• Effect on testosterone, dihydrotestosterone, dihydroepiandrosterone, estrogens, aromatase, parameters of the immune function, and circulating tumor cells [ Designated as safety issue: No ]
• Effect on PSA kinetics [ Designated as safety issue: No ]

RATIONALE: White button mushroom extract may stop or delay the development of recurrent prostate cancer.

PURPOSE: This phase I trial is studying the side effects and best dose of white button mushroom extract in treating patients with recurrent prostate cancer after local therapy.

OBJECTIVES:

Primary

• To assess the feasibility and toxicity of prolonged white button mushroom extract at six different dose levels in patients with biochemically recurrent, hormone-naive prostate cancer after local therapy.

Secondary

• To analyze the effect of this regimen on a variety of biomarkers including testosterone, dihydrotestosterone, dihydroepiandrosterone, estrogens, aromatase, parameters of immune function, and circulating tumor cells.
• To assess the effect of this regimen on PSA kinetics as a measure of disease activity in these patients.

OUTLINE: This is a dose-escalation study.

Patients receive oral white button mushroom extract twice daily on days 1-28. Courses repeat every 4 weeks in the absence of disease progression or unacceptable toxicity.

Blood and urine samples are collected periodically for pharmacokinetic, pharmacodynamic, and immunologic correlative studies. Plasma and urine samples are analyzed for quantification of conjugated unsaturated fatty acids via gas chromatography-mass spectometry. Plasma samples are analyzed for inhibition of aromatase via aromatase activity analysis and the effect of treatment on immune cytokines levels via immunobiologic assays. Peripheral blood mononuclear cells are analyzed for the effect of treatment on immune cell subsets and NK cell function via multi-parameter flow cytometry; effect of treatment on NK cell activation status via staining method; and measurement of circulating tumor cells via fluorescence microscopy, fiber-optic array scanning technology (FAST), or high-speed flow cytometry. Additional serum samples are collected for future studies.

Patients complete a diary listing days of administration of treatment and side effects.

• Drug: white button mushroom extract
• Other: chromatography
• Other: flow cytometry
• Other: immunologic technique
• Other: laboratory biomarker analysis
• Other: mass spectrometry
• Other: pharmacological study
• Other: staining method

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed adenocarcinoma of the prostate

• Biochemically recurrent disease

  • PSA failure defined as PSA ≥ 0.2 ng/mL that has increased above nadir following prostatectomy OR PSA increase of 2.0 ng/mL above nadir following primary therapy with radiotherapy or other local therapy
  • Increasing PSA value based on 2 consecutive measurements separated by ≥ 2 weeks AND no clinical or radiographic evidence of metastatic disease
• Must have undergone at least 3 PSA measurements over a minimum of 3 months
• No metastatic disease confirmed by bone scan and CT scan of the chest, abdomen, and pelvis within the past 2 months
• Hormone-naive disease

PATIENT CHARACTERISTICS:

• Performance status 0-2
• Life expectancy > 3 months
• WBC ≥ 2,000/mm^3
• Platelet count ≥ 50,000/mm^3
• Serum creatinine ≤ 2.5 mg/dL
• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• SGOT and SGPT ≤ 2.5 times ULN

• No uncontrolled intercurrent illness including, but not limited to, any of the following:

  • Ongoing active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia
  • Psychiatric illness/social situations that would limit compliance with study requirements
• No known allergy to mushrooms

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Any number of prior therapies (i.e., radical prostectomy, external beam radiotherapy, radioactive seed implantation, or cryotherapy) allowed
• No prior cytotoxic chemotherapy or androgen ablative therapy for this disease
• No adjuvant or neoadjuvant chemotherapy within the past 6 months
• No more than 9 months of neoadjuvant or adjuvant hormone ablation in conjunction with primary definitive therapy (androgen deprivation must have been completed ≥ 6 months prior and testosterone level must be > 50)
• No concurrent biological response modifiers or corticosteroids
• No concurrent complimentary or alternative therapy (e.g., St. John's wort, PC-SPES, or other herbal remedies taken for the purpose of treating prostate cancer)
• No concurrent antioxidant supplements (i.e., vitamin C or E)
• No other concurrent chemotherapy or hormone ablative agents including steroids