Prostate Cancer Prevention Trial

Finasteride reduces serum prostate-specific antigen concentrations (60). In participants in the Prostate Cancer Prevention Trial who had an end of study biopsy (928... 

Etzioni RD, Howlader N, Shaw PA, Ankerst DP, Penson DF, Goodman PJ, Thompson IM. Long-term effects of finasteride on prostate specific antigen levels results from the prostate cancer prevention trial. J Urol 2005 174(3) 877-81 [erratum 2071]. 

Klein, E.A., Thompson, I.M., Lippman, S.M., Goodman, P.J., Albanes, D., Taylor, P.R., and Coltman, C. 2001. SELECT the next prostate cancer prevention trial. Selenum and Vitamin E Cancer Prevention Trial. J. Urol. 166(4), 1311-1315. 

Considerable interest in preventing prostate cancer exists and several large chemoprevention trials are sponsored and ongoing by the National Cancer Institute. The first large chemoprevention trial in prostate cancer, the Prostate Cancer Prevention Trial (PCPT), began in 1993 and randomized 18,881 men older than 55 years with a low risk of prostate cancer (PSA = 3 ng/mL) to receive 5 mg finasteride daily (a 5-a-reductase inhibitor) or placebo to determine if inhibition of DHT synthesis in the prostate for a prolonged period (7 years) would lead to a decreased incidence of prostate cancer. " Finasteride is currently used in the treatment of BPH. 

Marberger M, Adolfsson J, Borkowski A, et al. The clinical implications of the prostate cancer prevention trial. BJU Int 2003 92 667-671. 

Brawley OW, Parnes H. 2000. Prostate cancer prevention trials in the USA. Eur J Cancer 36 1312-1315. 

The 5a-reductase inhibitors have been discussed previously (see Benign Prostatic Hyperplasia results of the Prostate Cancer Prevention Trial (128) for finasteride showed a 25% relative risk reduction in prostate cancer in men aged 55 years or older, albeit at an increased risk of invasive tumors (129). The risk of invasive tumors may outweigh the benefit of these agents. The 5a-reductase inhibitors have not been proven to be effective as chemoprevention against clinically significant prostate cancer. 

National Cancer Institute. The prostate cancer prevention trial. Available at http //www.cancer.gov/pcpt. 

Thompson IM, Pauler Ankerst D et al. (2007) Prediction of prostate cancer for patients receiving finasteride results from the Prostate Cancer Prevention Trial. J Clin Oncol... 

Kristal AR, Till C, Platz EA, Song X, King IB, Neuhouser ML, Ambrosone CB, Thompson IM (2011) Serum lycopene concentration and prostate cancer risk results from the prostate cancer prevention trial. Cancer Epidemiol Biomarkers Prev 20 638-646... 

A major concern associated with clinical trials designed to evaluate the health effects of micronutrients (as well as other dietary supplements and drugs) is that participants might take additional micronutrient supplements, which could influence trial outcomes. In the Prostate Cancer Prevention Trial (PCPT) of the drug finasteride, for example, almost half of the participants reported using a multivitamin/ mineral supplement, about one-third used single supplements of either vitamin C or E, and one in five used calcium supplements. Very little evidence is available on how individual micronutrient substances may interact with one another to influence health outcomes. For minerals, particularly, supplementation with one mineral may compromise the bioavailability of another. Also, much remains to be learned about how individual genetic susceptibilities may influence the health-related effects of micronutrient... 

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