Family history of colorectal cancer is not associated with colorectal cancer survival regardless of microsatellite instability status.

Publication Type:

Journal Article

Source:

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (2014)

Keywords:

2014, June 2014, Public Health Sciences Division

Abstract:

Background: Individuals with a family history of colorectal cancer (CRC) in first-degree relatives have an elevated risk of developing CRC themselves, particularly CRC exhibiting high microsatellite instability (MSI-high). Given that MSI-high CRC is associated with a favorable prognosis, it is plausible that having a family history of CRC could, in turn, be favorably associated with CRC survival. Methods: This study comprised N=4284 incident CRC cases enrolled in the Colon Cancer Family Registry via population-based cancer registries. Using Cox proportional hazards regression, we evaluated the association between family history and both overall and disease-specific survival, accounting for MSI status and tumor site via stratified analyses and statistical adjustment. Results: There was no evidence of association between family history and overall [hazard ratio (HR)=0.92, 95% confidence interval (CI): 0.79-1.08] or disease-specific survival (HR=1.03, 95% CI: 0.85-1.24) for all cases combined, after adjustment for MSI status or tumor site. Only for rectal cancer cases was CRC family history modestly associated with more favorable overall survival (HR=0.75, 95% CI: 0.56-0.99). Conclusions: Although individuals with a family history of CRC were more likely to have MSI-high tumors than those with non-familial disease, this did not translate to a survival benefit. Impact: Overall, there is no evidence that family history of CRC is associated with CRC survival; however, specific mechanisms underlying family history may have prognostic impact and merit further study.