For early breast cancer, the sentinel node procedure has been a breathtaking achievement. Historically, as a part of management, many lymph nodes were removed from the axilla (underarm area). Over time, we have learned that the number of nodes involved with regional spread of cancer is the most important prognostic factor for survival. More recently, we have discovered that the removal of axillary nodes serves this important purpose, but is not as important from a treatment perspective. Not surprisingly, we have moved from taken all of the dozens of nodes in the axilla, to 10 or 20, and now just a node or two.
The sentinel lymph node procedure involves the injection of trace amounts of radioactive material (or blue dye) around the time of surgery. A small incision is made in the underarm area, and a Geiger counter-like device brought near. The surgeon listens for the ticking node and plucks it. As cancer needs to travel through this first (sentinel) node, we can determine whether there is regional spread of cancer! Voila, lower chance of pain and arm swelling, or lymphedema. So what if the sentinel node is involved? What now? Go back and take more nodes or hope the radiation therapy that follows surgery will take of any more disease that might be left behind? We have more answers this week.
Radiotherapy is a better option than surgical dissection for women with breast cancer and a positive sentinel lymph node, according to an international multicenter phase 3 trial. In fact, axillary lymph node dissection (ALND) was associated with twice the rate of lymphedema as axillary radiotherapy, with no better locoregional control and fewer adverse effects (as compared to radiation therapy), in the European Organization for Research and Treatment of Cancer (EORTC) AMAROS (After Mapping of the Axilla: Radiotherapy or Surgery?) trial. The results were presented here at the 2013 Annual Meeting of the American Society of Clinical Oncology (ASCO®).
“We shifted from mastectomy to breast conservation, and now we will shift from complete axillary dissection to axillary-conserving strategies,” study author Emiel Rutgers, MD, PhD, surgical oncologist at the Netherlands Cancer Institute in Amsterdam, said during a press conference.
Outcomes no better with additional underarm surgery: There were no significant differences between the surgery and radiotherapy groups in disease-free survival (86.9% vs 82.7%; P = .1788) or overall survival (93.3% vs 92.5%; P = .3386).
Complications worse with completion axillary dissection: 5 years after therapy, the rate of lymphedema in the surgery group was twice that of the radiotherapy group (28% vs 14%).
Questions remain: 1) Extent of radiation therapy (is less more? Should we treat only the breast (with a bit of exit dose to the lower axilla) or more comprehensively (breast and of the regional nodes, recognizing more potential side effects). 2) What if a woman is not to receive radiation therapy? Should she go back for more surgery?
Still, progress. And good news for patients who have a sentinel node involved who receive radiation therapy. Your risk of regional recurrence is remarkably low, even if you don’t have more surgery.
Coming soon: Understand Breast Cancer in 60 Minutes (an e-book for IPad)
Fine print: The material herein is not aimed at providing advice for an individual, and is only general in nature. Check with your valued healthcare provider with any questions or concerns regarding your own management.