Isotretinoin, Interferon Alfa-2b, Docetaxel, and Estramustine in Treating Patients With Metastatic Prostate Cancer That Did Not Respond to Hormone Therapy

DISEASE CHARACTERISTICS: Histologically confirmed hormone-refractory metastatic prostate cancer Patients who have been recently withdrawn from treatment with bicalutamide or flutamide must demonstrate progression of disease Measurable disease OR prostate-specific antigen level ≥ 10 ng/mL PATIENT CHARACTERISTICS: ECOG performance status 0-2 Estimated life expectancy ≥ 6 months Absolute neutrophil count ≥ 1,500/mm³ Hemoglobin ≥ 8 g/dL Platelet count ≥ 100,000/mm³ Creatinine ≤ 1.5 mg/dL OR creatinine clearance ≥ 50 mL/min Bilirubin normal AST, ALT, and alkaline phosphatase (AP) must meet 1 of the following criteria: AP normal and AST and ALT ≤ 2.5 times upper limit of normal (ULN) AP elevated and AST and ALT normal No history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80 No peripheral neuropathy > grade 1 No concurrent active infections No concurrent major depression or suicidal ideation No concurrent medical condition that would preclude study participation No known HIV positivity Fertile patients must use effective contraception during and for 10 weeks after completion of study therapy PRIOR CONCURRENT THERAPY: Recovered from prior surgery or radiotherapy No prior chemotherapy, retinoids, or interferon therapy More than 4 weeks since prior flutamide More than 6 weeks since prior bicalutamide