Molecular characterization of nonmuscle invasive bladder cancer (NMIBC) may provide a biologic rationale for treatment response and novel therapeutic strategies.
To identify genetic alterations with potential clinical implications in NMIBC.
Pretreatment index tumors and matched germline DNA from 105 patients with NMIBC on a prospective Institutional Review Board-approved protocol underwent targeted exon sequencing analysis in a Clinical Laboratory Improvement Amendments-certified clinical laboratory.
Comutation patterns and copy number alterations were compared across stage and grade. Associations between genomic alterations and recurrence after intravesical bacillus Calmette-Guérin (BCG) were estimated using Kaplan-Meier and Cox regression analyses.
TERT promoter mutations (73%) and chromatin-modifying gene alterations (69%) were highly prevalent across grade and stage, suggesting these events occur early in tumorigenesis. ERBB2 or FGFR3 alterations were present in 57% of high-grade NMIBC tumors in a mutually exclusive pattern. DNA damage repair (DDR) gene alterations were seen in 30% (25/82) of high-grade NMIBC tumors, a rate similar to MIBC, and were associated with a higher mutational burden compared with tumors with intact DDR genes (p<0.001). ARID1A mutations were associated with an increased risk of recurrence after BCG (hazard ratio=3.14, 95% confidence interval: 1.51-6.51, p=0.002).
Next-generation sequencing of treatment-naive index NMIBC tumors demonstrated that the majority of NMIBC tumors had at least one potentially actionable alteration that could serve as a target in rationally designed trials of intravesical or systemic therapy. DDR gene alterations were frequent in high-grade NMIBC and were associated with increased mutational load, which may have therapeutic implications for BCG immunotherapy and ongoing trials of systemic checkpoint inhibitors. ARID1A mutations were associated with an increased risk of recurrence after BCG therapy. Whether ARID1A mutations represent a predictive biomarker of BCG response or are prognostic in NMIBC patients warrants further investigation.
Analysis of frequently mutated genes in superficial bladder cancer suggests potential targets for personalized treatment and predictors of treatment response, and also may help develop noninvasive tumor detection tests.
European urology. 2017 Jun 03 [Epub]
Eugene J Pietzak, Aditya Bagrodia, Eugene K Cha, Esther N Drill, Gopa Iyer, Sumit Isharwal, Irina Ostrovnaya, Priscilla Baez, Qiang Li, Michael F Berger, Ahmet Zehir, Nikolaus Schultz, Jonathan E Rosenberg, Dean F Bajorin, Guido Dalbagni, Hikmat Al-Ahmadie, David B Solit, Bernard H Bochner
Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address: .