New Ontario Cancer Registry rules increase t...

New Ontario Cancer Registry rules 
 September 2015

In October 2014, the Ontario Cancer Registry (OCR) implemented a new set of rules for identifying multiple primary cancers, which has led to an increase in the number of reported cases for certain cancer types. The OCR is the provincial database containing information about all newly diagnosed cancer cases in Ontario, except for basal cell and squamous cell carcinomas of the skin, and its new rules are applied to cases diagnosed from 2010 onwards.
Multiple primary cancers are two or more distinct cancers that occur in one person and are different from metastases, which develop when cells from a primary cancer spread to other parts of the body. The new rules, which follow standards for counting multiple primary cancers defined by the National Cancer Institute’s Surveillance, Epidemiology and End Results (NCI SEER) Program, replaced rules that were a modified version of the International Association of Cancer Registries (IACR) standards. With the new rules, the number of newly diagnosed cancer cases registered by the OCR in 2010–2011 is 5.8 per cent higher than the number of cases that would have been reported using the old rules.....