Phase II randomized clinical trial of lycopene supplementation before radical prostatectomy

An inverse association has been observed between dietary intake of lycopene and the risk of prostate cancer. We investigated the effects of lycopene s upplementation in patients with prostate cancer. Twenty-six men with newly diagnosed, clinically localized (14 T-1 and 12 T-2) prostate cancer were ra ndomly assigned to receive 15 mg of lycopene (n = 15) twice daily or no sup plementation (n 11) for 3 weeks before radical prostatectomy. Biomarkers of differentiation and apoptosis were assessed by Western blot analysis on be nign and malignant parts of the prostate gland. Prostatectomy specimens wer e entirely embedded, step-sectioned, and evaluated for pathological stage, Gleason score, volume of cancer, and extent of high-grade prostatic intraep ithelial neoplasia. Plasma levels of lycopene, insulin-like growth factor-1 (IGF-1), IGF binding protein-3, and prostate-specific antigen were measure d at baseline and after 3 weeks of supplementation or observation. Eleven ( 73%) subjects in the intervention group and two (18%) subjects in the contr ol group had no involvement of surgical margins and/or extra-prostatic tiss ues with cancer (P = 0.02). Twelve (84%) subjects in the lycopene group and five (45%) subjects in the control group had tumors <4 ml in size (P = 0.2 2). Diffuse involvement of the prostate by high-grade prostatic intraepithe lial neoplasia was present in 10 (67%) subjects in the intervention group a nd in 11 (100%) subjects in the control group (P = 0.05). Plasma prostate-s pecific antigen levels decreased by 18% in the intervention group, whereas they increased by 14% in the control group (P = 0.25). Expression of connex in 43 in cancerous prostate tissue was 0.63 +/- 0.19 absorbance in the lyco pene group compared with 0.25 +/- 0.08 in the control group (P = 0.13). Exp ression of bcl-2 and bax did not differ significantly between the two study groups. IGF-I levels decreased in both groups (P = 0.0002 and P = 0.0003, respectively). The results suggest that lycopene supplementation may decrea se the growth of prostate cancer. However, no firm conclusions can be drawn at this time because of the small sample size.