Patients with Cancer Detected on Screening Mammography Undergo Less Toxic Treatment
Women who have their breast cancers detected by physical examinations are at least twice as likely to undergo toxic treatments than those who have their cancer detected by mammography-regardless of the age of the woman, a new study shows.
The study reviewed 992 women with invasive breast cancer; 460 of them had their cancer detected on screening mammography and 532 on physical examination, said the lead author of the study, Richard J. Barth, Jr., MD, Chief of the Division of Surgical Oncology at Dartmouth-Hitchcock Medical Center.
The study appears in the American Journal of Roentgenology.
The accuracy of mammographic interpretation can vary widely, but the source of the variability has not been explained. To investigate the relationship between radiologists' characteristics and actual performance, William E. Barlow, Ph.D., of Cancer Research and Biostatistics in Seattle, and colleagues surveyed 124 radiologists and tracked cancer outcomes from the more than 460,000 screening mammograms they interpreted between 1996 and 2001.
Greater volume of mammograms interpreted and more years of experience were not associated with greater accuracy. However, greater volume was associated with higher sensitivity (more true positive results in women who had breast cancer) and lower specificity (more false positive results in women who did not have breast cancer) whereas more experience was associated with lower sensitivity and higher specificity. The authors conclude that increasing volume requirements for radiologists is unlikely to improve the interpretation of mammograms.