The major purpose of this study is to determine if a new drug called pazopanib decreases lymphedema in subjects previously treated for cancer. Lymphedema, or swelling of the arm, is a result of damage to the lymphatic vessels in the arm during surgery and/or radiation. The damaged vessels can not adequately drain fluid from the arm, resulting in increased pressure and swelling. Pazopanib has not previously been studied as a treatment for lymphedema.