PD-1/PD-L1 inhibitors in endometrial cancer with high microsatellite instability: a Kaplan-Meier-derived patient data meta-analysis.

[INTRODUCTION] Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of solid tumors. This meta-analysis of randomized controlled trials aimed to assess the survival benefit of anti-PD-1/PD-L1 therapies in women with advanced or recurrent endometrial cancer (EC) and mismatch repair deficiency (dMMR).

[METHODS] A systematic search was conducted in PubMed, Scopus, Cochrane, and Web of Science databases to compare PD-1/PD-L1 inhibitors versus standard therapy in patients with advanced/recurrent EC. Studies were screened based on predefined inclusion/exclusion criteria. Risk of bias was assessed using the Cochrane Risk of Bias Tool. We used DerSimonian and Laird random-effects models to estimate hazard ratios (HRs) and risk ratios (RRs) with 95% confidence intervals (CIs).

[RESULTS] Five studies including 2,739 patients were analyzed, with 627 (22.90%) having dMMR tumors. ICIs significantly improved progression-free survival (HR 0.35; 95% CI 0.28-0.44) and overall survival (HR 0.40; 95% CI 0.28-0.57) in dMMR patients. No significant difference was found in objective response rate (RR 1.72; 95% CI 0.88-3.36).

[CONCLUSIONS] The addition of immunotherapy for treating patients with advanced or recurrent endometrial cancer with dMMR and high microsatellite instability significantly improved PFS and OS outcomes.

[REGISTRATION] PROSPERO (CRD22057890200).