HT may lower colorectal cancer risk

Postmenopausal women receiving hormone therapy reduce their risk of developing colorectal cancer by more than half, according to a study published online Aug. 24 in the Journal of Clinical Oncology.

Gad Rennert, MD, from the Carmel Medical Center in Haifa, Israel, and colleagues compared the self-reported use of HRT from 2,460 peri- and postmenopausal women among 2,648 patients with colorectal cancer and 2,566 controls.

After adjusting for demographics, aspirin and statin use, sports activity, family history of colorectal cancer, and vegetable consumption, the researchers found that women reporting HRT use had a significantly lower risk of colorectal cancer (OR, 0.37). Women who took aspirin or played sports did not have a risk reduction. The reduced risk was observed mainly in women taking combined estrogen-progestin oral pills.

“The use of oral HRT was associated with a 63% relative reduction in the risk of colorectal cancer in postmenopausal women after adjustment for other known risk factors,” Rennert and colleagues conclude. “However, the absence of the risk reduction effect of aspirin in HRT users and the differences in risk reduction with preparation-type call for further study to understand the causes for these phenomena and calls for caution in indicating HRT for colorectal cancer prevention.”

Rennert G, Rennert HS, Pinchev M, et al. Use of Hormone Replacement Therapy and the Risk of Colorectal Cancer. J Clin Oncol. 2009 Aug 24.