Lynch Syndrome Another group in which a higher PCa risk has been reported is Lynch syndrome patients. Lynch syndrome is a multi-cancer syndrome caused by germline mutations in the MMR genes; MLH1, MSH2 or MSH6. Colorectal cancers are the predominant cancer phenotype and patients with this syndrome have a 70% probability of developing the disease by the age of 70. In addition, there is an increased risk of extracolonic tumours, including endometrium, stomach, small bowel, ovary, ureter, renal pelvis, biliary tract brain and pancreas. PCa has been reported in these families, but it is not until recently that it has been shown to be a feature of the Lynch syndrome. At the moment, little is known about the association between germline mutations in these genes and the PCa phenotype and outcome. Prostate cancer has been described as a component tumour of Lynch syndrome. The estimated cumulative lifetime risk is two-fold higher than the general population. The cumulative risk of prostate cancer at the age of 60 was 6.3% and at the age of 80 was 30%.