Genomic Profile of Urothelial Carcinoma of the Upper Tract from Ureteroscopic Biopsy: Feasibility and Validation Using Matched Radical Nephroureterectomy Specimens.

Urothelial carcinoma of the upper tract (UTUC) presents specific challenges regarding accurate staging and tumor sampling. We aimed to assess the feasibility of applying next-generation sequencing to biopsy specimens and gauged the concordance of their genetic profiles with matched radical nephroureterectomy (RNU) specimens. Of the 39 biopsy specimens collected, 36 (92%) had adequate material for sequencing using a hybridization-based exon capture assay (MSK-IMPACT). The most frequently altered genes across the patient cohort were consistent with the urothelial carcinoma-associated alterations identified in a cohort of 130 RNU specimens previously sequenced at our center, including mutations in the TERT promoter (64%), hotspot activating mutations in FGFR3 (64%), and frequent mutations in chromatin remodeling genes. For 12 patients, a matching tumor sample from a subsequent RNU was sequenced. We found a high level of concordance between matched biopsy and RNU specimens, up to 92% for the likely pathogenic alterations. PATIENT SUMMARY: We evaluated the feasibility of genomic characterization of tumor tissue collected at the time of ureteroscopic biopsy and found high concordance with subsequent radical nephroureterectomy specimens. Molecular characterization of urothelial carcinoma of the upper tract biopsies could guide treatment decision-making and identify high-risk patients who could benefit from neoadjuvant chemotherapy and low-risk patients who could benefit from conservative or organ-sparing strategies.