Changes in serum proteomic patterns by presurgical alpha-tocopherol and L-selenomethionine supplementation in prostate cancer.
BACKGROUND
Evidence of the chemopreventive effects of the dietary antioxidants alpha-tocopherol (vitamin E) and l-selenomethionine (selenium) comes from secondary analysis of two phase III clinical trials that found treatment with these antioxidants reduced the incidence of prostate cancer. To determine the effects of selenium and vitamin E in blood and prostate tissue, we undertook a preoperative feasibility study complementary to the currently ongoing Selenium and Vitamin E Cancer Prevention Trial.


METHODS
Forty-eight patients with clinically localized prostate cancer enrolled on this 2 x 2 factorial design study were randomized to take selenium, vitamin E, both, or placebo for 3 to 6 weeks before prostatectomy. Sera were collected from patients before and after dietary supplementation. Thirty-nine patients were evaluable, and 29 age-matched disease-free men served as controls. Mass profiling of lipophilic serum proteins of lower molecular weight (2-13.5 kDa) was conducted, and mass spectra data were analyzed using custom-designed software.


RESULTS
Weighted voting analyses showed a change in sera classification from cancerous to healthy for some patients with prostate cancer after dietary intervention. ANOVA analysis showed significantly different treatment effects on prediction strength changes among the four groups at a 95% confidence level. Eliminating an outlying value and performing post hoc analysis using Fisher's least significant difference method showed that effects in the group treated with the combination were significantly different from those of the other groups.


CONCLUSIONS
In sera from patients with prostate cancer, selenium and vitamin E combined induced statistically significant proteomic pattern changes associated with prostate cancer-free status.
Kim
Jeri
J
Department of Genitourinary Medical Oncology, University of Massachusetts Medical School, Lazare Research Building, Room 504, 364 Plantation Street, Worcester, MA 01605-2324, USA.
Sun
Peiyu
P
Lam
Ying-Wai
YW
Troncoso
Patricia
P
Sabichi
Anita L
AL
Babaian
Richard J
RJ
Pisters
Louis L
LL
Pettaway
Curtis A
CA
Wood
Christopher G
CG
Lippman
Scott M
SM
McDonnell
Timothy J
TJ
Lieberman
Ronald
R
Logothetis
Christopher
C
Ho
Shuk-Mei
SM
D000704:Analysis of Variance; D000975:Antioxidants / Q000627:therapeutic use*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000517:prevention & control*; D040901:Proteomics; D012645:Selenomethionine / Q000627:therapeutic use*; D014810:Vitamin E / Q000627:therapeutic use*
D000975:Antioxidants; D014810:Vitamin E; D012645:Selenomethionine