Geographical Differences in Kidney Cancer Outcomes of Patients Treated with Immunotherapy: A Systematic Review

BACKGROUND: Immune checkpoint inhibitors (ICI) have shown clinical benefit among patients with advanced kidney cancer. Their cost burden hardens its access, especially in low- and middle-income countries. To set solutions, the impact of geographical and socioeconomic differences in the clinical outcomes and survival of renal cell carcinoma (RCC) patients needs to be explored. OBJECTIVE: This review aimed to understand if geographical differences affected the clinical outcomes of RCC patients receiving immunotherapy. METHODS: This study reviewed 45 studies that examined the OS and PFS of RCC patients undergoing ICI (2010–2020) selected from a 3028-study database search conducted on PubMed and grey literature. The selected studies were divided into groups: Asia, multicentric studies, Europe and Anglo-America. The lethality and income of the geographical locations were measured and discussed. RESULTS: Weighted average (WAVG) of mPFS and mOS were 8,47 months, and 40,6 months in Asia. The WAVG of mOS were 12.2 months, and 20.22 months in the Anglo-American population (15 studies; 943 patients). In multicentric studies (4 studies; 1834 patients) the WAVG mPFS was 10,06. European group (13 studies; 3143 patients) had 6.1 and 20.24 months mPFS and mOS, respectively. The exploratory analysis on income and RCC lethality has shown an absolute decline of 8.7% (CI 10.1 to 7.3% - p <  0.05) in RCC lethality, when income is raised by 100% . CONCLUSION: Clinical benefit from ICI varies across the globe. A wide access to ICI, and evaluation of biological aspects of the disease will allow a better understanding of the impact of geographic regions in the clinical outcome of patients receiving ICI and the etiology of potential differences.