Yield of Universal Testing for DNA Mismatch Repair Protein Deficiency in Colorectal Carcinoma From an Australian Community-based Practice

摘要: Lynch syndrome is the most common cause of inherited colorectal carcinoma (CRC). Current surveillance guidelines are effective at decreasing morbidity and mortality syndrome-associated cancers, however many cases still missed. Among various screening strategies, testing all newly diagnosed carcinomas for MMR protein deficiency, known as universal testing, has recently emerged preferred approach to identify potential individuals, who then require genetic counselling. All CRCs from initial biopsy or surgical resection specimen were screened expression by immunohistochemistry. A 2-step was used: PMS2 MSH6 followed respective partner if one proteins lost. We retrospectively searched our pathology database results across a 5-year period (2012-2016) when performed. Clinical pathological data extracted report. total 2077 consecutive tested expression. Mean age diagnosis 68.4 years (range 18-96). deficiency identified in 399 (19.2%). The vast majority CRC with MLH1/PMS2 loss patients older than 70 (84%), them likely be secondary sporadic MLH1 methylation. In 8 loss, also present. patterns suggestive defect MSH2, comprised 42 cases, which 37 found individuals aged 50 older. MSH2/MSH6 commonly (57%). summary, identifies abnormal groups, including those excluded current guidelines. Further studies needed demonstrate actual rate this screening.