Principles of Oncology

Question 1

what is the average number of cells formed in any individual during an average lifetime?

Answer 1

10^16

10 million cells replaced every second!

Question 2

_____ result in defects in the regulatory circuits of a cell

Answer 2

DNA mutations

results in disruption of normal cell proliferation & behavior

Question 3

what are the two main factors that cause cancer? (think broad)

Answer 3

genes and lifestyle & environment

“bad genes load the gun, lifestyle & environment pull the trigger”

Question 4

name four major lifestyle and environment factors that contribute to causing cancer?

Answer 4

• diet (high fat, low fiber linked to bowel, pancreatic, breast & prostate cancer)
• exposure (carcinogens, mutagens)
• viruses (hepatitis B, papillomavirus, HIV = nasopharyngeal/cervical carcinomas & Kaposi’s sarcoma, FIV/FeLV =LSA/sarcomas
• age (decreased immune surveillance)

Question 5

what are the three steps of carcinogenesis?

Answer 5

initiation, promotion, and progression

Question 6

carcinogens induce DNA damage but not enough to induce neoplastic transformation

Answer 6

initiation (rapid)

Question 7

original carcinogens or normal growth promoters/hormones cause reversible tissue & cellular changes

Answer 7

promotion

Question 8

progressing agents are able to irreversibly convert an initiated cell into cell exhibiting malignancy

Answer 8

progression (slow)

Question 9

name the six hallmarks of a cancer cell

Answer 9

• evading apoptosis
• self-sufficiency in growth signals
• insensitivity to anti-growth signals
• tissue invasion & metastasis
• limitless replicative potential
• sustained angiogenesis

Question 10

T/F: all (most) cancer comes from four distinct cell types

Answer 10

FALSE, three

1) round cell 2) mesenchymal 3) epithelial

Question 11

rank the cell types in order from most exfoliation to lease

Answer 11

round (very good), epithelial (good), mesenchymal (ok, sometimes poor)

Question 12

individualized ___ cells arranged in monolayer

Answer 12

round

Question 13

spindle-shaped, stellate or oval cells arranged individually or in non-cohesive aggregates

Answer 13

mesenchymal

Question 14

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

Answer 14

epithelial

Question 15

what are the differential diagnoses for round cell tumors?

Answer 15

lymphoma, MCT, plasmacytoma, histiocytoma, TVT, melanoma

“please help me learn this”

Question 16

what are the differential diagnoses for mesenchymal cell tumors?

Answer 16

sarcomas (osteo, chondro, fibro, hemangio)

Question 17

what are the differential diagnoses for epithelial cell tumors?

Answer 17

carcinomas (squamous cell, adeno, undifferentiated)

Question 18

what are the characteristics of malignancy?

Answer 18

homogenous vs. heterogenous, pleomorphic, cellular/cytoplasmic criteria (anisocytosis, variable N:C ratio, hyperchromasia), nuclear criteria (anisokaryosis, multiple nuclei, increased mitosis)

Question 19

anisocytosis

Answer 19

variation of cell size

Question 20

anisokaryosis

Answer 20

variation of nucleus size

Question 21

T/F: cytopathology is highly sensitive but has low specificity

Answer 21

FALSE, opposite

cytopathology has low sensitivity meaning it can yield more false negative results

Question 22

of the cancer cell types, which one is most sensitive and which one is least sensitive?

Answer 22

round cells are most sensitive (exfoliate well!) and mesenchymal cells are least sensitive (known for being firm and not wanting to give up cells)

Question 23

in what four types of tumors is cytopathology more known to fail you?

Answer 23

oral (ALWAYS GET BIOPSY), splenic, liver, and mammary gland

Question 24

in what type of tumor would you be concerned with needle tract implantation?

Answer 24

urogenital neoplasms (carcinomas)

Question 25

T/F: in terms of slide preparation the vertical pull-apart method is used for fragile cells (LN's) and the horizontal pull-apart is overall the preferred technique

Answer 25

TRUE, horizontal pull-apart creates a feathered edge

Question 26

when obtaining a needle biopsy of a liver tumor, accuracy is more than or equal to ___% hence you should interpret with caution (warn owners!)

Answer 26

50%

Question 27

what type of stain used, when POSITIVE in cytology via US guided percutaneous technique of a bone tumor is 100% sensitive for OSA?

Answer 27

ALP sarcoma stain - ALP required for osteoblasts for bone mineralization - marker of osteoblastic lineage

Question 28

______ answers the question "is the tumor localized, spread regionally or diffusely?"

Answer 28

staging based on WHO TNM (tumor, node, metastasis system), 0-IV

Question 29

_____ establishes inherent aggressiveness of tumor using systematic approaches, allows definitive prognostication & may alter therapeutic recommendations

Answer 29

grading requires BLOCK of tissue, I (least aggressive, II & III (most aggressive)

Question 30

T/F: grading is determined using the TNM system

Answer 30

FALSE, staging

Question 31

what tests might you utilize for staging a tumor?

Answer 31

MDB (CBC/chem/T4/UA/FIV & FeLV), regional LN cytology, 3-view thoracic met check, abdominal US (+/- FNA), CT/MRI

Question 32

what is locoregional LN sampling based on?

Answer 32

sentinel node = unique to each patient and cancer

Question 33

___% of dogs with oral malignant melanoma had local LN metastasis when _______ WAS NOT present and 49% of dogs with enlarged lymph nodes DID NOT have metastasis

Answer 33

40%, lymphadenomegaly why you NEVER assume normal sized LN's are not metastatic

Question 34

metastatic process occurs in an orderly progression w/in the lymphatic system w/ tumor cells draining into a specific LN in a regional lymphatic field before draining into other regional or distant LN's

Answer 34

SLN concept distant metastasis should NOT be present if SLN does NOT have evidence of tumor

Question 35

a change in dx (i.e. missed mets) would have been made in ______ of patients when 3-view thoracic studies were compared to only 2-view

Answer 35

12-15% ALWAYS TAKE 3 VIEWS FOR STAGING THORACIC RADS

Question 36

what is the minimum threshold size of pulmonary nodules to reliably detect them on rads?

Answer 36

7-9 mm

Question 37

what organ is the most common receptacle of blood-borne metastasis?

Answer 37

liver = major "generalizing site"

Question 38

tumor associated alterations in bodily structure or function that occur distant to the tumor

Answer 38

paraneoplastic syndrome often first sign of malignancy and can be HALLMARK of certain malignancies

Question 39

what usually causes paraneoplastic syndromes?

Answer 39

secondary to small molecules (cytokines/hormones/peptides) secreted by tumor which mimic native substances causing effect

Question 40

what are the five classic paraneoplastic syndromes?

Answer 40

hypercalcemia, neurologic (myasthenia gravis), cutaneous (nodular dermatofibrosis), hypoglycemia, and bone (hypertrophic osteopathy)

Question 41

what are the four main cancers associated with hypercalcemia (PNS)?

Answer 41

anal sac ACA, LSA, multiple myeloma, mammary tumor

Question 42

what is a common cancer associated with hypoglycemia (PNS)?

Answer 42

intestinal leiomyosarcoma