Prostate cancer (PCa) is one of the most common malignancies associated with bone metastases, and palliative radiation therapy (RT) is an effective treatment option. A total of 2641 patients were identified with PCa and bone metastases at diagnosis from 2010 to 2014 in the NCDB. Fractionation scheme was designated as short course ([SC-RT]: 8 Gy in 1 fraction and 20 Gy in 5 fractions) vs long course ([LC-RT]: 30 Gy in 10 fractions and 37.5 Gy in 15 fractions). Patient characteristics were correlated with fractionation scheme using logistic regression. Overall survival was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses. A total of 2255 (85.4%) patients were included in the LC-RT group and 386 (14.6%) patients in the SC-RT group. SC-RT was more common in patients over 75 years age (odds ratio [OR]: 1.70, 95% confidence interval [CI] 1.32-2.20), treatment at an academic center (OR: 1.76, 1.20-2.57), living greater than 15 miles distance to treatment facility (OR: 1.38, 1.05-1.83), treatment to the rib (OR: 2.99, 1.36-6.60), and in 2014 (OR: 1.73, 1.19-2.51). RT to the spine was more commonly long course (P < .0001). In the propensity-matched cohort, LC-RT was associated with improved OS (P < .0001), but no OS difference was observed between 37.5 Gy and either 8 Gy in one fraction or 20 Gy in 5 fractions (P > .5). LC-RT remains the most common treatment fractionation scheme for palliative bone metastases in PCa patients. Use of palliative SC-RT is increasing, particularly in more recent years, for older patients, treatment at academic centers, and with increasing distance from a treatment center.
Keywords: National Cancer Database; metastatic prostate cancer; palliative radiation.
© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.