Characteristics of Metastasis as a Prognostic Factor for Immunotherapy in Metastatic Renal Cell Carcinoma

Abstract

Aims and background This study aimed to evaluate the significance of characteristics of metastasis as prognostic factors in metastatic renal cell carcinoma (RCC). Patients and methods A total of 148 patients who had received immunotherapy were included in the study. Patients were categorized in various ways according to the characteristics of metastasis, including a synchronous metastasis group (n = 77) vs a metachronous metastasis group (n = 71), and a solitary metastasis group (n = 93) vs a multiple metastases group (n = 55). Results In the synchronous and metachronous metastasis groups, median progression-free survival was 4.3 months (95% confidence interval [CI] 2.9-5.7) and 11.1 months (95% CI 6.7-15.5), respectively (P = 0.004). Median overall survival was 17.1 months (95% CI 9.5-24.7) and 54.8 months (95% CI 38.3-71.3) in the two groups (P = 0.019). In the solitary and multiple metastasis groups, median progression-free survival was 11.0 months (95% CI 6.6-15.5) and 3.9 months (95% CI 2.6-5.2), respectively (P <0.001). Median overall survival was 55.2 months (95% CI 50.7-59.7) and 15.6 months (95% CI 10.9-20.3) in the two groups (P <0.001). Multivariate Cox proportional hazards model analysis using the clinical variables showed that T stage (P = 0.026), number of metastatic sites (P = 0.009) and time to metastasis (P = 0.019) were independent predictors of progression-free survival. Using the same variables, only the number of metastatic sites was an independent prognostic predictor of overall survival (P = 0.014). Conclusions Our findings suggest that the time to metastasis and the number of metastases are important prognostic factors in metastatic RCC.