An inverse association has been observed between dietary intake of lycopene and the risk of prostate cancer. We investigated the effects of lycopene supplementation in patients with prostate cancer. Twenty-six men with newly diagnosed, clinically localized (14 T1 and 12 T2) prostate cancer were randomly assigned to receive 15 mg of lycopene (n = 15) twice daily or no supplementation (n = 11) for 3 weeks before radical prostatectomy. Biomarkers of differentiation and apoptosis were assessed by Western blot analysis on benign and malignant parts of the prostate gland. Prostatectomy specimens were entirely embedded, step-sectioned, and evaluated for pathological stage, Gleason score, volume of cancer, and extent of high-grade prostatic intraepithelial neoplasia. Plasma levels of lycopene, insulin-like growth factor-1 (IGF-1), IGF binding protein-3, and prostate-specific antigen were measured at baseline and after 3 weeks of supplementation or observation. Eleven (73%) subjects in the intervention group and two (18%) subjects in the control group had no involvement of surgical margins and/or extra-prostatic tissues 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 = 0.22). Diffuse involvement of the prostate by high-grade prostatic intraepithelial neoplasia was present in 10 (67%) subjects in the intervention group and in 11 (100%) subjects in the control group (P = 0.05). Plasma prostate-specific antigen levels decreased by 18% in the intervention group, whereas they increased by 14% in the control group (P = 0.25). Expression of connexin 43 in cancerous prostate tissue was 0.63 ± 0.19 absorbance in the lycopene group compared with 0.25 ± 0.08 in the control group (P = 0.13). Expression of bcl-2 and bax did not differ significantly between the two study groups. IGF-1 levels decreased in both groups (P = 0.0002 and P = 0.0003, respectively). The results suggest that lycopene supplementation may decrease the growth of prostate cancer. However, no firm conclusions can be drawn at this time because of the small sample size.
|Original language||English (US)|
|Number of pages||8|
|Journal||Cancer Epidemiology Biomarkers and Prevention|
|State||Published - 2001|
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