Ontario Cancer Incidence Data

Data Notes

• The Ontario Cancer Registry (OCR), housed at Cancer Care Ontario, is a computerized database of information on all Ontario residents who have been newly diagnosed with cancer ("incidence") or who have died of cancer ("mortality").
• This information is used to support management decision-making, planning, disease surveillance and research. 
• All new cases of cancer are registered, except non-melanoma skin cancer.
• The Registry is compiled by linking administrative data, clinical and demographic data from four major data sources:

1) hospital discharge and ambulatory care records with cancer diagnoses in the CIHI (Canadian Institute of Health information) DADS and NACRS databases (Discharge Abstract Database and National Ambulatory Care Reporting System),

2) pathology reports with any mention of cancer from hospitals and private laboratories,

3) records from Regional Cancer Centres or Princess Margaret Hospital, and

4) Ontario death certificates with cancer as the underlying cause of death.

All cancer-related data on these records are reviewed by an electronic system of medical logic to produce consolidated information about the cancer diagnosis.

• Cancer diagnoses are classified according to the International Classification of Diseases for Oncology, 3rd edition (ICDO-3). 
• Rates and proportions based on counts less than 6 must be suppressed.
• Ontario incidence data from the OCR are included in the annual Canadian Cancer Statistics publication for comparison with other provinces and territories; because of submission dates to the Canadian Cancer Registry, these published data will differ slightly from data published or obtained directly from Cancer Care Ontario.

References and Resources

1. Cancer Care Ontario. URL: http://www.cancercare.on.ca/
2. National Cancer Institute of Canada: Canadian Cancer Statistics 2009, Toronto, Canada, 2009. URL: www.cancer.ca