Vitamin E, Selenium, and Soy Protein in Preventing Cancer in Patients With High-Grade Prostate Neoplasia
RATIONALE: Chemoprevention therapy is the use of certain substances to try to prevent the development or recurrence of cancer. Vitamin E, selenium, and soy protein may be effective in preventing the development of prostate cancer.
PURPOSE: Randomized phase III trial to study the effectiveness of combining vitamin E, selenium, and soy protein in preventing prostate cancer in patients who have high-grade prostate neoplasia.
Dietary Supplement: selenium
Dietary Supplement: soy protein isolate
Dietary Supplement: vitamin E
|Study Design:||Allocation: Randomized
Primary Purpose: Prevention
|Official Title:||A Double-Blind, Placebo-Controlled, Randomized Study Of Combination Vitamin E, Selenium And Soy Protein Product In Subjects With High Grade Prostatic Intraepithelial Neoplasia|
|Study Start Date:||November 2001|
|Study Completion Date:||April 2008|
- Determine whether nutritional supplementation with soy protein isolate, vitamin E, and selenium can delay the time to development of invasive prostate cancer (disease-free survival) in patients with high-grade prostatic intraepithelial neoplasia.
- Determine the effect of this supplementation on intermediate endpoints that may reflect a lessened risk of invasive prostate cancer (e.g., serum PSA levels, hormone levels, lycopene, malondialdehyde, vitamin E, and reduced thiol groups) in these patients.
- Determine the safety of this supplementation in these patients.
OUTLINE: This is a randomized, double-blind, multicenter study. Patients are stratified according to participating center. Patients are randomized to 1 of 2 treatment arms.
- Arm I: Patients receive oral vitamin E, oral selenium, and oral soy protein isolate twice daily.
- Arm II: Patients receive oral placebo twice daily. In both arms, treatment continues for 3 years in the absence of invasive prostate cancer (demonstrated on biopsy) or unacceptable toxicity.
Patients are followed every 3 months for 1 year and then every 6 months for 2 years.
PROJECTED ACCRUAL: A total of 306 patients (153 per treatment arm) will be accrued for this study within 6 years.
|Canada, Nova Scotia|
|Nova Scotia Cancer Centre|
|Halifax, Nova Scotia, Canada, B3H 1V7|
|Princess Margaret Hospital|
|Toronto, Ontario, Canada, M5G 2M9|
|Toronto Sunnybrook Regional Cancer Centre|
|Toronto, Ontario, Canada, M4N 3M5|
|Study Chair:||Neil Fleshner||Princess Margaret Hospital, Canada|