Overdiagnosis is an often underappreciated harm of screening. In the context of cancer screening, it refers to the detection of cancers that appear histopathologically to be invasive malignant tumors but grow so slowly that they never would have become clinically evident during a usual lifetime or occur in a person who dies of another cause before the cancer symptoms appear.1,2 The causes of overdiagnosis include more sensitive screening tests, increasing biopsy rates, and lower thresholds for reporting abnormal-appearing cells in biopsy specimens as malignant.3-5