The impact of radiotherapy on the prognosis of metastatic clear cell renal cell carcinoma after surgery

Clear cell renal cell carcinoma, one of the most common types of renal cell carcinoma, has been increasing in incidence year by year. This study aims to investigate the impact of radiotherapy on the prognosis of patients with metastatic clear cell renal cell carcinoma (mccRCC) undergoing cytoreductive surgery. Clinical data of patients with mccRCC who underwent cytoreductive surgery were collected from the SEER database (2000-2021). This study employed propensity score matching (PSM) and R software to evaluate the overall survival (OS) of radiotherapy. Univariate and multivariate COX regression analyses were conducted to explore the impact of different variables on prognosis. Finally, a nomogram was developed to predict patient survival rates. A total of 2076 patients with mccRCC who underwent cytoreductive surgery were included in this study, with 538 (25.92%) in the radiotherapy group and 1539 (74.08%) in the non-radiotherapy group. After propensity score matching (PSM), there were 300 cases in each group. Kaplan-Meier values and the Cox proportional hazards model were used to plot the overall survival (OS) curves, which showed that the median survival time in the radiotherapy group was significantly lower than that in the non-radiotherapy group. Additionally, multivariate Cox regression analysis revealed that tumor grade, N stage, radiotherapy, lung metastasis, and liver metastasis were independent factors affecting the prognosis of patients with mccRCC undergoing cytoreductive surgery. Lastly, a nomogram was developed to estimate the survival rates of patients with mccRCC after cytoreductive surgery. Radiotherapy after cytoreductive surgery may have an adverse impact on the prognosis of patients with mccRCC.