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.