Soy Protein in Preventing Recurrent Cancer in Patients Who Have Undergone Surgery for Stage II Prostate Cancer
RATIONALE: Soy protein may help prevent prostate cancer recurrence in patients who have undergone surgery for prostate cancer.
PURPOSE: This randomized phase II/III trial is studying how well soy protein works and compares it to a placebo in preventing recurrent cancer in patients who have undergone surgery for stage II prostate cancer.
|Prostate Cancer||Dietary Supplement: soy protein isolate Other: placebo||Phase 2 Phase 3|
|Study Design:||Allocation: Randomized
Primary Purpose: Treatment
|Official Title:||Randomized Placebo-Controlled Adjuvant Study of Prevention of Prostate Cancer Recurrence After Radical Prostatectomy by Soy Protein Isolate|
- Two-year PSA failure rate (as surrogate for recurrence)
- Time to PSA failure
- Isoflavone uptake or compliance as measured by serum isoflavone concentration
- Serum total cholesterol levels
- Steroid hormone axis as measured by serum testosterone, estradiol, and SHBG levels
- Thyroid activity as measured by serum T3 and T4 levels
- Apoptotic activity as measured by serum soluble Fas and Fas-ligand levels
- Angiogenesis as measured by serum VEGF and bFGF levels
- Oxidative stress as measured by serum 8-isoprostane levels
- IGF axis as measured by serum IGF-1 and IGFBP-3 levels
- Equol production as measured by serum equol concentration
|Study Start Date:||December 2006|
|Study Completion Date:||July 2013|
|Primary Completion Date:||September 2011 (Final data collection date for primary outcome measure)|
Experimental: Arm I
Patients receive an oral soy protein isolate beverage once daily.
Dietary Supplement: soy protein isolate
Placebo Comparator: Arm II
Patients receive an oral casein placebo beverage once daily.
- Determine whether soy protein isolate reduces the PSA failure rate and time to PSA failure within 2 years following radical prostatectomy in patients who are at high risk for prostate cancer recurrence.
- Determine the effects of soy protein isolate on intermediate biomarkers of steroid hormone axis (testosterone, estradiol, and SHBG) and thyroid activity (T3 and T4).
- Determine the effects of soy protein isolate on intermediate biomarkers of apoptosis (soluble Fas and Fas-ligand), angiogenesis (VEGF and bFGF), antioxidant activity (8-isoprostanes), and IGF axis (IGF-1 and IGFBP-3).
- Compare patients who are equol producers to those who are non-producers.
OUTLINE: This is a multicenter study. Patients are stratified according to hospital/clinic site (NYU vs UIC or Jesse Brown VA Medical Center vs other sites), number of high-risk characteristics (1 vs > 1), and race (African American vs non-African American [i.e., non-Hispanic White, Hispanic, Asian, and other]). Patients are randomized to 1 of 2 treatment arms.
- Arm I: Patients receive an oral soy protein isolate beverage once daily.
- Arm II: Patients receive an oral casein placebo beverage once daily. Treatment in both arms continues for up to 2 years in the absence of disease progression or unacceptable toxicity.
Blood samples are collected periodically for biomarker laboratory studies. Samples are analyzed to measure PSA levels by Tosoh PSA assay; cholesterol levels; isoflavone and equol concentrations by HPLC and ESA; and indicators of steroid hormone axis (testosterone, estradiol, and SHBG), indicators of thyroid activity (T3 and T4), indicators of apoptosis (soluble Fas and Fas-ligand), indicators of angiogenesis (VEGF and bFGF), indicators of oxidative stress (8-isoprostanes), and indicators of IGF axis (IGF-1 and IGFBP-3) by ELISA.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00765479
|United States, Illinois|
|University of Illinois Cancer Center|
|Chicago, Illinois, United States, 60612-7243|
|Principal Investigator:||Maarten C. Bosland, DVSc, PhD||University of Illinois at Chicago|
|OverallOfficial:||Roohollah Sharifi, MD||University of Illinois at Chicago|