Vitamin E, Selenium, and Soy Protein in Preventing Cancer in Patients With High-Grade Prostate Neoplasia

Sponsor

NCIC Clinical Trials Group (Other)

Overall Status

Completed

CT.gov ID

NCT00064194

Collaborator

(none)

310

Enrollment

Locations

Actual Duration (Months)

103.3

Patients Per Site

1.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Precancerous/Nonmalignant Condition Prostate Cancer	Dietary Supplement: selenium Dietary Supplement: soy protein isolate Dietary Supplement: vitamin E	Phase 3

Detailed Description

OBJECTIVES:

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.

Study Design

Study Type:

Interventional

Actual Enrollment :

310 participants

Allocation:

Randomized

Masking:

Triple (Participant, Care Provider, Investigator)

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

Actual Study Start Date :

Nov 28, 2001

Actual Primary Completion Date :

Apr 30, 2008

Actual Study Completion Date :

Apr 30, 2008

Outcome Measures

Primary Outcome Measures

Eligibility Criteria

Criteria

Ages Eligible for Study:

N/A to 120 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

DISEASE CHARACTERISTICS:

Histologically confirmed high-grade prostatic intraepithelial neoplasia (HGPIN)
No evidence of invasive prostate cancer by at least 2 biopsies within the past 18 months
At least 1 biopsy must show evidence of HGPIN within the past 6 months
No prior invasive prostate cancer

PATIENT CHARACTERISTICS:

Age

Not specified

Performance status

Not specified

Life expectancy

More than 5 years

Hematopoietic

Platelet count at least 75,000/mm^3
No coagulopathies

Hepatic

Bilirubin no greater than 2 times upper limit of normal (ULN)
PT (INR) no greater than 1.5 times ULN
PTT no greater than 1.5 times ULN
No hepatic insufficiencies

Renal

Creatinine no greater than 2 times ULN
No renal insufficiencies

Other

No prior nonmelanoma skin cancer (e.g., squamous cell or basal cell carcinoma)
No other malignancy within the past 5 years except superficial bladder cancer
No known bowel malabsorption
No dietary behavior (e.g., morbid obesity or eating disorders) that would limit adherence to study therapy
No major illness, including psychiatric illness, that would preclude study compliance and follow-up

PRIOR CONCURRENT THERAPY:

Biologic therapy

Not specified

Chemotherapy

Not specified

Endocrine therapy

More than 3 months since prior androgen therapy
More than 3 months since prior hormonal therapy for benign prostatic hyperplasia (e.g., finasteride)
No concurrent finasteride
No concurrent androgen therapy

Radiotherapy

More than 2 years since prior radiotherapy to the pelvic region

Surgery

Not specified

Other

More than 2 weeks since prior supplemental vitamin E or selenium
No other concurrent vitamin E (greater than 100 IU/day), selenium, or soy protein isolate (more than 2 servings/week)
No other concurrent treatment for high-grade prostatic intraepithelial neoplasia

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Nova Scotia Cancer Centre	Halifax	Nova Scotia	Canada	B3H 1V7
2	Toronto Sunnybrook Regional Cancer Centre	Toronto	Ontario	Canada	M4N 3M5
3	Princess Margaret Hospital	Toronto	Ontario	Canada	M5G 2M9