Multivitamin use and risk of prostate cancer recurrence: Data from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE).

Abstract

70 Background: Multivitamin (MV) use is common among men with prostate cancer (PCa). Yet, data on MV use and risk of PCa recurrence are limited. Methods: We conducted a prospective study among 1,373 men with non-metastatic PCa to examine whether MV use after diagnosis was associated with risk of recurrence. Participants completed a comprehensive lifestyle survey a median of 2 y after diagnosis and were followed through 2016. We defined an event of recurrence as the first of the following: PCa death, bone metastasis from PCa, biochemical recurrence, or initiation of secondary treatment. Multivariate Cox Proportional Hazards regression models were used to calculate hazards ratios (HRs) and 95% confidence intervals (CI) for the association between MV use and PCa recurrence. We adjusted for time between diagnosis and the survey, age at diagnosis, Gleason grade, clinical T-stage, PSA at diagnosis, smoking, BMI, walking pace, and primary treatment. We also explored whether age at diagnosis, BMI, time since diagnosis, smoking, or clinical features (grade, stage, treatment) modified the association between MV use and recurrence. Results: We observed 142 events of PCa recurrence over a median follow-up of 10 y; 858 (62%) men were current MV users, 216 (16%) were past users, and 299 (22%) were never users. Overall, MV use was not associated with risk of PCa recurrence (current vs. never HR: 0.69; 95% CI: 0.45, 1.07; p-trend: 0.09). However, long-term MV users (≥10 y; n = 396) had a 56% lower risk of PCa recurrence compared to never users (HR: 0.44; 95% CI: 0.25, 0.78; p-trend: 0.006). Additionally, treatment modified the association between MV use and risk of PCa recurrence ( p-interaction: 0.02). Among the 845 men who had a radical prostatectomy (RP), current MV users had a 44% lower risk of PCa recurrence compared to past/never users (HR: 0.56; 95% CI: 0.34, 0.91; p-value: 0.02). MV use was not associated with risk of PCa recurrence among the 441 men who did not have a RP. Conclusions: Long-term MV use may be associated with lower risk of PCa recurrence.