Concurrent endometrial cancer in atypical endometrial hyperplasia and the role of sentinel lymph nodes: clinical insights from a multicenter experience

Objective This study aimed to evaluate the prevalence of concurrent endometrial cancer in patients pre-operatively diagnosed with atypical endometrial hyperplasia undergoing hysterectomy. Additionally, we assessed the occurrence of high to intermediate-risk and high-risk tumors according to the ESGO-ESTRO-ESP classification. The study also compared surgical outcomes and complications between patients undergoing simple hysterectomy and those undergoing hysterectomy with sentinel lymph node biopsy. Methods In this multicenter retrospective study, patients with a pre-operative diagnosis of atypical endometrial hyperplasia were identified and divided into two groups: Group 1, which included patients treated with total hysterectomy with or without bilateral salpingo-oophorectomy, and Group 2, where sentinel lymph node biopsy was incorporated into the standard surgical treatment. Results Among 460 patients with atypical endometrial hyperplasia, 192 received standard surgical management (Group 1) and 268 underwent sentinel lymph node biopsy (Group 2). A total of 47.2% (95% CI 42.6% to 51.7%) of patients were upgraded to endometrial cancer on final histopathological examination. High to intermediate-risk and high-risk tumors constituted 12.3% and 9.2% in Group 2 and 7.4% and 3.7% in Group 1. Lymph node metastases were identified in 7.6% of patients with concurrent endometrial cancer who underwent nodal assessment with at least unilateral mapping. Of the 12 sentinel lymph node metastases, 75.0% were micrometastases, 16.7% macrometastases, and 8.3% isolated tumor cells. No significant differences were found in estimated blood loss, operative time, and intra-operative and post-operative complications between the two groups. The rate of patients undergoing sentinel lymph node biopsy doubled every 2 years (OR 2.010, p<0.001), reaching 79.1% in the last 2 years. Conclusion This study found a prevalence of concurrent endometrial cancer of 47.2%, and sentinel lymph node biopsy provided prognostic and therapeutic information in 60.8% of cases. It also allowed for the adjustment of adjuvant therapy in 12.3% of high to intermediate-risk patients without increasing operative time or complication rates.