What is a false negative result?
A false negative result occurs when a cancer is present but is not diagnosed. A breast cancer may be present at the time of the mammogram and be large enough to detect yet still not be spotted by the radiologist who reads and interprets the film. Other small cancers may be present but may be too small to see (less than 5 mm, or the size of a grain of rice) at the time. Yet other cancers are large enough to be seen on a mammogram but are not interpreted as an abnormal finding. What causes a false negative result? There are two factors that lead to false negatives: breast density and doctor error. Breast cancers are easier to locate in postmenopausal women because their breasts have less dense breast tissue and more fat, which the mammogram can “see” through. Most younger (premenopausal) women have dense breasts: the milk ducts occupy much of the space within the breast and have the same density as a solid breast cancer. This means that the mammogram film shows the same overall white col
