The authors, from the University of California, San Francisco, noted that even when DCIS becomes an invasive cancer, it's treatable when found at an early stage: The odds that a 60-year old woman with a 7 millimeter breast tumor, would die from it in the next 10 years are less than 3%, half the risk she faces of dying from another cause during that time.

WSJ: Can Breast Cancer Be Overtreated?