GENPROS aims to analyse the outcomes of patients with rare gene mutations in the cancer predisposition genes, BRCA1, BRCA2, HOXB13, and Lynch Syndrome, after a diagnosis of and treatment for prostate cancer (PCa). The study includes a cohort of gene mutation carriers with PCa matched with a control group of men with PCa who are known not to carry a mutation in the same gene. Clinical data regarding treatment and patient outcome will be collected retrospectively and prospectively. Archived tumour samples will also be collected for tumour profiling. A blood or saliva sample will be taken, if the participant consents to this part of the study, for genetic profiling to investigate any association of other inherited factors with PCa outcomes. Information obtained from this study will be of critical importance to support clinical trials investigating the most appropriate management of PCa in this group of patients at increased risk of prostate cancer.