Because of the complex nature of breast cancer, the severity and progression are categorised by stages and grades to help make a more accurate diagnosis and determine the most effective treatment plan. It's important to note that different stages and grades of breast cancer can affect treatment options and prognosis, but early detection and treatment can improve outcomes.
Stages of Breast Cancer
Your doctor will use the TNM system to determine your staging:
T - relates to the primary tumour, its size, and whether it has spread to nearby tissue
N - identifies if the cancer is in the lymph nodes
M - explains if the cancer has spread beyond the breast into other organs of the body
The different stages specify the size of tumours and if cancer cells have spread to other areas of your body.
Early breast cancer (also described as localised)
- Stage 0: Non-invasive breast cancer, where the abnormal cells are contained within the ducts or lobules (such as ductal carcinoma in situ)
- Stage I: Invasive; the cancer is small, around 2cm or less, and is confined to the breast.
- Stage II (may be divided into IIA or IIB): Invasive; the tumour is between 2-5cm and has likely spread to the nearby lymph nodes under the armpit.
Locally advanced breast cancer (also described as regional)
- Stage III (may be divided into IIIA, IIIB, IIIC): In this stage, cancer may be larger than 5cm and has spread to regional lymph nodes, or into the chest wall including the underlying muscle or overlying skin.
Metastatic breast cancer
- Stage IV: In this stage, the cancer has spread to distant organs, such as the bones, brain, or lungs.
Grades of Breast Cancer
The pathologist will use the Nottingham Grading system to describe the abnormality of the tumour cells and discover how quickly they’re growing. This grading system will look at the following:
- The size and shape of the nucleus (the “brain” of the cell)
- The organisation of the cells and if they look like they’re working together.
- How many of the cells are dividing and growing.
Based upon the above criteria. The cancer is then graded from 1-3:
- Grade 1 (low): The cancer cells are growing slowly and do not look very disorganised compared to normal cells.
- Grade 2 (intermediate): The cancer cells are abnormal and look a bit more disorganised, but not as much as Grade 3 cells and grow at a moderate rate.
- Grade 3 (high): The cancer cells are highly abnormal, look very disorganised and growing rapidly.
