• Plasma levels of isoflavones and lycopene as measured by plasma analysis at baseline and post-study intervention [ Designated as safety issue: No ]
• Correlation of plasma and tissue levels of isoflavones and lycopene as measured by plasma and tissue analysis at baseline and post-study intervention [ Designated as safety issue: No ]
• Effect of isoflavones and lycopene on markers of disease progression as measured by prostate-specific antigen (PSA) levels at baseline and post-study intervention [ Designated as safety issue: No ]
• Effect of isoflavones and lycopene on serum steriod hormones as measured by sex-hormone-binding globulin, estradiol, and free testosterone at baseline and post-study intervention [ Designated as safety issue: No ]

• Plasma levels of isoflavones and lycopene as measured by plasma analysis at baseline and post-study intervention
• Correlation of plasma and tissue levels of isoflavones and lycopene as measured by plasma and tissue analysis at baseline and post-study intervention
• Effect of isoflavones and lycopene on markers of disease progression as measured by prostate-specific antigen (PSA) levels at baseline and post-study intervention
• Effect of isoflavones and lycopene on serum steriod hormones as measured by sex-hormone-binding globulin, estradiol, and free testosterone at baseline and post-study intervention

RATIONALE: Eating a diet rich in isoflavones, compounds found in soy foods, or lycopene, a substance found in tomatoes, may keep prostate cancer from growing. Giving isoflavones or lycopene before surgery may be an effective treatment for prostate cancer.

PURPOSE: Randomized clinical trial to compare the effectiveness of isoflavones with that of lycopene before surgery in treating patients who have stage I or stage II prostate cancer.

OBJECTIVES:

• Compare the effect of isoflavones vs lycopene prior to radical prostatectomy on intermediate biomarkers (e.g., indices of cell proliferation and apoptosis) in patients with localized prostate cancer.
• Compare the effects of these nutritional supplements on increases in plasma levels and tissue levels of these agents in these patients.
• Compare the effects of these nutritional supplements on changes in surrogate markers of disease progression (e.g., prostate-specific antigen levels) in these patients.
• Compare the effects of these nutritional supplements on changes in serum steroid hormones, estradiol, and free testosterone in these patients.
• Compare the magnitude of these changes in patients treated with these nutritional supplements vs patients in the control group.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to disease stage (stage I vs stage II) and presence of high-grade prostatic intraepithelial neoplasia. Patients are randomized to 1 of 7 treatment arms.

• Arms I-III: Patients receive 1 of 3 doses of oral isoflavones twice daily and a multivitamin once daily.
• Arms IV-VI: Patients receive 1 of 3 doses of oral lycopene twice daily and a multivitamin once daily.
• Arm VII: Patients receive a multivitamin once daily. Treatment in all arms continues for 4-6 weeks, until prostatectomy.

PROJECTED ACCRUAL: A total of 87 patients will be accrued for this study within 1 year.

• Dietary Supplement: lycopene
• Dietary Supplement: multivitamin
• Dietary Supplement: soy isoflavones
• Other: laboratory biomarker analysis
• Procedure: neoadjuvant therapy

DISEASE CHARACTERISTICS:

• Histologically confirmed localized prostate cancer

  • Stage I or II
• Scheduled prostatectomy between 4-6 weeks after initial biopsy

PATIENT CHARACTERISTICS:

Age:

• 45 to 80

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• No known history of hepatic disease

Renal:

• No known history of renal disease

Other:

• No known history of thyroid disease
• Body mass index no greater than 32
• Omnivorous diet
• No known allergy to study supplements
• No evidence of prostatitis or urinary tract infection
• No other prior malignancy except nonmelanoma skin cancer
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Not specified

Endocrine therapy:

• No concurrent thyroid hormone replacement medications

Radiotherapy:

• Not specified

Surgery:

• See Disease Characteristics

Other:

• At least 30 days since prior antibiotics
• At least 30 days since prior diet high in soy and/or lycopene products (e.g., greater than 40 mg soy/day and/or greater than 15 mg lycopene/day)
• No other concurrent nutritional supplements, including modular supplements with other carotenoids and isoflavones
• No prior or concurrent therapy for prostate cancer