Prostate Cancer: Polyunsaturated Fatty Acids in Treating Patients With Prostate Cancer

RATIONALE: Polyunsaturated fatty acids are important for normal growth and development. One type, called omega-3 fatty acids (found in fish, fish oil, and some other foods), may keep prostate cancer from growing.

PURPOSE: This randomized clinical trial is studying polyunsaturated fatty acids in treating patients with prostate cancer undergoing prostate biopsy and/or surgery.

• Level of eIF2α phosphorylation and Gleason score in prostate biopsy samples (Part 1)
• Change in phosphorylation level of eIF2α before and after n–3 polyunsaturated fatty acid supplementation (Part 2)

• Relapse-free survival (Part 2)

OBJECTIVES:

• Compare fatty acid analysis of red blood cells, levels of eIF2α phosphorylation, and tumor differentiation grade, as measured by Gleason score, in patients undergoing prostate biopsy. (Part 1)
• Determine if neoadjuvant n–3 polyunsaturated fatty acids (PUFAs) induce phosphorylation of eIF2α in these patients. (Part 2)
• Compare eIF2α phosphorylation, Gleason score, and the time to prostate-specific antigen failure in prostate tumor samples obtained from the Gelb Center of the Dana-Farber Cancer Institute prostate tissue repository. (Part 3)

OUTLINE: This is a prospective study, followed by a randomized, double-blind, placebo-controlled study, followed by a retrospective study.

• Part 1: Patients undergo tumor biopsy and blood sample collection at baseline. Samples are analyzed by gas-liquid chromatography for determination of n–3 and n–6 polyunsaturated fatty acid (PUFA) red cell membrane concentrations. Biopsy samples are analyzed for eIF2α phosphorylation by immunohistochemistry. Some patients proceed to part 2.

• Part 2: Patients undergo blood sampling as in part 1 with additional tumor and blood collection on day 28. Patients are randomized to 1 of 2 treatment arms.

  • Arm I: Patients receive oral n–3 PUFAs (fish oil) once daily for 28 days prior to tumor resection.
  • Arm II (control): Patients receive oral n–6 PUFAs (corn oil) once daily for 28 days prior to tumor resection.
• Part 3: Tumor samples and associated pathology data (Gleason score) and clinical data (PSA values and patient's outcome) are obtained from a prostate tissue repository at the Gelb Center of the Dana-Farber Cancer Institute. Samples are analyzed to correlate eIF2α phosphorylation, Gleason scores, and time to PSA failure.

PROJECTED ACCRUAL: A total of 600 patients and 1,000 stored tissue samples will be accrued for this study.

DISEASE CHARACTERISTICS:

• Part 1: Patients undergoing prostate biopsy at Brigham and Women's Hospital (BWH), meeting the following criteria:

  • Prostate biopsy available for analysis
  • Able to access clinical information for follow-up studies
  • Able to donate 10 mL of blood for fatty acid analysis in red blood cells

  • No concurrent diagnoses that may interfere with measurements of fatty acids in red blood cell membranes, including the following:

    • Severe anemia (i.e., hemoglobin < 9 g/dL)
    • Familial dyslipoproteinemia
    • Liver cirrhosis
    • Advanced renal failure
    • Malabsorption syndrome
    • Other disease of lipid metabolism

• Part 2: Patients who participated in part 1 who were subsequently diagnosed with prostate cancer and are pursuing a total prostatectomy at BWH OR patients referred to BWH from independent physicians for prostate cancer surgery

  • Patients with indication for radical prostatectomy who refuse surgery or schedule it at a location other than BWH are ineligible
• Part 3: Tissue samples from the prostate tumor registry at the Dana-Farber Cancer Institute

PATIENT CHARACTERISTICS:

• See Disease Characteristics

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics