title: Selective Versus Universal Screening for Lynch Syndrome: A Six-Year Clinical Experience.
abstract: BACKGROUND
  Lynch syndrome is the most common cause of hereditary colorectal cancer (CRC) and confers increased risk of other cancers. Identification of patients improves morbidity and mortality. Screening tumors for absent mismatch repair (MMR) protein expression by immunohistochemistry (IHC) is a recommended approach. Despite guidelines advocating universal screening, significant variation in clinical practice exists.
  
  
  OBJECTIVE
  A retrospective study of two different IHC-based Lynch syndrome screening protocols at an urban, university hospital was performed. Outcomes from a "selective" screening strategy utilized from August 2007-July 2010 on CRC tumors from patients with high-risk features were compared with a "universal" strategy of screening all CRC tumors from July 2010-August 2013. Positively screened patients were referred for genetic counseling and offered germline testing.
  
  
  RESULTS
  A total of 392 patients with CRC were screened: 107 selectively and 285 universally. The prevalence of Lynch syndrome was 3.1 %, with no difference by strategy. There was a trend (p = 0.06) toward fewer universally screened patients agreeing to genetic counseling compared with those selectively screened. Selective criteria failed to identify one of eight cases of Lynch syndrome from the universal group, though the universal strategy screened 166 additional tumors to find this additional patient.
  
  
  CONCLUSIONS
  Selective screening for Lynch syndrome has similar outcomes as universal screening in terms of identifying Lynch syndrome, despite screening far fewer patients. In addition, fewer eligible patients in our study agreed to undergo genetic counseling and germline testing than in prior studies. These lower rates may better reflect uptake of these services in clinical practice.
authors.affiliation: Department of Internal Medicine, University of California, San Francisco, 1701 Divisadero, Suite 120, San Francisco, CA, 94115, USA, Trilokesh.Kidambi@ucsf.edu.
authors.forename: Trilokesh D
authors.initials: TD
authors.lastname: Kidambi
authors.forename: Amie
authors.initials: A
authors.lastname: Blanco
authors.forename: Megan
authors.initials: M
authors.lastname: Myers
authors.forename: Peggy
authors.initials: P
authors.lastname: Conrad
authors.forename: Kate
authors.initials: K
authors.lastname: Loranger
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Terdiman
mesh_terms: D000328:Adult; D000368:Aged; D002985:Clinical Protocols; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics; D053843:DNA Mismatch Repair; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008403:Mass Screening / Q000379:methods*; D053842:Microsatellite Instability; D008875:Middle Aged; D009687:Nuclear Proteins / Q000378:metabolism; D018579:Patient Selection; D012189:Retrospective Studies
chemical_list: D009687:Nuclear Proteins