The relationship between adjuvant radiotherapy and survival of osteosarcoma: a case-control study.

To investigate whether adjuvant radiotherapy (RT) is associated with survival rate of osteosarcoma patients. A total of 3938 osteosarcoma patients between 1975 and 2016 from Surveillance, Epidemiology, and End Results (SEER) database were enrolled in this study. Survival rate was obtained by Kaplan-Meier method, with log-rank test identifying the difference. Multivariate Cox regression analysis was used to explore independent prognostic factors. The 5-year overall survival (OS) and cancer-specific survival (CSS) rates in surgery plus adjuvant RT group and surgery alone group were 38.2%, 66.3% (OS), and 41.6%, 68% (CSS), respectively. Multivariate analysis showed that adjuvant RT served as the independent unfavorable prognostic factor for OS and CSS. Based on the propensity score matching (PSM) method, the patients who received adjuvant RT had a poorer prognosis. Adjuvant RT showed an association with survival of osteosarcoma. Patients who received adjuvant RT had poorer survival. In the clinical use of adjuvant RT for osteosarcoma, the potential for reduced survival should be considered.