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Medline ® Abstract for Reference 101

of 'Molecular genetics of colorectal cancer'

Characterisation of familial colorectal cancer Type X, Lynch syndrome, and non-familial colorectal cancer.
Shiovitz S, Copeland WK, Passarelli MN, Burnett-Hartman AN, Grady WM, Potter JD, Gallinger S, Buchanan DD, Rosty C, Win AK, Jenkins M, Thibodeau SN, Haile R, Baron JA, Marchand LL, Newcomb PA, Lindor NM, Colon Cancer Family Registry
Br J Cancer. 2014 Jul;111(3):598-602. Epub 2014 Jun 10.
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.
1]Department of Medicine, University of Washington, Seattle, WA, USA [2]Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.