Cancer stage refers to the extent of a cancer patient’s disease. For instance, a patient with advanced breast cancer may be classified as having Stage III or Stage IV breast cancer. Determining cancer stage is critical for prognosis and helps healthcare providers make informed decisions.
Staging information is also used for:
- planning and managing cancer services
- evaluating, measuring and reporting cancer treatment patterns and outcomes
Components of Cancer Stage
- Clinical stage is based on information obtained before surgery to remove a tumour through procedures such as a physical examination, radiologic examination, endoscopy and biopsy.
- Pathologic stage is based on a pathologist’s analysis of tissue samples after surgery.
Capturing Stage Data
Cancer Care Ontario uses collaborative staging to collect cancer stage data directly from patient records at cancer centres and community hospitals in Ontario. This method is consistent with the most common cancer staging coding system in the world – TNM staging.
Historically, only regional cancer centres submitted TNM data to Cancer Care Ontario for patients diagnosed and treated there. To augment the process, we have expanded the use of collaborative staging to all Ontario hospitals that report cancer staging data.
TNM staging, the basis for collaborative staging, comes from the American Joint Committee on Cancer and the International Union Against Cancer. It is the global standard used by clinicians to assess the extent or severity of cancer at diagnosis.
- T stands for the size and extent of the tumour
- N stands for the lymph nodes involved
- M stands for metastasis, or the spread of the cancer to other parts of the body