The MarginProbe System uses electromagnetic waves to evaluate the edges of the lump that is removed (those edges are called the margins). It was developed to help surgeons better judge how much tissue needs to be removed during lumpectomy, making it less likely that a woman will need more surgery after lumpectomy.

During lumpectomy, the surgeon removes the cancer tumor and some of the normal tissue (called the margin ) that surrounds it. After lumpectomy, a pathologist examines the tissue that was removed to see if cancer cells are present in the margins. Margins that are free of cancer are called “negative” or “clean.” Margins that have cancer cells in them are called “positive.”

Ideally, the surgeon would learn the status of the margins before the lumpectomy is finished, so tissue can be removed until the margins are clean. Unfortunately, analyzing the removed tissue takes about a week. Sometimes after the pathology report is done, the margins are found to contain cancer cells and more surgery is needed. This additional surgery is called a re-excision lumpectomy.

The MarginProbe System detects subtle electromagnetic differences between breast cancer cells and normal breast tissue. In 3 to 5 minutes, a surgeon can test the margins and decide if more tissue needs to be removed. MarginProbe can be used during lumpectomy for both DCIS (ductal carcinoma in situ) and invasive breast cancer.