Clinicopathological features and prognostic evaluation of bone metastasis in triple-negative breast cancer

BACKGROUND: Bone metastases (BMs) are common for breast cancer patients. However, triple-negative breast cancer (TNBC) with BM is relatively rare and few data on it are available. In this study, we aim to investigate the incidence and clinicopathological features and to evaluate the prognosis of TNBC patients with BM. MATERIALS AND METHODS: A total of 616 patients with TNBC (120 out of them had BM) between 2007 and 2011 were involved in the study. Clinicopathological characteristics were statistically analyzed. RESULTS: A total of 120 (19.5%) patients developed BM with a median age of 53.1 years. The median overall survival (OS) was 40 months, and the 5-year OS rate was 37.3% in TNBC patients with BM. Patients without BM had longer survival time than those with BM (P < 0.001). In the univariate analysis, lymph nodes metastasis, tumor Stage III-IV, multiple BMs, and coexistence of visceral metastasis were correlated to a poor prognosis (P = 0.020; P < 0.001; P < 0.001; P < 0.001). Moreover, multivariate analysis demonstrated that tumor stage, number of BM, and visceral metastasis were significantly independent factors for OS (P < 0.001; P < 0.001; P < 0.001). CONCLUSIONS: Tumor Stage III-IV, multiple BMs, or coexistence of visceral metastasis were associated with poor prognosis for OS in TNBC patients with BM. These associations may contribute to prevention, early detection, and goal-directed treatment of bone metastatic TNBC.