Sentinel node biopsy for Breast Cancer

Overview
Sentinel node biopsy is the surgical removal of one or more lymph nodes for testing. It is a diagnostic procedure performed in order to determine whether breast cancer has developed the ability to spread through the body. A negative sentinel node biopsy indicates that the cancer is still localized in the breast, whereas a positive sentinel node biopsy suggests that the cancer is metastasizing, or spreading. Sentinel node biopsy helps doctors determine the stage of the cancer and decide what the best treatment options are.

Lymph nodes are part of the lymphatic system. The lymphatic system drains the fluid that bathes your tissues, nourishes your cells, and carries away waste products. Lymph nodes are important to the immune system because they contain white blood cells that fight infection such as T lymphocytes and B lymphocytes.

The sentinel nodes are the first lymph nodes cancer might spread to from the original tumor. In breast cancer, the sentinel nodes are usually in the axillary area, or underarm. They may also be located in the middle of the chest, beneath the breastbone. There are usually one to three sentinel nodes.

Sentinel node biopsy is often performed during a lumpectomy, but it may also be performed before or after lumpectomy. Sentinel node biopsy is a newer, less invasive alternative to axillary lymph node dissection as a diagnostic technique. It usually offers faster recovery time and fewer side effects such as swelling, infection or nerve damage. However, positive results from a sentinel node biopsy may require follow-up with axillary lymph node dissection or radiation therapy to the underarm area.

What does it involve?
Sentinel node biopsy is often an outpatient procedure, but may necessitate one or two days of hospital stay for monitoring.

On the day scheduled for the sentinel node biopsy, you may need to stop eating and drinking eight hours before the procedure starts. You will arrive at the hospital and change into a gown. Before surgery, your surgeon may inject blue dye or a weak radioactive substance into the area around the tumor. This will help the surgeon identify the sentinel node or nodes visually or using a device that detects radiation. You will likely receive a relaxing medication followed by a general anesthetic.

During the surgery, the surgeon will make a small incision, approximately half an inch long, over the area containing the lymph nodes. They will identify the sentinel node or nodes using the dye or radiation detection device and remove them. The removed nodes may be examined for cancer immediately, during the procedure, or be processed later. If cancer is found during the sentinel node biopsy, additional nodes may be removed.

After sentinel node biopsy surgery, you will be sent to a recovery room. Depending on the extent of your surgery, you will spend either a few hours or a night or two. During this time, your blood pressure, heart rate and temperature will be monitored. You will be discharged when your condition is stable. Your surgeon will provide instructions on how to care for your wound, how to exercise your arm so it does not become stiff, and how to recognize signs of infection. You will be given prescriptions for medication to help manage your pain. Make sure you understand the instructions, and do not be afraid to ask questions.

While you finish your recovery at home, get plenty of rest. Take pain medications as needed. Carefully monitor for signs of complications. Call your doctor immediately if you experience swelling or redness in the arm or hand on the side you had the sentinel node biopsy.

The tissue removed during the sentinel node biopsy will be sent to the lab for testing. It may take one or two weeks to receive results. If cancer is found, more nodes may need to be removed.

Intended Outcomes
Sentinel node biopsy can diagnose the stage of the cancer and help determine appropriate treatment plans.

Results
A summary of clinical studies found that sentinel node biopsy accurately predicted cancer in the axillary lymph nodes more than 90 percent of the time. The summary was updated in 2013.

Another summary of clinical studies completed in 2012 found that more false negative results were associated with the use of blue dye alone as a marker. Blue dye combined with a radioactive solution provided significantly fewer false negatives.

Constraints
After sentinel node biopsy, you can expect some pain during recovery and some numbness at the site of the incision. There will be one or more small scars.

You may experience lymphedema (swelling) or seroma (build-up of lymph fluid) around the surgical site. The swelling may affect the hand or arm on that side. There may also be increased likelihood of infection in the affected area.

One danger inherent in a sentinel node biopsy is the potential for a false negative result. If cancer has spread, but no cancer cells are found during testing of the sentinel nodes, this may provide a mistaken sense of security and prevent you from receiving the treatment you need.

Any type of surgery carries risks including blood clots, blood loss, infection, breathing problems, reactions to medication, and heart attack or stroke during the surgery.