Usually stage 0 or 1
The breast is composed of glands that can produce milk (lobules), tubes that transport the milk to the nipple (ducts), and fatty tissue.
may begin in the lobules or ducts. If it is only found inside these structures, the stage is 0 (zero). If it grows out of the lobules or ducts into the fatty tissue, but is not in the lymph nodes, it is stage 1 (one).