Advancing Precision Oncology: Whole-Exome Sequencing in Endometrial Cancer Liquid-Based Cytology.

Context.—: Diagnostic strategies for endometrial cancer have been evolving, with cytologic analysis being considered a key method in integrated oncologic diagnostics because of its less invasive nature and adaptability to various assessments. Liquid-based cytology (LBC) has emerged as a promising method for intact DNA preservation; it exhibits improved efficiency in advanced sequencing applications such as next-generation sequencing. However, despite the use of LBC in panel assays, its application in whole-exome sequencing (WES) for comprehensive genomic profiling remains underexplored.

Objective.—: To investigate whether molecular classification is possible based on WES using DNA derived from LBC specimens.

Design.—: We combined WES with targeted gene panel analysis to compare genomic findings of LBC and traditional tissue samples obtained from 7 cases of endometrial cancer. We investigated pathogenic mutations, tumor mutational burden, and microsatellite instability, and achieved molecular classification with high accuracy.

Results.—: We found a substantial concordance between LBC and traditional tissue samples in terms of pathogenic mutation detection, with a 95% match in the LBC samples and 94% in the tissue samples. Notably, our results highlight the importance of combining WES with panel-based analysis in identifying the ultramutated status of a case that had been missed during panel analysis.

Conclusions.—: Our findings emphasize the potential of LBC samples in the precise and noninvasive genomic analysis of cases of endometrial cancer and offer a new avenue for developing diagnostic and therapeutic strategies in precision oncology.