Hi - The surgeon will make sure that there are clean margins - i.e., that there are no cancerous cells in any of the remaining surrounding tissue. Then hopefully radiation should take care of any stray cancer cells that escaped everyone's observation. There's no guarantee, of course; with cancer, there never is. After a lumpectomy and radiation, there's still a chance the cancer could come back. Taking hormone therapy, if the patient is ER/PR-receptive; or Herceptin, if she's HER2-neu-receptive, is another way to lower the risk of recurrence. I'm sure you'll be presented with all of these options. We take our best shot with treatment, then wait and hope. Good luck - PJH