Underarm Surgery: Sentinel Lymph Node Biopsy and Lymphoedema

Breast cancer usually spreads first to the lymph nodes under the arm. The status of these nodes determines both the stage and the need for additional treatment. In the past, all the underarm nodes were removed in most patients; today there are far less burdensome methods.

What is a sentinel lymph node?

The sentinel lymph node is the first node reached by lymph draining from the tumour. If there is no cancer in this node, the chance that the other nodes are clear is very high. During surgery a tracer (a radioactive marker and/or a dye) is injected into the breast; it lets us find the first node, and only one to three nodes are removed.

If the node is clear

Nothing more is done to the underarm, so problems such as lymphoedema and limited shoulder–arm movement are markedly reduced.

If the node is involved

Not every involved node means a full axillary dissection. In selected patients (for example, those having breast-conserving surgery plus radiotherapy with only a few nodes involved), radiotherapy or systemic treatment alone may be enough. In patients who receive chemotherapy before surgery, methods such as targeted axillary surgery are also used. The decision is made together in the board.

What is lymphoedema?

Swelling of the arm caused by a build-up of lymph fluid. It can appear after underarm surgery and/or radiotherapy, even months or years after the operation. Noticing it early makes it easier to manage.

Prevention and everyday tips

• Start shoulder exercises after surgery at the time and in the way your physiotherapist advises.
• Keep your weight in balance; increase heavy or strenuous activity gradually, not suddenly.
• Take small injuries and infections of the operated arm seriously, and keep the skin moisturised.
• Do not wait if you notice swelling around the arm.

Many of the old restrictions on arm use (e.g. “never lift weights again”) have today been replaced by controlled, gradual exercise.