Many patients diagnosed with bladder cancer will have to undergo bladder removal surgery. However, researchers at Fox Chase Cancer Center are conducting a new study — the INSITE trial — to try to identify a better set of biomarkers that can help clinicians more accurately identify patients with localized bladder cancer who can forgo cystectomy.
Alexander Kutikov, MD, FACS
“The goal [of INSITE] is to create a test where we can say, ‘Your bladder is clean,’” said Alexander Kutikov, MD, FACS, Chair of the Department of Urology, who is the primary investigator for the trial.
This concept is not a new one for Dr. Kutikov and colleagues in Fox Chase’s Genitourinary Cancer Service. A few years ago, a similar study used cystoscopy to examine the lining of the bladder and attempted to predict who had disease left inside the bladder, and who did not.
“We found that about one-fourth of the time, patients [who appeared to have clean bladders] had bladders that still had tumor that had grown into the muscle,” said Matthew R. Zibelman, MD, a co-author on the study and an Associate Professor in the Department of Hematology/Oncology at Fox Chase. “That risk is too high. We couldn’t confidently say, ‘We don’t need to take your bladder out’ if there is a 25 percent chance that they are still going to have cancer.”
Matthew R. Zibelman, MD
The INSITE trial, a sort of “sequel” trial, will use a combination of biomarkers to try to predict the presence of residual tumor remaining in the bladder at the time of cystectomy. The trial will combine a diagnostic panel including imaging, systematic endoscopy evaluation, a blood-based ctDNA assay, and a urine-based cell free DNA assay.
There are several groups of patients who would be eligible candidates for the trial, Dr. Zibelman explained. The first is patients with high-grade T1 urothelial carcinoma who elect for “early” cystectomy. Second is patients with non-muscle invasive bladder cancer (NMIBC) who have relapsed or refractory/unresponsive disease after intravesical therapy and are recommended to have cystectomy. Third is patients with cT2-T3 muscle invasive bladder cancer (MIBC) irrespective of receipt of neoadjuvant chemotherapy.
Drs. Kutikov and Zibelman acknowledged that tools are rarely ever 100 percent effective, but with data from this trial, the researchers hope to improve the efficacy of these presurgical evaluations with a goal closer to 90 percent.
“These are big surgeries that have significant risks,” Dr. Kutikov said. “We want to help patients make more informed decisions about whether or not going to surgery is worthwhile.”
The trial will require the type of multidisciplinary collaboration inherent to Fox Chase’s Genitourinary Cancer Service. Medical oncologists, radiation oncologists, urologic oncologists, and surgical oncologists, all work together to tackle a question commonly seen in clinical practice.
“Physicians considering options for their patients with bladder cancer may want to refer them to Fox Chase,” Dr. Zibelman said. “At Fox Chase, we are trying to answer the type of critical questions that can really make a difference.”
Fox Chase is one of only two trial sites evaluating this diagnostic panel. Former Fox Chase Urologic Oncology Fellow Jared Schober, MD, Assistant Professor of Surgery in the Division of Urologic Surgery at University of Nebraska Medical Center (UNMC), helped write the INSITE trial and is working to get a second site opened at UNMC.