DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed adenocarcinoma of the prostate

  • Measurable or non-measurable disease
  • Metastatic disease allowed
• Castrate levels of serum testosterone (either after orchiectomy or maintained on a luteinizing hormone-releasing hormone agonist or antagonist)
• Prostate-specific antigen (PSA) greater than 10 ng/mL at baseline and rising, with 2 consecutive increases measured at least 1 week apart*
• No known brain metastases NOTE: *If the third PSA value has not risen above the second PSA value, a fourth measurement must be obtained that is higher than the second value

PATIENT CHARACTERISTICS:

Age

• Over 18

Performance status

• ECOG 0-1

Life expectancy

• More than 12 weeks

Hematopoietic

• Absolute neutrophil count greater than 1,500/mm^3
• WBC greater than 3,000/mm^3
• Platelet count greater than 100,000/mm^3

Hepatic

• AST and ALT no greater than 2.5 times upper limit of normal
• Bilirubin normal

Renal

• Creatinine normal OR
• Creatinine clearance greater than 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other

• Able to tolerate oral medication
• Fertile patients must use effective contraception
• No prior allergic reaction to compounds of similar chemical or biological composition to fenretinide
• No other concurrent uncontrolled illness
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No prior cytotoxic chemotherapy

Endocrine therapy

• See Disease Characteristics

• At least 6 weeks since prior antiandrogen therapy with any of the following:

  • Cyproterone
  • Flutamide
  • Bicalutamide
  • Nilutamide
• Concurrent corticosteroids allowed provided therapy was initiated before study entry

Radiotherapy

• At least 4 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy, including for pain
• No concurrent radioisotopes (e.g., strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium)

Other

• More than 4 weeks since prior investigational agents
• No concurrent antioxidants (e.g., ascorbic acid or vitamin E), vitamin A, or beta carotene supplements
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational or commercial anticancer agents or therapies