Canada reports first-ever cancer stage data
The data can also help policymakers and others determine where best to focus efforts to reduce the burden of cancer, whether through screening and early detection or better access to improved treatment.
The Cancer Stage in Performance Measurement: A First Look - A System Performance Spotlight Report shows the baseline results of the National Staging Initiative, in which nine provinces collected and shared population-based stage data for Canadians diagnosed with breast, colorectal, lung or prostate cancer.
Cancers are staged based on the size or extent of the primary tumour, whether cancer cells have spread to nearby lymph nodes and whether the cancer has spread to other distant parts of the body.
Stage 0 cancers are considered to be the earliest form of the disease, while Stage IV cancers are the most advanced, having spread from the initial site to other parts of the body. Bigger tumours and greater spread of disease will result in a higher stage.
Figures from the report show the vast majority of Canadians diagnosed with breast cancer in 2010 had Stage I or II disease. The incidence of Stage I breast cancer was more than 10 times higher than the rate for Stage IV disease. This is to a large extent due to the success of screening and early detection efforts of the last 20 years.
The report also shows colorectal cancer was most commonly diagnosed at Stage III, when it is still curable through surgery and chemotherapy. The incidence rate for Stage IV colorectal cancer was similar to the incidence for Stage I disease. However that pattern is expected to shift within the next 10 years as the impact of colorectal cancer screening programs begin to be realized.
The incidence rate of Stage IV lung cancer was found to be more than twice that of Stage I or II, the report shows. Lung cancer is responsible for more deaths than in other cancer in Canada, but increased smoking cessation is helping to bring down those numbers. The Partnership has also been facilitating the development of a framework for potential screening programs for people at high risk of developing lung cancer.
Knowing the stage of cancer when it is first diagnosed helps identify treatment options. Over time, it may also point to the effectiveness of screening programs. When combined with data on treatment, stage data can help track whether cancer care is being delivered according to recommended practice guidelines.
Data on cancer survival-by-stage are also being collected and will be available in 2015. ■
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