Breast cancer patients won a breakthrough new treatment late on Friday as the Food and Drug Administration approved Herceptin the first in what promises to be a wave of therapies attacting cancer at its genetic roots. Herceptin is not for every woman with breast cancer. But for the 30 per cent whose especially aggressive tumors are fueled by a bad gene called 'HER 2', Herceptin substantially increases the chances of battling the cancer and living a little longer.