title: Frequency of familial colon cancer and hereditary nonpolyposis colorectal cancer (Lynch syndrome) in a large population database.
abstract: OBJECTIVE
  Estimates have been made concerning the fraction of colorectal cancer (CRC) cases that meet Amsterdam I criteria but not Amsterdam II criteria. The aim of this study was to determine in a population setting what fraction of CRC cases can be considered familial high-risk, what fraction of these meet Amsterdam I or II criteria, and what fraction of CRC cases overall meet Amsterdam I and II criteria.
  
  
  METHODS
  The Utah Population Data Base (UPDB), which links Utah genealogies to the Utah Cancer Registry, was used to examine the aims of the study. Familial high-risk was operationally defined as CRC occurring at an age <50 years or as a part of a first-degree relative pair. A subset of Amsterdam positive cancers was tested for microsatellite instability (MSI) to determine what fraction of Amsterdam families was likely to have hereditary nonpolyposis colorectal cancer (HNPCC).
  
  
  RESULTS
  Of the 6,628 CRC cases in the UPDB, 24.5% met the criteria for familial high-risk. Of these, 2.6% met Amsterdam I criteria and 5.5% Amsterdam II. Of total data base CRC cases, 0.8% met Amsterdam I criteria and 2.3% Amsterdam II. In a subset of colon tumors from Amsterdam families, 70% were MSI stable.
  
  
  CONCLUSIONS
  Although nearly 25% of CRC cases in our population data base met a simple definition of familial high-risk, only a small fraction of these and a smaller fraction of total CRC cases met Amsterdam I or II criteria. Less than half of a limited set of tumors from Amsterdam families were MSI positive.
authors.affiliation: Department of Oncological Sciences, University of Utah, School of Medicine, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kerber
authors.forename: Deborah W
authors.initials: DW
authors.lastname: Neklason
authors.forename: Wade S
authors.initials: WS
authors.lastname: Samowitz
authors.forename: Randall W
authors.initials: RW
authors.lastname: Burt
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins / Q000235:genetics; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D042822:Genomic Instability; D006801:Humans; D018895:Microsatellite Repeats; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D009687:Nuclear Proteins / Q000235:genetics; D012307:Risk Factors
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000070957:MutL Protein Homolog 1