It is important for surgeons performing breast biopsies, to correctly identify which lymph nodes among the cluster of them in the armpit, would be the first ones to come in contact with the cancer cells. When we refer to sentinel nodes, these are the nodes we are referring to. Cancer cells will drain into these nodes first, thereby spreading cancer to the rest of the body.

The sentinel nodes are identified by injecting a radioactive tracer and blue dye into the area around the areola (the dimpled skin around the nipple) or the area around the cancer. A skilled surgeon is able to detect the blue dye and remove only the first few nodes in about 95% of cases. Many women prefer to select a surgeon who only specializes in breast cancer and sentinel node biopsies rather than a general surgeon. It is not rude to ask your surgeon what percentage of times he/she has correctly identified the sentinel nodes. Since treatment will be directed around these results, it is important to correctly identify how many, if any, nodes are involved.

Studies have shown that sentinel node biopsy is very accurate in identifying whether the cancer has spread to the lymph nodes. In the past, surgeons used to remove all the nodes in the armpit in order to see if the cancer had spread. Because only a few nodes are removed this procedure, there is much less chance of developing lymphedema, painful swelling of the arm, which can occur when a large number of these nodes are removed.

For more information on sentinel node biopsy, follow this link to the National Cancer Institute.