

22
Q

Paraneoplastic causes of hypercalcemia

A

Anal sac adenocarcinoma
Lymphoma
Mammary tumors
Multiple Myeloma

23
Q

Paraneoplastic cause of hypoglycemia

A

Intestinal leiomyosarcoma

24
Q

2 Goals of conventional chemotherapy

A
  • enhane or maintain QOL and family bond

- stabilize, diminish or eliminate neoplastic process

25
Q

T/F: chemotherapy drugs only target cancer cells

A

false, target ALL rapidly dividing cells

- cancer cells, gut, bone marrow, hair

26
Q

Fractionation

A

allows recovery of normal tissue between treatment intervals

27
Q

Adjuvant chemotherapy

A

used after Sx as adjunct to local therapy

28
Q

Neoadjuvant chemotherapy

A

used prior to definitive Tx (Sx) in attempt to shrink tumor

29
Q

Induction/Maintenance chemotherapy

A

the sole Tx for measurable dz

30
Q

Palliateive chemotherapy

A

improve QOL by helping to alleviate signs, but won’t cure

31
Q

Chemotherapy dosing

A
  • based on maximum tolerated dose (toxicity) rather than efficacy
  • dose response curves very steep in most cancers
  • BSA body surface area -though to be better estimate vs BW, but doesn’t predict drug metabolism and absorption/excretion
  • smaller patients receive higher dose based on mg/m basis
32
Q

Which drugs are risky to give small animal patients based off of BSA dosing calculations?

A

doxorubicin, melphalan, cis- and carboplatin

33
Q

how many people should do dosing calculations for chemo drugs?

A

2

34
Q

important when writing chemo doses

A

no trailing zeros or naked decimals

35
Q

4 Rs of chemo Tx

A

right drug, right dose, right route, right patient

36
Q

MDR-1 gene/ABCB gene

A

Collie, Australian shepherds, long haired whippet
- gene encodes production of pgp pumps which remove drugs from individual cells
- increased risk in drugs that are substrates for pumps
Vincristine, vinblastine, paclitaxel, doxorubracin

37
Q

Which drugs should you probably not give to Collies, Aussies, or long haired whippets?

A

they have ABCB gene

Vincristine, vinblastine, paclitaxel, doxorubicin

38
Q

Common adverse effects of cytotoxic chemotherapy

A
BAG
Bone marrow suppression
Alopecia - non-shedding breeds only
Gastrointestinal - crypt cells destroyed = V/D
- only in 3-5%
39
Q

Monitoring chemo patient

A

On day of Tx - do a CBC, neuts >3000/ul and Plt >100000/ul. if too low, NO TX THAT DAY, recheck 3-7d later
After 1st chemo, check weekly after 1st dose to establish nadir (expected low point of bone marrow insult)

If neut at nadir <1500/ul or PLT <60000/ul, subsequent dose should be decreased by 20-25%

40
Q

Management of chemo side effects: myelosupression

A

risk of systemic infection - prophylactic antibiotics warranted (neutropenia)
- clavamox or baytril
- infection from opportunistic pathogens
- severe cases may need ICU
*MAY NOT HAVE FEVER (lack fever producing cells)
WBCs make IL-1 and TNF but levels are too low to yield a fever
Nupogen - granulocyte colony stimulating factor, stems WBC prod from BM, rarely used because tolerance built after 1st use (human origin)

41
Q

Management of chemo side effects: thrombocytopenia

A

exercise restriction, close monitoring for bleeding, careful w/ lomustine and melphalan (cumulative effect)

42
Q

Management of chemo side effects: GI effects

A

MOA for GI toxicity: (1)direct stim of CRTZ and (2)damage to crypt cells

  • 1 causes V <24h of tx
  • 2 causes anorexia, V or D w/in 2-5d of Tx
  • key drug players: cisplatin, streptozocin, dacarbazine, mustargen, doxorubracin
  • Tx symptoms (anti-emetics, anti-diarrheals, palatable food)
43
Q

4 main classes of chemo drugs

A

1) antimitotics
2) alkylating agents
3) antibiotic agents
4) Antimetabolites

also platinum agents

44
Q

Antimitotics/microtubule toxins

A

Disrupt or immobilize mitotic spindle, cell-cycle-phase-specific (mitosis)

