A sentinel lymph node biopsy (SLNB) procedure identifies the first lymph nodes that breast cancer cells may travel to. To do this, the surgeon injects a radioactive substance and/or a blue dye into the breast at the time of surgery. Lymphatic vessels will carry these substances along the same path that the cancer would take if it traveled to the lymph nodes. The first lymph node(s) the dye or radioactive substance travels to are called the sentinel node(s). These sentinel nodes are then removed through a small incision in the armpit.

sentinel lymph node biopsy

(Photo credit: https://www.cancer.gov/about-cancer/diagnosis-staging/staging/sentinel-node-biopsy-fact-sheet)

The removed lymph nodes (on average one-to-three nodes) are then checked closely for cancer cells by a pathologist under a microscope. If cancer is found in the sentinel node(s), additional treatment (like radiation) or additional surgery (axillary lymph node dissection (ALND)) may be recommended. This recommendation is based on certain factors, such as the size of the breast cancer, what type of surgery is used to remove the tumor, what treatment is planned after surgery, and if a woman had chemotherapy prior to surgery.

Based on the research, skipping the axillary lymph node dissection may be an option for:

  • Women with tumors 5 cm (2 inches) or smaller who have only one or two positive sentinel lymph nodes and are having breast conserving surgery followed by radiation.
  • Women who have had a mastectomy and will also have radiation.

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 will be needed.

SLNB is often performed for women with early-stage breast cancer. There is some data regarding omission of SLNB in women over age 70 with certain types of cancer. Your breast surgeon will discuss your options in more detail. Women with more advanced cancers may require an ALND.

Although sentinel lymph node biopsy 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. OHC’s breast surgical oncologists, Nicole M. Melchior, DO, FACS, and Abigail M. Tremelling, MD, FACS, have extensive experience with this technique, including women undergoing sentinel lymph node biopsy after neoadjuvant chemotherapy (chemotherapy given before surgery).

Reference: https://www.cancer.org/cancer/breast-cancer/treatment/surgery-for-breast-cancer/lymph-node-surgery-for-breast-cancer.html