Cancer stages

In addition to considering the type of breast cancer you have, your doctors will also look at other characteristics to help decide on the most appropriate treatment for you.

The stage of a cancer is the term used to describe the size of a tumour and the extent of spread.

Breast cancer staging

Stage 1 – the tumour is less than 2cm, the lymph nodes in the armpit (axilla) are not affected and the cancer has not spread outside the breast.

Stage 2 – this is divided into two groups as follows:

• Stage 2A – the tumour is less than 2cm, the lymph nodes under the arm are affected but are not stuck to each other and the cancer has not spread; or the tumour is more than 2cm but less than 5cm, there are no cancer cells in the lymph nodes in the armpit and the cancer has not spread; or there is no tumour seen in the breast, the lymph nodes under the arm are affected but are not stuck to each other and there is no sign of spread to other parts of the body.
• Stage 2B – the tumour is more than 2cm but less than 5cm and the lymph nodes under the arm are affected but the cancer has not spread; or the tumour is bigger than 5cm, there are no affected lymph nodes in the armpit and the cancer has not spread.

Stage 3 – this is divided into three groups as follows:

• Stage 3A – although no tumour is seen in the breast, the lymph nodes under the arm contain cancer cells and are stuck to each other, but there is no sign of cancer spread; or the tumour is more than 2cm but less than 5cm, the lymph nodes in the armpit contain cancer cells and are stuck to each other, but the cancer has not spread elsewhere; or the tumour is more than 5cm, the lymph nodes in the armpit contain cancer cells and may be stuck together, but there is no further spread.
• Stage 3B – the tumour is fixed to the skin or chest wall, the lymph nodes may or may not contain cancer cells, but there is no further spread.
• Stage 3C – the tumour can be any size and has spread to lymph nodes in the armpit and under the breast bone, or to nodes above (supraclavicular nodes) or below (infraclavicular nodes) the collarbone but there is no further spread.

Stage 4 – the tumour can be any size, the lymph nodes may or may not contain cancer cells but the cancer has spread to other parts of the body.

If cancer is found in the lymph nodes under your arm but nowhere else in the body you do not have stage 4 breast cancer.

Source: Cancer Research UK