Clinical performance of the urine-based TERT promoter AbsoluteQ Digital PCR for non-invasive detection of bladder cancer.

Abstract

Bladder cancer (BC) is the ninth most common cancer worldwide, with urothelial carcinoma accounting for approximately 90% of all cases and presenting predominantly as non-muscle-invasive disease. Due to its high recurrence rate and the need for long-term surveillance, BC is associated with the highest lifetime treatment costs per patient among all cancers, making its effective management a significant clinical and economic challenge. The most frequently identified variants in the TERT gene promoter are c.-124C>T (C228T) and c.-146C>T (C250T), located within a region characterized by high guanine-cytosine (GC) content, which makes amplification challenging. We aimed to validate the AbsoluteQ Digital PCR assay for the detection of urine-based TERT promoter variants for the diagnosis of urothelial bladder cancer and to assess its diagnostic performance in comparison with standard methods. Urine samples were collected from patients with histopathologically confirmed bladder cancer (n = 58) and compared with a control group (n = 55). The C228T and C250T variants were tested using the AbsoluteQ Digital PCR assay. Sensitivity, specificity, and predictive values were calculated to evaluate the performance of the assessed method. The AbsoluteQ Digital PCR demonstrated superior diagnostic performance compared to conventional Sanger sequencing for detecting TERT promoter variants, achieving a sensitivity of 89.65% (95% CI: 78.16-95.72) and a specificity of 100% (95% CI: 91.87-100), with no false positives observed. Given its robustness and clinical relevance, AbsoluteQ Digital PCR is emerging as a promising tool for non-invasive molecular diagnostics targeting TERT promoter variants.