Nutritional Supplement With Fermented Soy in Men With an Elevated Risk of Prostate Cancer and Negative Prostate Biopsies: General and Oncological Results From the Prospective PRAECAP Trial

OBJECTIVE: To investigate the effect of a dietary supplement containing fermented soy on PSA, IPSS, changes in prostate volume and prostate cancer (PCa) development after a 6-month challenge in men at increased risk of PCa and negative previous biopsies. MATERIALS AND METHODS: Patients with an elevated risk of PCa, defined by either 1 of the following criteria: PSA >3 ng/mL, suspect lesion at digital rectal examination (DRE), suspect lesion at transrectal ultrasound (TRUS)/magnetic resonance imaging (MRI) and previous negative prostate biopsies (at least 8 cores) within 12 months before inclusion. Statistical analysis was carried out using a non-parametric 1-sided paired Wilcoxon rank sum test, chi-square test, and Fisher's exact test.

RESULTS: In this trial, 94 patients were eligible for analysis. A PSA response was detected in 81% of the cases. In 25.8% (24/93) of patients, a decrease of at least 3 points on the IPSS was observed. The median prostate volume did not statistically change after 6 months (P = .908). Patients with PSA modulation required fewer investigations and had fewer positive biopsies (P <.001) and significantly fewer ISUP ≥3 lesions (P = .02).

CONCLUSION: We observed a significantly lower PSA level after a 6-month challenge with a fermented soy-containing supplement, and an effect on IPSS in a subset of patients. Prescribing a fermented soy supplement in patients with an increased PCa risk could lead to a better selection of patients at real increased risk of having occult PCa.