Risk-Adapted Approaches to Managing Muscle-Invasive Bladder Cancer
Posted: Friday, March 12, 2021
Interim findings from the phase II RETAIN BLADDER trial, presented during the virtual edition of the 2021 Genitourinary (GU) Cancers Symposium (Abstract 397), revealed that a risk-adapted treatment of muscle-invasive bladder cancer resulted in about a 50% rate of any recurrence and an 11% rate of recurrence of locally advanced or metastatic disease. Elizabeth R. Plimack, MD, of the Fox Chase Cancer Center, Philadelphia, and colleagues used a risk-adaptive therapy that utilized a selection of clinical and genomic factors in patients with cT2 to T3 muscle-invasive bladder cancer.
In this trial, 71 patients with cT2 to T3N0M0 muscle-invasive bladder cancer received neoadjuvant chemotherapy with accelerated methotrexate, vinblastine, doxorubicin, and cisplatin (AMVAC). The authors sequenced preneoadjuvant chemotherapy transurethral resection of a bladder tumor (TURBT) specimens from patients for mutations in ATM, ERCC2, FANCC, or RB1. Those with at least one mutation and no clinical evidence of disease began active surveillance, whereas the remaining patients underwent bladder-directed therapy.
Nearly all patients (90%) completed three cycles of neoadjuvant chemotherapy, with 17% experiencing grade 3 or 4 treatment-related adverse events. One patient died during AMVAC treatment. Among the study patients, 32 had a cystectomy, 5 underwent chemoradiation therapy, and 7 had intravesical therapy.
The authors determined that 33 patients had a mutation of interest, with 28 patients starting active surveillance. Of those patients with a mutation, 76% had cT0 disease after neoadjuvant chemotherapy TURBT. After a median follow-up of 14.9 months, 14 patients on active surveillance had a recurrence. Of those patients, two had locally advanced or metastatic disease and died, five had muscle-invasive bladder cancer and one eventual metastatic recurrence, and seven had non–muscle-invasive bladder cancer. Six of the patients not on active surveillance died.
The bladder preservation rate for the intention-to-treat patients was 55%, and it was 89% for those on active surveillance.
Disclosure: For full disclosure of the study authors, visit coi.asco.org.