Screening mammography. (Guest Editorial).

Physicians need to let screening mammographic examinations screen. The most fundamental error one can make when interpreting the results of a screening mammogram is to confuse it with a diagnostic mammogram. Physicians often try to minimize the significance of a positive result from screening mammography out of concern that it may upset the patient and lead to unnecessary follow-up procedures. But as a screening tool, mammography works effectively only if it is properly used as a screen. That means that following up on positive findings with appropriate additional tests is mandatory.

The results of screening mammography are assessed very simply: Is the result normal or not? If it is not normal, then further studies are necessary. The best way to avoid unnecessary callback examinations is to ensure that the initial examination is a technically excellent study This will minimize the number of indeterminate findings that require a callback and further testing.

Results from a cross-sectional survey of women reported in 2000 showed that women are highly tolerant of false-positive results from screening mammograms. One of the reasons for this is clear: A false positive-result on an initial screening is much more desirable than a false negative, that is, a missed early diagnosis of breast cancer.

When screening mammography is done correctly, it should generate a callback rate of about 10%. The ideal rate is 5%-7%, but this is unusual. At my institution, M.D. Anderson Cancer Center, we request additional imaging or other tests on 12% of the women who undergo screening mammography, but our patient population has a greater proportion of women who are at high risk of having breast cancer. When the callback rate exceeds about 20%, the physicians who are reading the mammograms require remedial training.

If a screening mammography image is difficult to interpret or suggests a possible problem, the best strategy is to quickly reschedule the patient for ...