Toenail selenium levels and the subsequent risk of prostate cancer: a prospective cohort study.

Abstract

Results of a randomized controlled trial have suggested a protective effect of selenium against prostate cancer. Few other prospective studies have been conducted to confirm or refute this. The association between prostate cancer and baseline toenail selenium level was evaluated in the Netherlands Cohort Study, conducted among 58,279 men, aged 55-69 years at entry. In September 1986, the cohort members completed a questionnaire on risk factors for cancer and provided toenail clippings for determination of baseline selenium status. After 6.3 years of follow-up, 540 incident prostate carcinoma cases and 1,211 subcohort members with complete toenail selenium data were available for case-cohort analyses. In multivariate survival analysis, an inverse association between toenail selenium level and prostate cancer risk was observed. Incidence rate ratios in increasing selenium quintiles were 1.00 (ref), 1.05, 0.69, 0.75, and 0.69 (95% confidence interval, 0.48-0.99), respectively (P-trend=0.008). This association persisted after exclusion of cases diagnosed during early follow-up. The inverse association was more pronounced in ex-smokers than current smokers, and unclear in never-smokers. Analysis of effect modification by intake of antioxidant vitamins C, E, and the carotenoids alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin showed a strong, significant interaction with beta-cryptoxanthin, and to a lesser extent with vitamin C. These results confirm the hypothesis that higher selenium intake may reduce prostate cancer risk. Future research on optimum dose level is needed.

• Authors: Piet A van den Brandt, Maurice P A Zeegers, Peter Bode, R Alexandra Goldbohm
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 12 Issue 9 Pg. 866-71 (Sep 2003) ISSN: 1055-9965 [Print] United States
• PMID: 14504196 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Cryptoxanthins
• Xanthophylls
• beta Carotene
• Vitamin E
• Carotenoids
• alpha-carotene
• Selenium
• Ascorbic Acid
• Lycopene

Topics

• Aged
• Antioxidants (administration & dosage)
• Ascorbic Acid (administration & dosage)
• Carotenoids (administration & dosage)
• Cohort Studies
• Cryptoxanthins
• Follow-Up Studies
• Humans
• Lycopene
• Male
• Middle Aged
• Nails (chemistry)
• Netherlands (epidemiology)
• Prospective Studies
• Prostatic Neoplasms (diagnosis, epidemiology)
• Risk Factors
• Selenium (analysis)
• Smoking (adverse effects)
• Surveys and Questionnaires
• Vitamin E (administration & dosage)
• Xanthophylls
• beta Carotene (administration & dosage, analogs & derivatives)