Are there any breast cancer cells in the lymph nodes?

Breasts have a network of lymph vessels that drain into the lymph nodes (glands) in the armpit (axilla).

There are about 20 lymph nodes in the armpit, though this can vary from person to person.

Breast cancer cells can spread to the lymph nodes, so if you have invasive cancer, a number of nodes may be removed during surgery. These are then checked to see whether or not they contain any cancer cells.

Negative lymph nodes means the nodes tested are free of cancer cells. Positive lymph nodes means they do contain cancer cells.

The pathology report will state (usually in numbers) how many nodes were removed during surgery and how many contain breast cancer cells. For example, 2/10 means 10 lymph nodes were removed and 2 contained cancer cells. The more positive nodes there are, the higher the chance of cancer spreading elsewhere in the body.

Sometimes there’s only a very tiny area of breast cancer cells in the lymph nodes. When this measures between 0.2mm and 2mm it is called micrometastases (or sometimes micro invasion). When it is less than 0.2mm, it is called isolated tumour cells.

Micrometastases are classed as lymph node positive, whereas isolated tumour cells are considered lymph node negative.

Treatment options

People with lymph node positive breast cancer are more likely to have chemotherapy and radiotherapy recommended to help destroy any cells that may have got in to the lymphatic system.