Phase 3 clinical trial investigating the effect of selenium supplementation in men at high-risk for prostate cancer
ABSTRACT PURPOSE: This study was conducted to investigate the effect of Se supplementation on prostate cancer incidence in men at high risk for prostate cancer. METHODS: A Phase 3 randomized, double-blind, placebo-controlled clinical trial was conducted in 699 men at high risk for prostate cancer (prostate specific antigen (PSA) >4 ng/ml and/or suspicious digital rectal examination and/or PSA velocity >0.75 ng/ml/year), but with a negative prostate biopsy. Participants were randomized to receive daily oral placebo (N = 232), 200 µg selenium (N = 234), or 400 µg selenium (N = 233) as selenized yeast. They were followed every 6 months for up to 5 years. The time to diagnosis of prostate cancer was compared between treatment groups using the Cox proportional hazards model. RESULT: Compared to placebo, the hazard ratios [95% confidence intervals] for risk of developing prostate cancer in the selenium 200 µg/day or the selenium 400 µg/day group were 0.94 [0.52, 1.7] and 0.90 [0.48, 1.7], respectively. PSA velocity in the selenium arms was not significantly different from that observed in the placebo group (P = 0.18 and P = 0.17, respectively). CONCLUSION: Selenium supplementation appeared to have no effect on the incidence of prostate cancer in men at high risk. In conjunction with results of other studies, these data indicate that selenium supplementation may not have a role in prostate cancer chemoprevention. Prostate © 2012 Wiley Periodicals, Inc.
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ABSTRACT: Screening for prostate cancer by use of serum prostate specific antigen (PSA) remains controversial. In the recent Cochrane analysis, an attempt is made to clarify the issue by conducting a meta analysis of available randomized screening trials. Two large trials are considered to provide data of similar and sufficient quality to conduct a separate meta analysis. However, in the view of this author, this analysis fails because standard Cochrand quality criteria are not observed. Details are given and the outcome suggests that one of the trials, the European Randomized Study of Screening for Prostate Cancer (ERSPC) should be considered superior to the Prostate, Lung, Colon, Ovary screening trial (PLCO) conducted in the USA.Recent results in cancer research. Fortschritte der Krebsforschung. Progrès dans les recherches sur le cancer 01/2014; 202:59-63. DOI:10.1007/978-3-642-45195-9_7
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ABSTRACT: In vitro and in vivo preclinical results suggest that inhibition of polyamine synthesis inhibits the progression of prostate cancer. These findings has led to two clinical trials in patients at risk for invasive prostate cancer with difluoromethylornithine which specifically and irreversibly inhibits ornithine decarboxylase which catalyses the conversion of ornithine to putrescine the rate limiting step in polyamines synthesis. We have conducted a phase IIa one month and placebo randomized phase IIb 12 months trials in patients at increased risk for invasive prostate cancer. Favorable reduction in prostate polyamine levels and prostate volume was documented with no difference in clinical hearing changes. Patients with Gleason's VI lesions in a surveillance cohort would be appropriate candidates for a definitive risk reduction trial although the unavailability of validated biomarkers for invasive progression would require a large and lengthy study.Recent results in cancer research. Fortschritte der Krebsforschung. Progrès dans les recherches sur le cancer 01/2014; 202:115-120. DOI:10.1007/978-3-642-45195-9_14
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ABSTRACT: Chemopreventive effects of the essential trace element selenium against prostate cancer have been shown in preclinical models and human observational studies, but results from clinical trials have been disappointing. It appears that there is a threshold Se status below which improvement will decrease prostate cancer risk but above which supplemental Se may be deleterious. Different forms of selenium have different effects, and genetic and other factors modify selenium's chemopreventive potential. Identification of men most likely to benefit from Se status improvement could have significant public health benefits.Cancer Prevention Research 07/2014; 7(8). DOI:10.1158/1940-6207.CAPR-14-0197 · 5.27 Impact Factor