Breast cancer is a cancer that starts in the tissues of the breast.
There are two main types of breast cancer:
- Ductal carcinoma starts in the tubes (ducts) that move milk from the breast to the nipple. Most breast cancers are of this type.
- Lobular carcinoma starts the lobules, the parts of the breast that produce milk.
- In rare cases, breast cancer can start in other areas of the breast.