Principles of Oncology Flashcards
what is the average number of cells formed in any individual during an average lifetime?
10^16
10 million cells replaced every second!
_____ result in defects in the regulatory circuits of a cell
DNA mutations
results in disruption of normal cell proliferation & behavior
what are the two main factors that cause cancer? (think broad)
genes and lifestyle & environment
“bad genes load the gun, lifestyle & environment pull the trigger”
name four major lifestyle and environment factors that contribute to causing cancer?
- 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)
what are the three steps of carcinogenesis?
initiation, promotion, and progression
carcinogens induce DNA damage but not enough to induce neoplastic transformation
initiation (rapid)
original carcinogens or normal growth promoters/hormones cause reversible tissue & cellular changes
promotion
progressing agents are able to irreversibly convert an initiated cell into cell exhibiting malignancy
progression (slow)
name the six hallmarks of a cancer cell
- evading apoptosis
- self-sufficiency in growth signals
- insensitivity to anti-growth signals
- tissue invasion & metastasis
- limitless replicative potential
- sustained angiogenesis
T/F: all (most) cancer comes from four distinct cell types
FALSE, three
1) round cell 2) mesenchymal 3) epithelial
rank the cell types in order from most exfoliation to lease
round (very good), epithelial (good), mesenchymal (ok, sometimes poor)
individualized ___ cells arranged in monolayer
round
spindle-shaped, stellate or oval cells arranged individually or in non-cohesive aggregates
mesenchymal
round, cuboidal, columnar or polygonal cells arranged in cohesive sheets or clusters
epithelial
what are the differential diagnoses for round cell tumors?
lymphoma, MCT, plasmacytoma, histiocytoma, TVT, melanoma
“please help me learn this”
what are the differential diagnoses for mesenchymal cell tumors?
sarcomas (osteo, chondro, fibro, hemangio)
what are the differential diagnoses for epithelial cell tumors?
carcinomas (squamous cell, adeno, undifferentiated)
what are the characteristics of malignancy?
homogenous vs. heterogenous, pleomorphic, cellular/cytoplasmic criteria (anisocytosis, variable N:C ratio, hyperchromasia), nuclear criteria (anisokaryosis, multiple nuclei, increased mitosis)
anisocytosis
variation of cell size
anisokaryosis
variation of nucleus size
T/F: cytopathology is highly sensitive but has low specificity
FALSE, opposite
cytopathology has low sensitivity meaning it can yield more false negative results
of the cancer cell types, which one is most sensitive and which one is least sensitive?
round cells are most sensitive (exfoliate well!) and mesenchymal cells are least sensitive (known for being firm and not wanting to give up cells)
in what four types of tumors is cytopathology more known to fail you?
oral (ALWAYS GET BIOPSY), splenic, liver, and mammary gland
in what type of tumor would you be concerned with needle tract implantation?
urogenital neoplasms (carcinomas)
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
TRUE, horizontal pull-apart creates a feathered edge
when obtaining a needle biopsy of a liver tumor, accuracy is more than or equal to ___% hence you should interpret with caution (warn owners!)
50%
what type of stain used, when POSITIVE in cytology via US guided percutaneous technique of a bone tumor is 100% sensitive for OSA?
ALP sarcoma stain
- ALP required for osteoblasts for bone mineralization
- marker of osteoblastic lineage
______ answers the question “is the tumor localized, spread regionally or diffusely?”
staging
based on WHO TNM (tumor, node, metastasis system), 0-IV
_____ establishes inherent aggressiveness of tumor using systematic approaches, allows definitive prognostication & may alter therapeutic recommendations
grading
requires BLOCK of tissue, I (least aggressive, II & III (most aggressive)
T/F: grading is determined using the TNM system
FALSE, staging
what tests might you utilize for staging a tumor?
MDB (CBC/chem/T4/UA/FIV & FeLV), regional LN cytology, 3-view thoracic met check, abdominal US (+/- FNA), CT/MRI
what is locoregional LN sampling based on?
sentinel node = unique to each patient and cancer
___% 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
40%, lymphadenomegaly
why you NEVER assume normal sized LN’s are not metastatic
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
SLN concept
distant metastasis should NOT be present if SLN does NOT have evidence of tumor
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
12-15%
ALWAYS TAKE 3 VIEWS FOR STAGING THORACIC RADS
what is the minimum threshold size of pulmonary nodules to reliably detect them on rads?
7-9 mm
what organ is the most common receptacle of blood-borne metastasis?
liver = major “generalizing site”
tumor associated alterations in bodily structure or function that occur distant to the tumor
paraneoplastic syndrome
often first sign of malignancy and can be HALLMARK of certain malignancies
what usually causes paraneoplastic syndromes?
secondary to small molecules (cytokines/hormones/peptides) secreted by tumor which mimic native substances causing effect
what are the five classic paraneoplastic syndromes?
hypercalcemia, neurologic (myasthenia gravis), cutaneous (nodular dermatofibrosis), hypoglycemia, and bone (hypertrophic osteopathy)
what are the four main cancers associated with hypercalcemia (PNS)?
anal sac ACA, LSA, multiple myeloma, mammary tumor
what is a common cancer associated with hypoglycemia (PNS)?
intestinal leiomyosarcoma
