Analysis by Next-Generation Sequencing Panel Covered 60 Genes and 17 Microsatellite Foci in Endometrial Screening Liquid-Based Cytology Specimens A Comparative Study to Tissue Specimens
Background Liquid-based cytology (LBC) is now a widely used method for cytologic screening and diagnosis of cancers. Since the cells are fixed with alcohol-based fixatives and the specimens are stored in a liquid condition, LBC specimens are also conducive for genetic analysis. Methods Here, we established a small cancer gene panel including 60 genes and 17 microsatellite markers for next-generation sequencing and applied to residual LBC specimens obtained by endometrial cancer screening to
... er screening to compare with corresponding formalin-fixed paraffin-embedded (FFPE) tissues. Results A total of 53 FFPE and LBC specimens (n=24) were analyzed, revealing characteristic mutations for endometrial cancer including those of PTEN, CTNNB1, PIK3CA, and PIK3R1 . Eight cases had higher scores for both tumor mutation burden (TMB) and microsatellite instability (MSI), which agree with defective mismatch repair (MMR) protein expression. Paired endometrial LBC, and biopsied and/or resected FFPE tissues from 7 cases, demonstrated almost the same mutations, TMB, and MSI profiles in all cases. Conclusion These findings demonstrate that the small cancer gene panel proved to be able to detect therapeutically actionable gene mutations in endometrial LBC and FFPE specimens and that LBC specimens obtained by endometrial cancer screening is an alternative and useful source of molecular testing.