RATIONALE: Male hormones can stimulate the growth of prostate cancer cells. Hormone therapy using flutamide and finasteride may fight prostate cancer by reducing the production of male hormones.

PURPOSE: Phase II trial to study the effectiveness of flutamide and finasteride in treating prostate cancer patients with high PSA levels who were previously treated with radiation therapy or radical prostatectomy.

OBJECTIVES:

• Determine the efficacy of finasteride and flutamide in suppressing prostate specific antigen (PSA) levels in patients with elevated PSA after definitive radiation therapy or radical prostatectomy for prostate cancer.
• Assess sexual function and other quality of life issues during this therapy.
• Estimate the response to flutamide withdrawal in this group of patients who have not had a major reduction in circulating testosterone levels.
• Measure the response rate to further hormonal manipulation with combined androgen blockade after the failure of this therapy.
• Obtain data that may predict more aggressive disease.

OUTLINE: This is a multicenter study.

Patients receive finasteride and flutamide by mouth three times a day. Patients experiencing recurrence or a greater than 4 nu/mL (above 50%) increase in PSA level will discontinue flutamide treatments. Otherwise, patients continue therapy in the absence of unacceptable toxicity or disease progression.

Quality of life is assessed prior to therapy and at 3 and 6 months.

Patients are followed every 3 months for one year and every 6 months thereafter.

PROJECTED ACCRUAL: This study will accrue 100 patients over 2 years.

• Prostate Cancer
• Sexual Dysfunction and Infertility

• Drug: finasteride
• Drug: flutamide
• Procedure: quality-of-life assessment

DISEASE CHARACTERISTICS:

• Histologically proven previously treated adenocarcinoma of the prostate

• Prior definitive therapy must have occurred at least 6 months, but no more than 10 years, prior to study

  • Definitive therapy is defined as one of the following:

    • Prior radical prostatectomy
    • Radiotherapy to the prostate no more than 3 months before prostatectomy
    • Brachytherapy
    • Brachytherapy with external beam radiotherapy given as single therapy
    • External beam radiation therapy alone
• Must have a PSA level between 1-10 nu/mL, with a rise of at least 1 nu/mL above the nadir produced by definitive therapy
• No evidence of local recurrence
• No metastatic disease

PATIENT CHARACTERISTICS:

Age:

• Not specified

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 2 times upper limit of normal (ULN)
• SGOT/SGPT no greater than 2 times ULN

Renal:

• Creatinine no greater than 2 times ULN

Other:

• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy for prostate cancer

Endocrine therapy:

• At least 2 years since finasteride or other 5a-reductase inhibitors
• At least 12 months since prior hormone therapy for prostate cancer
• No more than 6 months of prior hormone therapy
• No corticosteroids in excess of standard replacement doses
• No concurrent systemic steroids
• No other concurrent antiandrogenic drugs or 5a-reductase inhibitors

Radiotherapy:

• See Disease Characteristics
• No concurrent palliative radiotherapy

Surgery:

• See Disease Characteristics
• No orchiectomy