Molecular Stratification Profiling Protocol in Metastatic Castration Resistant Prostate Cancer (mCRPC) - MAESTRO

This study is a prospective, observational, molecular stratification profiling study. mCRPC patients who have received at least one standard treatment for mCRPC will be approached to participate in MAESTRO. Patients must have archival tumour available and be willing to undergo a fresh tumour biopsy for molecular analyses. Following consent to MAESTRO, tumour tissue (archival and fresh), along with the research blood samples and saliva sample will be sent to the central laboratory for analysis to identify molecular aberrations through targeted or broader genomic analyses (e.g. exome, transcriptome) and orthogonal assays (e.g. immunohistochemistry; digital droplet PCR). Patients will not receive any treatment as part of MAESTRO. Results of the molecular characterisation will be provided to the treating investigator to be fed back to the patient, depending on patient's choice on disclosing the results. The following research samples are collected under as part of this study: * Where available, excess archival tumour tissue from previous biopsies or routine surgical procedures will be retrospectively collected. * Fresh tissue specimens will be obtained for patients who are undergoing standard of care interventions OR patient will undergo a bone marrow biopsy or an ultrasound /CT guided tumour biopsy of a safely accessible lesion. Fresh tumour specimens will be processed and/or frozen. * Sequencing analysis of tissues will be done and results will be made available in real time. Clinically significant results will be disclosed to patients and their clinicians as per patient consent. * Research samples for blood, serum, plasma and saliva will be collected at the time of the biopsy. Patients who elected (optional consent) to receive sequencing results regarding incidental clinically significant findings, will be referred for genetic counselling.