We really do not want to do this stuff. I think @Afraser is on the money with the advice about the mastectomy, assuming that is even suggested for you. If doing nothing is likely to kill you, a mastectomy has the potential to remove the cancer if it seems to be confined to your breast and avoids a situation where you have a lumpectomy and find further surgery is recommended. Which means making, or resisting, more decisions. It means committing yourself to one action which--depending on your diagnosis--may give you the best chance of survival.
Losing a boob is horrible but, physically, the anaesthetic and drains are the worse part. There may be a bit of puddling around while you heal, but, if you can get your head around the concept, it's probably the least intrusive action.
I personally know three ladies who, for a variety of reasons, have decided not to undergo any treatment. Two of them are really struggling to cope with the idea of a toxic tit and associated cancer still attached to their bodies and, in my opinion, are having a tougher time of it than they would have if they had removed the breast. The other doesn't give a hoot and is just living her life. I guess it depends on your temperament and view of the world. Marg xxx