PHILADELPHIALycopene, the phytonutrient that produces the red color in tomatoes, showed beneficial effects on the prostate cancers of a group of men scheduled for prostatectomy, researchers reported at the American Association for Cancer Research annual meeting.
To our knowledge, this is the first report from a randomized, prospective clinical trial showing its efficacy against prostate cancer, said Omer Kucuk, MD, professor of medicine and oncology, Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit. Previous reports, he said, were largely epidemiologic studies showing an association between consumption of tomato products and decreased prostate cancer risk.
The researchers studied 26 men with localized prostate cancer who were scheduled to undergo radical prostatectomy. The study participants were randomly assigned to receive either 15 mg of lycopene as a pure tomato extract (Lyc-O-Mato capsules from LycoRed Company, Beer-Sheva, Israel) twice daily or no intervention for 3 weeks before the surgery. The glands were analyzed following surgery to determine any differences between the two study groups.
Dr. Kucuk said that serum and tissue lycopene levels increased significantly in the intervention group. The treated group had smaller tumors: 80% had tumors 4 cm3 or less in volume vs 45% of controls. In the treatment group, tumors were more likely to be confined to the prostate (73% vs 18%).
Decline in PSA Levels
Serum PSA levels declined by 18% in those who received lycopene, Dr. Kucuk said. In addition, the tumors in patients who consumed lycopene showed signs of regression and decreased malignancy, ie, less glandular involvement by prostatic intraepithelial neoplasia (PIN) and an increase in the expression of biomarkers of differentiation.
The results suggest that lycopene as tomato extract may not only help prevent prostate cancer, but also may be useful in treating prostate cancer, Dr. Kucuk said at a press conference. However, on the basis of this one small study, he would not recommend that men go to nutrition stores and supplement their diet with lycopene. As you know, there may be other studies in the future that may not find the same beneficial effect, he said.