Colon Cancer Trends and Colonoscopy Use in Manitoba

Previous studies in both the U.S. and Canada have suggested that colonoscopy is less protective against right-sided colon cancers than against left-sided ones. Now, a study conducted in Manitoba, Canada, suggests that this might be particularly true among older individuals.

Investigators evaluated rates of right- and left-sided cancers, in conjunction with rates of endoscopy, for the entire population of Manitoba, using the national cancer registry and a provincial health-insurance database. From January 1964 through December 2004, 23,916 cases of colon cancer were diagnosed. The average age at diagnosis increased during the study period — from 67 in 1964–1969 to 71 in 1999–2004. Since the late 1970s, colon cancer incidence rates have remain…