- Stage 0:
Also called in situ or noninvasive cancer. Very little breast cancer or preinvasive cancer. This type of cancer has not spread within or outside of the breast.
- Stage 1:
Cancer cells have not spread beyond the breast. Tumor is smaller than 1 inch.
- Stage 2:
Cancer has spread to underarm lymph nodes. Tumor in the breast is 1 to 2 inches across.
- Stage 3:
Called locally advanced cancer. Cancer is extensive in the underarm lymph nodes, or has spread to other lymph node areas or to other tissues near the breast. Tumor in the breast is large (more than 2 inches across)
- Stage 4:
Called metastatic cancer. Cancer has spread from the breast to other parts of the body, such as the bones, lungs, liver or brain.