Yes, there is always hope. I was just like your mother in that I always had annual mammograms -- and they always came back clear. Then in March 2007 I had terrible back pains and had to go to emergency. They discovered that I had 4th stage metastatic breast cancer. My lesions are all along my spine. (To this day, nothing has ever shown up in my breasts. The random cancer cell that was once there traveled through my blood stream to my bones.) They gave me 2 months to one year to live. Here it is September 2009 and I am not only alive but back to work full-time. I of course, still have the cancer; I have to think of it as a chronic condition. I have chemo off and on and also get treatments of Zometa for my bones; but it is something I've learned to live with.
So you have lots of hope for your mother. Don't let her give up the fight!!
Cindy