Description of a cruciferous vegetable intervention trial to test the efficacy of a maintenance component to reduce bladder cancer recurrence and progression.

BACKGROUND: Bladder cancer is primarily (70-80 %) diagnosed at non-muscle invasive stages (NMIBC), which can be removed but typically recurs (up to 75 %) and progresses, necessitating active surveillance and high cost of care. Treatment options are limited. Built on our preclinical findings on the role of isothiocyanates (ITCs) from cruciferous vegetables (cruciferae) in bladder cancer, we developed and tested an intervention (POW-R Health) that increased cruciferae intake and urinary ITC from 6 to 24 months to the levels hypothesized to inhibit cancer growth. To ensure the intervention's impact on NMIBC prognosis, our goal is to sustain urinary ITC levels from baseline to 24 months, the time window when the majority of NMIBCs recur.

OBJECTIVES: To develop a maintenance component to our dietary intervention and test its sustained impact on cruciferae intake and urinary ITC levels through 24 months in NMIBC survivors.

METHODS: After developing the maintenance component, we will conduct a randomized controlled trial with 344 NMIBC survivors to compare our intervention with a maintenance component (POW-R Health + Maintenance) vs. POW-R Health alone (POW-R Health Core). All participants will receive a 6-month dietary intervention, with half randomized to receive an additional 18-month maintenance component. Assessments will occur at baseline, 6, 12, 18, and 24 months.

DISCUSSION: POW-R Health is a scalable intervention that could meaningfully impact bladder cancer survivorship. If shown to impact outcomes, POW-R Health would be the first non-pharmacological dietary preventative strategy for cancer recurrence and progression, providing a cost-effective and easily accessible intervention to improve NMIBC survivorship.