Efficacy and safety of adding PD-1 Inhibitors to standard therapies in advanced and recurrent endometrial cancer: A single-center retrospective case-control study

Background Endometrial cancer (EC) is the most prevalent gynecological malignancy in developed nations, with a poor prognosis for advanced or metastatic cases. Immune checkpoint inhibitors targeting PD-1/PD-L1 have emerged as promising therapies, but their efficacy as part of combination regimens remains underexplored. Objective This retrospective cohort study evaluates the clinical outcomes and safety of adding PD-1 inhibitors to standard therapies (chemotherapy, radiotherapy, and targeted therapy) for recurrent and metastatic EC. Methods Ninety-four patients treated for recurrent/metastatic EC between January 2018 and January 2022 were divided into two groups: a treatment group (n = 46) receiving combination therapy with PD-1 inhibitors and a control group (n = 48) receiving standard therapies alone. Clinical tumor markers (CA125, HE4, ROMA scores), disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS), and adverse events were analyzed. Statistical methods included Kaplan-Meier survival analysis and Cox regression. Results The treatment group demonstrated significantly improved outcomes compared to the control group. Median PFS was 39 months versus 16 months (p < 0.001), DCR was 89.13% versus 72.92% (p = 0.046), and ORR showed a trend toward significance at 65.22% versus 45.83% (p = 0.059). Tumor markers such as CA125 and HE4 were significantly reduced in the treatment group post-therapy (p < 0.05). Adverse events were comparable between groups, with most reactions being mild to moderate and manageable. Conclusion PD-1 inhibitor-based combination therapy significantly improves survival outcomes and disease control in recurrent/metastatic EC without increasing severe adverse events. These findings suggest that this approach is both effective and safe, warranting further investigation in larger clinical trials to refine treatment strategies and expand personalized care options for EC patients.