Distribution of adenomatous polyps in African-Americans.

OBJECTIVES

Previous research has suggested that polyps and colon cancer occur more commonly in the right colon in African-Americans compared with the general population. The purpose of this study is to determine the pattern of distribution of colonic polyps in African-Americans.

METHODS

We retrospectively evaluated 141 colonoscopies in which 179 polypectomies were done. The polyps were described on the basis of anatomical distribution, gross description, size, and histology. Sixty-nine males and 72 females had colonoscopic polypectomies. The mean age was 67 yr (range, 43-91 yr).

RESULTS

Seventy-seven (43%) were classified as left sided, and 102 (57%) were right sided. Left-sided polyps were more likely to be pedunculated than right-sided polyps (p < 0.01). Larger polyps were more common on the left side than the right side (p < 0.01), but villous histology was almost as high on the right side as on the left side. Polyps that had the highest malignant potential were found almost as commonly on the right side as on the left side.

CONCLUSIONS

This study supports previous work that suggests that there is a significant shift to the right in the anatomical distribution of polyps in African-Americans. It also shows that the malignant potential is as high for right-sided polyps as it is for those on the left. Current screening recommendations may not be effective enough for preventing colon cancer in this population.