Bone mineral density as a potential predictive factor for luminal-type breast cancer in postmenopausal women

BACKGROUND: We performed a case-control study to evaluate whether bone mineral density (BMD) can be considered a potential predictive factor for luminal-type breast cancer (BC), that could be useful in constructing a predictive risk model. MATERIALS AND METHODS: The medical records of 297 postmenopausal women with luminal-type node-negative BC who underwent lumbar-spine dual-energy X-ray absorptiometry (DXA) with BMD measurement before surgery, were analyzed and compared with those of 297 age-matched randomly selected healthy controls. The correlations between women's reproductive history, including the age at menarche and menopause, parity, oral contraceptives and hormone replacement therapy (HRT) use, the results of DXA, and BC risk were evaluated in univariate and multivariate analyses. RESULTS: Overall, 168 (28.3%) women had osteoporosis and/or osteopenia (low BMD). Both bone alterations were protective factors for BC, especially when they were considered together (p=0.001). Only the interval between menarche and menopause (MMI), dichotomized at 37.5 years as an optimal cut-off, and the HRT use reached a statistical significance (p<0.01) as risk factors. The three parameters were independent because they remained significant in the stepwise logistic regression analysis. The area under the receiver operating characteristic (ROC) curve (AUC) obtained with the model was 0.694 (95%CI=0.694-0.731). CONCLUSION: This hypothesized predictive model is fairly accurate and could identify patients at increased risk of developing luminal-type BC in a population of postmenopausal women who performed DXA, simply based on their history.