Effects of Dietary Soy on Biomarkers of Prostate Cancer: A Prospective Phase II Study
Trial Snapshot
- Phase
- Phase 2
- Status
- Completed
- Enrollment
- 26
- Locations
- 5
- Primary Endpoint
- Reduction of prostatic cellular proliferation rates by 50% as measured by Ki-67
Study Overview
Brief Summary
RATIONALE: Soy protein supplement may prevent or delay the development of prostate cancer in patients who have elevated prostate-specific antigen (PSA) levels.
PURPOSE: Randomized phase II trial to determine the effectiveness of soy protein supplement in preventing prostate cancer in patients who have elevated PSA levels.
Detailed Description
OBJECTIVES:
- Compare the reduction in the rate of prostatic cellular proliferation in patients with an elevated PSA (5 to 10 ng/mL) and a negative biopsy for prostate cancer when treated with daily soy protein supplements vs placebo.
- Compare the effect of these regimens on additional biomarkers of prostate cancer (PSA, high-grade prostate intraepithelial neoplasia, induction of apoptosis, sex steroid receptor expression, and loss of glutathione S-transferase-pi) in these patients.
- Compare the effect of these regimens on quality of life, including urinary and sexual function, in these patients.
OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to race (Caucasian vs African American). After 2 weeks of daily oral placebo, patients are randomized to 1 of 2 arms.
- Arm I: Patients receive oral soy protein supplement daily for 12 months.
- Arm II: Patients receive oral placebo daily for 12 months. Quality of life is assessed at baseline and at 6 and 12 months.
PROJECTED ACCRUAL: A total of 160 patients (80 per arm) will be accrued for this study within 12 months.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Prevention
- Masking
- Double (Participant, Care Provider)
Eligibility Criteria
- Ages
- 50 Years to — (Adult, Older Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •DISEASE CHARACTERISTICS:
- •Histologically confirmed absence of prostate cancer
- •Atypical adenomatous hyperplasia or prostatic intraepithelial neoplasia (high-grade or low-grade) allowed
- •Abnormal baseline transrectal ultrasound and digital rectal exam allowed
- •Biopsy may be before or after study entry, but must be within the past 90 days
- •PSA 5-10 ng/mL
- •PATIENT CHARACTERISTICS:
- •50 and over
- •Performance status:
- •Life expectancy:
- •Not specified
- •Hematopoietic:
- •Not specified
- •Not specified
- •Not specified
- •No known allergy to soy protein or milk protein
- •No invasive cancer within the past 5 years except non-melanoma skin cancer
- •PRIOR CONCURRENT THERAPY:
- •Biologic therapy:
- •Not specified
- •Chemotherapy:
- •Not specified
- •Endocrine therapy:
- •No prior hormonal therapy
- •No prior finasteride
- •No concurrent hormonal therapy
- •No concurrent finasteride
- •Radiotherapy:
- •Not specified
- •At least 6 months since prior transurethral resection of the prostate
- •No prior orchiectomy
- •No concurrent orchiectomy
- •No other concurrent soy products
Exclusion Criteria
- Not provided
Arms & Interventions
soy protein + isoflavones
Intervention: soy protein isolate (Dietary Supplement)
casein proteins
Intervention: casein proteins (Dietary Supplement)
Outcomes
Primary Outcomes
Reduction of prostatic cellular proliferation rates by 50% as measured by Ki-67
Time Frame: 12 months
Secondary Outcomes
No secondary outcomes reported