Purpose: Next-generation sequencing (NGS)-based profiling of both urinary tumor DNA (utDNA) and circulating tumor DNA (ctDNA) shows promise for noninvasive detection and surveillance of urothelial bladder cancer (UBC). However, the analytical performance of these assays remains undefined in the real-world setting. Here, we sought to evaluate the concordance between tumor DNA (tDNA) profiling and utDNA or ctDNA assays using a UBC patient cohort from the intended-use population.
Materials and methods: Fifty-nine cases with pathologically confirmed disease and matching tissue/urine pairs were prospectively enrolled. Baseline peripheral blood mononuclear cell and plasma specimens were collected during clinic visits. The PredicineCARETM NGS assay was applied for ultra-deep targeted sequencing and somatic alteration identification in tDNA, utDNA and ctDNA.
Results: Diverse quantitative metrics including cancer cell fraction, variant allele frequency and tumor mutation burden were invariably concordant between tDNA and utDNA, but not ctDNA. The mutational landscapes captured by tDNA or utDNA were highly similar, whereas a considerable proportion of ctDNA aberrations stemmed from clonal hematopoiesis. Using tDNA-informed somatic events as reference, utDNA assays achieved a specificity of 99.3%, a sensitivity of 86.7%, a positive predictive value of 67.2%, a negative predictive value of 99.8% and a diagnostic accuracy of 99.1%. Higher preoperative utDNA or tDNA abundance correlated with worse relapse-free survival. Actionable variants including FGFR3 alteration and ERBB2 amplification were identified in utDNA.
Conclusions: Urine-based molecular pathology provides a valid and complete genetic profile of bladder cancer, and represents a faithful surrogate for genotyping and monitoring newly diagnosed UBC.
Keywords: circulating tumor DNA; high-throughput nucleotide sequencing; liquid biopsy; urinary bladder neoplasms; urine.