Carboplatin-Etoposide Combination in Hormone-Resistant Prostate Cancers

Inclusion Criteria: * Histological evidence of prostate adenocarcinoma * Metastatic disease, either measurable (lymph nodes, hepatic lesion, pulmonary lesions with longest diameter \> or = 1 cm on spiral scan), or non measurable (bone metastasis) * Patients must: * Have received hormonal therapy via surgical or chemical castration (LH-RH agonist) with or without anti-androgens. Anti-androgen withdrawal is recommended before inclusion, with an off-treatment period of at least 4 weeks. LH-RH agonist treatment must be continued. * Have a relapse or disease refractory to hormonal treatment (defined by a testosterone level \< 0.5 µg/ml) * Have neuroendocrine progression defined, whatever the PSA level, as: * NSE and/or Chromogranin A \> 1.5 x upper limit of normal (ULN) with or without visceral metastases (liver, lung, lymph node) * No increase of NSE or Chromogranin A, but visceral metastases (either hepatic, pleuro-pulmonary, or nodal) with cytological or histological confirmation of the presence of an undifferentiated or neuro-endocrine component of prostatic origin * Prior treatment by radiotherapy is allowed but radiation therapy must have been completed for at least 4 weeks before inclusion and irradiated areas must not represent more than 25% of marrow reserves * Prior treatment by estramustine is allowed but must have been stopped at least 4 weeks before inclusion * Age\> or = 18 years * Life expectancy\> or = 3 months * Karnofsky index\> or = 50% * Adequate haematological function: neutrophils\> or = 1.5 G/l, platelets\> or = 100 G/l, haemoglobin\> or = 8 g/dl. Use of erythropoietin is allowed. * Adequate liver function: bilirubin level within the institution's normal range, AST and ALT\< or = 1.5 ULN * Adequate renal function: creatinine clearance\> or = 40 ml/min (Gault and Cockroft method) * Signed written informed consent. Exclusion Criteria: * Patients having no\> 1.5 x ULN increase of at least one neuro-endocrine marker (NSE or chromogranin A) and no cytological or histological (undifferentiated or neuro-endocrine type) evidence of visceral metastasis (hepatic, pleuro-pulmonary, or nodal) * History of other malignancies, other than curatively treated basal cell skin carcinoma or any other curatively treated cancer with no sign of recurrence within 5 years * Symptomatically uncontrolled brain metastasis * Interstitial radiation therapy (using strontium or samarium) within the previous 3 months * Prior treatment with platinum salts or etoposide. Other chemotherapy regimens are allowed provided that the last dose has been administered\> or = 4 weeks prior to inclusion. * Concomitant treatment with other anti-cancer drugs, except corticoid or LH-RH agonist injections * Peripheral neuropathy\> or = 2 (NCI-CTCAE) * Uncontrolled progressive thrombo-embolic disease * Uncontrolled infection * Medical history of acute myocardial infection or uncontrolled angina pectoris, or hypertension or uncontrolled arrythmia * Inclusion in another clinical trial * Impaired follow-up for social, geographical, familial or psychological reasons * Any other unstable disease.