Ch 7 Carcinogenic Agents and Their Cellular Interactions

Question 1

initiation

Answer 1

exposure of cells to sufficient dose of a carcinogenic agent making it potentially capable of giving rise to a tumor, not sufficient for tumor formation
permanent DNA damage, rapid and irreversible, non memory

Question 2

promotors

Answer 2

can induce tumor to arise from initiated cells, but they are non tumorigenic by themselves

Question 3

direct acting carcinogens

Answer 3

require no metabolic conversion to become carcinogenic

Question 4

indirect acting carcinogens

Answer 4

chemicals that require metabolic conversion to become active carcinogens

Question 5

aflatoxin B1

Answer 5

produced by mold called aspergillus

leads to hepatocellular carcinoma

Question 6

UV rays

Answer 6

associated w/ increased incidence of squamous cell carcinoma, basal cell carcinoma, melanoma of the skin

Question 7

nonmelanoma skin cancers

Answer 7

associated w/ total cumulative exposure to UV radiation

Question 8

melanomas

Answer 8

associated w/ intense intermittent exposure

Question 9

UVB

Answer 9

responsible for the induction of cutaneous cancer

carcinogenicty is due to the formation of pyrimidine dimers in DNA

Question 10

HTLV-1

Answer 10

causes adult T cell leukemia/lymphoma
after long latent period leukemia/lymphoma involving CD4+ cells due to acquisition of mutations of host genome
TAX- increased pro growth signaling and cell survival through PI3K and AKT - polyclonal expansion of T cells

Question 11

HPV

Answer 11

integration of viral DNA is important for malignant transformation
E6-p53
E7-Rb
both allow progression through the cell cycle

Question 12

EBV

Answer 12

most common associated tumors are derived from B cels and nasopharyngeal carcinoma
associated w/ Burkitt lymphoma
absence of T cell immunity will lead to EBV positive B cell lymphomas which can be reversed

Question 13

HBV and HCV

Answer 13

70-85% of hepatocellular carcinomas
oncogenic effects are multifactorial
dominant effect is immunologically mediated chronic inflammation and hepatocyte death leading to regeneration and over time genomic damage
HBx gene can activate transcription factors and signal transduction pathways

Question 14

H. pylori

Answer 14

implicated in genesis of gastric adenocarcinomas and gastric lymphomas
pathogenesis - multifactorial, chronic inflammation, reparative gastric cell proliferation
CagA - gastric adenocarcinoma, penetrates into gastric epithelial cells where it initiates signaling cascade that mimics uregulated GF stimulation
chronic - polycolonal B cell proliferation leading to B cell tumor of the stomach

Question 15

cancer cachexia

Answer 15

progressive loss of body fat and lean body mass accompanied by profound weakness, anorexia, and anemia

Question 16

paraneoplastic syndromes

Answer 16

signs and symptoms that cannot readily be explained by the anatomic distribution of the tumor or by the elaboration of hormones indigenous to the tissue from which the tumor arose

Question 17

endocrinopathies

Answer 17

not of endocrine origin and the secretory activity of the tumors is referred to as ectopic hormone production

Question 18

hypercalcemia

Answer 18

MOST COMMON

osteolysis induced by cancer

Question 19

neuromyopathic paraneoplastic syndrome

Answer 19

peripheral neuropathies, cortical cerebellar degeneration, polymyopathy resembling polymyositis, myasthenic syndrome

Question 20

acanthosis nigricans

Answer 20

gray black patches of thickened hyperkeratotic skin w/ velvety appearance

Question 21

hypertrophic osteoarthropathy

Answer 21

perosteal new bone formation at distal end of long bones, metatarsals, metacarpals, proximal phalanges

Question 22

migratory thrombophlebitis

Answer 22

associated w/ deep seated cancers (pancreas and lung)

Question 23

disseminated intravascular coagulation

Answer 23

associated w/ promyelocytic leukemia and prostatic adenocarcinoma

Question 24

grading

Answer 24

cytologic
behavior and differentiation are related
pathologist

Question 25

staging

Answer 25

surgical
based on size of primary lesion, extent of spread to regional lymph nodes, presence or absence of blood borne metastases
clinical