VINCRISTINE (vinca alkaloids) - used for LSA or TVT
- Toxicity: BAG, GI signs, Vesicant (if outside vessel causes necrosis, Tx w/ hyaluronidase + heat), ileus (nausea), neuropathy (peripheral, pelvic limbs)

Vinblastine - used for MCT in dogs
- Toxicity: BAG

45
Q

Alkylating agents

A

Bind DNA, insert alkyl group and change DNA structure to interfere w/ transcription, replication and repair machinery, cell-cycle-phase- non-specific

Melphan - Multiple myeloma
- Toxicity: BAG
Cyclophosphamide - LSA, Metronomica
- Toxicity: BAG, Sterile hemorrhagic cystitis - metabolite toxic to bladder epithelium
Lomustine - LSA, MCT, Histiocytic sarcoma
- Toxicity: BAG, Liver toxicity (give w/ Denamarin, hepatoprotectant)
Chlorambucil - CLL, low grade LSA (cats)
- Toxicity: BAG

46
Q

Antibiotic agents

A

several mechanisms of action, cell-cycle phase non-specific

Doxorubricin (red death, adriamycin) - LSA, OSA, mesenchymal + epithelial tumors
- Toxicity: BAG, dose related cardiotoxicity (prescreen Boxers + Dobes w/ echo) and give w/ Dexrazoxane to decrease cardiotoxicity, Tinnitus (ear ringing), Vesicant (ice ASAP and give w/ dexrazoxane to localize + neutralize)
Mitoxantrone (blue thunder) - TCC, LSA
- Toxicity: BAG, cardiac sparing

47
Q

Antimetabolites

A

nucleotide analogs or substrates of active metabolic processes within the cell = S phase, cell-cycle-phase-specific (S phase)

Cytosine arabinoside (Cytosar) - CNS tumors, +/- LSA
- Toxicity = *B*AG
48
Q

Platinum agents

A

covalent binding to DNA strands, forming interstrand crosslinks which are cytotoxic (cell-cycle phase non-specific)

L-Asparaginase (Elspar) - LSA relapse

  • inhibit protein synth by hydrolysis of L-asparginase to L-aspartic acid
  • Toxicity: hypersensitivity rxn, pancreatitis, DIC

Cisplatin - OSA DOGS ONLY, SPLATS CATS
- Toxicity: BAG, nephrotoxic (diuresis during Tx)

Carboplatin - OSA and other sarcomas, ok in cats
- Toxicity: BAG, NO nephrotoxicty

49
Q

Novel Agents (Tanovea - CA1)

A

inhibits proliferation of lymphocytes and LSA cell lines by inhibiting DNA synthesis
1st FDA approved Tx for lymphoma in dogs
Used as RESCUE - once patient fails after standard chemo Tx

50
Q

Metronomic chemotherapy (MC)

A

revolves around concept of eliminating break period by giving low dose continuous chemotherapy
not designed to cure, meant for palliative care
MOA
- angiogenesis - up regulation of endogenous angiogenesis inhibitor thrombospondin - 1, blockade of COX and circulating endothelial precursor cells
- immunomodulation - tumor cells up regulate Treg to decrease host immune response (and host defence), MC combats tumor Treg proliferation
- Direct targeting - despite low dose has some direct cytotoxic effect on cancer cells
cyclophosphamide

51
Q

Cyclophosphamide

A

alkylating agent commonly used in metronomic chemotherapy
- inexpensive, low GI/hematologic toxicity and PO route
Unique SE: sterile hemorrhagic cystitis due to metabolite acrolein - incidence = 7-32% in MC protocols
- prevent w/ environmental control (give w/ water access), concurrent GC or furosemide to promote diuresis

52
Q

Toceranib phosphate

A

blocks receptor tyrosine kinases on cell surface
approved for use on MAST CELL TUMORS in dogs
- a lot of off label use

53
Q

Immunotherapy

A

non specific tumor IT, monoclonal antibiotics, T cell therapy (cytotoxic T cells NOT Treg), tumor vaccines

54
Q

Tumor vaccine - Oncept canine melanoma vaccine

A

DNA based vaccine, uses tyrosinase in a small DNA ring, labelled for dogs with stage II or III oral melanoma

55
Q

C vesicolor mushroom (turkey tail)

