Years ago they use to believe that once cancer was exposed to air it would spread. This is not so. Years ago when people were diagnosed it was usually late stage cancer. However, I would say that the surgeon who removes the cancerous tumor should be experienced in that type of surgery. Cells left behind could possibly seed and set up house a later time. That is why you sometimes hear the word "margins". It is important with most cancers removed to obtain a clear border surrounding the tumor or "clear margins".