(Associated Press files)
June 3, 2012
This undated image made available by the Duke University Department of Medicine in 2007 shows a right breast MRI from a 55-year-old woman with extreme breast density. The superimposed arrow points to a 2 cm rapidly enhancing lesion which was later confirmed by biopsy to be invasive breast cancer. Doctors have successfully dropped the first "smart bomb" on breast cancer, using a drug to deliver a toxic payload to tumor cells while leaving healthy ones alone, doctors reported Sunday.