The Association Between Socio-Economic Status and Colon Cancer Survival By KRAS, BRAF and MSI status: A Molecular Pathology Epidemiology Cohort Study.
AuthorsMT Doherty,1 RT Gray,1 MB Loughrey,2,5 AT Gavin,4 S McQuaid,2,3 RF O’Neill,1JA James,2,3,5 M Salto-Tellez,2,5 LJ Murray,1 HG Coleman.1
Departments / Institutions1Cancer Epidemiology and Health Services Research Group, Centre for Public Health, 2Centre for Cancer Research and Cell Biology, 3Northern Ireland Biobank, and 4Northern Ireland Cancer Registry, Queen’s University Belfast; 5Department of Pathology.
Publication DateAutumn 2017
Previous studies have highlighted socio-economic disparities in colon cancer survival. However, it is unclear if this is due to differences in lifestyle factors, tumour biology or broader issues in healthcare access.
To investigate the association between socio-economic status and colon cancer survival by MSI, KRAS and BRAF status, in a large population-based study.
Northern Ireland (NI) Cancer Registry data was analysed, including all n=1,426 patients who underwent surgery for their Stage II or III colon cancer between 2004 and 2008. Of these, n=661 patients within the NI Biobank jurisdiction were included in molecular analyses. Death information was retrieved via linkage to NI Registrar General’s Office up to end 2013. Socio-economic status was derived using the Northern Ireland multiple deprivation measure. The association between socio-economic variables and survival was tested using Cox Proportional Hazard models
A non-significant increased risk of death were observed for individuals residing in the most compared with the least deprived areas (Most v. least deprived HR 1.21; 95%CI 0.90,1.63). This rose to a significant two-fold increased risk of death in patients with KRAS mutant colorectal tumours (Most v. least deprived HR 2.06; 95%CI 1.25, 3.40), which was not observed for patients KRAS wild-type tumours. Results for survival stratified by MSI and BRAF status remained non-significant.
Colon cancer patients living in more deprived areas of NI had an increased risk of dying, particularly if they had a KRAS mutant tumour, compared with counterparts residing in less deprived areas.