Lymph Node Dissection in Breast Cancer

Results set the stage for the creation of your treatment plan

In This Article

Once you've been diagnosed with breast cancer, your oncologist will need to determine if cancer cells have spread to your lymph nodes by removing, or dissecting, some of them so they can be examined under a microscope. There are two types of lymph node removal: sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND), the latter of which is more invasive. These may be done during breast surgery or in a separate procedure.

Lymph nodes are present throughout your body and work as filters that catch bacteria, viruses, and cancer cells. The nodes work with your circulating blood to provide nutrients to all your cells, as well as remove cellular waste products. Cancer cells present in the lymph nodes near your breast and arm have the potential to spread (metastasize) to other areas of your body, increasing your risk of metastatic breast cancer.

Sentinel Lymph Node Biopsy (SLNB)

what to expect during a sentinel node biopsy
 Verywell / Emily Roberts

This is a diagnostic procedure done to determine the extent of lymph node involvement if there is any.

A blue dye and a weak radioactive agent are injected into the breast tumor. The first lymph node the dye or radioactive substance travels to is called the sentinel node; this is the lymph node that cancer cells are most likely to reach before going any further.

Once the sentinel lymph node is located, the surgeon makes a small incision to remove the node, which is then checked for the presence of cancer cells by a pathologist. If cancer is found, the surgeon may remove additional lymph nodes, either during the same biopsy procedure or during a follow-up surgical procedure. SLNBs may be done on an outpatient basis or may require a short stay in the hospital.

In addition to helping doctors stage cancers and estimate the risk that tumor cells have developed the ability to spread to other parts of the body, SLNB may help some patients avoid more extensive lymph node surgery.

Axillary Lymph Node Dissection (ALND)

If cancer is found during your sentinel node biopsy, your surgeon may remove some or all of your axillary lymph nodes—those in the area of your armpit—for additional testing.

Axillary lymph node dissection may be done as part of a lumpectomy or mastectomy. As few as 10 or as many as 40 lymph nodes may be removed. These will be sent to the pathology lab where they will be carefully examined for cancer cells.

Your pathology report will say how many nodes were removed and how many of them, if any, contained cancer cells. This important information affects the staging of your cancer and influences your treatment options.

Side Effects

The most common side effect of a lymph node dissection is lymphedema, in which the arm swells, sometimes significantly. Since you'll have fewer lymph nodes under your arm to process lymphatic fluid, the fluid may build up and cause swelling along your arm and sometimes your hand.

If just a few nodes are removed, lymphedema may be a temporary condition, but if most of your lymph nodes were removed, it may be a long-lasting problem. Therapeutic massage and compression garments can help.

Other side effects of lymph node removal may include:

  • Loss of sensation/numbness in the breast or axilla due to procedure-related nerve damage
  • Limited arm mobility
  • Muscle weakness
  • Reduced arm and shoulder range of motion

Women are typically advised to avoid lifting heavy objects and unnecessarily straining the area for up to six weeks after surgery. Light lymphedema exercises, however, may be recommended to help address swelling.

Be sure to ask for physical therapy to help regain your motion and strength.

How Lymph Node Status Affects Treatment

Based on the number of positive nodes, your lymph node involvement will be given a rating from N0 to N3. This rating is an important part of your complete diagnosis, as well as what treatments will be considered.

Understanding Lymph Node Status
Lymph Node Rating Definition
N0 Negative, or clean: Nodes contain no cancer or micrometastases.
N1 Positive: Cancer is found in 1 to 3 lymph nodes under the arm or in the breast.
N2 Positive: Cancer is found in 4 to 9 lymph nodes under the arm or in the breast.
N3 PositiveCancer is found in 10 or more lymph nodes under the arm or has spread under or over the collarbone. It may have been found in the underarm nodes as well as lymph nodes within the breast.

Clear nodes and a small tumor may not require further treatment with chemotherapy or radiation because the chance of metastasis is low, while a larger tumor and/or positive nodes may be followed up with chemotherapy, radiation, or both.

A Word From Verywell

Always check your underarm area during your monthly breast self-exam to keep tabs on your axillary lymph nodes, which are likely to swell if cancer is present.

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