Cancer Treatment Centers of America

Sentinel lymph node biopsy for breast cancer

Sentinel lymph node biopsy for breast cancer

Depending on the stage of the breast cancer, your surgical care team may recommend an axillary sentinel lymph node biopsy as part of your breast cancer surgery.

An axillary sentinel lymph node biopsy:

  • Helps evaluate the extent of disease and enables your care team to determine whether chemotherapy or radiation therapy is required as part of your treatment.
  • Helps your surgeon determine whether an axillary lymph node dissection is needed
  • Can potentially avoid unnecessary removal of lymph nodes in the axilla, helping to reduce both the length of surgery and the risk of developing lymphedema, a condition in which excess (lymphatic) fluid collects in soft tissue of the arm and causes swelling.

What is a sentinel lymph node biopsy?

Axillary sentinel lymph nodes are the first lymph nodes under the arm (axilla) to which breast cancer cells may spread from the primary tumor location in the breast. Depending on the stage of the breast cancer, your surgeon may perform an axillary sentinel lymph node biopsy at the same time as lumpectomy or mastectomy.

During surgery, a radiotracer and/or dye is first injected into the breast. After allowing time for it to travel to the axillary sentinel lymph node, the surgeon makes a small incision under the arm to identify and remove the lymph node.

A pathologist will then analyze the sentinel lymph node to determine whether cancer has spread to it. If cancer has spread to three sentinel lymph nodes, and you have chosen to preserve your breast (breast conservation), your surgeon will likely remove the remaining lymph nodes (called an axillary lymph node dissection). 

Prior to this concept of a sentinel lymph node biopsy, surgeons needed to remove all of the lymph nodes in the axilla and the risk of developing lymphedema was much greater.

If you have chosen to have a mastectomy, and a sentinel lymph node is positive for carcinoma, your surgeon will perform an axillary lymph node dissection.