Patient case: 70-year-old male with prostate cancer; genetic feature: PTEN

Clinical trial: Low-Fat Diet and/or Flaxseed in Preventing Prostate Cancer

Summary: 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.

Detailed description: 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.

Eligibility: 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

Relevance to patient case: not relevant