Later, if breast cancer cells get into the lymphatic system or bloodstream, they can travel to other parts of the body and start growing there. These cancers are called secondary cancers or metastases.

If breast cancer does spread to distant parts it may be to the lungs, liver or bones, or less often to the spine or brain.

Our lymphatic system includes nodes and channels that carry a fluid called lymph around the body. There are groups of lymph nodes in each armpit (the axillary lymph nodes). Most patients with breast cancer have axillary nodes taken out during surgery, to find out whether the cancer has spread. This helps the doctor to decide whether further treatment is needed.