Objective: To examine the effectiveness of progestin re-treatment for recurrent endometrial intraepithelial neoplasia (EIN), atypical endometrial hyperplasia (AH) and endometrial cancer (EC) following initial fertility-sparing treatment. Methods: A comprehensive systematic review and meta-analysis were conducted by an Expert Panel of the Japan Society of Gynecologic Oncology Endometrial Cancer Committee. Multiple search engines, including PubMed/MEDLINE and the Cochrane Database, were searched in December 2021 using the keywords “Endometrial neoplasms,” “Endometrial hyperplasia,” “Endometrial intraepithelial neoplasia,” “Fertility preservation,” “Progestins,” AND “Recurrence.” Cases describing progestin re-treatment for recurrent EIN, AH and EC were compared with cases that underwent conventional hysterectomy. The primary outcomes were survival and disease recurrence, and the secondary outcome was pregnancy. Results: After screening 238 studies, 32 with results for recurrent treatment were identified. These studies included 365 patients (270 received progestin re-treatment and 95 underwent hysterectomy). Most progestin re-treatment involved medroxyprogesterone acetate or megestrol acetate (94.5%). Complete remission (CR) following progestin re-treatment was achieved in 219 (81.1%) cases, with 3-, 6- and 9-month cumulative CR rates of 22.8%, 51.7% and 82.6%, respectively. Progestin re-treatment was associated with higher risk of disease recurrence than conventional hysterectomy was (odds ratio [OR]=6.78; 95% confidence interval [CI]=1.99–23.10), and one patient (0.4%) died of disease. Fifty-one (14.0%) women became pregnant after recurrence, and progestin re-treatment demonstrated a possibility of pregnancy (OR=2.48; 95% CI=0.94–6.58). Conclusion This meta-analysis suggests that repeat progestin therapy is an effective option for women with recurrent EIN, AH and EC, who wish to retain their fertility.

Objectives: This review aims to introduce preoperative scoring systems to predict lymph node metastasis (LNM) and ongoing clinical trials to investigate the therapeutic role of lymphadenectomy for endometrial cancer. Methods: We summarized previous reports on the preoperative prediction models for LNM and evaluated their validity to omit lymphadenectomy in our recent cohorts. Next, we compared characteristics of two ongoing lymphadenectomy trials (JCOG1412, ECLAT) to examine the survival benefit of lymphadenectomy in endometrial cancer, and described the details of JCOG1412. Results: Lymphadenectomy has been omitted for 64 endometrial cancer patients who met lowrisk criteria to omit lymphadenectomy using our scoring system (LNM score) and no lymphatic failure has been observed. Other two models also produced comparable results. Two randomized phase III trials to evaluate survival benefit of lymphadenectomy are ongoing for endometrial cancer. JCOG1412 compares pelvic lymphadenectomy alone with pelvic and para-aortic lymphadenectomy to evaluate the therapeutic role of para-aortic lymphadenectomy for patients at risk of LNM. For quality assurance of lymphadenectomy, we defined several regulations, including lower limit of the number of resected nodes, and submission of photos of dissected area to evaluate thoroughness of lymphadenectomy in the protocol. The latest monitoring report showed that the quality of lymphadenectomy has been well-controlled in JCOG1412. Conclusion Our strategy seems reasonable to omit lymphadenectomy and could be generalized in clinical practice. JCOG1412 is a high-quality lymphadenectomy trial in terms of the quality of surgical procedures, which would draw the bona-fide conclusions regarding the therapeutic role of lymphadenectomy for endometrial cancer.