Characterisation of familial colorectal cancer Type X, Lynch syndrome, and non-familial colorectal cancer

Br J Cancer. 2014 Jul 29;111(3):598-602. doi: 10.1038/bjc.2014.309. Epub 2014 Jun 10.

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Colorectal Neoplasms, Hereditary Nonpolyposis / epidemiology*
  • Colorectal Neoplasms, Hereditary Nonpolyposis / pathology
  • Comorbidity
  • Female
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Neoplasms, Cystic, Mucinous, and Serous / epidemiology*
  • Neoplasms, Cystic, Mucinous, and Serous / pathology
  • Odds Ratio
  • Registries
  • Surveys and Questionnaires