Modifying surgical extents in patients with preoperatively presumed early-stage endometrial cancer based on ProMisE classification: a retrospective, single-center study.

Objective: This study aimed to explore differences in disease extent based on the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) classification and to establish personalized staging surgery strategies in patients with preoperatively presumed uterus-confined endometrial cancer.

Methods: In this retrospective, single-center study, we reviewed the medical records of patients with endometrial cancer. These patients were classified according to the ProMisE classification based on tissue samples obtained from dilation and curettage or staging surgeries, and the disease extent was analyzed based on pathologic reports.

Results: A total of 345 patients were clinically estimated to be in stage 1/2 before staging surgery, with immunohistochemistry (IHC) results available. This cohort included 332 patients (96.2%) with clinical stage 1 and 13 patients (3.8%) with stage 2 based on the 2009 FIGO staging system. Among these, 81 patients (23.5%) were assigned to an mismatch repair deficient group (MMRd), 33 (9.6%) to an abnormal p53 group, and 123 (71.1%) to a no specific molecular profile (NSMP) group. Overall, 13 patients had nodal metastasis, with a higher rate observed in the abnormal p53 group (1.2%, 12.1%, and 2.2% for the MMRd, abnormal p53, and NSMP groups, respectively, p=0.013). One patient (0.3%) had parametrial metastasis and four (1.1%) had peritoneal metastasis.

Conclusion: Patients with abnormal p53 IHC results exhibited a higher likelihood of lymph node metastasis, even when initially presumed to be at an early stage. For the abnormal p53 group, proactive lymphadenectomy surgery appears beneficial for accurate staging and establishing a subsequent treatment plan.