A

most commonly prescribed integrative medicine

- cell-cycle arrest at G1/S checkpoint = a reduction in proliferation and an increase in apoptosis in cancer cells

56
Q

Yunnan Baiyao

A

Chinese herbal formula - improves clotting and platelet function

  • prolong survival in HSA dogs
  • dose and time dependent HSA cell death
57
Q

Tissue effects of radiation therapy

A

Early responding tissue - epithelial layers of skin/mucosa and bone marrow - looks like massive sunburn, effects seen within weeks of exposure

Late responding tissue - nervous tissue and bone, severe, late effects seen within months or years, blindness, nerve death

58
Q

Fractioning of radiation

A

Tx better tolerated and more effective if dose is delivered in multiple small Tx as opposed to delivering dose all at once (fractions)

59
Q

Big 3 - variables that dictate response of tissues to radiation

A
  1. Total dose - related to both tumor response and toxicity
  2. Fraction size - larger fraction size = higher probability of late effect
  3. Duration of Tx - longer protocol =. fewer/milder acute effects but increased chance for tumor to repopulate during Tx
60
Q

Teletherapy

A

external beam radiation
- orthovoltage = obsolete
- protons/particle therapy = not used in vet med
Megavoltage - most common teletherapy
- used for abdominal or deep tumors
- cobalt machine and linear accelerators produce high energy x-rays for even, predictable distribution and deep penetration

61
Q

Brachytherapy

A

radioactive beads sealed source

62
Q

Nuclear medicine

A

radioactive iodine

63
Q

Standard radiation therapy

A

40Gy over 20 daily fractions = 2Gy/fraction

64
Q

Hypofractional dosing

A

total dose divided into larger doses in shorter period of time - good for rapidly. growing tumors

65
Q

3D CRT (conformational radiation therapy)

A

Intensity-modulated RT (IMRT)

Stereotactic RT (SRT)

  • radiation beams from different direction to match shape of tumor
66
Q

Measuring response to radiation therapy

A

RECIST
- response, evaluation, criteria, in solid tumors

Complete response: 100% resolution of tumor
Partial response: >30% reduction in overall tumor size
Progressive disease: >20% increase in overall tumor size
Stable disease: <30% reduction, <20% increase in tumor size

67
Q

Nasal planum tumors signalment

A

common in cats (15% of skin tumors)
older, lightly pigmented, outdoor cats
Hx of crusting/erythema progressing to superficial ulcers then deep erosive lesions
SCC - variations dictate Tx plan

68
Q

Staging of nasal planum tumors

A

cytology NOT effective bc lesions are flat and ulcerated
wedge or punch biopsy for tissue dx - take tiny sample from center of lesion, NOT under sedation
- low metastatic rate - goes late
- LN staging w/ FNA - sentinel LN with H&N tumors unpredictable, check prescaps too (check ALL LNs)

69
Q

Tx of nasal planum tumors

A
  • prevention and client education
  • if superficial lesion, many options but preferred is cryoablation (minimally invasive, cheap, available)

Infiltrative lesions = nasal planectomy (nosectomy)

70
Q

Prognosis of nasal planum

A

Aggressive surgical therapy yields improved prognosis
- combination of intra-lesional carboplatin with orthovoltage
ECT - combined use of chemo drugs (bleomycin or cisplatin) in combo with high-voltage electric pulses

71
Q

Signalment of ear canal tumors

A

recurrent signs of infection with visible mass effect in canal

  • pruritus, bleeding, pain or reluctance to open mouth
  • cocker spaniels, poodles, GSD
  • more likely benign in younger cats
72
Q

Ddx of ear canal tumors

A

ceruminous glad adenocarcinoma
cats develop more malignant disease than benign, more split in dogs
- other carcinomas (SCC/undifferentiated), round cell tumors (plasmacytomas), sarcomas

73
Q

Staging of ear canal tumors

A

sedated or anesthetized, shave or pinch biopsy - small alligator or clamp shell forceps to fit through otoscope cone
FNA usually unrewarding
stage LNs w/ cytology, 3 view rads for metastasis check (low yield but should do)
CT if suspect invasion through canal, jaw pain and swelling could mean deep infiltration

74
Q

Tx of ear canal tumors

A

Aggressive Sx - total ear canal ablation with bulla osteotomy (TECA-BO)
- likely also have otitis media, need to remove epithelial lining and flush + Tx with antibiotics

