There are no prospective data available on the prevalence of colonic neoplasia in asymptomatic African Americans. Recent data indicate that colorectal cancer incidence and mortality in Caucasian Americans has been declining since 1985 at a rate of 2-3% per year. In African Americans, however, mortality from colorectal cancer appears to be increasing and there may be a more proximal distribution of cancers. Recent colonoscopy studies have defined adenoma (AD) prevalence in average-risk populations that were largely Caucasian and male. Methods: We performed a cross-sectional colonoscopy screening study to determine the prevalence of colonic neoplasia in asymptomatic African Americans age 50 yr with no history of colon polyps, cancer or colon surgery, and no bowel work-up in the last three years. Results: 140 asymptomatic subjects were enrolled into the study and 19 were excluded from this analysis (4 had bowel work-up within 3 yrs; 4 had heme positive stools; 9 gave a family history of a first degree relative with colon cancer; and 2 had an incomplete examination). Of the remaining 121, 69 were female (mean age 59.9 yrs) and 52 were male (mean age 60.2 yrs). 42 patients had ≥ 1 AD (42.3% of males and 29% of femaes). A total of 72 AD (67 tubular and 5 villo-glandular) were found; 47 (65.3%) of these were proximal to the splenic flexure. 22 subjects (52.3%) did not have any AD distal to the splenic flexure. Three had 1 AD ≥ 1 cm and none had severe dysplasia. The location and size of the adenomas were as follows: size/sit CE AC HF TC SF DC SC RE Total e ≤5 mm 7 17 4 11 1 8 5 4 57 6-9 mm 1 3 1 1 0 0 6 0 12 ≥ 1 cm 2 0 0 0 0 0 1 0 3 In the 19 excluded subjects, 15 subjects had 23 AD and one Dukes A adenocarcinoma. Summary: These data do not suggest a higher prevalence of advanced AD in average-risk African Americans. A relatively high percentage of adenomas was proximal. Conclusion: Because of a relatively high prevalence of proximal disease, these data suggest a need for further evaluation of colonoscopy versus sigmoidoscopy as the most appropriate screening test in this population .
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging