The Association of Age and Race and the Risk of Large Bowel Polyps

Background: Blacks have a higher incidence of colorectal cancer and a younger age at diagnosis compared with whites. Few studies have investigated racial differences in risk of meta-chronous adenomas and serrated polyps and whether this risk differs by polyp characteristics or age of patient. Methods: We analyzed data pooled from three placebo-controlled adenoma chemoprevention trials to explore racial differences in the risk of large bowel polyps in patients <= 50 and >50 years of age. Using generalized linear regression, we estimated risk ratios (RR) and 95% confidence intervals (CI) as measures of the association between race and risk of one or more adenomas or serrated polyps after randomization. Results: Among the 2,605 subjects who completed at least one follow-up exam, blacks <= 50 years of age had a higher risk of any conventional adenoma (RR, 1.70; 95% CI, 0.99-2.92) and advanced neoplasms (RR, 4.05; 95% CI, 1.43-11.46) and a nonsignificantly lower risk of serrated polyps (RR, 0.75; 95% CI, 0.34-1.62) compared with whites. Among patients >50 years, there was no racial difference in risk of adenomas (RR, 1.08; 95% CI, 0.92-1.27) or advanced neoplasms (RR, 1.05; 95% CI, 0.71-1.56). However, blacks had a significantly lower risk of serrated polyps (RR, 0.65; 95% CI, 0.49-0.87) than whites. Conclusions: Our results demonstrate a higher risk of meta-chronous adenomas in blacks compared with whites at younger ages. Impact: Our results suggest that the racial disparity in colorectal cancer incidence may be due to an excess of neoplasia in younger blacks. (C)2014 AACR.