Sentinel lymph node dissection is an alternative to traditional axillary lymph node dissection, and many women believe that it can spare them more invasive surgery and side effects. However, the sentinel node procedure is not appropriate for everyone. Research shows that even after the sentinel node procedure, more surgery may be necessary. It has its own limitations and drawbacks, and must be done by a surgeon who has significant experience with the technique.
The dictionary defines "sentinel" as a guard, watchdog, or protector. Likewise, the sentinel lymph node is the first node "standing guard" for your breast. In sentinel lymph node dissection, the surgeon looks for the very first lymph node that filters fluid draining away from the area of the breast that contained the breast cancer. If cancer cells are breaking away from the tumor and traveling away from your breast via the lymph system, the sentinel lymph node is more likely than other lymph nodes to contain cancer.
The idea behind sentinel node dissection is this: Instead of removing 10 or more lymph nodes and analyzing all of them to look for cancer, remove only the one node that is most likely to have it. If this node is clean, chances are the other nodes have not been affected. In reality, the surgeon usually removes a cluster of two or three nodes — the sentinel node and those closest to it.
Strategic removal of just one or a few key underarm nodes can accurately assess overall lymph node status in women who have relatively small breast cancers (smaller than 5 cm) and who have lymph nodes that don't feel abnormal before surgery. Studies have shown that after almost 5 years, women who had just the sentinel node removed were as likely to be alive and free of cancer as women who had more lymph nodes removed.