title: Characterisation of familial colorectal cancer Type X, Lynch syndrome, and non-familial colorectal cancer.
abstract: BACKGROUND
  Familial Colorectal Cancer Type X (FCCTX) is defined as individuals with colorectal cancer (CRC) who families meet Amsterdam Criteria-1 (AC1), but whose tumours are DNA-mismatch-repair-proficient, unlike Lynch syndrome (LS). FCCTX does not have an increased risk of extra-colonic cancers. This analysis compares epidemiologic and clinicopathologic features among FCCTX, LS, and 'non-familial' (non-AC1) CRC cases.
  
  
  METHODS
  From the Colon Cancer Family Registry, FCCTX (n=173), LS (n=303), and non-AC1 (n=9603) CRC cases were identified. Questionnaire-based epidemiologic information and CRC pathologic features were compared across case groups using polytomous logistic regression.
  
  
  RESULTS
  Compared with LS, FCCTX cases were less likely to be current (vs never) smokers; have a proximal subsite (vs rectal) tumour; or have mucinous histology, poor differentiation, or tumour-infiltrating lymphocytes. There were no observed differences in co-morbidities or medication usage.
  
  
  CONCLUSIONS
  FCCTX were less likely to be current tobacco users; other exposures were similar between these groups. Histopathologic differences highly suggestive of LS CRCs do not appear to be shared by FCCTX.
authors.affiliation: 1] Department of Medicine, University of Washington, Seattle, WA, USA [2] Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shiovitz
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: W K
authors.initials: WK
authors.lastname: Copeland
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: M N
authors.initials: MN
authors.lastname: Passarelli
authors.affiliation: 1] Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Burnett-Hartman
authors.affiliation: 1] Department of Medicine, University of Washington, Seattle, WA, USA [2] Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA [3] Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Grady
authors.affiliation: 1] Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA [3] Centre for Public Health Research, Massey University, Wellington, New Zealand.
authors.forename: J D
authors.initials: JD
authors.lastname: Potter
authors.affiliation: Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Gallinger
authors.affiliation: 1] University of Melbourne, Parkville, VIC, Australia [2] Cancer and Population Studies Group, Queensland Institute of Medical Research, Brisbane, QLD, Australia.
authors.forename: D D
authors.initials: DD
authors.lastname: Buchanan
authors.affiliation: 1] Cancer and Population Studies Group, Queensland Institute of Medical Research, Brisbane, QLD, Australia [2] University of Queensland, School of Medicine, Herston, QLD, Australia [3] Envoi Pathology, Herston, QLD, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Rosty
authors.affiliation: University of Melbourne, Parkville, VIC, Australia.
authors.forename: A K
authors.initials: AK
authors.lastname: Win
authors.affiliation: University of Melbourne, Parkville, VIC, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Jenkins
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: S N
authors.initials: SN
authors.lastname: Thibodeau
authors.affiliation: Stanford Cancer Institute, Palo Alto, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Haile
authors.affiliation: Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Baron
authors.affiliation: University of Hawaii Cancer Center, Honolulu, HI, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Marchand
authors.affiliation: 1] Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Newcomb
authors.affiliation: Department of Health Science Research, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: N M
authors.initials: NM
authors.lastname: Lindor
mesh_terms: D000368:Aged; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000453:epidemiology* / Q000473:pathology; D015897:Comorbidity; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000453:epidemiology* / Q000473:pathology; D016017:Odds Ratio; D012042:Registries; D011795:Surveys and Questionnaires