A shorter regimen of a drug used to treat early-stage breast cancer works just as well as using it for twice as long, saving patients thousands of dollars and sparing them serious side effects. A new study, paid for by the British government, followed thousands of patients with aggressive early-stage breast cancer tumors with high levels of a protein called HER2, which promotes cancer growth. Herceptin, also known as trastuzumab, is an antibody that targets the protein to stop the breast cancer…