Analysis of fertility-preserving treatment outcomes in patients with POLE-mutated endometrioid carcinoma

To explore the clinical outcomes of fertility-sparing treatment (FST) in patients with POLE-mutated endometrioid carcinoma (EEC). A total of 9 EEC patients who received FST and were classified to the POLE-mutated subtype in Peking University People's Hospital from April 2020 to October 2023, were retrospectively collected. Clinical and pathological data were analyzed to describe the outcomes of FST in patients with POLE-mutated EEC. A total of 9 patients with EEC including 6 cases with well-differentiated (G1) and 3 cases with moderately-differentiated (G2). The average age was 34.8±2.1 years. POLE mutation sites were P286R (5 cases), V411L (2 cases), L424I (1 cases), and S459F (1 cases), respectively. The median follow-up time was 16 months (9-41 months). The complete response (CR) rate was 88.9% (8/9), with a median time to CR of 5.5 months (3-18 months). The partial response (PR) rate was 11.1% (1/9). The relapse rate was 50.0% (4/8), with a median recurrence time of 9.5 months (5-25 months). Of these, 75% (3/4) underwent secondary FST, with all achieving CR again (3/3). Three of 5 who were out-of-indication patients achieved CR by individual therapy. FST in patients with POLE-mutated EEC achieve a CR rate of 88.9% in this study, the largest number of retrievable reports. In certain patients who are out-of-indication, individualized treatment may also result in remission. However, unlike surgical patients, some patients experience disease recurrence and whether POLE-mutated EEC is sensitive to conventional therapy in FST is controversial given its pathogenesis.