8.An epidemiologic study investigates the potential cellular molecular alterations that may contribute to the development of cancers in a population.Molecular data from resected colonic lesions show changes involved in the evolution of a sporadic colonic adenoma into an invasive carcinoma.Which of the following best describes the mechanism producing these changes? A.Extensive regeneration of tissues increases the risk of cancer-causing mutations B.Inherited defects in DNA repair genes increase the susceptibility to develop cancer C.Malignant transformation involves accumulation of mutations in protooncogenes and tumor suppressor genes in a step-wise fashion D.Overexpression of growth factor receptor genes are associated with poor prognosis. E.Protooncogenes can be activated by chromosomal translocation Ans:C Malignant transformation inv of mutations in protooncogenes and tmor suppresso gene o canc ar carcinom red defe repair gen which increase the susceptib ry to evelop cancer ar 22singorhacorecepiorsschas9HER2Wgema associated with ritable cancers HNPCC or xero cancers hav n breast cancer.Chromosoma franslocations are frequently found in lymphomas and leukemias. 9.An epidemiologic study of cancer deaths recorded in the last half of the 20th century is conducted.The number of deaths for one particular type of cancer has been increasing in developed nations.Which of the following neoplasms was most likely to be identified by this study? A.Angiosarcoma of the liver B.Carcinoma of the lung C.Colorectal carcinoma D.Gastric adenocarcinoma E Leukemia Ans:B use of smoki de- moking is also is a rare mg carcinoma.Other risk factors in lopec nations inc However.the connection between smoking and lung cancer is still the best ans er. carcinoma is more common in developing countries or countries with diets high in smoked. pickled,or salted foods.Leukemia incidence does not vary significantly by national socioeconomics. 1 8. An epidemiologic study investigates the potential cellular molecular alterations that may contribute to the development of cancers in a population. Molecular data from resected colonic lesions show changes involved in the evolution of a sporadic colonic adenoma into an invasive carcinoma. Which of the following best describes the mechanism producing these changes? A. Extensive regeneration of tissues increases the risk of cancer-causing mutations B. Inherited defects in DNA repair genes increase the susceptibility to develop cancer C. Malignant transformation involves accumulation of mutations in protooncogenes and tumor suppressor genes in a step-wise fashion D. Overexpression of growth factor receptor genes are associated with poor prognosis. E. Protooncogenes can be activated by chromosomal translocation Ans: C Malignant transformation involves accumulation of mutations in protooncogenes and tumor suppressor genes in a step-wise fashion to eventually cause colon cancer. Extensive regeneration of tissues increases the risk of cancer-causing mutations leading to hepatocellular carcinoma. Inherited defects in DNA repair genes which increase the susceptibility to develop cancer are associated with heritable cancers HNPCC or xeroderma pigmentosa. Many cancers have overexpression of growth factor receptors such as HER2 in breast cancer. Chromosomal translocations are frequently found in lymphomas and leukemias. 9. An epidemiologic study of cancer deaths recorded in the last half of the 20th century is conducted. The number of deaths for one particular type of cancer has been increasing in developed nations. Which of the following neoplasms was most likely to be identified by this study? A. Angiosarcoma of the liver B. Carcinoma of the lung C. Colorectal carcinoma D. Gastric adenocarcinoma E. Leukemia Ans: B The incidence of lung cancer is on the rise because of smoking tobacco. Angiosarcoma is a rare tumor associated with exposure to vinyl chloride. Smoking is also linked to increased risk of colorectal carcinoma, but to a lesser extent than lung carcinoma. Other risk factors in developed nations include high fat diet, physical inactivity, alcohol or red meat consumption, and older age. However, the connection between smoking and lung cancer is still the best answer. Gastric carcinoma is more common in developing countries or countries with diets high in smoked, pickled, or salted foods. Leukemia incidence does not vary significantly by national socioeconomics