75
Q

Negative prognostic factors of ear canal tumors

A

Extension beyond ear canal - ruptures outside cartilage of canal
Dx of SCC or undifferentiated carcinoma - increased predilection for metastasis and local invasion
Neuro signs at Dx - muscle paralysis, seizures, etc
PO histo criteria

76
Q

Feline sinonasal tumor signalment

A

malignancies 90% of the time, need good biopsy to ddx LSA from lymphoplasmocytic rhinitis

77
Q

Canine sinonasal tumor signalment

A

older dog, median 10y
medium to large breed, focilocephalic (long snout)
environmental exposure - kerosene indoor heaters
2-3m of unilateral epistaxis, facial deformity = advanced

78
Q

Ddx of sinonasal tumors

A

2/3 are carcinomas, must do work up to determine cause of epistaxis

Dogs - sarcoma, fungal disease
Cats - LSA LSA LSA

79
Q

Staging of Sinonasal tumors

A

x-rays - open mouth DV oblique view to show caudal nasal cavity/cribiform, ipsilateral turbinate loss, bone invasion, sinus infiltration = neoplasia likely
- cross sectional imaging preferred
Biopsy - blind trans-nostril using cup forceps, if no blood on floor not good enough biopsy, measure to medial canthus and place tape for max safe insertion
regional LN - 10-24% incidence, 46% have late metastasis

80
Q

Tx of sinonasal tumors

A

Palliative only, not curative
NSAIDs - COX2 over expression - a must for dogs
low dose 6-9Gy week radiation tx
Palladia
hemorrhage control
Curative intent. - radiation therapy external bean, course fractioned, can do image guided IMRT or SRT; SE profile better in SRT

81
Q

Negative prognostic factors of sinonasal tumors

A

age - older is worse
presence of epistaxis
longer duration of CS
tumor stage; cribriform involvement = BAD
presence of metastatic dz
Histological subtype - SCC/undifferentiated carcinomas are worse
failure to achieve resolution of CS after tx

82
Q

Salivary tumors

A

older dogs (spaniels) and cats (siamese) - more aggressive in cats
most commonly mandibular/parotid SG
locally invasive - cause local effects, regional LN mets common
Staging: FNA/cytology, biopsy but don’t risk compromising 2nd sx
Tx: Sx alone rarely curative, need adjuvant RT for margins

83
Q

Thyroid tumor dog signalment

A

older (9-11y), golden, huskies, beagles, boxers
chief complaint = palpable cervical mass
signs of hyperthyroidism if functional
if invasive - coughing, dysphagia, dyspnea, horners

84
Q

Thyroid tumor cat signalment

A

older (12-15y), think hyper T4
siamese/himalayan have reduced risk
weight loss despite good appetite, PU/PD, palpable nodule, GI signs

85
Q

What is the 90:10 rule for thyroid tumors?

A

Dog are 90% malignant, 10% benign

Cats are 10% malignant and 90% benign

86
Q

Dog thyroid tumor DDx

A

CARCINOMAs

r/o abscesses or granuloma, ectopic salivary mucocele, carotid body tumor or medial retropharyngeal LN enlargment

87
Q

Cat thyroid tumor DDx

A

ADENOMAS

88
Q

Staging of thyroid tumors

A

Metastasis to regional LNs and lungs
unique phenomenon: some dogs w/ thyroid tumors have multiple malignancy
FNA/cytology is ok - needle off, use US to guide bc can be very vascular
fixed vs not fixed - use hands to feel for slip

89
Q

Tx of thyroid tumors

A

thyroidectomy, I131 therapy

90
Q

Prognosis of thyroid tumors

A

Best: Sx>RT
fractioned RT better than hypofractioned
issue with RRT is it can take time before tumor shrinks so if sick cannot be feasible

91
Q

Px of animals w/ bilateral thyroid tumor

A

do fine if resectable, careful w/ PO management = hypoCa (parathyroids gone)
MST = +3y

92
Q

Negative prognostic factors of thyroid tumors

A

size - tumor volume
movability - invasion into neighbour tissue = poor prognostic factor
bilateral = greater risk of metastasis
non-medullary thyroid carcinomas = more likely to develop metastatic dz