Results of a multi-institutional study published by St-Laurent et al in Science Direct revealed that testing urine-based tumor DNA (utDNA) may help to predict which patients with bladder cancer are at higher risk for recurrence after not responding to first-line treatment.
The study analyzed utDNA from patients in the SWOG S1605 trial, who were treated with the PD-L1 inhibitor atezolizumab after not responding to bacillus Calmette-Guérin (BCG), the main immunotherapy for early-stage bladder cancer. Their goal was to see whether utDNA could help to identify which patients were most likely to respond to atezolizumab therapy in the second-line setting.
“This approach could help improve patient care by guiding more effective treatments and supporting more personalized plans,” said Robert Svatek, MD, MSCI, Professor and Chair of Urology at the Joe R. and Teresa Lozano Long School of Medicine at The University of Texas Health Science Center at San Antonio. “It means we may be able to tailor therapy sooner, reduce unnecessary delays, and help patients avoid major surgery without compromising the quality of their care.”
SWOG S1605 was a phase II clinical trial testing atezolizumab in the second-line setting in patients with high-risk bladder cancer. Samples were collected from participants before treatment and again 3 months later. Researchers used the UroAmp assay, a noninvasive urine test that detects bladder cancer–related mutations, to analyze utDNA and generate a genomic profile for each patient. They examined urine samples from 89 patients at the start of treatment and from 77 patients 3 months later.
The levels of utDNA were linked to how well patients responded to therapy after 6 months and how long they stayed cancer-free over 18 months. Patients with positive utDNA results were found to be less likely to respond and more likely to have their cancer return.
According to the American Cancer Society, bladder cancer is the sixth most common cancer in the United States, with more than 83,000 new cases diagnosed annually. Of these cases, approximately 75% are non–muscle-invasive.
Patients who do not respond to immunotherapy may face the difficult decision of either continuing therapies that spare the bladder but carry high risks of recurrence or undergoing major surgery that removes the bladder and would profoundly impact their quality of life.
Disclosure: For full disclosures of the study authors, visit sciencedirect.com.
