美国癌症协会ACS：2024-2025乳腺癌事实与数据报告（英文版）

Breast cancer is the most common cancer diagnosedamong women in the US. It occurs when cells in breasttissue change and divide uncontrolled, typicallyresulting in a lump or mass. Most breast cancers beginin the milk glands (lobules) or in the tubes (ducts) thatconnect milk glands to the nipple.Breast cancer typically has no symptoms when it issmall and easily treated, which is why mammographyscreening is important for early detection. A painlesslump in the breast or underarm lymph nodes is th