Staging
After a diagnosis of cancer is made, the disease will be staged.
Staging of the disease reflects the spread of cancer, both extension locally and to other areas of the body.
Cancer is staged for two reasons.
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To establish a more complete picture and therefore, to aid in a decision for appropriate management.
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To establish a prognosis.
The staging of each cancer is done differently, but they largely follow the Stage 1 – 4 system. The stage is determined by imaging +/- surgical excision and tissue examination under a microscope.
Stage 1: The cancer cells have not invaded deeper into the surrounding tissue or spread around the body.
Stage 2/3: Spread more extensively locally, invading the surrounding tissues and involving the lymph nodes.
Stage 4: The cancer has spread to a distant site, unrelated to the primary tumour. This is often referred to as metastatic disease, with each separate cancer site called a “met” (short for metastases).
An oncologist will treat a patient differently depending on the stage of their cancer. If it is stage 1, surgical excision alone may suffice, if the microscopic investigation shows clean borders.
If it is stage 4, surgical excision alone will not be sufficient as the cancer has spread. Sometimes the primary/largest tumour will still be removed, before commencing chemo/immunotherapy and/or radiotherapy.
As mentioned, the staging is also helpful in terms of establishing a prognosis. Your oncologist may use the term "5-year survival rate”. Essentially, this is the percentage of patients that have survived their cancer five years on from diagnosis depending on the stage and tumour subtype.
Some patients would prefer not to know such numbers, which is absolutely their right. But many find it helpful, in understanding their chance of a positive outcome. These numbers are established by studying thousands of cases with the same cancer, stage, and received treatment as the prospective patient.