Globally, breast cancer remains the most common cause of cancer-related deaths in women. However, investigations related to breast cancer showed substantial progress in the understanding of the disease. Still, many women face unfortunate occurrences of metastasis and relapse of breast cancer despite the significant advancements in the diagnosis and treatment of early-stage cases. Over the past few years, systemic therapy for breast cancer has significantly improved. It includes drugs that spread throughout the body to kill cancer cells wherever they may be. That comprises immunotherapy, hormone treatment, chemotherapy, and targeted drugs. This entry aims to review the diagnosis and treatment of breast cancer, including screening, staging, and multidisciplinary management. Further, it strives to focus on progress for advanced and early breast cancer in systemic medical therapy.