Lynch syndrome screening patterns in colorectal cancer patients in a large multi-institutional cohort [poster]
- View All
Background/Aims: Up to 5% of colorectal cancer (CRC) patients have a hereditary predisposition to CRC called Lynch Syndrome (LS). Here we use the CERGEN population to investigate how frequently institutions document family history of cancer in a meaningful manner for LS identification. We characterize the individuals who receive LS testing, and determine the pattern of usage among the institutions with regard to the multiple recommended testing schemes. Methods: The study population includes 1220 patients with stage III or stage IV CRC, from one of the seven participating Cancer Research Network (CRN) study sites. Eligible patients were initially diagnosed with stage IV CRC between January 1, 2006 and December 31, 2009 or stage III CRC between January 1, 2004 and December 31, 2006. We compute descriptive statistics, such as proportions, counts, means, and variances, to summarize the derived information. Data analyses were conducted using SAS Release 9 (SAS Institute, Cary, NC). Results: Family history documentation in the EMR varied, with 3 sites clustering below 70% (279/436, 70/103, 137/199) and 4 sites with over 85% (111/127, 61/63, 119/136, 147/156). Of those with family history documentation 61% (591/971) have a relative with cancer and 20% of these (120/591) report CRC in at least one first degree relative. Less than 5% of the population received LS testing. These individuals tended to be younger (53 versus 67), and have a documented CRC family history. The decision to test for Lynch syndrome tended to be made soon after diagnosis (median 59 days). Microsatellite instability testing and immunohistochemistry testing were both used for initial LS testing, with some individuals receiving both, while a small number of individuals proceeded directly to germline sequencing. Of the individuals who received germline testing, 2 were diagnosed with LS. Conclusions: Family history of colon cancer is documented for the majority of individuals although this varies by site. Very few individuals are tested for LS at any site, representing a potential under diagnosis of this hereditary condition in patients and their families. When testing is performed, there does not seem to be a preference for immunohistochemistry or microsatellite instability testing for any site.