Purpose: Bone mass has been proposed as a biomarker of the cumulative exposure to calcium, vitamin D and endogenous and exogenous estrogens. Postmenopausal women with higher levels of bone mass have a decreased risk of colon cancer. No prior studies, however, have examined the role between bone mass and the risk of colon adenomas, which are precursor lesions that, if not removed, may lead to colon cancer.

Methods: We evaluated the potential association between bone mass, as measured by bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA), and colon adenomas in 167 patients who underwent colonoscopy screening at University Hospitals in Cleveland, Ohio.

Results: We found that women with a total body BMD exceeding 1.294 g/cm2 (third tertile) compared to those with a total body BMD less than 1.167 g/cm2 (first tertile) had a much lower risk of colon adenomas (OR = 0.10; 95% C.I.: 0.02-0.74; P = 0.02). Similarly, women with a total body BMD between 1.167 and 1.294 g/cm2 (second tertile) compared to those with a BMD less than 1.167 g/cm2 had a decreased risk for colon adenomas (OR = 0.15; 95% C.I.: 0.03-0.80; P = 0.03; p-trend = 0.01). Postmenopausal women with a total body BMD in the second and third highest tertiles combined compared to those in the first tertile also had a decreased risk of colon adenomas.

Conclusions: Our results show, for the first time, that bone mass, as measured by total body BMD, is inversely associated with colon adenomas in women, which suggests the mechanisms underlying the synergistic actions of calcium, vitamin D, estrogen exposure and other factors affecting BMD including exercise are key to preventing the development of colonic lesions, particularly among women.

This abstract is one of the 17 highest scoring abstracts of those submitted for presentation at the 34th Annual Meeting of the American Society of Preventive Oncology, to be held March 20-23, 2010 in Bethesda, MD.