What are lymph nodes, and what does it mean that they're finding cancer there?

Lymph nodes are areas in the body, where lymph fluid flows and there often the body fights disease. The fluid carries the disease but also brings white blood cells and antibodies and other disease fighters to the lymph node where the fight often takes place. The fact that your mother's cancer has moved to her lymph nodes is a bad sign. it means that her cancer is now not just in the breast but has gotten outside the breast and has started to spread. When a surgeon removes a cancer (breast or many others) they will often check the lymph nodes near the cancer site to see if the cancer has spread. If the cancer has made it to the lymph nodes, it is likely, but not certain that it has spread farther.