Grant: Operating Grant: Data Analysis Using Existing Databases and Cohorts

Lung cancer and colorectal cancer are the two most common cancers, and the two most common causes of cancer death, in Canada. Approximately 50% of all cases of LC diagnosed in Canada between 2011 and 2015 were diagnosed at stage IV; 49% of CRC cases diagnosed in the same time period were diagnosed at stage III or IV. Stage of diagnosis is directly related to survival, with stage IV survival estimated at less than 10% for lung cancer and 11% for colorectal cancer. As with many other health outcomes, there is evidence for disparities in stage of diagnosis based on social factors. However, although disparities in cancer screening for immigrants are well documented, little is known on disparities in diagnosis of lung cancer or colorectal cancer among immigrants to Canada, despite foreign-born persons making up approximately 20% of the national population. Reducing mortality due to these two cancers will require rich data to develop an understanding of where disparities lie in early stage diagnosis, and how they can be addressed. In this study, we will explore stage of diagnosis for these two cancers for immigrants as compared to Canadian-born persons. We will also examine the role of other factors in early-stage diagnosis, such as primary care access, socio-economic status and health status. We will use Ontario-level databases housed at the Institute for Clinical Evaluative Sciences to conduct this work, including the Immigration Refugee & Citizenship Canada database, which includes data on country of birth, immigrant class, and date of landing, and the Ontario Cancer Registry, which includes all incidence cases of common adult cancers including LC and CRC. Our findings will provide important new knowledge on how to reduce disparities, and target interventions, for lung cancer and colorectal cancer diagnosis and survival in Canada for immigrants and other potentially marginalized groups.