Aspirin and intensive exercise eliminate HRT colorectal cancer benefits
MedWire News: The beneficial effects of HRT on the risk for colorectal cancer are eliminated by aspirin use and intensive physical activity, report investigators.
Gad Rennert, from Carmel Medical Center in Haifa, Israel, and colleagues studied 2648 colorectal cancer patients and 2566 age-, gender-, clinic-, and ethnicity-matched healthy controls diagnosed 1998 through 2006, selecting a total of 2460 peri/postmenopausal women to assess the effects of HRT.
HRT was used by 8.7 percent of patients and 12.3 percent of controls. On univariate analysis, the use of HRT was associated with an overall colorectal cancer risk reduction, at an odds ratio of 0.67.
On multivariate analysis adjusting for age, gender, use of aspirin and statins, sports activity, family history of colorectal cancer, ethnic group, and level of vegetable consumption, HRT remained significantly associated with a reduced risk for colorectal cancer, at an odds ratio of 0.37.
However, further analysis demonstrated that HRT was associated with an increased risk for colorectal cancer among aspirin users and individuals engaging in intensive sports activity, at odds ratios of 3.55 and 2.25, respectively.
"The associations were significantly stronger in sedentary women and a clear interaction was found with the use of aspirin, where a strong negative association between HRT and colorectal cancer risk was noted only among nonaspirin users who used HRT," the team notes.
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By Liam Davenport