Breast cancer is the most common cancer among women worldwide, with an estimated 2.3 million new cases and 685,000 deaths in 2020 alone. It occurs when cells in the breast tissue begin to grow uncontrollably, forming a tumor. The majority of breast cancers start in the ducts (milk-carrying tubes) or lobules (milk-producing glands).

The exact causes of breast cancer are not fully understood, but certain risk factors include age, family history of the disease, genetic mutations, obesity, hormone therapy, and radiation exposure. Common symptoms of breast cancer include a lump or mass in the breast or armpit, changes in breast size or shape, nipple discharge, and skin changes around the nipple or breast.

Early detection and diagnosis are crucial for successful breast cancer treatment. Screening methods such as mammograms, ultrasounds, and magnetic resonance imaging (MRI) are used to detect breast abnormalities. Treatment options vary depending on the stage and type of breast cancer, and may include surgery, chemotherapy, radiation therapy, hormone therapy, and targeted therapy.