Oral selenium supplementation has no effect on prostate-specific antigen velocity in men undergoing active surveillance for localized prostate cancer.
The Nutritional Prevention of Cancer trial showed a 52% lower incidence of prostate cancer in men supplemented with selenium. As a result, our study was designed to assess whether selenium supplementation attenuates the progression of prostate cancer. A phase 2 randomized, double-blind, placebo-controlled clinical trial was conducted in men with localized nonmetastatic prostate cancer who had elected to forgo active treatment and be followed by active surveillance. A total of 140 men were randomized to placebo (n = 46), 200 microg/d (n = 47), or 800 microg/d (n = 47) selenium p.o. (as selenized yeast) and followed every 3 months for up to 5 years. Prostate-specific antigen (PSA) velocity was used as a marker of prostate cancer progression and was estimated using mixed-effects regression. Adjusting for age, body mass index, baseline selenium, smoking, baseline PSA, race, PSA method, and Gleason score, PSA velocities for the 200 microg/d and 800 microg/d treatment groups were not statistically significantly different from placebo (P = 0.32 and P = 0.61, respectively). In the highest quartile of baseline selenium, men supplemented with 800 microg selenium showed statistically significantly higher PSA velocity as compared with placebo (P = 0.018). Selenium supplementation did not show a protective effect on PSA velocity in subjects with localized prostate cancer. On the contrary, supplementation with high-dose selenium was observed to be a risk factor for increased PSA velocity in men with high baseline plasma selenium concentrations.
Stratton
M Suzanne
MS
Arizona Cancer Center, University of Arizona, Tucson, 85724, USA.
Algotar
Amit M
AM
Ranger-Moore
James
J
Stratton
Steven P
SP
Slate
Elizabeth H
EH
Hsu
Chiu-Hsieh
CH
Thompson
Patricia A
PA
Clark
Larry C
LC
Ahmann
Frederick R
FR
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002277:Carcinoma / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D019587:Dietary Supplements / Q000009:adverse effects; D018450:Disease Progression; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D017430:Prostate-Specific Antigen / Q000097:blood / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D012643:Selenium / Q000008:administration & dosage* / Q000009:adverse effects
D010919:Placebos; D017430:Prostate-Specific Antigen; D012643:Selenium