Prostate Cancer, Androgen Deprivation Withdrawal and Intermittent Chemotherapy

Inclusion Criteria: 1. age over 18 years, 2. histologically documented adenocarcinoma of the prostate, 3. written informed consent to the study, 4. Castrate resistant metastatic prostate cancer in the presence of castrate levels of testosterone (\<50 ng/ml) and eligible to docetaxel chemotherapy. The condition of castrate resistant prostate cancer is the defined either as the documentation of a new metastasis or PSA increase more than 50% or increase more than 25% from a lower PSA value during previous hormone therapy in case of disease response or stabilization to previous hormone therapy, respectively. Absolute PSA increase should be greater than 5 ng/ml, 5. an elevated PSA level must have been documented within 4 weeks of initiating docetaxel chemotherapy, 6. more than 4 weeks since major surgery and fully recovered, 7. more than 4 weeks since any prior radiation with any toxicity attributable to radiation resolved to grade 1 or less, 8. more than 8 weeks since the last dose of strontium or samarium, 9. ECOG Performance Status more than/equal to 2, 10. life expectancy \>6 months, 11. required initial laboratory values: absolute neutrophil count \> 1500/ul Platelets \> 100,000/ul., Hemoglobin \> 8.0 g/dl, Creatinine, SGOT, SGPT less than 2.0 X upper limit of normal, Bilirubin less than/equal to upper limit of normal (ULN). 12. Appropriate patient compliance Exclusion Criteria: 1. Patients with increased serum PSA levels with negative bone scan and CT scan. 2. Prior systemic chemotherapy for prostate cancer. Prior neoadjuvant or adjuvant chemotherapy is permitted if there was no evidence of disease relapse within 12 months of the last dose of chemotherapy, 3. Peripheral neuropathy \>grade 1, 4. myocardial infarction or significant change in anginal pattern within the last 6 months, symptomatic congestive heart failure (NYHA Class III or higher) or uncontrolled cardiac arrhythmia, 5. patients with a history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80, 6. poorly controlled diabetes (fasting blood glucose \>250) despite optimization of medical therapy, peptic ulcers or other contraindications to steroid therapy, 7. previous history of malignant disease with the exception of non melanoma skin cancer curatively treated, 8. significant neurologic or psychiatric diseases preventing patients to give a valid informed consent, 9. brain metastases, 10. prisoner status 11. because patients with immune deficiency are at increased risk of lethal infections when treated with marrow-suppressive therapy, HIV-positive patients receiving combination anti-retroviral therapy are excluded. \-