Q. In your article last month, you mentioned sentinel node sampling of lymph nodes. I am not sure what that means.

A. When a woman is diagnosed with breast cancer, it is important to determine whether the cancer has gone to her lymph nodes.

In the old days, at the time the woman had a lumpectomy, the surgeon would also “strip the lymph nodes” from her underarm. This was a debilitating procedure that left the woman with a lot of subsequent medical issues. She had swelling in her arm (lymphedema), she had a lot of arm, shoulder and underarm pain, and she often had significant decreased range of motion (limited use) of that arm. These terrible side effects would often last her whole life. Sometimes she had to wear special compression sleeves on her arm to help with the swelling.

Over time, we began to ask ourselves, “Is there a better way?” Surgeons had already known from Melanoma Cancers that it was not necessary to take out all the regional lymph nodes when treating a person who had a leg melanoma. They had learned that they could inject a special dye and a special radio tracer into the skin around the leg melanoma and only take out one, two, or three of the lymph nodes that first took up the dye – the so-called sentinel nodes, or guardian nodes. They learned that if those lymph nodes were free of melanoma, then the cancer had not spread.

So surgeons experimented with this idea in the breast. They injected the skin around the breast cancer with special dye and special radio tracer to see if it would “always migrate” to the same series of lymph nodes – the sentinel nodes of the breast, and it did. Instead of stripping the underarm of all lymph nodes, we can now simply remove the one, two, or three guardian nodes, and if they are free of tumor, then there is no reason to perform the debilitating underarm surgery I described above.

However, in order to get successful sentinel node surgery results, it is important that the lymphatic drainage of the breast not be interrupted (not be cut into). That is why I wrote last month that it was important to do a needle biopsy instead of a surgical biopsy to determine if a lump was cancerous.

If a surgical biopsy is done, it more likely will interrupt the normal lymphatic drainage of the breast and reduce the chances of obtaining a subsequent successful sentinel node procedure.

Michael J. Ulissey, M.D., is a partner at the Breast Diagnostic Centers of Auburn and Federal Way. In addition to taking care of patients locally, he continues to participate in research as an adjunct professor at the University of Texas Health Sciences Center. You can reach him at mike@breastdiagnostic.com.