Screening colonoscopy in asymptomatic average-risk African Americans

Recent data indicate that colorectal cancer incidence and mortality in white Americans have been declining since 1985 at a rate of 2% to 3% per year. In African Americans, however, mortality from colorectal cancer appears to be increasing. We sought to evaluate the prevalence of colonic neoplasia in asymptomatic African Americans.

We performed a cross-sectional colonoscopy screening study to determine the prevalence of colonic neoplasia in asymptomatic African Americans older than 50 years of age.

One hundred sixty-six subjects were evaluated for the study of whom 121 (69 women) were deemed to be asymptomatic average-risk persons and completed colonoscopy. Forty-two individuals (35%) had a total of 72 adenomas (67 tubular and 5 tubulovillous); 47 (65.3%) of these were proximal to the splenic flexure. Three subjects had an adenoma 1 cm or greater in diameter and none had severe dysplasia.

The overall prevalence of adenomas in asymptomatic average-risk African Americans was comparable to that of previously described populations. The predominance of right-sided adenomas in this study confirms previous findings and is an area requiring further study. Until this issue is resolved, we suggest the use of colonoscopy rather than sigmoidoscopy for screening for colorectal neoplasia in asymptomatic, average-risk African Americans.