PROSTAC: Prospective Multi-centre Study of Prognostic Factors in mCRPC Patients Treated With Docetaxel or Cabazitaxel.

Inclusion Criteria: 1. Male age ≥ 18 years 2. Histologically confirmed adenocarcinome of the prostate 3. ECOG Performance Status ≤ 2 4. Castration resistance must be documented with surgical or medical castration with serum testosterone \< 50 ng/mL (\< 2.0 nM). 5. Men diagnosed with at least one metastatic lesion on CT or bone scan. 6. Documented biochemical and/or radiographic progression to previous treatment according to PCWG2 criteria. 7. Patients who are candidates for standard of care treatment with docetaxel 75mg/m2 every 3 weeks or cabazitaxel 20-25mg/m2 every 3 weeks intravenously. 8. Availability of formalin-fixed paraffin-embedded blocks from the prostate biopsy and/or radical prostatectomy. 9. Acceptable hematological, hepatic and renal functions. Exclusion Criteria: 1. Previous cancer diagnosis, except those patients who had a localized malignant tumour and who are five years cancer-free or those diagnosed with skin cancers (of non-melanoma type) or excised in situ carcinomas. 2. Any condition or reason that, in the opinion of the Investigator, interferes with the ability of the patient to participate in the trial, which places the patient at undue risk, or complicates the interpretation of safety data