Primary chemoprevention of familial adenomatous polyposis with sulindac

Abstract

Background: Familial adenomatous polyposis is caused by a germ-line mutation in the adenomatous polyposis coli gene and is characterized by the development of hundreds of colorectal adenomas and, eventually, colorectal cancer. Nonsteroidal antiinflammatory drugs can cause regression of adenomas, but whether they can prevent adenomas is unknown.

Methods: We conducted a randomized, double-blind, placebo-controlled study of 41 young subjects (age range, 8 to 25 years) who were genotypically affected with familial adenomatous polyposis but phenotypically unaffected. The subjects received either 75 or 150 mg of sulindac orally twice a day or identical-appearing placebo tablets for 48 months. The number and size of new adenomas and side effects of therapy were evaluated every four months for four years, and the levels of five major prostaglandins were serially measured in biopsy specimens of normal-appearing colorectal mucosa.

Results: After four years of treatment, the average rate of compliance exceeded 76 percent in the sulindac group, and mucosal prostaglandin levels were lower in this group than in the placebo group. During the course of the study, adenomas developed in 9 of 21 subjects (43 percent) in the sulindac group and 11 of 20 subjects in the placebo group (55 percent) (P=0.54). There were no significant differences in the mean number (P=0.69) or size (P=0.17) of polyps between the groups. Sulindac did not slow the development of adenomas, according to an evaluation involving linear longitudinal methods.

Conclusions: Standard doses of sulindac did not prevent the development of adenomas in subjects with familial adenomatous polyposis.

Figure 1. Random-Effects Linear Longitudinal Analysis of the Effect of Sulindac on the Number (Panel A) and Size (Panel B) of Polyps, According to the Intention to Treat and to the Treatment Actually Received

All subjects were included in the intention-to-treat analysis, and all subjects who completed the study (16 in the sulindac group and 14 in the placebo group) were included in the analysis according to the treatment received. There were no significant differences between groups in the number or size of polyps in either analysis.