Docetaxel and Cetuximab in Treating Patients With Metastatic Prostate Cancer

DISEASE CHARACTERISTICS: * Metastatic adenocarcinoma of the prostate * Must have received one of the following treatment schedules for at least 12 weeks prior to study therapy: * Docetaxel 75 mg/m\^2 on day 1 of a 21-day course * Docetaxel 35 mg/m\^2 on days 1, 8, and 15 of a 28-day course * Must demonstrate hormone-resistance, defined as tumor progression after orchiectomy or during treatment with hormonal agents (i.e., luteinizing hormone-releasing hormone \[LHRH\] agonists) * Elevated prostate-specific antigen (PSA) \> 2 ng/mL and PSA progression after at least 12 weeks treatment with docetaxel/prednisone, within 90 days after discontinuation of docetaxel/prednisone treatment, under continued hormonal treatment (i.e., LHRH agonists or orchiectomy), and meets 1 of the following criteria for PSA progression: * PSA increase of ≥ 25% above the nadir * PSA increase of ≥ 25% above the baseline if no decrease has been observed * The increase is a minimum of 2 ng/mL, and it is confirmed 1 week later * No presence or history of CNS metastases PATIENT CHARACTERISTICS: * WHO performance status 0-2 * Neutrophils ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Bilirubin ≤ 1.5 times upper limit of normal (ULN) * ALT ≤ 2.5 times ULN * Creatinine clearance ≥ 30 mL/min * Patient compliance and geographic proximity allow proper staging and follow-up * Peripheral neuropathy \< grade 2 * No prior malignancy within the past 5 years with the exception of localized nonmelanoma skin cancer or Ta or Tis bladder cancer * No known hypersensitivity to trial drugs or any of their components * No serious underlying medical condition that, in the judgment of the investigator, would preclude the patient's ability to participate in the trial (e.g., active autoimmune disease, uncontrolled or acute severe infection, or uncontrolled diabetes) * No psychiatric disorder precluding understanding of information on trial related topics, giving informed consent, or interfering with oral drug intake compliance PRIOR CONCURRENT THERAPY: * See Disease Characteristics * More than 2 weeks since prior radiotherapy * More than 6 weeks since prior treatment with antiandrogens (i.e., flutamide or bicalutamide) * No prior chemotherapy other than docetaxel for metastatic prostate cancer * No other concurrent experimental drugs or other anticancer therapy * Concurrent bisphosphonates and LHRH agonists allowed provided these medications started at least 2 months prior to study therapy * No treatment in a clinical trial within the past 30 days * No prior treatment with drugs interacting with epidermal growth factor receptor (i.e., cetuximab, panitumumab, gefitinib, erlotinib hydrochloride, or multi-tyrosine kinase inhibitors) * No concurrent drugs that, according to the Swissmedic-approved product information, are contraindicated for use with the trial drugs