Re-operation rates following breast conservation (lumpectomy and radiation) for early invasive breast cancer have been highly variable historically, mainly because of uncertainty and variability in what surgeons deemed safe.
When a tumor is removed, the specimen is painted with a special ink before it is evaluated by a pathologist. This ink allows the pathologist to clearly see the outer edges, or ‘margins’, of the tissue under the microscope.
In 2014, the Society of Surgical Oncology and American Society for Radiation Oncology released new guidelines stating that as long as the tumor has no ink on it, the margin is clear. A clear margin means there are no cancer cells at the edge of the surgical specimen and tells the surgeon that all the cancer was removed.
Prior to the new guidelines, some surgeons wanted at least 2mm of normal breast tissue around the cancer. Others accepted less. Even though wider clear margins don’t reduce the risk of cancer recurrence, because of this lack of consensus, 25%-30% of patients having a lumpectomy required more surgery to ensure a larger clear margin.
A recent study in the American Journal of Surgery shows that the new guidelines have led to a decrease in re-operation rates. This offers peace of mind that you likely won’t need another “re-excision” surgery after a lumpectomy if the margins are clear, irrespective of how small the clear margins are, as long as there is “no ink”. Additionally, surgeons now have an evidence-based standard to follow. Very reassuring news indeed!