Impact of Metastatic Site in Favorable-Risk Renal Cell Carcinoma Receiving Sunitinib or Pazopanib

Background Although in metastatic renal cell carcinoma (mRCC) patients with intermediate and poor risk the benefit of combination strategies versus tyrosine kinase inhibitor (TKI) has been ascertained, in those with favorable risk data are ambiguous. Herein, we investigated the impact of number and type of metastatic site in patients with favorable risk to contribute to the best therapeutic choice. Material and Methods Multicenter data regarding patients with favorable risk mRCC carcinoma receiving first-line TKIs, sunitinib or pazopanib, were retrospectively collected. We divided our population into two groups based on the number of metastatic sites and analyzed its impact on tumor response and efficacy outcome. The Kaplan-Meier method was used to estimate efficacy outcomes and the log-rank test to examine differences between subgroups. Results A total of 107 patients with a median age of 69 years were included in the final analysis. Patients with one metastatic site, compared with patients with >1 site, had a significantly longer overall survival (OS) (not reached vs. 66 months) and a trend, although not statistically significant, of better progression-free survival (PFS) (31 vs. 17 months). In patients with one metastatic site, liver involvement was correlated with worse PFS and OS at the univariate analysis (p=0.01) and was confirmed as independent poor prognostic factor for PFS at multivariate analysis. Conclusion In conclusion, we reported a longer OS in favorable risk mRCC patients receiving TKI with only one metastatic site. Nevertheless, in patients with a single metastatic site, hepatic involvement correlated with worse PFS compared to other metastatic sites.