Missed cancers on mammograms: causes and measures of prevention.

Mammographically missed breast cancers remain a major medical and legal issue. In order to clarify causes and methods of the limitations, we present the experience of our Unit on this field. During the years 1999 and 2000, 319 breast cancer patients were admitted for surgical treatment to our Unit. Their files were reviewed in order to identify cases with mammography-related delayed diagnosis. Thirty-three cases of mammographically missed cancers were found (10.3%). The usual reasons for the delayed diagnoses were: retrospectively visible cancers, in benign looking lesions no further action was taken, and lesions with a rather malignant appearance were reported as benign. Missed cancers could be reduced by simple measures such as the full assessment of breast patients with clinical, radiologic, and cytologic-histologic evaluation, the double screening of mammograms, and improvement of the mammographic equipment and technique.