Epirubicin and Docetaxel in Treating Patients With Metastatic Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the prostate * Meets 1 of the following criteria: * Measurable disease with any prostate-specific antigen (PSA) value * Unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * Histologic confirmation required if measurable disease is confined to a solitary lesion * Non-measurable disease with PSA ≥ 5 ng/mL\* * The following are considered non-measurable disease: * Bone lesions * Pleural or pericardial effusion * Ascites * CNS lesions * Leptomeningeal disease * Irradiated lesions unless disease progression was documented after prior radiotherapy NOTE: \*Patients with PSA ≥ 5 ng/mL only are not eligible * Progressive systemic disease despite ≥ 1 prior standard endocrine therapy with orchiectomy, luteinizing hormone-releasing hormone (LHRH) agonist, or diethylstilbestrol, as indicated by 1 of the following criteria: * Objective evidence of increase \> 20% in the sum of the longest diameters of target lesions from the time of maximal regression OR the appearance of 1 or more new lesions * One or more new lesions on bone scan secondary to prostate cancer AND PSA ≥ 5 ng/mL * Elevated PSA (≥ 5 ng/mL) with 2 consecutive increases from baseline (taken ≥ 1 week apart) * Serum testosterone ≤ 50 ng/dL for patients without bilateral orchiectomy * Patients who have not had a bilateral orchiectomy should continue therapy with primary testicular androgen suppression (e.g., LHRH analogues) PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Granulocyte count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 Hepatic * Meets 1 of the following criteria: * AST or ALT normal AND alkaline phosphatase ≤ 5 times upper limit of normal (ULN) * AST or ALT ≤ 1.5 times ULN AND alkaline phosphatase ≤ 2.5 times ULN * AST or ALT ≤ 5 times ULN AND alkaline phosphatase normal * Bilirubin normal Renal * Creatinine ≤ 1.5 times ULN Cardiovascular * No uncontrolled high blood pressure * No unstable angina * No symptomatic congestive heart failure * No myocardial infarction within the past 6 months * No serious uncontrolled cardiac arrhythmia * No New York Heart Association class III or IV heart disease Other * Fertile patients must use effective contraception during and for at least 3 months after study participation * No peripheral neuropathy ≥ grade 2 * No prior severe hypersensitivity reaction to docetaxel or other drug formulated with polysorbate 80 PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent filgrastim (G-CSF) or sargramostim (GM-CSF) Chemotherapy * No prior chemotherapy, including estramustine or suramin for prostate cancer * No other concurrent chemotherapy Endocrine therapy * See Disease Characteristics * At least 4 weeks since prior antiandrogen therapy * No concurrent hormonal therapy except steroids for adrenal insufficiency, hormones for non-disease-related conditions (e.g., insulin for diabetes), or intermittent dexamethasone as an antiemetic Radiotherapy * See Disease Characteristics * At least 4 weeks since prior radiotherapy * At least 8 weeks since prior strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium * No concurrent palliative radiotherapy Surgery * See Disease Characteristics * At least 4 weeks since prior surgery and recovered