Breast Cancer and Lymph Nodes

Q:  A close friend if mine who is only 37 was just diagnosed with breast cancer. After her surgery, it was discovered that the cancer had spread to her lymph nodes. Just what are lymph nodes and what do they do? Why are they important in the diagnosis and treatment of cancer?

A:  First, let me extend my sympathy and encouragement to your friend. The treatment of breast cancer has many more options than in the past, with real cause for hope of a complete recovery.

Lymph nodes are part of the lymphatic system circulating a fluid known as lymph, rich in proteins and fats from the digestive tract. Lymph has its own separate circulatory system that interconnects with the bloodstream. Lymph nodes are organized collections of lymphatic tissue interposed throughout the lymphatic stream. These bodies vary from the size of a pinhead to that of a small olive and are frequently larger in the presence of disease.

One of the principal functions of lymph nodes is the production of lymphocytes that are directed to the bloodstream to fight infection. Lymph nodes enlarge during infections or if invaded by cancer cells and may themselves become infected, swollen and tender. The lymphatic system is utilized by some kinds of cancer cells as a medium to spread through the body. This process of metastasis accounts for the wide dissemination of cancers in certain cases.

Lymph nodes are widely distributed in the body on a regional basis. It is not unusual to be able to feel some nodes in the absence of disease, although they should be quite small. They are often clustered in groups. For example, there are nodes in each armpit. These are the ones removed when breast cancer is diagnosed. Your tonsils are also lymph nodes. There are some behind each ear and under the chin. There are clusters near your lungs and intestines as well.

Most of the time, enlarged lymph nodes are not a source of great concern. You should contact your doctor if they remain enlarged in the absence of infection and fail to decrease in size over a few weeks. He or she will perform a careful examination and may recommend observation, a blood test, or perhaps a biopsy.

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