If you or someone you love has been diagnosed with breast cancer, you may hear the doctor talk about breast cancer stages. While learning what stage cancer you have may be depressing, this information is key to figuring out just what can be done about your cancer. It will help you understand your prognosis that is what chance you have of surviving the cancer. It will help you learn about available treatments. Once you know what you are dealing with, you can get prepared to fight it.

There are essentially four breast cancer stages. Stage 0 signifies non-invasive breast cancer. That means that there is no evidence of cancer cells outside of the part of the breast that it started in. Lobular carcinoma in situ (LCIS) is considered a stage 0 cancer. It is a cancer confined to the lobules – the glands that make milk.

Stage I is an invasive breast cancer, which means that the cancer cells are invading neighboring tissue. It includes tumors that measure up to two centimeters and in which no lymph nodes are involved. Stage II breast cancer occurs when the tumor measures more than two centimeters, but no more than five centimeters. It also means the cancer has spread to the underarm lymph nodes on the same side where the breast cancer occurs.

Stage III breast cancer is divided up into two subcategories: IIIA and IIIB. Stage III A is invasive breast cancer where the tumor is larger than five centimeters and there is significant involvement with the lymph nodes, i.e. they are clumped together or stick to one another. Stage IIIB is a breast cancer tumor of any size that has spread to the breast skin, chest wall, or internal mammary lymph nodes. This breast cancer stage includes inflammatory breast cancer, which is a rare, but aggressive form of breast cancer.

The final of the breast cancer stages, Stage IV, is a tumor that has spread beyond the breast, underarm or internal mammary lymph nodes and may have spread to the lymph nodes located at the base of the neck, the lungs, liver, bone, or brain.

Other terms are used when talking about breast cancer stages. The doctor may mention early stage, later stage, or advanced stage. Stage 0, I, and II are considered early stages. If your breast cancer is caught in an earlier stage, your survival rate should be much better. Stage II (when lymph nodes are involved) and Stage IIIA and Stage IIIB are considered later stages. These may require more aggressive treatment as well advanced stage, Stage IV.

The doctor may also mention tumor size. TX means the tumor cannot be assessed. T0 means there is no evidence of a tumor. Tis means the cancer may be LCIS, DCIS, or Paget's disease. T1 means the tumor is less than two centimeters. T2 means the tumor is between two and five centimeters. T3 means the tumor is larger than five centimeters. T4 is used to refer to a tumor that can be of any size, but one that has attached itself to the chest wall and spread to the lymph nodes.