Cancer in Women

Understanding Breast Cancer


Breast cancer usually begins either in the cells of the lobules, which are milk-producing glands, or the ducts, the passages that drain milk from the lobules to the nipple. The pathology report will tell you whether or not the cancer has spread outside the milk ducts or lobules of the breast where it started.

Non-invasive cancers stay within the milk ducts or lobules in the breast. They do not grow into or invade normal tissues within or beyond the breast.

Non-invasive cancers are sometimes called carcinoma in situ (“in the same place”) or pre-cancers. Invasive cancers do grow into normal, healthy tissues. Most breast cancers are invasive. Whether the cancer is non-invasive or invasive will determine your treatment choices and how you might respond to the treatments you receive.


breastcancer.org