Additional Study Information: The purpose of this study is to examine whether removing some of the lymph nodes from the armpit, but not removing them all followed with radiation therapy (experimental) will be as good as having the majority of the lymph nodes from the armpit removed during breast surgery followed with radiation(standard of care). Patients will be randomized to either of the following Arms: If you are randomized to the treatment group called Arm 1 more lymph nodes from your armpit will be removed (this is called axillary lymph node dissection). If you are randomized to this treatment group after the surgery to examine your lymph nodes, you will have another surgery to remove more lymph nodes from your armpit (axillary lymph node dissection). You will begin your radiation therapy treatments4 to 6 weeks after surgery. The radiation treatments will be given 5 days a week over 5 6 weeks. The starting day and the details of the treatments will be explained to you by your radiation doctor. If you are assigned to the treatment group called "Arm 2 you will not have any more lymph nodes removed. You will begin your radiation therapy treatments 4 to 6 weeks after surgery. The radiation treatments will be given 5 days a week over 5 6 weeks. The starting day and the details of the treatments will be explained to you by your radiation doctor.