Those who read the most mammograms miss fewest cancers. (Study of U.S., British Radiologists).

KAUAI, HAWAII -- Radiologists who read the most mammograms found the most and missed the fewest breast cancers, compared with their counterparts who interpreted fewer of the imaging tests, Dr. Laura J. Esserman said.

In a study of radiologists, those who read more than 300 mammograms per month (high-volume readers) achieved better results than did those who read 101-300 mammograms per month (medium-volume readers) or 100 or fewer mammograms per month (low-volume readers), she reported at a conference on obstetrics, gynecology, perinatal medicine, neonatology, and the law.

A total of 194 high-volume radiologists from the United Kingdom and 60 radiologists from the United States undertook a standard 60-film mammography test. The U.K. radiologists had an average sensitivity of 0.785 for diagnosing cancer when the specificity equaled 0.90. Of 60 U.S. mammographers, the average sensitivity was 0.756 in the high-volume group, 0.702 in the medium-volume group, and 0.648 in the low-volume group. The low-volume U.S. radiologists had significantly lower sensitivities, compared with the U.K. radiologists and the high-volume U.S. radiologists. Medium-volume U.S. radiologists had lower sensitivities than the U.K. radiologists, Dr. Esserman and her associates reported (J. Natl. Cancer Inst. [5] 94:36975, 2002).

The United States could improve care and cut costs by concentrating mammography in the hands of experts, as several European countries do, she suggested at the meeting. The enormous costs of U.S. mammography are driven in part by variation in practice styles and the ratio of cancers found per biopsies done.

The U.S. Mammography Quality Standards Act requires mammography centers to perform a minimum of 480 mammograms per year. In the United Kingdom, the requirement is 1,500 mammograms per year, but centers average 5,000 per year. Swedish centers average 5,000-15,000 per year. Swedish cancer-to-biopsy rates are at least twice as high as those in the United States, meaning the Swedes are more efficient in their use of biopsies, said Dr. Esserman, who is director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco.

Higher-quality mammography should help reduce the number of unnecessary biopsies, which incur emotional as well as ...