Preclinical models of prostate cancer have proved to be poorly predictive of the behaviour of the disease in patients. This protocol describes the acquisition of prostate cancer tissue or cells from patients with treatment naïve/hormone-sensitive and castration-resistant prostate cancer or patients undergoing diagnostic or follow up investigations. The knowledge gained will improve the investigators' understanding of the steps leading to the development of castration resistance and identify new molecular targets for treatment. The human microbiome has been under investigation in a range of human diseases (i.e. metabolic disease/obesity, neurological disorders, cardiovascular disease, mental disorders, autoimmune disease, asthma and allergies) and cancer. The human microbiota can have direct (e.g. via direct genotoxicity, induction of chronic inflammation, etc.) and/or indirect (e.g. effects on tumour effects on tumour development or progression exerted through microbial communities that exist at a site distant to the tumour) effects on the disease. Emerging data supports the influence of the gut microbiota on the efficacy of anti-cancer treatments, including immunotherapy. To date, the impact of the gut microbiome on prostate cancer therapies is virtually unexplored. Based on the evidence to date, the investigators hypothesize that the gut flora may be altered by certain treatments for advanced prostate cancer, and that the composition of the microbiome in the gastrointestinal tract may be used to predict therapeutic efficacy or therapy-related toxicities; as well as prevent treatment toxicity and/or enhance treatment response. Furthermore, the purpose is to investigate the association between gut flora and treatment response and related toxicities/morbidities in advanced prostate cancer.