A case series on the efficacy and safety of a PD-1 inhibitor combined with antiangiogenic agents in the treatment of recurrent MSI-H endometrial cancer

BACKGROUND: Endometrial cancer (EC) is one of the most common gynecological malignancies in developed countries worldwide. The treatment of recurrent endometrial cancer is a very difficult problem in clinical work. Studies on patients with recurrent EC microsatellite instability-high (MSI-H) are very rare. The objective of this study is to initially evaluate the therapeutic effect of a PD-1 inhibitor combined with antiangiogenic agents in the treatment of recurrent MSI-H endometrial cancer. METHODS: Eight patients with recurrent MSI-H endometrial cancer were recruited from Tianjin Medical University Cancer Institute and Hospital from July 2019 to July 2021, and their median age was 55.3 (range, 46–62) years. All patients experienced recurrence after surgical treatment, and the median recurrence and metastasis time was 6.6 (range, 4–10) months. The pathological types were all endometrioid carcinomas. PD-1 inhibitors were selected from camrelizumab or pembrolizumab, and antiangiogenic targeted agents were selected from apatinib or anlotinib. RESULTS: The median follow-up time was 11.0 (range, 5–19) months. In the case series, all 8 cases could be evaluated for curative effect with complete response in 4 cases and partial response in 4 cases. The overall objective response rate was 100%. CONCLUSIONS: PD-1 inhibitors combined with antiangiogenic agents may have good therapeutic effects on patients with recurrent MSI-H endometrial cancer and may become an important method for the treatment of recurrent endometrial cancer in the future.