HER2

March 2005, I was diagnosed with breast cancer and was told I was HER2 neu positive. Apparently, my 12/04 mammogram was misread. By March, the lump was 4-5 cms. I began with weekly treatments of Herceptin (no side effects) and 3 weeks later the tumor shrunk 35% and Carboplatin every 21 days. Since I had an adverse reaction to Taxol, I am now on a lowered weekly infusion of Taxotere. Now instead of a mastectomy, the doctors are talking lumpectomy maybe in June or July 2005. Question: will Herceptin prevent a reoccurrence of a tumor?