African Americans (AAs) have a higher incidence of colorectal cancer (CRC) and present with more advanced disease compared with whites. An increased prevalence of polyps has also been noted in men regardless of race. We sought to validate these observations and assess whether the increase in CRC in AAs is owing to polyp prevalence or incidence differences vs other factors.
A detailed endoscopy database was used to identify patients undergoing their first outpatient colonoscopy for screening or minimal symptoms from January 26, 1996, through September 19, 2006. Multivariate models were constructed to predict prevalence and incidence of polyps.
Of individuals undergoing colonoscopies, 3732 met our study criteria (41.3% male and 29.2% AA); 761 (20.4%) had polyps. Male sex (odds ratio, 1.67; 95% confidence interval [CI], 1.39-2.02) independently predicted polyps but race did not. A random 100-patient sample showed no significant racial difference in the proportion of adenomatous polyps among those with polyps (68.0% white vs 60.0% AA, P = .60). Of 57 patients who had a follow-up colonoscopy a median of 3.6 years after their index procedure, 18 (31.6%) were male, 7 (12.3%) were AA, and 19 (33.3%) were older than 65 years. Thirty-five (61.4%) had a polyp recurrence. Adjusting for time to subsequent colonoscopy and other confounders, neither male sex (adjusted hazard ratio, 0.98; 95% CI, 0.43-2.21) nor race (1.89; 0.68-5.24) significantly predicted incidence of recurrent polyps.
In this series, male sex but not race predicted prevalence of polyps. Incidence of recurrent polyps was higher in neither male patients nor AAs, but the power of this analysis is limited.