Circulating tumor DNA (ctDNA) identifies post-surgery patients at high risk of relapse. By targeting adjuvant immunotherapy to only this ctDNA-positive group, previously negative clinical trials demonstrate a significant survival benefit. This approach spares low-risk, ctDNA-negative patients from unnecessary treatment and toxicity.
A positive ctDNA (blood) but negative utDNA (urine) test suggests systemic, metastatic disease. Conversely, a positive utDNA with negative ctDNA points to a tumor confined to the bladder. This integrated biomarker approach can help determine whether systemic therapy or local treatment like surgery is the priority.
With therapies like Enfortumab Vedotin + Pembrolizumab (EVPembro) inducing a pathological complete response (PathCR) in 60% of patients, many undergo radical cystectomies only to find no residual cancer. This success rate is driving trials for bladder-sparing approaches like active surveillance.
In bladder preservation strategies, circulating tumor DNA (ctDNA) from blood is poor at detecting non-muscle invasive local recurrences. This limitation makes urine tumor DNA (utDNA) a necessary future tool for monitoring patients under active surveillance, potentially replacing invasive cystoscopies.