Randomized Comparison of Magnetic Resonance Imaging Versus Transurethral Resection for Staging New Bladder Cancers: Results From the Prospective BladderPath Trial.

Abstract

Transurethral resection of bladder tumor (TURBT) is the initial staging procedure for new bladder cancers (BCs). For muscle-invasive bladder cancers (MIBCs), TURBT may delay definitive treatment. We investigated whether definitive treatment can be expedited for MIBC using flexible cystoscopic biopsy and multiparametric magnetic resonance imaging (mpMRI) for initial staging. We conducted a prospective open-label, randomized study conducted within 17 UK hospitals (registered as ISRCTN 35296862). Participants with suspected new BC were randomly assigned 1:1 to TURBT-staged or mpMRI-staged care, with minimization factors of sex, age, and clinician visual assessment of stage. Blinding was not possible. Patients unable/unwilling to undergo mpMRI or with previous BC were ineligible. The study had two stages with separate primary outcomes of feasibility and time to correct treatment (TTCT) for MIBC, respectively. Between May 31, 2018, and December 31, 2021, 638 patients were screened, and 143 participants randomly assigned to TURBT (n = 72; 55 males, 15 MIBCs) or initial mpMRI (n = 71; 53 males, 14 MIBCs). For feasibility, 36 of 39 (92% [95% CI, 79 to 98]) participants with suspected MIBC underwent mpMRI. The median TTCT for participants with MIBC was significantly shorter with initial mpMRI (n = 12, 53 days [95% CI, 20 to 89] <i>v</i> n = 14, 98 days [95% CI, 72 to 125] for TURBT, log-rank <i>P</i> .02). There was no detriment for participants with non-MIBC (median TTCT: n = 30, 17 days [95% CI, 8 to 25] for mpMRI <i>v</i> n = 28, 14 days [95% CI, 10 to 29] for TURBT, log-rank <i>P</i> = .67). No serious adverse events were reported. The mpMRI-directed pathway led to a 45-day reduction in TTCT for MIBC. Incorporating mpMRI ahead of TURBT into the standard pathway was beneficial for all patients with suspected MIBC.