Fertility-sparing treatment in MSI-H/MMRd endometrial carcinoma or atypical endometrial hyperplasia: A systematic review and meta-analysis

Introduction: This systematic review and meta-analysis aimed to describe the oncological and reproductive outcomes of patients with MSI-H/MMRd endometrial carcinoma (EC) or atypical endometrial hyperplasia (AEH) undergoing fertility-sparing treatment. Methods: The study protocol was registered with the PROSPERO database (No: CRD42024530406). A systematic literature search in major electronic databases (PubMed, Embase, and Cochrane Library) was conducted from January 1, 2013 to August 10, 2024. The primary outcomes were complete remission (CR) rate and recurrence rate. Other outcomes included oncological outcomes in patients with Lynch syndrome and overall patient fertility status. Results: The study included ten retrospective studies summarizing 66 patients with MSI-H/MMRd undergoing fertility-sparing treatment. The publication bias analysis was low. The length of follow-up varied from 3 to 164 months according to the different studies analyzed. After fertility-sparing treatment, 61.8 % of patients achieved CR, and 41.2 % of patients relapsed. Twelve patients were identified with germline mutations in Lynch syndrome, nine (75 %) achieved CR, and seven (77.8 %) relapsed. Only one study with active use of assisted reproductive technology reported a 1-year cumulative pregnancy rate of more than 60 % and more than half live births, while the remaining five studies assessed fertility outcomes and reported only one live birth. Conclusion: EC and AEH patients with the MSI-H/MMRd subtype had a low remission rate and high recurrence rate compared to conservative treatment. Caution is recommended when evaluating fertility-sparing therapy for patients with the MSI-H/MMRd subtype.