Did you ask your doctor this question? If not, you should. There are any number of reasons to have radiation after a lumpectomy and chemo: the doctor may feel it was close enough to your chest wall it could have invaded there; or, since you won't be taking hormone therapy drugs, he/she is doing everything possible to ensure as many cancer cells as possible are wiped out. Chemo doesn't necessarily kill all the cancer cells in your body; radiation is a second-line defense. Used to be radiation sometimes caused secondary cancers; but it's so much better than it used to be, I wouldn't worry about this. My advice: do what the doctor says, or get a second opinion. Good luck - PJH