Incidence and Distribution of UroSEEK Gene Panel in a Multi-institutional Cohort of Bladder Urothelial Carcinoma

Non-invasive approaches for early detection of bladder cancer are actively being investigated. We recently developed a urine based molecular assay for the detection and surveillance of bladder neoplasms (UroSEEK). UroSEEK is designed to detect alterations in 11 genes that includes most common genetic alterations in bladder cancer. In this study we analyzed 527 cases including 373 non-invasive and 154 invasive urothelial carcinomas of bladder from trans-urethral resections or cystectomies performed at 4 institutions (1991–2016). Two different mutational analysis assays of a representative tumor area were performed: first, a singleplex PCR assay for evaluation of the TERT promoter region (TERTSeqS) and second, a multiplex PCR assay using primers designed to amplify regions of interest of 10 (FGFR3, PIK3CA, TP53, HRAS, KRAS, ERBB2, CDKN2A, MET, MLL, and VHL) genes (UroSeqS). Overall 92% of all bladder tumors were positive for at least one genetic alteration in the UroSEEK panel. We found TERT promoter mutations in 77% of low-grade non-invasive papillary carcinomas with relatively lower incidence of 65% in high-grade non-invasive papillary carcinomas and carcinomas in situ; p=0.017. Seventy-two percent of pT1 and 63% of muscle-invasive bladder tumors harbored TERT promoter mutations with g.1295228C>T alteration being the most common in all groups. FGFR3 and PIK3CA mutations were more frequent in low-grade non-invasive papillary carcinomas compared to high-grade non-invasive papillary carcinomas and carcinomas in situ (p<0.0001), while the opposite was true for TP53 (p<0.0001). Significantly higher rates of TP53 and CDKN2A mutation rates (p=0.005 and 0.035, respectively) were encountered in muscle-invasive bladder tumors compared to those of pT1 stage. The overwhelming majority of all investigated tumors showed at least one mutation among UroSEEK assay genes confirming the comprehensive coverage of the panel and supporting its potential utility as a non-invasive urine based assay.