Is bone mineral density a prognostic factor in postmenopausal women with luminal A breast cancer?

PURPOSE: Several studies are concerned about the association between bone mineral density (BMD) and the risk of breast cancer in postmenopausal women, but it is controversial. Therefore, we evaluated whether BMD might be a risk factor for recurrences, or metastases in menopausal luminal A breast cancer patients. METHODS: In this retrospective study, data of 348 patients with luminal A breast cancer who received treatment at Pusan National University Yangsan Hospital between 2012 and 2016 were analyzed. Patients were divided into two groups: normal BMD and low BMD including osteopenia or osteoporosis in preoperative examination. Patients were also divided into three groups according to BMD changes: no change in BMD; improvement in BMD, and deterioration in BMD. Events were defined as recurrence, occurrence of contralateral breast cancer, and metastasis to any other organ. RESULTS: Preoperative examination revealed normal BMD in 129 of 348 patients and low BMD in 219 patients. During a median follow-up period of 78 months, only 14 patients (4.0%) experienced recurrences, distant metastases, or occurrences of contralateral breast cancer. Five-year disease-free survival rate was 98.2% for 219 patients with low BMD and 95.0% for 129 patients with normal BMD (P=0.33). Disease-free survival at 5 years was 97.0% for the no change in the BMD group, 94.6% for the BMD improvement group, and 98.4% for the BMD deterioration group (P=0.79). CONCLUSION: In this study, BMD had no statistically significant associations on recurrences, metastases, or incidences of contralateral breast cancer in postmenopausal patients with luminal A breast cancer.