• Prostatic Carcinoma Apoptotic Index by TUNEL assay at time of prostatectomy [ Designated as safety issue: No ]
• Prostate-specific antigen by Hybritech assay at baseline and follow-up [ Designated as safety issue: No ]
• Total testosterone, sex hormone binding globulin, insulin-like growth factor (IGF), and IGF-binding protein-3, total cholesterol, and low-density lipoprotein cholesterol by ELISA assays at baseline and follow-up [ Designated as safety issue: No ]

• Prostatic Carcinoma Apoptotic Index by TUNEL assay at time of prostatectomy
• Prostate-specific antigen by Hybritech assay at baseline and follow-up
• Total testosterone, sex hormone binding globulin, insulin-like growth factor (IGF), and IGF-binding protein-3, total cholesterol, and low-density lipoprotein cholesterol by ELISA assays at baseline and follow-up

RATIONALE: A diet that is low in fat and/or high in flaxseed may slow or prevent disease progression of prostate cancer.

PURPOSE: Randomized phase II trial to study the effectiveness of a diet that is low in fat and/or high in flaxseed in slowing or preventing disease progression in patients who have newly diagnosed prostate cancer.

OBJECTIVES:

• Compare tumor proliferation in patients with newly diagnosed prostate cancer eating fat- and/or flaxseed-modified diets.
• Compare differences in histopathological markers associated with prostate cancer (rates of apoptosis, extent of high-grade prostatic intraepithelial neoplasia) among patients in these diet groups.
• Compare changes in serum prostate specific antigen among patients in these diet groups.
• Compare changes in hormone-related factors (total serum testosterone and free androgen index, insulin-like growth factor [IGF], and IGF-binding protein-3) among patients in these diet groups.
• Compare the effects of diet on nutritional biomarkers (levels of lignans in the urine and ejaculate, fatty acid profiles of erythrocytes and prostatic tissue) in these patients.
• Determine associations between dietary modification and changes in dietary biomarkers, hormonal intermediates, and study endpoints in these patients.

OUTLINE: This is a randomized study. Patients are stratified according to Gleason score (less than 7 vs at least 7) and race (black vs non-black). Patients are randomized to 1 of 4 diet groups.

• Arm I (Flaxseed-supplemented diet): Patients are instructed to incorporate ground flaxseed into their daily diets.
• Arm II (Low-fat diet): Patients are instructed on ways to achieve a diet with no greater than 20% of total energy from dietary fat.
• Arm III (Flaxseed-supplemented, low-fat diet): Patients are instructed as in arm I and arm II.
• Arm IV (Control diet): Patients are contacted weekly, but do not receive dietary counseling until after surgery.

All patients ingest the diets for at least 3 weeks and complete diet diaries until surgery. After surgery, all patients receive dietary counseling.

PROJECTED ACCRUAL: A total of 160 patients (40 per treatment arm) will be accrued for this study.

• Dietary Supplement: dietary intervention
• Dietary Supplement: flaxseed
• Procedure: neoadjuvant therapy

• Demark-Wahnefried W, Polascik TJ, George SL, Switzer BR, Madden JF, Ruffin MT 4th, Snyder DC, Owzar K, Hars V, Albala DM, Walther PJ, Robertson CN, Moul JW, Dunn BK, Brenner D, Minasian L, Stella P, Vollmer RT. Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery. Cancer Epidemiol Biomarkers Prev. 2008 Dec;17(12):3577-87.
• Demark-Wahnefried W, Robertson CN, Walther PJ, Polascik TJ, Paulson DF, Vollmer RT. Pilot study to explore effects of low-fat, flaxseed-supplemented diet on proliferation of benign prostatic epithelium and prostate-specific antigen. Urology. 2004 May;63(5):900-4.
• Lin X, Gingrich JR, Bao W, Li J, Haroon ZA, Demark-Wahnefried W. Effect of flaxseed supplementation on prostatic carcinoma in transgenic mice. Urology. 2002 Nov;60(5):919-24.

DISEASE CHARACTERISTICS:

• Histologically confirmed prostate cancer
• At least 3 weeks until planned prostatectomy (24 days between day 1 visit and surgery)
• Current diet that provides more than 30% of calories from fat

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Not specified

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

Other

• Mentally competent
• Able to speak and write English
• Must have telephone access

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• Not specified

Endocrine therapy

• No concurrent hormonal therapy

Radiotherapy

• Not specified

Surgery

• At least 2 weeks since prior prostate biopsy

Other

• At least 7 days since prior antibiotics
• No prior therapy for prostate cancer
• No concurrent dietary supplements initiated within the past 3 months or anticipated to begin during study except standard multivitamin/mineral preparations (e.g., One-A-Day, Theragran, or Centrum) that do not supply > 100% of the recommended daily allowance of any vitamin or mineral
• No other concurrent neoadjuvant therapies
• No other concurrent flaxseed consumption