Breast cancer is the cancer that develops in the tissues of the breast. The signs of breast cancer include change in the shape of breast, secretion of fluid from the nipple, scaly red patch of skin, lump in the breast, and a new inverted nipple. Metastasis is the process through which cancer cells spread. Metastatic breast cancer is the condition where cancer cells originated in the breast spread to other body parts, like brain, lungs, liver and bones. Metastatic cancer originates when cancer cells from the primary tumor break away and enter the lymphatic system or blood stream, which carry fluids across the body. The cancer cells travel from the primary tumor through these fluids, and then they settle and develop new tumors in other parts of the body. This book unravels the recent studies on the metastasis of breast cancer. It consists of contributions made by international experts. This book aims to equip students and experts with the advanced topics and upcoming concepts in this area of study.