Sentinel Lymph Node Biopsy

After you find out you have breast cancer, your doctor may recommend a sentinel lymph node biopsy. This is a procedure used to see if cancer has spread beyond the place where it started and into the nearby lymph nodes. This type of biopsy is based on the idea that cancer cells spread in an orderly way from where they start to the sentinel lymph node(s), then to other nearby lymph nodes. The sentinel lymph node is the first lymph node to which cancer is likely to spread. In some cases, there can be more than one sentinel lymph node. 

In a sentinel lymph node biopsy the sentinel lymph node is identified, removed, and examined under a microscope to see if cancer cells are present. This information may help the doctor determine the stage of the cancer (the extent of the cancer in your body) and develop the best treatment plan for you. For instance, if the sentinel biopsy does not show cancer in your lymph node, you can preserve your other underarm lymph nodes. Having your underarm lymph nodes removed isn’t a dangerous operation, but it can cause side effects, such as numbness and a life-long risk of swelling in your arm (called lymphedema).

If your doctor suggests a sentinel lymph node biopsy, talk about why this may be needed in your situation and how it can help you. This type of biopsy requires a lot of skill and it should only be done by a surgical team with experience. Ask your doctor how many sentinel lymph node biopsies he or she has done.  

What happens during a sentinel node biopsy

During a sentinel lymph node biopsy, a specially trained surgeon injects a radioactive dye in the area of the tumor. This dye travels to the sentinel node. The dye lets your surgeon find the sentinel node so that he or she can remove it through a tiny cut made in your skin. Then, the surgeon sends it to a lab for examination.

If there is no cancer in the sentinel node, then the rest of your underarm nodes don’t need to be taken out.

If there is cancer in the sentinel node, your surgeon may remove more of your underarm lymph nodes. This may be done at the same time or several days later, depending upon how easily the cancer can be seen in the sentinel node at the time of surgery.

Sentinel node biopsy is often followed by breast-conserving surgery or a mastectomy.

This biopsy may be scheduled for the same time as breast-conserving surgery, or it can be done separately.