Devita, Hellman, and Rosenberg's Cancer

LWBK1006-12 LWW-Govindan-Review November 24, 2011 11:21

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

is more common thanBRCA2. In contrast toBRCA1 mutants, who usu-

ally develop ovarian cancer by their mid-1940s, the median age at pre-

sentation forBRCA2 mutants is 63 years.

Answer 12.11. The answer is C.

FAP is an autosomal-dominant disorder characterized by at least 100 col-

orectal adenomatous polyps, and virtually all patients develop colorectal

cancer in the absence of surgery. This disease, however, is uncommon,

representing less than 1% of the total number of colorectal cancer cases.

Answer 12.12. The answer is D.

Because of the virtually universal risk of developing cancer by the age of 40

years in the absence of therapy, patients with FAP should undergo surgery,

with the timing depending on the extent of disease. Among the surgical

options, TPC is rarely used and most patients will be treated with IRA or

IPAA. One of the main factors in deciding whether to remove the rectum

is the risk of rectal cancer. Therefore, IRA may be considered in patients

with less than 1000 colorectal polyps and less than 20 rectal adenomas.

In contrast, patients with a higher number of rectal adenomas, adenomas

larger than 3 cm, or severe dysplasia should undergo proctectomy in

addition to colectomy, through IPAA.

Answer 12.13. The answer is C.

The revised Bethesda criteria are used to identify individuals and fam-

ilies at high risk for HNPCC, where the MSI testing is indicated. The

five criteria include (a) colorectal cancer in a patient aged less than

50 years, (b) presence of synchronous or metachronous HNPCC cancer

regardless of age, (c) colorectal cancer with MSI histology in patients aged

less than 60 years, (d) colorectal cancer diagnosed in one or more first-

degree relatives with an HNPCC-related tumor with one of the cancers

being diagnosed at age less than 50 years old, and (e) colorectal can-

cer diagnosed in two or more first-degree or second-degree relatives with

HNPCC-related tumor regardless of age. Therefore, answer C is incorrect

because only patients aged less than 60 years with MSI histology should be

screened. MSI histology includes the presence of tumor-infiltrating lym-

phocytes, Crohn’s-like lymphocytic reaction, signet ring differentiation,

and medullary growth pattern.

Answer 12.14. The answer is D.

HNPCC is associated with several extracolonic malignancies, including

endometrial cancer, ovarian cancer, urothelial tumors, biliary and pan-

creatic cancers, carcinomas of the small bowel, and brain tumors. Breast

cancer, although commonly associated with multiple familiary disorders,

is not considered one of the HNPCC-related tumors.

Answer 12.15. The answer is D.

MEN 2A, MEN 2B, familial medullary thyroid carcinoma and sporadic

medullary carcinoma are associated with germ line mutations in theRET

protooncogene.