Lymph Node Surgery for Breast Cancer
If breast cancer spreads, it often goes first to nearby lymph nodes. Knowing whether the cancer has spread to your lymph nodes helps medical providers find the best way to treat your cancer.
If you have been diagnosed with breast cancer, it’s important to find out how far the cancer has spread. To help find out if the cancer has spread beyond the breast, one or more of the lymph nodes under the arm (axillary lymph nodes) are removed and checked under a microscope. This is an important part of staging. When the lymph nodes contain cancer cells, there is a higher chance that cancer cells have also spread to other parts of the body. Treatment decisions will often depend on whether cancer is found in the lymph nodes.
Lymph node removal can be done in different ways, depending on whether any lymph nodes are enlarged, how big the breast tumor is, and other factors.
Biopsy of an enlarged lymph node
If any of the lymph nodes under the arm or around the collar bone are swollen, they may be checked for cancer spread directly with a needle biopsy (either a fine needle aspiration [FNA] or a core needle biopsy). Less often, the enlarged node is removed with surgery. If cancer is found in the lymph node, more nodes will need to be removed during an axillary lymph node dissection (described below).
Types of lymph node surgery
Even if the nearby lymph nodes are not enlarged, they will still need to be checked for cancer. This can be done in two different ways. Sentinel lymph node biopsy is the most common and least invasive way, but in some cases a more extensive axillary lymph node dissection might be needed.
Lymph node surgery is often done as part of the main surgery to remove the breast cancer, but in some cases it might be done as a separate operation.
Sentinel lymph node biopsy (SLNB)
In a sentinel lymph node biopsy (SLNB), the surgeon finds and removes the first lymph node(s) to which a tumor is likely to spread (called the sentinel nodes). To do this, the surgeon injects a radioactive substance and/or a blue dye into the tumor, the area around it, or the area around the nipple. Lymphatic vessels will carry these substances along the same path that the cancer would be likely to take. The first lymph node(s) the dye or radioactive substance travels to will be the sentinel node(s).
After the substance has been injected, the sentinel node(s) can be found either by using a special device to detect radioactivity in the nodes, or by looking for nodes that have turned blue. To double check, both methods are often used. The surgeon cuts the skin over the area and removes the node(s) containing the dye or radiation.
The removed lymph nodes (often 2 or 3 nodes) are then checked closely for cancer cells by a doctor called a pathologist. This is sometimes done during the surgery. This way, if cancer is found in the sentinel lymph node(s), the surgeon may do a full axillary dissection (ALND) to remove more lymph nodes. If no cancer cells are seen in the node(s) at the time of the surgery, or if the sentinel node(s) are not checked by a pathologist at the time of the surgery, they will be examined more closely over the next several days.
If cancer is found in the sentinel node(s) later, the surgeon may recommend a full ALND at a later time to check more nodes for cancer. Recently, however, studies have shown that in some cases it may be just as safe to leave the rest of the lymph nodes behind. This is based on certain factors, such as the size of the breast tumor, what type of surgery is used to remove the tumor, and what treatment is planned after surgery. Based on the studies that have looked at this, skipping the ALND may be an option for women with tumors 5 cm (2 inches) or smaller who are having breast-conserving surgery followed by radiation. Because this hasn’t been studied well in women who have had mastectomy, it isn’t clear that skipping the ALND would be safe for them.
If there is no cancer in the sentinel node(s), it's very unlikely that the cancer has spread to other lymph nodes, so no further lymph node surgery is needed.
Although SLNB has become a common procedure, it requires a great deal of skill. It should be done only by a surgeon who has experience with this technique. If you are thinking about having this type of biopsy, ask your health care team if they do them regularly.
Axillary lymph node dissection (ALND)
In this procedure, anywhere from about 10 to 40 (though usually less than 20) lymph nodes are removed from the area under the arm (axilla) and checked for cancer spread. ALND is usually done at the same time as a mastectomy or breast-conserving surgery (BCS), but it can be done in a second operation. This was once the most common way to check for breast cancer spread to nearby lymph nodes, and it is still sometimes needed. For example, an ALND may be done if a previous biopsy has shown one or more of the underarm lymph nodes have cancer cells.
Side effects of lymph node surgery
As with any operation, pain, swelling, bleeding, blood clots, and infection are possible.
A possible long-term effect of lymph node surgery is swelling in the arm or chest called lymphedema. Because any excess fluid in the arms normally travels back into the bloodstream through the lymphatic system, removing the lymph nodes sometimes blocks drainage from the arm, causing this fluid to build up.
This is less common after a sentinel lymph node biopsy (SLNB) than an axillary lymph node dissection (ALND).
Up to 30% of women who have ALND develop lymphedema. It also occurs in up to 3% of women who have SLNB. It may be more common if radiation is given after surgery. Sometimes the swelling lasts for only a few weeks and then goes away. But in some women, it lasts a long time. If your arm is swollen, tight, or painful after lymph node surgery, be sure to tell someone on your cancer care team right away.
Limited arm and shoulder movement
You might also have limited movement in your arm and shoulder after surgery. This is more common after ALND than SLNB. Your doctor may advise exercises to help keep you from having permanent problems (a frozen shoulder).
Some women notice a rope-like structure that begins under the arm and can extend down toward the elbow. This is sometimes called axillary web syndrome or lymphatic cording. It is more common after ALND than SLNB. Symptoms may not appear for weeks or even months after surgery. It can cause pain and limit movement of the arm and shoulder. This often goes away without treatment, although some women may find physical therapy helpful.
Numbness of the skin on the upper, inner arm is a common side effect because the nerve that controls sensation here travels through the lymph node area.
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Last Medical Review: June 1, 2016 Last Revised: August 18, 2016