Identification of molecular subtypes for endometrial carcinoma using a 46-gene next-generation sequencing panel: a retrospective study on a consecutive cohort

Background: Traditional classification tools for endometrial carcinoma (EC), such as DNA sequencing, immunohistochemistry (IHC), or PCR, are cumbersome and time-consuming. Large next-generation sequencing (NGS) panels have simplified testing but are expensive. In this study, we propose a concise NGS panel as an effectively viable approach for classifying EC. Materials and methods: We retrospectively enrolled a consecutive EC cohort of hysterectomy with bilateral salpingooophorectomy from Fudan University Shanghai Cancer Center between 2020 and 2022. A 46-gene NGS panel was utilized to identify POLE exonuclease domain mutations, microsatellite instability-high (MSI-H), TP53 mutations, and other clinically relevant targets. Results: Tumor tissue samples from 331 EC patients were evaluated, with 284 (85.8%) cases classified as endometrioid endometrial carcinoma. The median follow-up time was 32.6 months (n = 303), during which 23 patients experienced recurrence or disease progression. Using the concise NGS panel, patients were stratified into four molecular subgroups according to the World Health Organization classification criteria: POLE mut (n = 47; 14.2%), mismatch repair deficiency (dMMR) (n = 79; 23.9%), non-specific molecular profile (n = 148; 44.7%), and abnormal p53 expression (p53 abn) (n = 57; 17.2%). POLE mut displayed the most favorable prognosis, while p53 abn had the worst prognosis (P < 0.001). The concordance between NGS and IHC was 91.8% (269/293) for detecting MMR status and 65.3% (201/308) for detecting p53 status. Patients detected solely by NGS had significantly worse prognosis than those detected solely by IHC, indicating higher accuracy of the NGS panel. With the molecular subtyping information, adjuvant treatment plans for 19.6% of patients could potentially be altered, mainly concentrated in the POLE mut and p53 abn subtypes. This panel also aids targeted therapy and poly (ADP-ribose) polymerase (PARP) inhibitor-related gene mutation detection, as well as auxiliary genetic screening. Conclusion: Our study demonstrates that the concise NGS panel is an effective 'one-stop' strategy for precisely classifying EC with high clinical availability.