Socioeconomic inequalities in colorectal cancer incidence in Canada: trends over two decades

Purpose Colorectal cancer is the third most commonly diagnosed cancer in Canada. This study aimed to measure and examine trends in socioeconomic inequalities in the incidence of colorectal cancer in Canada. Methods This study is a time trend ecological study based on Canadian Census Division level data constructed from the Canadian Cancer Registry, Canadian Census of Population, and National Household Survey. We assessed trends in income and education inequalities in colorectal cancer incidence in Canada from 1992 to 2010. The age-standardized Concentration index ( C ), which measures inequality across all socioeconomic groups, was used to quantify socioeconomic inequalities in colorectal cancer incidence in Canada. Results The average crude colorectal cancer incidence was found to be 61.52 per 100,000 population over the study period, with males having a higher incidence rate than females (males: 66.98; females: 56.25 per 100,000 population). The crude incidence increased over time and varied by province. The age-standardized C indicated a higher concentration of colorectal cancer incidence among lower income and less-educated neighborhoods in Canada. Income and education inequalities increased over time among males. Conclusion The concentration of colorectal cancer incidence in low socioeconomic neighborhoods in Canada has implications for primary prevention and screening.