Devita, Hellman, and Rosenberg's Cancer

LWBK1006-20 LWW-Govindan-Review December 12, 2011 19:4

Chapter 20•Cancer of the Gastrointestinal Tract 269

Question 20.5.2. A 55-year-old woman underwent a right hemicolectomy for a cecal mass

15 years ago. Four years later, she was found to have a hepatic flexure

adenocarcinoma and a total colectomy was performed. Four years ago,

she presented with postmenopausal bleeding and was found to have

endometrial adenocarcinoma. She also had multiple skin malignancies,

including sebaceous adenomas and keratoacanthomas. One year ago, she

underwent a Whipple procedure for a duodenal adenocarcinoma invad-

ing into the pancreas. She has three siblings and a paternal uncle with

colorectal cancer all diagnosed in their late 30s. What is the most prob-

able PRIMARY genetic explanation for her inherited colorectal cancer

syndrome?

A. Chromosomal instability characterized by the deletion or mutation

of a tumor suppressor gene

B. Chromosomal instability characterized by activation of an oncogene

C. Microsatellite instability (MSI) caused by germ line mutations in a

DNA mismatch repair (MMR) gene

D. MSI caused by epigenetic changes associated with hypermethylation

in CpG islands

Question 20.5.3. Other than genetic counseling, which test would you order to confirm the

diagnosis?

A. p53 mutation and loss of heterozygosity of chromosome 18q

B. APC mutation, including the I1307K allele

C. MSI testing and methylation of CpG islands

D. MSI test and MMR gene mutation including MLH1, MSH2, MSH6

Question 20.5.4. The patient in Question 20.5.3 had a positive test result. What screen-

ing tests and surveillance program would you recommend to her three

daughters aged 24, 22, and 20 years?

A. Colonoscopy now and repeat every 1 to 2 years and transvaginal

ultrasound for her daughters starting by age 30 to 35 years

B. Colonoscopy for all and transvaginal ultrasound for her daughters

starting at age 30 to 35 years

C. Colonoscopy now and repeat every 1 to 2 years with transvaginal

ultrasound at age 30 to 35 years only for her children confirmed to

have the same genetic mutation as the patient; colonoscopy at age 40

to 50 years for those with no mutation

D. Colonoscopy and transvaginal ultrasound at age 30 to 35 years

only for those confirmed with the same mutation as the patient;

colonoscopy by age 40 to 50 years for those with no mutation

Question 20.5.5. Which gene is associated with hereditary nonpolyposis colorectal cancer

(HNPCC)?

A. APC

B. MYH

C. STK11

D. MSH2