A Randomized, Double Blind, Placebo Controlled Clinical Trial of Supplementation of L-Selenomethionine in Patients With Prostate Cancer Prior to Prostatectomy or Brachytherapy (Se Pre-Prostatectomy/Pre-Brachytherapy Trial)
- To investigate the down-regulation of the androgen receptor using tissue samples from
patients with stage I or II prostate cancer treated with selenomethionine for 8-9 weeks
prior to undergoing prostatectomy or brachytherapy.
- To evaluate the down regulation of a number of genes regulated by the androgen receptor
(i.e., prostate-specific antigen, kallikrein 2, cell division cycle 6, and
dehydrocholesterol reductase 24) using tissue samples from these patients.
- To evaluate the down-regulation of haptic nuclear factor 3-alpha using tissue samples
from these patients.
- To evaluate whether the thiol methyltransferase phenotype modifies the prostatic
response to short-term selenomethionine supplementation in these patients.
- To use quantitative nuclear morphometry to index cellular abnormality in tissue samples
as measured by nuclear texture (e.g., total optical density, nuclear area, mean nuclear
density, and optical heterogeneity).
OUTLINE: Patients are stratified according to planned treatment (brachytherapy vs
prostatectomy). Patients are randomized to 1 of 2 treatment arms.
- Arm I: Patients receive oral selenomethionine once daily for 8-9 weeks. Patients then
undergo prostatectomy or brachytherapy.
- Arm II: Patients receive oral placebo once daily for 8-9 weeks. Patients then undergo
prostatectomy or brachytherapy.
Blood samples are collected at baseline and on the day of prostatectomy or brachytherapy.
Samples are analyzed for selenium accumulation by atomic absorption spectrophotometry.
Additional blood samples are stored for future analysis of alpha tocopherol, lycopene, and
other vitamin levels, as well as oxidative stress biomarkers. Selenium accumulation is also
evaluated in toenail samples at baseline to assess long-term selenium status. Prostate
tissue samples are obtained during prostatectomy or brachytherapy and analyzed for RNA and
expression of selenium-linked biomarkers (e.g., androgen receptor, prostate-specific
antigen, kallikrein 2, cell division cycle 6, dehydrocholesterol reductase 24, and haptic
nuclear factor 3 alpha) by quantitative reverse transcription (RT)-PCR. Biomarker expression
is compared in both prostatectomy and brachytherapy specimens.
Allocation: Randomized, Masking: Double-Blind, Primary Purpose: Treatment
Quantity of androgen receptor message expression
James L. Mohler, MD
Roswell Park Cancer Institute
United States: Federal Government