Molecular classification of endometrial carcinoma: clinical utility of an NGS panel with targeted detection of 116 cancer-related genes.

BACKGROUND: This study aimed to evaluate the efficacy of a single-test, targeted DNA next-generation sequencing (NGS) panel in classifying endometrial carcinoma (EC) into molecular subtypes and to compare its performance with that of the established Sanger sequencing + immunohistochemistry (Sanger + IHC) molecular classification. METHODS: Targeted DNA NGS was performed on 131 samples using the clinically validated AmoyDx® Comprehensive Panel, and a commercially available targeted AmoyDx EC Panel covering POLE, TP53, and MSI was used for 63 samples. RESULTS: The concordance between the NGS and Sanger + IHC classifications was 93.8% (182/194 cases), with a kappa value of 0.908. The exclusion of seven discordant POLE mutations improved concordance to 97.4% (kappa = 0.962). NGS identified 30 POLE mutations compared to 23 detected by Sanger sequencing, which missed low-frequency variants. Microsatellite instability (MSI) analysis and mismatch repair (MMR) immunohistochemistry (IHC) results were highly concordant (97.9%). However, NGS-based TP53 mutation detection showed moderate agreement with the p53 IHC results (kappa = 0.688). Mutations associated with targeted therapy trials, including PTEN (76.3%), PIK3CA (50.4%), and ARID1A (35.9%), were found in 131 EC samples. CONCLUSION: These findings indicate that NGS-based molecular classification aligns well with Sanger + IHC molecular classification and offers higher sensitivity than Sanger sequencing, thereby improving the identification of mutations associated with targeted therapy trials. This enhances the prognosis and treatment planning for patients with advanced EC.