This book presents current research in the study of various cancer treatments. Topics discussed include anticancer drugs and anticancer agents; design of novel anticancer drugs; aromatase inhibitors; aromatase inhibitors for the medical treatment of endometriosis; the use of aromatase inhibitors in ovarian cancer and identification of responsive tumors; inherent and microenvironment-mediated mechanisms of drug resistance; targeting adverse features of hormone-resistant breast cancer; systematic analysis of patterns of cross resistance between anticancer agents and treating drug resistant malignancy.