Table 1.

Summary of clinical trials of selenium for prostate cancer prevention

Baseline plasma/serum Se (μg/L)Baseline PSA (μg/L)Form of SeDaily supplementAdjusted HR Se vs. placeboReference
NPCTTertiles (n)≤4 (624)Selenized yeast200 μgPlasma Se tertilesDuffield-Lillico et al. (6)
 ≤106.4 (317)>4 (70)(Se-yeast)≤106.4: 0.14
 106.8–123.3 (305) 106.8–123.3: 0.33
 >123.2 (305) >123.2: 1.14
Overall median: 113PSA
≤4: 0.33
>4 0.95
SELECTMedians of 4 treatment groups: 137.6, 135.9, 135.0, 136.4; Overall median: 135Selection criterion ≤ 4L-seleno-methionine (Se-Met)200 μgSeMet: 1.09Klein et al. (7)
SeMet + Vti E: 1.05
Phase III trial in men with HGPINMedians (n)
Se (46): 138.1<4 (40%)Se-Met200 μgRR: 0.97Marshall et al. (8)
Placebo (51): 135.24–10 (60%)
Phase III trial in high-risk menMeans of 3 treatment groups: 124.5, 126.6, 127.2; Overall mean: 126.1Selection criterion > 4Se-yeast200 or 400 μg200 μg: 0.94Algotar et al. (9)
400 μg: 0.90
Baseline Toenail Se (μg/g)
SELECTQuintile cutoffs: 0.758, 0.832, 0.901, and 1.003Selection criterion ≤ 4L-seleno-methionine (Se-Met)200 μgSe+Vitamin E, in quintiles 4 and 5 combined: 2.24Kristal et al. (10)
Overall mean: 0.89

NOTE: Underlined values indicate the adjusted HR, comparing Se with placebo. Bold and italicized values indicate statistically significant hazard ratios (P < 0.01).