Lynch syndrome-chasing a better ascertainment rate in British Columbia

Background With a population of approximately 4.380 million people and an estimated Lynch syndrome mutation prevalence of 1/531, there are an expected 8000 individuals with Lynch syndrome in British Columbia. The Hereditary Cancer Program (HCP) of the BC Cancer Agency (BCCA) has provided clinical testing for Lynch syndrome since 2004 to patients across the province. Currently, there are approximately 100 patients with confirmed Lynch syndrome mutations in the BCCA database. Potential obstacles in ascertaining Lynch syndrome through a traditional clinic-based approach include physician awareness of referral criteria, patient’s lack of knowledge of cancer family history, patient compliance, and availability of tumour tissue for testing. Given these obstacles, a population based approach to identifying Lynch syndrome through incident testing of newly diagnosed colorectal cancers under age 50 by microsatellite instability testing (MSI) was launched in BC in June of 2008.