Study of Prediagnostic Selenium Level in Toenails and the Risk of Advanced Prostate Cancer

Abstract

Background:In a recent randomized intervention trial, the risk of prostate cancer for men receiving a daily supplement of 200 µg selenium was one third of that for men receiving placebo. By use of a nested case-control design within a prospective study, i.e., the Health Professionals Follow-Up Study, we investigated the association between risk of prostate cancer and prediagnostic level of selenium in toenails, a measure of long-term selenium intake. Methods: In 1986, 51 529 male health professionals aged 40-75 years responded to a mailed questionnaire to form the prospective study. In 1987, 33 737 cohort members provided toenail clippings. In 1988, 1990, 1992, and 1994, follow-up questionnaires were mailed. From 1989 through 1994, 181 new cases of advanced prostate cancer were reported. Case and control subjects were matched by age, smoking status, and month of toenail return. Selenium levels were determined by neutron activation. All P values are twosided. Results: The selenium level in toenails varied substantially among men, with quintile medians ranging from 0.66 to 1.14 µg/g for control subjects. When matched case-control data were analyzed, higher selenium levels were associated with a reduced risk of advanced prostate cancer (odds ratio [OR] for comparison of highest to lowest quintile = 0.49; 95% confidence in-terval [CI] = 0.25-0.96; P for trend = .11). After additionally controlling for family history of prostate cancer, body mass index, calcium intake, lycopene intake, saturated fat intake, vasectomy, and geographical region, the OR was 0.35 (95% CI = 0.16-0.78; P for trend = .03). Conclusions: Our results support earlier findings that higher selenium intakes may reduce the risk of prostate cancer. Further prospective studies and randomized trials of this relationship should be conducted. [J Natl Cancer Inst 1998;90:1219-24]

Trace elements in nails as biomarkers in clinical research

“…Studies also examined toenail Se in relation to risk of prostate cancer. The results were inconsistent and inconclusive based on the current evidence [17][18][19][20][21][22][23]. Some studies have related toenail Se to other cancers [24][25][26] In addition, nail specimens were used as biomarkers for other trace elements in cancer studies.…”

Selenium and Vitamin E Cancer Prevention Trial

“…5 A recent nested case-control study found that the risk of advanced prostate cancer was reduced by one-half to two-thirds for men with the highest selenium status. 11,12 Enthusiasm for selenium in the prevention of prostate cancer comes from Nutrional Prevention of Cancer Study. 4 In this study, 1312 subjects with a prior history of skin cancer were randomized to receive 200 µg/day of selenium in the form of selenized yeast or placebo and had their progress followed for an average of 4.5 years for the development of basal or squamous cell carcinoma of the skin and other cancers.…”

Correlation between selenium concentrations and glutathione peroxidase activity in serum and human prostate tissue

“…While most observational studies have shown an inverse association between serum selenium and prostate cancer risk [1][2][3][4][5][6][7][8][9][10], results from two clinical trials are mixed [11,12]. The Nutrition Prevention of Cancer Trial (NPCT) showed a strong protective effect, limited to men with low baseline serum selenium concentrations, while the Selenium and Vitamin E Trial (SELECT), one of the largest cancer prevention trials conducted to date, found no effect of selenium supplementation on prostate cancer.…”