While breast cancer can occur in any part of your breasts, it is more likely to be found in the ducts and lobules. Ductal breast cancer starts in the cells that line the milk ducts. Lobular breast cancer starts in the cells that line the lobules. Breast cancer is also described based on how likely it is to spread to other parts of the breast or body. It is called either non-invasive or invasive. Non-invasive breast cancer is breast cancer that usually does not spread. Your doctor may call this ductal carcinoma in situ or DCIS For short. It stays in the ducts or lobules of the breast. Occasionally, when a biopsy shows DCIS, other types of breast cancer may be found at the time of surgery. Invasive breast cancer is much more common. It can spread to other parts of the breast lymph nodes or even other parts of the body. Most invasive breast cancers, about 8 out of 10 cases, are invasive ductal cancer. Far less, only one out of 10 cases are invasive lobular cancer.