Association between selenium and lycopene supplementation and incidence of prostate cancer: Results from the post-hoc analysis of the procomb trial

Background: Many potential chemopreventive agents have been used in PCa prevention, including selenium (Se) and lycopene (Ly). However, their role has been matter of debate over the years, due to potential of promotion of PCa. Purpose: In this study we aimed at evaluating the incidence risk of prostate cancer (PCa) in a cohort of patients treated with Se and Ly. Methods: The Procomb trial design has been previously published (ISRCTN78639965). From April 2012 to April 2014 209 patients were followed and underwent prostate biopsy when PSA >= 4 ng/ml and/or suspicion of PCa. The all cohort was composed by patients treated with Se and Ly (Group A = 134 patients) and control (Group B = 75 patients). Results: During the follow-up time of 2 years, a total of 24 patients (11.5%) underwent prostate biopsy, of which 9 (4.3%) where diagnosed with PCa and 15 (7.2%) where diagnosed with benign prostatic hyperplasia. We did not observe statistical differences in terms of mean changes of PSA between the two groups (p-value for trend = 0.33). The relative risk (RR) for PCa was 1.07 and 0.89 in group A and B, respectively (p = 0.95). At the multivariate Cox regression analysis supplementation with Se and Ly was not associated with greater risk of PCa (hazard ratio: 1.38; p = 0.67). Conclusion: In this analysis we did not show evidences supporting a detrimental role of Selenium and Lycopene supplementation in increasing PCa after 2 years of therapy, nor supporting a protective role.