Colorectal Cancer Prevention (PDQ®): Prevention - Health Professional Information [NCI] - Description of the Evidence
Cardiovascular Risks Associated With Celecoxib and Rofecoxib Dose/Drugs continued...
In a large cohort study, an association between recent daily aspirin use and lower-cancer mortality in the gastrointestinal tract (RR = 0.61; 95% CI, 0.47–0.78), liver (RR = 0.52; 95% CI, 0.30–0.93), and bladder (RR = 0.52; 95% CI, 0.28–0.97) were observed among the 100,139 analysis-eligible participants from the Cancer Prevention Study II Nutrition Cohort established by the American Cancer Society in 1982. The analysis excluded participants who had a history of cancer in the baseline year or whose records contained incomplete information on aspirin use or smoking, and was based on follow-up questionnaires mailed to participants in 1997 (the baseline year for the analysis), 1999, 2001, and 2003. Mortality follow-up continued through Dec 31, 2008 via automated linkage to the National Death Index vital status and cause of death codes (ICD-10); death certificates were obtained for 99.3% of known deaths.
Postmenopausal female hormone supplements
Several observational studies have suggested a decreased risk of colon cancer among users of postmenopausal female hormone supplements.[66,67,68,69] For rectal cancer, most studies have observed no association or a slightly elevated risk.[70,71,72]
The Women's Health Initiative (WHI) trial examined, as a secondary endpoint, the effect of combined estrogen and progestin therapy and estrogen-only therapy on CRC incidence and mortality. Among women in the combined estrogen plus progestin group of the WHI, an extended follow-up (mean, 11.6 years) confirmed that fewer CRC were diagnosed in the combined hormone therapy group than in the placebo group (HR = 0.72; 95% CI, 0.56–0.94); the CRCs in women in the combined group were more likely to have lymph node involvement than the CRCs in women in the placebo group (50.5% vs. 28.6%; P < .001) and were classified at higher stages (regional and distant) (68.8% vs. 51.4%; P = .003). The number of CRC deaths in the combined group was higher than in the placebo group (37 vs. 27 deaths), but the difference was not statistically significant (HR =1 .29; 95% CI, 0.78–2.11).