Endometrial Carcinoma Molecular Subtype Correlates With the Presence of Lymph Node Metastases

Endometrial cancer (EC) continues to increase in incidence and mortality globally and represents the most common gynecologic cancer in North America. Approximately 22% of patients with stage 1 EC have extrauterine disease, most commonly in pelvic and/or para-aortic lymph nodes. Although studies have demonstrated lymphadenectomy has no therapeutic role, lymph node dissection remains standard practice in many institutions because of its role in prognostication and guiding the use of adjuvant therapy. Sentinel lymph node biopsy (SLNB) has become a valuable diagnostic technique; however, there remains controversy over which EC patients should be offered nodal assessment and what factors should guide this decision. Histotype and cancer grade can be determined preoperatively as a risk assessment for lymph node metastasis (LNM); however, results are poorly reproducible among expert pathologists. The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE), a clinically validated immunohistochemistry (IHC) tool, can assign EC to 1 of 4 molecular subtypes: POLEmut, MMRd, p53abn, and NSMP (no specific molecular profile). These classifications have a stronger prognostic significance than histopathological features and are highly reproducible when performed on endometrial biopsy.