Prognostic assessment of patients who receive radiotherapy for bone metastases from breast cancer

For prognostic assessment in women who receive radiotherapy (RT) for bone metastases (BMs) from breast cancer (BC), prognostic factors specific for BMs from BC were investigated in the present study. The prognostic assessment was performed by retrospectively reviewing 143 women who received first-time RT for BMs from BC between January 2007 and June 2018. The median follow-up time and median overall survival (OS) time from the first-time RT for BMs were 22 and 18 months, respectively. In the multivariate analysis, nuclear grade 3 (NG 3) [hazard ratio, 2.18; 95% confidence interval (CI), 1.34-3.53], brain metastases (hazard ratio, 1.96; 95% CI, 1.01-3.81), liver metastases (hazard ratio, 1.75; 95% CI, 1.17-2.63), performance status (PS) (hazard ratio, 1.63; 95% CI, 1.10-2.41) and previous systemic therapy (hazard ratio, 1.58; 95% CI, 1.03-2.42) were significant factors for OS, whereas age, hormone-receptor/human epidermal growth factor receptor 2 status, number of BMs and synchronous lung metastases were not significant factors. When points according to risk levels [unfavorable points (UFPs)] were assigned to each risk factor (1.5 points for NG 3 and brain metastases; and 1 point for PS ≥2, previous systemic therapy and liver metastases), the median OS times of patients with a total number of UFPs ≤1 (n=45), 1.5–3 (n=55) and ≥3.5 (n=43) were 36, 17 and 6 months, respectively. Overall, in patients who received first-time RT for BMs from BC, NG 3, brain/liver metastases, poor PS and previous systemic therapy were unfavorable prognostic factors. Comprehensive prognostic assessment using these factors seemed to be useful for the prediction of prognoses in patients with BMs from BC.