Incidence, prognosis and nomograms of breast cancer with bone metastases at initial diagnosis: a large population-based study.

Background: Bone is the most common metastatic site for breast cancer, and patients' condition will deteriorate when it occurs.

Methods: We performed a retrospective analysis on 6482 breast cancer patients with bone metastases (BCBM), who were selected from the Surveillance, Epidemiology, and End Result (SEER) 18 registry database. The optimal age cut-points were generated by using the X-tile software.