Non-invasive breast cancers are cancers that stay within the ducts or lobes of your breast and don't spread to surrounding tissue or to other parts of the body. The most common type of non-invasive breast cancer is ductal carcinoma in situ (DCIS). This is a very early type of breast cancer where the cancer cells are only found inside the milk ducts and haven't spread into the breast tissue. In some cases, DCIS can develop into an invasive form of breast cancer.
Attribution: BUPA