Devita, Hellman, and Rosenberg's Cancer

LWBK1006-04 LWW-Govindan-Review November 24, 2011 11:19

58 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

Question 4.5. Studies in animal models have led to which of the following conclusions?

A. Carcinogenic agents activate oncogenes.

B. Carcinogenic agents inactivate tumor suppressor genes.

C. Carcinogenic agents cause genomic changes that are required for pro-

duction of malignant phenotype.

D. All of the above.

Question 4.6. Which of the following statements is FALSE regarding fundamental prin-

ciples of molecular epidemiology?

A. Carcinogenesis is a multistage process.

B. Carcinogenesis involves numerous genetic events at each stage.

C. Human response to carcinogen exposure is homogeneous.

D. There is a wide range of interindividual variation in carcinogen expo-

sure.

Question 4.7. Which of the following components are involved in the estimation of dose

and corresponding risk in epidemiological studies?

A. Measurement of external and internal exposure

B. Biomarkers estimating the biologically effective dose

C. Biomarkers of harm

D. All of the above

Question 4.8. Which of the following statements about benzene is NOT true?

A. Benzene is metabolized in the liver by CYP2E1 (P-4502E1).

B. Benzene oxide and hydroquinone are reactive metabolites of benzene.

C. Presence of functional polymorphisms of myeloperoxidase in humans

may have a protective role against toxicity of benzene to bone

marrow.

D. There exists a perfect dose-response relationship of benzene in

humans, and genetically susceptible individuals can be easily iden-

tified.

Question 4.9. Which of the following statements is NOT TRUE?

A. UVC light is the most damaging to DNA compared to UVA or UVB.

B. UVA can induce reactive oxygen species leading to single-strand

breaks and base lesions.

C. Living organisms are mostly exposed to UVA and UVC.

D. UVB and UVC induce predominantly pyrimidine dimers.

Question 4.10. Which of the following is TRUE about UV light?

A. Proliferating skin cells are very vulnerable to UV light because UV

lesions block DNA replication.

B. The risk of melanoma is related to the cumulative lifetime exposure

to UV light.

C. The risk of nonmelanoma skin cancers is related to high sunlight

exposure during childhood.

D. All of the above.