Stages of breast cancer

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Before describing stages of breast cancer it is worth mentioning the process of staging alone. Staging refers to how advanced the tumour has grown both locally or spread elsewhere. There are a number of staging systems used throughout the world but the most popular are the TNM (size of local tumour, whether spread to local lymph nodes, whether metastasied) bladder cancer stage is described using this system.  Other tumour use a number of other systems such as AJCC, FIGO (gynaecological tumours), Duke's (colorectal carcinoma) and Ann Arbor classification (lymphoma). The main advantages of an internationally agreed staging system are:-

• To aid the clinician to plan the most appropriate treatment

• To give an indication of prognosis

• To assist in the evaluation of the results of treatment

• To facilitate the exchange of information between hospitals

• To contribute the investigation of cancer

What are the stages of breast cancer?

Carcinoma in situ - there are two types of breast cancer in situ. They are called ductal and lobular carcinoma in situ (often referred to as DCIS or LCIS respectively). They are considered to be pre-cancerous stages of the actual disease. In some classifications these are referred to as stage 0. This level of the disease is considered to be non-invasive.

Stage I -  Malignant cells have spread from ducts or lobules to neighbouring  tissue in the breast. Lymph nodes are not involved at this level. The tumour is not larger than 2 centimeters in diameter (about 1 inch). Starting with this stage the cancer is described as invasive.

Stage II  - This stage describes invasive form of cancer in which either the tumour size ranges from 2 to 5centimeters (about 1 to 2 inches) or  malignant cells have spread to the lymph nodes. When lymph nodes are involved the tumour can be any size.

Stage III - distinguishes between stages IIIA and IIIB:

Stage IIIA describes invasive form of the disease in which :

• either the tumour is smaller than 5 centimeters (about 2 inches) and has spread to the underarm lymph nodes, and the lymph nodes are attached to each other or to other structures.

• or the tumour is larger than 5 centimeters and has spread to the underarm lymph nodes.

Stage IIIB describes invasive form of the disease in which:

• the disease has spread to tissues surrounding the breast (skin or chest wall, including the ribs and muscles in the chest).

• the disease has spread to lymph nodes inside the chest wall along the 

Stage IV - known as metastatic, i.e. the primary cancer has spread beyond the breast and nearby lymph nodes to other parts of the body (such as liver, bone, brain, lungs).