Bladder Cancer with Undetectable Circulating Tumor DNA After Radical Cystectomy May Be Amenable to a Less Intense...

Area of Science:

• Uro-oncology
• Molecular diagnostics
• Cancer biomarkers

Background:

• Muscle-invasive bladder cancer (MIBC) management involves intensive postoperative surveillance.
• Circulating tumor DNA (ctDNA) is a promising prognostic biomarker for bladder cancer.
• Current surveillance relies heavily on imaging studies.

Purpose of the Study:

• To evaluate the diagnostic performance of ctDNA for detecting bladder cancer recurrence post-radical cystectomy.
• To compare ctDNA's accuracy against traditional imaging studies.
• To explore ctDNA's potential role in refining surveillance strategies.

Main Methods:

• Prospective analysis of 94 patients undergoing robot-assisted radical cystectomy and tumor-informed ctDNA testing (Signatera™).
• Inclusion criteria: postoperative imaging and ctDNA results; exclusion: nonurothelial histology or missing ctDNA data.
• Diagnostic accuracy assessed using imaging as reference standard; calculation of sensitivity, specificity, PPV, and NPV for ctDNA.

Main Results:

• ctDNA demonstrated 100.0% sensitivity and 91.8% specificity for detecting recurrence.
• Positive predictive value (PPV) was 84.5%, and negative predictive value (NPV) was 100.0%.
• Study included patients with predominantly ≥pT2, node-negative disease, with a median follow-up of 16 months.

Conclusions:

• ctDNA measurement is a valuable tool for bladder cancer surveillance after cystectomy.
• Undetectable ctDNA may indicate a lower recurrence risk, potentially enabling less intensive surveillance.
• Further research is needed to validate ctDNA's clinical utility and integration into routine practice.