What do lymph nodes have to do with breast cancer?
Lymph nodes are small, bean-shaped structures located at stations along the vessels of the lymphatic system. The lymphatic system is a network of vessels that transports fluids around your body. A major function of this transportation network is to filter foreign substances from the body. Unfortunately, when cancer is present, it may use the lymphatic system to gain access to other parts of the body. Once cancer cells reach the lymph vessels in the breast, the cancer can use this transportation network to spread to nearby lymph nodes in the armpit (axilla) and to more distant parts of the body, such as the bones or lungs. Even when the lymph nodes are not involved by cancer, it is still possible, although less likely, for the cancer to spread (e.g., through the bloodstream).
