Both black men and black women are more likely to have large polyps found during screening colonoscopies than whites. Results of a large study that collected information from 67 gastrointestinal practices over two years found 6.2 percent of whites and 7.7 percent of blacks had colorectal polyps (adenomas) were larger than 9 millimeters. These advanced adenomas have the most risk of developing into colon or rectal cancer.
While black men were about 13 percent more likely to have a large polyp, black women were even more at risk with a 62 percent increased likelihood of polyps over 9 millimeters.
Overall, there was no difference between the risk of polyps in the proximal colon between blacks and whites. However, when age was considered blacks over 60 were more likely to have large adenomas in the proximal colon, the area farthest from the rectum.
The proximal colon cannot be viewed during a sigmoidoscopy. Colonoscopy is necessary to see polyps that high in the colorectal tract.
Records of more than 85,000 people were collected during the study — 80,061 whites and 5,464 blacks. Large polyps were found in 4,964 whites and 422 blacks.
David A. Lieberman MD and his team concluded,
Compared with white individuals, black men and women undergoing screening colonoscopy have a higher risk of polyps sized more than 9 mm, and black individuals older than 60 years are more likely to have proximal polyps sized more than 9 mm.
SOURCE: Lieberman et al. New England Journal of Medicine, Volume 300, Number 12, September 24, 2008.