Purpose@#Universal
screening for
Lynch syndrome (LS) refers to routine
tumor testing for
microsatellite instability (MSI) among all
patients with
colorectal cancer (CRC). Despite its widespread
adoption , real-world data on the yield is lacking in Korean
population . We studied the yield of adopting universal
screening for LS in comparison with
pedigree -based
screening in a tertiary center. @*Materials and
Methods @#CRC
patients from 2007-2018 were reviewed.
Family histories were obtained and were evaluated for
hereditary nonpolyposis colorectal cancer (HNPCC) using Amsterdam II criteria.
Tumor testing for MSI began in 2007 and
genetic testing was offered using all available clinicopathologic data. Yield of
genetic testing for LS was compared for each approach and step. @*Results@#Of the 5,520
patients ,
tumor testing was performed in 4,701
patients (85.2%) and
family histories were obtained from 4,241
patients (76.8%). Hereditary CRC (LS or HNPCC) was present in 69
patients (1.3%). MSI-high was present in 6.9%, and 25
patients had confirmed LS.
Genetic testing was performed in 41.2% (47/114) of MSI-high
patients , out of which 40.4% (19/47) were diagnosed with LS. There were six additional LS
patients found outside of
tumor testing. For
pedigree -based
screening , Amsterdam II criteria diagnosed 55
patients with HNPCC. Fifteen of these
patients underwent
genetic testing , and 11 (73.3%) were diagnosed with LS. Two
patients without prior
family history were diagnosed with LS and relied solely on
tumor testing results. @*Conclusion@#Despite widespread
adoption of routine
tumor testing for MSI, this is not a fail-safe approach to screen all LS
patients . Obtaining a thorough
family history in combination with universal
screening provides a more comprehensive ‘universal’
screening method for LS.