Staging is the process of finding out how widespread the cancer is when it is found. The stage is the most important factor in deciding how to treat breast cancer and determining how successful treatment might be.
In order to stage breast cancer fully, we use information from 3 resources:
- physical examination of breasts and armpits
- mammogram and ultrasound reports
- biopsy results
To determine cancer’s stage, we must answer these questions:
- How big is the breast tumour? Has it grown into nearby areas?
- Has cancer spread to nearby lymph nodes? If so, how many are involved?
- Is the cancer invasive or non-invasive?
- Has cancer spread to other parts of the body?
Sometimes we may need more tests to help determine the stage, such bone scans, CT scans, MRI, and/or PET scans. Blood tests may also be done to evaluate your overall health or to check for spread to certain organs.
The earliest stage cancers are called stage 0 (carcinoma in situ), and then range from stages I (1) through IV (4). Some of the stages have sub-stages with the letters A, B, and C.
As a rule, the lower the number, the less cancer has spread. A higher number, such as stage IV, means a more advanced cancer. And within a stage, an earlier letter means a lower (and often better) stage.
- stage is – the tumour is “in situ” and there’s no evidence of invasion (pre-invasive)
- stage 1 – the tumour measures less than 2cm and the lymph nodes in the armpit aren’t affected; there are no signs that the cancer has spread elsewhere in the body
- stage 2 – the tumour measures 2-5cm, the lymph nodes in the armpit are affected, or both; there are no signs that the cancer has spread elsewhere in the body
- stage 3 – the tumour measures 2-5cm and may be attached to structures in the breast, such as skin or surrounding tissues, and the lymph nodes in the armpit are affected; there are no signs that the cancer has spread elsewhere in the body
- stage 4 – the tumour is of any size and the cancer has spread to other parts of the body (metastasis)