It may not. But something does. What causes the cells to die in large volumes, which is what the word 'cancer' denotes? And why specifically in the breast?
P.S. How many men do you know that have had breast cancer?
One cell transcribes incorrectly, and from then on all of it's daughter cells are the same way defective. The body does not recognize the aberrant cells as non self, and the cells grow uncontrolled.
It is the uncontrolled growth with no stop code that is the cancer.
it is called a cancer because it grows into local tissue much like a crab's claws, a cancer.
Not that they all do that. Some do not invade, just grow in their own capsule. Others break off in small cell size bits and take a ride down stream in the blood or lymphatics to set up shop elsewhere.
Any mass dying is most often after the growth outstrips it's own blood supply, then undergoes necrosis due to lack of blood within the center of the mass(oxygen).
My goodness, no. Cancer is not necrosis (cell death) although it may cause necrosis. Simplified, cancer is the uncontrolled growth and multiplication of abnormal cells.
Cancer is cells that grow and reproduce without the normal off switch that stops repeated division, in spite of nuclear errors and invasion of other tissues.