A retrospective comparative study of progression-free survival and overall survival between metachronous and synchronous metastatic renal cell carcinoma in intermediate- or poor-risk patients treated with VEGF-targeted therapy

INTRODUCTION: The aim of this study was to compare progression-free survival (PFS) and overall survival (OS) between metachronous and synchronous metastatic renal cell carcinomas treated with VEGF-targeted therapy. METHODS: Between 2005 and 2014, 93 (78.8%) intermediate- and 25 (21.2%) poor-Heng-risk patients, including 32 (27.1%) patients with metachronous and 86 (72.9%) patients with synchronous renal cell carcinoma, were enrolled retrospectively. PFS and OS values were compared according to the number of risk factors and treatment-free interval using the Kaplan-Meier method and log-rank test. The prognostic risk factors were also evaluated using a Cox proportional hazard model, with a p-value < 0.05 indicating statistical significance. RESULTS: During a median 5.0-month treatment and 59.3-month follow-up, analysis of the PFS/OS of SM (5.2/9.6 months) and MM (9.6/20.1 months) yielded a significant difference in OS (p = 0.010). However, there was no significant difference when Heng risk groups and treatment-free interval were considered (p > 0.05). There was a significant difference in PFS (hazard ratio: 1.81) and OS (hazard ratio: 2.19) with increasing number of Heng risk factors among patients with synchronous renal cell carcinoma and a treatment-free interval <1 year. Metastatic type, anemia, and neutrophilia were significant predictive factors for OS in multivariable analysis (p < 0.05). CONCLUSION: The metastatic type of renal cell carcinoma (synchronous or metachronous) significantly affects survival; metachronous type is associated with more favorable outcomes than synchronous type. However, after stratification according to Heng risk factors and treatment-free interval, the differences in survival between metachronous and synchronous type were insignificant.