Examining how chronic inflammation impacts colorectal cancer incidence in Atlantic Canada

Abstract

Background: Colorectal cancer (CRC) is the third most common cancer in Canada. Incidence of CRC in Canada is highest in the Atlantic provinces. This may be, in part, due to increased exposure to risk factors and common genetic susceptibilities in the region. Atlantic Canada is more ethnically homogenous than other parts of Canada, which may allow certain genetic mutations to be more prevalent. Chronic inflammation is a risk factor for cancer. Therefore, genetic variations in inflammatory pathways may be contributing to regional differences in CRC risk, due to their role in tumour development. Objectives: This study aims to examine the associations between single nucleotide polymorphisms (SNPs) of inflammatory genes and CRC. Methods: A case-control study was conducted using data from 2,500 participants from the Atlantic PATH and BC Generations Project cohorts of CanPath. Multivariable logistic regression was used to assess CRC risk among nearly 1,200 SNPs, while the Benjamini-Hochberg procedure was applied to correct for multiple testing. Results: 87 SNPs were found to be significantly associated with CRC and, after adjusting for the false discovery rate, 4 remained significant. Three of the four significant SNPs also had allele distributions that differed significantly by region. Discussion: These findings suggest that SNPs may contribute to the elevated CRC incidence in Atlantic Canada. Additionally, regional differences in allele distribution support the role of genetic factors in shaping disease risk. Understanding these associations could help identify populations with increased CRC risk and inform targeted prevention efforts in Atlantic Canada.