title: A retrospective observational study of the relationship between family history and survival from colorectal cancer.
abstract: BACKGROUND
  Although family history is well established to be a risk factor for developing colorectal cancer (CRC), much less is known about its impact on patient survival. This study aimed to link CRC patient data from the National Study of Colorectal Cancer Genetics (NSCCG) to the National Cancer Data Repository (NCDR) to examine the relationship between family history and the characteristics and outcomes of CRC.
  
  
  METHODS
  All eligible NSCCG patients underwent a matching process to the NCDR using combinations of their personal identifiers. The characteristics and survival of CRC patients with and without a family history of CRC were compared.
  
  
  RESULTS
  Of the 10 937 NSCCG patients eligible to be matched into the NCDR, 10 782 (98.6%) could be fully linked. There were no significant differences between those with and without a family history of CRC (defined as having at least one affected first-degree relative) in terms of age, sex, tumour stage at diagnosis, presence of multiple cancers, mode of presentation to hospital and surgical management, although patients with familial CRC were more likely to have right-sided tumours (P<0.01). The survival of patients with familial CRC was significantly better than those with sporadic CRC (HR 0.89, 95%CI: 0.81-0.98, P=0.02).
  
  
  CONCLUSIONS
  We have demonstrated that it is possible to robustly match patients recruited into the NSCCG into the NCDR and, by using this record linkage, enable genetic data to be related to CRC phenotype, clinical management and outcome. This study provides evidence that a family history of CRC is associated with better survival after a diagnosis of CRC.
authors.affiliation: Colorectal Cancer Epidemiology Group, Section of Epidemiology and Biostatistics, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK. eva.morris@nycris.leedsth.nhs.uk
authors.forename: E J A
authors.initials: EJ
authors.lastname: Morris
authors.forename: S
authors.initials: S
authors.lastname: Penegar
authors.forename: L E
authors.initials: LE
authors.lastname: Whitehouse
authors.forename: P
authors.initials: P
authors.lastname: Quirke
authors.forename: P
authors.initials: P
authors.lastname: Finan
authors.forename: D T
authors.initials: DT
authors.lastname: Bishop
authors.forename: J
authors.initials: J
authors.lastname: Wilkinson
authors.forename: R S
authors.initials: RS
authors.lastname: Houlston
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000235:genetics / Q000401:mortality* / Q000473:pathology; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D006113:United Kingdom / Q000453:epidemiology