Christine Johnson

Henry Ford Health System

PLCO (Learn more about this study)

2006-0155

Jul 1, 2006

Colorectal Adenoma Other Factors -NSAIDs

Nonsteroidal anti-inflammatory drugs have been documented in animal and human studies to reduce the risk for colorectal cancer and adenomatous polyps, although effects for hyperplastic polyps and risk modification by other personal characteristics have been less studied. Data on recent use of two frequently used nonsteroidal anti-inflammatory drugs, aspirin and ibuprofen, were collected at baseline from participants aged 55-74 years in the ten center Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). Participants randomized to the intervention arm of the trial received a flexible sigmoidoscopy during a baseline examination and detection of polyps was documented. Follow-up of polyps was accomplished outside the Trial setting but relevant records were actively sought and abstracted. Cases (n=4017) included subjects with a biopsy-proven polyp in the left side of the colon (descending colon, sigmoid and rectum) detected as a consequence of PLCO screening; controls (n=38,396) were subjects with no evidence of a left-sided colon polyp. Regular use of aspirin (= 4 times/month) in the past year was inversely associated with hyperplastic polyps (OR=0.8, 95% confidence interval (CI) 0.7-0.9), adenomatous polyps (OR=0.8, 95% CI 0.8-0.9), and advanced adenomas (OR=0.8, 95% CI=0.7-0.9). As frequency of use of aspirin increased, the prevalence of polyps decreased significantly for each histological classification. Patterns were similar, but generally not statistically significant, for ibuprofen. This overall protection was consistent in both the descending colon or sigmoid and the rectum, and in both whites and blacks, but was only evident in males. In males, the frequency of aspirin use was inversely related to adenoma prevalence (p for trend < 0.001), with the OR for heavy use (2 times/day) at 0.6 (95% CI 0.5-0.8). The decrease in risk was more evident among individuals who were not overweight, in the 70-74 years age group, and in women with a history of hormone replacement therapy use. This study of a large general risk population supports previous work that recent use of aspirin and ibuprofen protects against colorectal adenomatous polyps and additionally demonstrates that this protection may be restricted to certain population subgroups and is evident for hyperplastic polyps.