Association Between Preoperative Osteopenia and Prognosis in Breast Cancer Patients

Background/Aim: Osteopenia, the loss of bone mineral density (BMD), was recently reported as a prognostic factor in various cancers. However, the prognostic significance of preoperative osteopenia in breast cancer remains unclear. This study aimed to clarify the clinical significance of preoperative osteopenia in breast cancer. Patients and Methods: We retrospectively analyzed the relationship between osteopenia and clinical factors and prognosis in 532 patients with pathological Stage I-III primary breast cancer between 2009 and 2017. Osteopenia was assessed by measuring the average pixel density (Hounsfield unit) in the midvertebral core of the 11^th thoracic vertebra on enhanced preoperative computed tomography. Results: Osteopenia was diagnosed in 186 (35.0%) patients. The recurrence-free survival (RFS) rate was significantly worse in the osteopenia group than in the non-osteopenia group (p=0.0275), but there was no significant difference in overall survival (OS) between the two groups. When evaluated by menopausal status, RFS and OS were significantly worse in the osteopenia group than in the non-osteopenia group (p=0.0094 and p=0.0264, respectively) in premenopausal patients. However, there were no significant differences in RFS and OS between the two groups among postmenopausal patients. In premenopausal patients, osteopenia was an independent prognostic factor for RFS in a multivariate analysis (p=0.0266). Conclusion: Preoperative osteopenia was independently associated with recurrence of breast cancer.