Colorectal cancer genetics

Abstract Colorectal cancer (CRC) is a common disease often occurring in multiple members of the same family by chance. Nevertheless, some families with CRC not only contain multiple affected relatives but also have features that are in some way unusual. These features can include early age of cancer diagnosis, the presence of multiple benign colorectal polyps, the occurrence of more than one CRC or cancers of other specific organs, tumours of unusual histological types, and even features that are non-neoplastic and/or not clearly related to cancer. Historically, the realization that clusters of clinical features tend to co-occur in families led to the notion that there exist specific CRC syndromes, most of which are now known to have a Mendelian inheritance, caused by germline mutations in one of about 16 genes. Scientists have spent the last 30 to 40 years discovering and describing these syndromes, some of which have opened new avenues for therapeutics.