Expediting muscle-invasive bladder cancer treatment using multiparametric MRI

13th February 2025

Multiparametric magnetic resonance imaging (mpMRI) for the initial staging of muscle-invasive bladder cancer (MIBC) is both feasible and beneficial in reducing treatment delays, a new study shows.

New bladder cancers are initially staged using transurethral resection of bladder tumour (TURBT), however, in the case of MIBC, this may delay the primary treatment. The study therefore investigated whether using flexible cystoscopic biopsy and mpMRI for initial staging would be more effective.

The researchers conducted a prospective open-label, randomised study within 17 UK hospitals between May 2018 and December 2021. Over 600 patients with suspected new bladder cancer were screened. A total of 143 patients were randomly assigned to one of two groups: 72 patients received the standard staging care with TURBT and 71 patients received mpMRI-staged care. The primary outcomes assessed were feasibility and the time to correct treatment (TTCT) for MIBC.

Feasibility was tested on 36 out of 39 participants who had suspected MIBC and were in the mpMRI group. The median TTCT for patients with MIBC was 53 days for the mpMRI group (with a confidence interval of 20-89 days) and was significantly shorter with mpMRI compared to 98 days for the TURBT group (confidence interval of 72-125 days).

For patients without MIBC, the TTCT was similar whether they underwent initial mpMRI or TURBT, and there were no significant differences in primary outcomes between the two groups. The median TTCT was 17 days for the mpMRI group and 14 days for the TURBT group. The researchers reported no serious adverse events in either group.

Secondary outcomes included TTCT for all recruited participants and for those confirmed to have non-MIBC. The correct treatment for non-MIBC was TURBT, while for MIBC it was either chemotherapy, radiotherapy, cystectomy or palliative care.

The findings showed that using mpMRI in the MIBC pathway reduced TTCT by 45 days compared to standard investigation. The researchers concluded that introducing mpMRI ahead of TURBT into the standard pathway was beneficial for all patients with suspected MIBC as it could improve clinical decision making and accelerate the time to treatment.

Reference
Bryan, R et al. Randomized Comparison of Magnetic Resonance Imaging Versus Transurethral Resection for Staging New Bladder Cancers: Results From the Prospective BladderPath Trial. JCO 0 2025, Jan. 14: DOI:10.1200/JCO.23.02398.

Pembrolizumab shows benefit in high-risk BCG non-responsive bladder cancer

24th February 2023

Pembrolizumab therapy in patients with high-risk, non-muscle-invasive bladder cancer unresponsive to BCG treatment shows anti-tumour activity

Data presented at the 2023 American Society for Clinical Oncology (ASCO) genitourinary cancer symposium, showed that pembrolizumab monotherapy in patients with Bacillus Calmette-Guerin (BGC) unresponsive, high-risk, non-muscle invasive bladder cancer, showed notable anti-tumour activity after roughly 45 months of follow-up.

The vast majority (75 to 80%) of newly diagnosed bladder cancers are categorised as non-muscle invasive cancers (NMIBC). BCG has been used in the treatment of NMIBC for many years although in roughly half of high-risk patients, intra-vesical BCG treatment fails and NMIBC persists or recurs early. In an earlier Phase II study (KEYNOTE-057), patients with histologically confirmed BCG-unresponsive carcinoma in situ with or without papillary tumours, treated with pembrolizumab monotherapy showed that the drug was both tolerable and demonstrated promising anti-tumour activity.

The data presented at the ASCO symposium relates to a second patient cohort from KEYNOTE-057 who had papillary tumours but without carcinoma in situ. These individuals received pembrolizumab at a dose of 200 mg every three weeks for less than 35 cycles. The primary endpoint as 12-month disease-free survival (DFS) as determined by central pathology and radiology review. Other outcomes explored included the 12-month DFS of any disease, progression-free survival (PFS) to worsening of grade, stage, or death as well as PFS to muscle invasion, metastasis, or death and finally, overall survival (OS).

Pembrolizumab and disease-free survival

A total of 132 patients with a median age of 72 years were included and who had received a median of 10 prior BCG instillations. The median follow-up was 45.4 months.

The 12-month DFS rate was 43.5 % and the median DFS was 7.7 months (95% CI 6.5 – 13.6). In addition, for any level of disease recurrence, the 12 month DFS was estimated as 41.7% with a median DFS of 6 months. The 12-month PFS to either invasive or metastatic disease or death was 88.2% with a median PFS of 46.2 months and the estimated overall survival rate at 12 months was 96.2%.

The authors concluded that patients with BCG unresponsive, non-carcinoma in situ papillary high risk NMIBC may benefit from pembrolizumab monotherapy.

Citation
Necchi A et al. Pembrolizumab (pembro) monotherapy for patients (pts) with high-risk non–muscle-invasive bladder cancer (HR NMIBC) unresponsive to bacillus Calmette–Guérin (BCG): Results from cohort B of the phase 2 KEYNOTE-057 trial. Abstract LBA442, GuCS 2023