Clinicopathological characteristics and prognostic risk factors of breast cancer patients with bone metastasis

Background: A retrospective study was performed to summarize the clinicopathological characteristics of breast cancer patients with bone metastasis, to clarify the metastasis sites, and to explore the risk factors affecting prognosis. Methods: Breast cancer patients with bone metastasis diagnosed in our hospital from January 2008 to January 2019 were included. Through follow-up by telephone call or return visit, the metastasis sites and clinicopathological characteristics were summarized. The risk factors influencing prognosis were analyzed by univariate and multivariate regression analyses. Results: Multifocal bone metastases were dominant in the 150 patients, and the metastatic rates in the spine, chest, pelvis, limbs, and skull were 75.3%, 74.0%, 56.0%, 46.7%, and 28.7%, respectively, with significant differences (P<0.01). Kaplan-Meier univariate analysis showed that age, menstrual status, number of metastatic lymph nodes, clinical stage, endocrine therapy, alkaline phosphatase level, visceral metastasis, and number of bone metastasis sites affected the overall survival. Cox multivariate regression analysis revealed that endocrine therapy, number of metastatic lymph nodes, visceral metastasis, number of bone metastasis sites, and c-erbB-2 expression were independent prognostic factors. Conclusions: Middle-aged and elderly patients with breast cancer, mainly aged 40-60 years old, are prone to bone metastasis. The incidence rate of bone metastasis is high within 3 years after surgery, involving the spine, chest, pelvis, limbs, and skull in descending order. The number of metastatic lymph nodes, endocrine therapy, visceral metastasis, number of bone metastasis lesions at the first onset, and c-erbB-2 expression are independent prognostic factors influencing the survival rate of breast cancer patients with bone metastasis.