Association of use of bisphosphonates with risk of colorectal cancer.

Abstract

371 Background: Bisphosphonates are commonly used for the treatment of osteoporosis and of bone metastases due to breast cancer and were recently reported to be associated with reduced risk of breast cancer, but their association with risk of other cancers is unknown. Methods: The Molecular Epidemiology of Colorectal Cancer (MECC) study is a population-based case-control study in northern Israel of colorectal cancer cases and age/sex/clinic/ethnic-group matched controls. Use of bisphosphonates prior to diagnosis was assessed in a subset of 933 pairs of post-menopausal female cases and controls, enrolled in Clalit Health Services (CHS), using computerized pharmacy records. Results: The use of bisphosphonates for more than one year prior to diagnosis, but not for less than a year, was associated with a significantly reduced relative risk of colorectal cancer (odds ratio=0.50, 95% CI: 0.35-0.71). This association remained statistically significant after adjustment for, vegetable consumption, sports activity, family history of colorectal cancer, , BMI, use of low-dose aspirin, statins, vitamin D and post-menopausal hormones (OR=0.40, 0.24-0.64). Concomitant use of bisphosphonates and statins did not further reduce the risk. Conclusions: The use of oral bisphosphonates for more than 1 year was associated with a 60% relative reduction in the risk of colorectal cancer similar to the recently reported association of this drug class with reduction in breast cancer risk. No significant financial relationships to disclose.