Abstract 4410: The CpG island methylator phenotype is closely associated with prognosis in patients with oral squamous cell carcinomas

Abstract

Abstract Few abnormalities are known to be closely associated with prognosis in OSCC cases. In this study, genomic abnormalities of cancer-related genes and epigenomic abnormalities of genes methylation-silenced in OSCCs were analyzed to identify abnormalities associated with prognosis. Thirty-nine OSCC cases and their surgical materials were analyzed for the presence of mutations using next-generation sequencing. Methylation status of promoter CpG islands of five genes was analyzed by methylation-specific PCR. Mutations in CRG, TP53 and PIK3CA were observed in 64.1%, 38.5%, and 33.3%, respectively, of the cases. However, no significant association between mutation status and overall survival (OS) was observed. Aberrant methylation of CMTM3, NKX2-3, RBP4, EGFLAM, and MAP6 were observed in 51.3%, 41.0%, 66.7%, 38.5%, and 41.0%, respectively. Methylation of NKX2-3, EGFLAM, and MAP6 were significantly associated with OS in OSCC cases (p=0.006, 0.006, and 0.012, respectively). Cases with methylation of CMTM3 and RBP4 showed a trend toward poor prognosis (p=0.052 and 0.059, respectively). Methylation profiles of the five genes indicated the presence of the CpG island methylator phenotype (CIMP), and the CIMP-positive cases showed poor prognosis (HR=20.5, p<0.001). In conclusion, CIMP was closely associated with the prognosis of OSCC cases. Citation Format: Masanobu Abe, Satoshi Yamashita, Toshikazu Ushijima, Kazuto Hoshi. The CpG island methylator phenotype is closely associated with prognosis in patients with oral squamous cell carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4410.