LWBK1006-20 LWW-Govindan-Review December 12, 2011 19:4
Chapter 20•Cancer of the Gastrointestinal Tract 243is associated with increased expression of the enzyme cyclooxygenase-2
(COX-2). COX-2 inhibitors such as aspirin inhibit Barrett’s esophagus-
adenocarcinoma. Consumption of raw fruits and vegetables also exerts a
protective effect.Answer 20.1.18. The answer is D.
All of these molecular mechanisms are involved in the pathogenesis of
esophageal cancer.Answer 20.1.19. The answer is D.
Microsatellite instability is found in 13% to 44% of sporadic gastric carci-
nomas. A high degree of microsatellite instability occurs in gastric cancer
of the intestinal type, reduced involvement of lymph nodes and better
prognosis. p53 is consistently altered in most cases of gastric cancers.SECTION 2 PANCREAS
RENUKA V. IYER•RAVI CHHATRALADIRECTIONS Each of the numbered items below is followed by lettered answers. Select the
ONE lettered answer that is BEST in each case unless instructed otherwise.QUESTIONS
Question 20.2.1. Which of the following factors are not associated with an increased risk
of pancreatic cancer?
A. Cigarette smoke
B. Cirrhosis
C. High-protein diet
D. African American menQuestion 20.2.2. Which of the following statements regarding pancreatic cancer is NOT
true?
A. At diagnosis, 31% have evidence of distant metastases.
B. Pancreatic cancer tends to occur later in life.
C. Activation of the K-ras oncogene plus inactivation of tumor suppres-
sor genes (p53, DPC4, p16, and BRCA2) are associated with the
development of pancreatic cancer.
D. Pancreatic intraepithelial neoplasms (PanINs) are intraductal prolif-
erative epithelial lesions that are precancerous.
E. Patients with advanced pancreatic cancer may have undetectable lev-
els of CA 19-9 if they are Lewis antigen-a or -b negative.Corresponding Chapters inCancer: Principles & Practice of Oncology,Ninth Edition: 81 (Molecular Biology of
Pancreas Cancer), and 82 (Cancer of the Pancreas).