I was told lumpectomy plus radiation is equal to mastectomy as far as 10 yr survivial. As I understand, if you do lumpectomy it is very important to do the radiation, to make sure they don't miss any stray cancer cells, in the breast.
I opted for bilateral mast with reconstruction, but I had a strong family hx and was much older than you, at 48 when dxed in 06. Whether you do mast or lumpectomy is a very personal decison and based on what your most comfortable with.
Good luck with your surgery, this wk and wishing you a fast recovery.

Leea