RCC Real-World Data: Prognostic Factors and Risk Stratification in the Immunotherapy Era.

Immunotherapy has transformed the landscape of treatment in metastatic renal cell carcinoma (mRCC) in the last decade. Currently, prognostic risk stratification is based on the model developed in the era of vascular endothelial growth factor receptor inhibitors (VEGFRi) by Heng in 2009. Our study aims to find the most relevant risk criteria for mRCC patients treated with checkpoint inhibitors (CPI). In a retrospective cohort study, laboratory, pathology, demographic, and clinical data were retrieved from electronic medical records of consecutive mRCC patients treated with CPI in a tertiary center between 2015 and 2020. An unbiased multivariate analysis was performed to define predictive variables with a bootstrap validation step. We analyzed data on 127 patients with a median follow-up of 60 months. The median overall survival (OS) since the diagnosis of metastatic disease was 57 months. The response rate for CPI was 39%. Five risk factors were correlated with worse OS: intact primary kidney tumor (HR 2.33, p = 0.012), liver metastasis (HR 3.33, p = 0.001), <one year to treatment start (HR 1.98, p = 0.029), elevated platelets (HR 3.06, p = 0.015), and Karnofsky performance status <80% (HR = 3.42, p = 0.001). The model received a C-index of 70.7 compared with a score of 62.0 for the Heng’s model. When dividing patients into “low-risk” (0−1 risk factors) and “high-risk” (2−5 risk factors), there was good separation between the groups, with an HR of 5.9 (p < 0.0001). This study presents a new prognostic model for mRCC in the immunotherapy era with improved accuracy. Further research is needed to validate this model in larger cohorts.