Medical Update: Lymph Node Removal for Breast Cancer

Have you ever had a leak in your air conditioning unit? The service technician probably injected a dye into the system so he could find the exact location of the leak. Researchers are experimenting with a similar procedure to help physicians determine appropriate treatment for breast cancer patients.

Lymphatic System and Breast Cancer

This new procedure involves the lymphatic system, which is part of our body's defense system. Just as arteries and veins circulate blood throughout the body, lymph vessels circulate lymph fluid. Lymph nodes are small round organs that cluster in groups in the neck, underarm area, chest, abdomen, and groin. They trap cancer cells, bacteria, and other harmful substances from lymph fluid before they endanger your health. When breast cancer spreads, the cancer cells detach from the primary tumor and enter the blood through the lymph nodes.

If you have breast cancer, your oncologist must determine the stage of your cancer to plan the best course of treatment. This requires her to remove the tumor and lymph nodes under the arm (biopsy). Cancer stage depends on the size of the tumor and whether it has spread (metastasized).

Sentinel lymph node (SNL) biopsy is standard procedure in breast cancer. The sentinel lymph node is the one most likely to have breast cancer cells if your cancer has spread. When the biopsy reveals cancer cells in the SNL, your surgeon may then also remove lymph nodes under your arm (auxiliary lymph nodes), which drain lymph fluid from the breast and nearby areas. SNL biopsy removes fewer lymph nodes, so women are less likely to develop lymphedema, a painful side effect in which the area around the surgery swells and causes pain.

New Diagnostic Technique

Researchers at the University of California, San Diego, are testing a non-surgical method to identify critical lymph nodes that have cancer-without unnecessary and invasive surgery. The procedure uses ultrasound (high-frequency sound waves) and gas-filled microbubbles. Physicians inject the bubbles, which have fluorescent outer shells loaded with dye, into the tumor and use the ultrasound to track them as they move away from the tumor and into the lymph system. Once they identify the sentinel lymph node, they burst the bubbles, releasing a non-toxic substance that sticks to the lymph nodes. Physicians then only need to remove those lymph nodes that show signs of cancer, sparing women surgery if their cancer has not spread.

Mulcahy, Nick. "Positive Nodes, But Axillary Dissection Not Needed; Patients only had 1 or 2 positive nodes." Medscape Medical News. Web. 9 February 2011.

University of California, San Diego. "Microbubbles to Light the Way to Sentinel Lymph Nodes of Breast Cancer Patients. Press release. Web. 23 February 2011.

National Cancer Institute. "Sentinel Lymph Node Biopsy. Web. 27 April 2005.

National Cancer Institute. "What you need to know about breast cancer." Web. 15 October 2009.