New information from sentinel lymph node studies in breast cancer

Over the last decade, the use of sentinel node biopsy has reduced the number of patients who need a full axillary lymph node dissection for treatment and staging of breast cancer.This represents a very important advance because a sentinel node biopsy is much less likely to lead to long term lymphedema--chronic swelling of the arm that can have a large impact on day-to-day activities and quality of life. However, when one or more sentinel nodes, which are identified by using a blue colored dye and radioactive tracer, are found to contain tumor cells, a full axillary dissection is recommended. Sentinel node biopsies are done in patients who do not have any nodes felt on physical examination, but about one third of patients who are found to have tumor in the sentinel nodes are currently treated with follow-up complete surgery. To determine whether additional surgery and its attendant risks are really needed, the American College of Surgeons conducted a trial to see if patients with up to three positive sentinel nodes could be spared a full dissection. This randomized trial compared no further surgery to full dissection in such patients, and the results showed no difference in the number of patients that had a recurrence in the breast or under the arm--about 3 to 4 percent overall, with six years of follow-up. In the commentary provided on this abstract it was stated that these results are "practice changing" and if adopted, would make a big difference in the side effect profile of breast surgery in the estimated 50,000 of patients who undergo axillary dissection in the United States.