What are the stages of breast cancer?
Depending on the tumor size, nodal status and the status of distant 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 making the treatment plan according to 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 tumors, degree of invasion, status of lymph node involvement, growth rate of the tumor(s), and the status of spreading (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 data about the following:
- The size of the tumor
- Identification of whether the tumor is invasive
- Identification of whether the tumor has reached lymph nodes
- Identification of whether the tumor 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 more detailed staging, a numeric format has also been developed and is widely accepted. This includes:
Types of early breast cancer:
[Also see: Treatment for early breast cancer]
Stage 0 breast cancer: This is also known as pre-cancer, and includes early and non-invasive types of breast cancer
Stage 1A breast cancer: This is a form of early, mostly invasive type of breast cancer, which has not progressed extensively to the lymph nodes
Stage 1B breast cancer: This is a form of early, mostly invasive type of breast cancer, which has mildly progressed to the lymph nodes
Types of locally advanced breast cancer:
[Also see: Treatment for locally advanced breast cancer]
Stage 2A breast cancer: This is a form of localized invasive breast cancer, which 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 tumor 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 and extensive lymph node involvement
Stage 3C breast cancer: This is an aggressive form of locally advanced and invasive breast cancer, with a significantly large tumor, extensive lymph node involvement, and nearby spread to tissues and organs near the breast area
Types of metastatic breast cancer:
Also see: Treatment for metastatic breast cancer
Stage 4 breast cancer: This is the stage at which cancer has spread from the breast tissue area, the lymph nodes, and has extended to organs such as the lungs, liver, bone and/or brain. This is generally considered harder to treat as 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 for an existing breast cancer patient.
Also see: Treatment for recurrent breast cancer