Somatic Mutation of the Non-Muscle-Invasive Bladder Cancer Associated with Early Recurrence

Next-generation sequencing (NGS) is widely used in muscle-invasive bladder cancer but has limited use in non-muscle-invasive bladder cancer (NMIBC) due to significant heterogeneity and high cancer-specific survival. Therefore, we evaluated the genomic information of NMIBC and identified molecular alterations associated with tumour recurrence. A total of 43 patients with NMIBC who underwent transurethral resection of the bladder were enrolled. We performed NGS using an Oncomine panel of tumour specimens and blood samples corresponding to each specimen. The somatic mutation results were analysed by pairwise comparison and logistic regression according to the recurrence of bladder tumours within 1 year. The median incidence of genetic variations in 43 tumour samples was 56 variations per sample, and a high tumour mutation burden (TMB) was associated with tumour recurrence (median variation 33 vs. 64, p = 0.023). The most mutated gene was adipose tissue macrophages (ATM) (79%), followed by neurofibromatosis-1 (NF1) (79%), and neurogenic locus notch homolog protein 1 (NOTCH1) (79%). In multivariable analysis, mutation of epidermal growth factor receptor (EGFR) (odds ratio [OR], 9.95; 95% confidence interval [CI], 1.40-70.96; p = 0.022) and telomerase reverse transcriptase (TERT) (OR, 7.92; 95% CI, 1.22-51.51; p = 0.030) were significant factors associated with the recurrence of bladder tumour within 1 year. Our results revealed that high TMB, EGFR mutation, and TERT mutation had a significant association with tumour recurrence in NMIBC. In addition, somatic mutations in EGFR and TERT could be useful prognostic biomarkers in NMIBC.