What is Lymph Node Surgery?

Breast cancer surgery is always accompanied by an examination of one or more of the lymph nodes in the armpit, sometimes referred to as the axilla. If cancer spreads from the breast, it travels to these “sentinel” lymph nodes first.

Knowing if the cancer has spread also helps us to stage it (find out how much cancer there is in the body and where it is located), advise on further treatment and determine your prognosis.

In the past, all women found with a breast tumour had an axillary clearance, where all the lymph nodes in the armpit were removed. But this extensive removal can be associated with more post-operative complications, such as pain, swelling and nerve damage, without any added benefit to the woman. A newer technique – sentinel node biopsy - is now used in a large number of women. This procedure reduces the possible side effects, while still providing the information needed for treatment planning.

What is the sentinel
lymph node?

A fine network of vessels drains the breast up to the lymph nodes in the armpit (less commonly, to the sternum). If breast cancer spreads it travels by this pathway. The sentinel lymph node is the “guardian” node, or the first that the cancer will spread to. There are one to four sentinel lymph nodes.

What is an axillary dissection?

If your cancer is not suitable for a sentinel node biopsy, an axillary dissection (clearance) will be performed. This usually means 10-20 lymph nodes are removed, from what surgeons describe as level one and level two areas – this denotes how far surgeons go into the surrounding tissue to remove lymph nodes. A plastic drain is left in the armpit after the operation to drain excess fluid. This is well tolerated by most women, and other nodes are left intact to carry out normal lymphatic function.

Any surgery on the lymph nodes under the arm requires a post-operative treatment plan for arm exercises, and women are given information about lymphoedema (chronic swelling) and its prevention.

How is the sentinel
node located?

Prior to surgery, radioactive fluid is injected just above the nipple. The fluid moves through the fine lymphatic vessels up to the lymph nodes in the armpit. During surgery, a radioactive scanner, or probe, is then inserted into a small cut made under the arm, or into the end of the mastectomy wound, to identify the “hot” sentinel nodes, which are removed during surgery. A pathologist examines them to determine if they contain cancer or not.

While you are under anaesthetic, your surgeon may also inject a blue dye and massage it up to the armpit; this can also be used to identify the sentinel nodes.

Not all cancers are suitable for a sentinel node biopsy, and your specialist and nurse will discuss this with you.

What is a sentinel
node biopsy?

A sentinel node biopsy is the removal and examination of these nodes to determine if the breast cancer has spread. A pathologist examines the lymph nodes during surgery - if they do not contain cancer, no further nodes are removed. If the nodes do contain cancer, an axillary dissection - removing more lymph nodes from a wider area – will be performed.