Genomic Features of Cervical Cancer in Okinawa, Japan: Preliminary Findings From 23 Patients

Regional differences in genomic mutation profiles of uterine cervical cancer have been reported. Japanese people are divided into two genetic background clusters, originating from mainland Japan and Okinawa. Okinawa is an island prefecture surrounded by the sea, located more than 800 km from the southernmost point of mainland Japan. No studies have examined gene mutation profiles of cervical cancer in Okinawa. This study aimed to investigate the mutation profile of cervical cancer in Okinawa.

Twenty-three patients with biopsy-proven squamous cell carcinoma and adenocarcinoma of the intact uterine cervix who were treated with definitive radiotherapy were analyzed. Genomic DNA was extracted from fresh frozen tissue samples collected by tumor biopsy prior to treatment. Variants of 224 cancer-related genes were identified using next-generation sequencing.

A total of 29 gene mutations were observed in 16 patients, including nine genes mutated in multiple samples: SCN7A (17%), PIK3CA (13%), FGFR4 (13%), USP6 (13%), SETD2 (9%), KIT (9%), TSC1 (9%), SERPING1 (9%), and NOTCH3 (9%). Compared to a report from mainland Japan, significant differences in mutation frequency were observed in PIK3CA, FBXW7, and ARID1A. Significant mutations in ARID1A, FBXW7, PTEN, TP53, and EP300, reported as relatively common in cervical cancer in other regions were not detected in this study. The rate of 2-year overall survival and progression-free survival was 95.5% and 73.4%, respectively.

Gene mutation profiles of cervical cancer in Okinawa may differ from those in other regions.