Additional Study Information: The purpose of this study is to test the good and bad effects of olaparib in combination with temozolomide for the treatment of advanced uterine leiomyosarcoma (LMS). Olaparib and temozolomide could shrink your cancer, but could also cause side effects, which are described in the risks section below. The study doctors hope to learn if the study drug will be a safe and effective treatment for people with this type of cancer.