Stages Of Breast Cancer
What are the stages of breast cancer?
Depending on the tumour size, nodal status and the spread of the disease, breast cancer is classified into different stages, from stage 0 to 4. At the time of diagnosis, the disease is staged with the help of clinical examination and radiological imaging. Staging helps doctors decide on a treatment plan for optimum outcome possibilities.
Broadly speaking, breast cancer is classified as either early, locally advanced, metastatic or recurrent. In medical terms, breast cancer is staged based on the size of the tumours, the degree of invasion, the status of lymph node involvement, growth rate of the tumour(s), and the extent of spread (metastasis) to other parts of the body. Oncologists have developed several strategies to determine the stage of breast cancer in each patient, such as physical exams, biopsies, x-rays, bone imaging tests and blood tests.
Stages of breast cancer: What information do they provide?
An accurate breast cancer stage provides information about the following:
- The size of the tumour
- Identification of whether the tumour is invasive
- Identification of whether the tumour has reached the lymph nodes
- Identification of whether the tumour has spread (metastasized) to other parts of the body
- Identification of whether this is a recurrent (relapsed) version of cancer
Broadly, breast cancer can be classified as early breast cancer (EBC), locally advanced breast cancer (LABC), metastatic breast cancer (MBC) or recurrent breast cancer (RBC). The treatment protocols for different stages are distinct. However, for a more detailed staging, a numeric format has also been developed and is widely accepted. The numeric format can be explained as follows.
Types of early breast cancer:
Stage 0 breast cancer: This is also known as carcinoma in situ( precancerous stage) and includes early and non-invasive types of breast cancer.
Stage 1A breast cancer: This is a form of early breast cancer, in which the cancer is mostly invasive and has not progressed extensively to the lymph nodes.
Stage 1B breast cancer: This is a form of early breast cancer, which is mostly invasive, and has mildly progressed to the lymph nodes
Types of locally advanced breast cancer:
Stage 2A breast cancer: This is a form of localized, invasive breast cancer, in which the cancer has progressed to the lymph nodes.
Stage 2B breast cancer: This is a form of localized, invasive breast cancer with significant lymph node involvement.
Stage 3A breast cancer: This is a form of locally advanced, invasive breast cancer with significant lymph node involvement and a medium-to-large tumour at the original site.
Stage 3B breast cancer: This is a mildly aggressive form of locally advanced and invasive breast cancer, with involvement of skin or chest wall, as well as extensive lymph node involvement.
Stage 3C breast cancer: This is an aggressive form of locally advanced and invasive breast cancer, with a significantly large tumour, extensive lymph node involvement, and spread to the nodal stations above and below the clavicle.
Types of metastatic breast cancer:
Stage 4 breast cancer: This is the stage at which cancer has spread from the breast tissue area and the lymph nodes, and has extended to organs such as the lungs, liver, bone and/or brain. This is generally considered harder to treat when compared to early and locally advanced stages of breast cancer.
Recurrent breast cancer: This is not a progressive stage. It refers to a condition where the cancer has relapsed after the completion of treatment in the same breast cancer patient.