Capecitabine and Docetaxel in Treating Patients With Metastatic Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the prostate * Metastatic disease * Androgen-independent disease * Progressive disease, as documented by ≥ 1 of the following criteria: * Rising prostate-specific antigen (PSA) despite androgen deprivation therapy and anti-androgen withdrawal * Demonstrates a rising PSA trend with 2 successive elevations ≥ 1 week apart * Measurable disease progression * Nonmeasurable disease progression, defined as the following: * PSA ≥ 5 ng/mL * New areas of bone metastases on bone scan * Serum testosterone ≤ 0.5 ng/mL (castrate level) * Concurrent luteinizing hormone-releasing hormone agonist therapy required for medically castrated patients PATIENT CHARACTERISTICS: Performance status * Zubrod 0-2 Life expectancy * At least 12 weeks Hematopoietic * Absolute neutrophil count ≥ 1,500/ mm\^3 * Hemoglobin ≥ 8.0 g/dL * Platelet count ≥ 100,000/mm\^3 Hepatic * Bilirubin normal * Transaminases meeting 1 of the following criteria: * AST and/or ALT ≤ 2.5 times upper limit of normal (ULN) if alkaline phosphatase (AP) normal * AP ≤ 4 times ULN if AST and/or ALT normal Renal * Creatinine clearance ≥ 50 mL/min OR * Creatinine ≤ 2 mg/dL Cardiovascular * No congestive heart failure * No second- or third-degree heart block * No myocardial infarction within the past 3 months Other * Fertile patients must use effective contraception during and for 6 months after completion of study treatment * No other malignancy within the past 2 years except adequately treated skin cancer or other cancer in complete remission * No history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80 * No peripheral neuropathy ≥ grade 2 PRIOR CONCURRENT THERAPY: Chemotherapy * No prior chemotherapy for metastatic disease Endocrine therapy * See Disease Characteristics * More than 4 weeks since prior flutamide * More than 6 weeks since prior bicalutamide or nilutamide Radiotherapy * At least 4 weeks since prior radiotherapy Other * At least 28 days since prior investigational drugs for prostate cancer * No other concurrent anti-cancer therapy