(Ivanhoe Newswire) -- Supplemental ultrasound screening for women at high
risk for breast cancer can detect small node tumors that mammography may miss.
But according to a new study, the downside is ultrasound increases the number of
false positive results.
The study looked at the diagnostic effectiveness of mammography alone,
ultrasound alone and a combination of both. It was conducted at the American
Radiology Services Inc., of Johns Hopkins Green Spring, in Lutherville, Md.
The researchers found the diagnostic accuracy of mammography was 78 percent; for
ultrasound it was 80 percent and for a combination of the two showed 91 percent
accuracy.
After a full diagnostic workup, the predictive value of biopsy recommendation
was highest after mammography (22.6 percent). For ultra sound alone it dropped
to 8.9 percent and combined mammography and ultrasound was 11.2 percent.
The false-positive rate for mammography was also the lowest -- 4.4 percent. For
ultrasound alone, it nearly doubled -- 8.1 percent. The highest percent of
false-positive results was 10.4 percent with combined screening.
“A single screening ultrasound in women at elevated risk of breast cancer is now
well validated,” study authors wrote. “However, it comes with a high risk of
false-positive results.” They go on to say that their findings should be viewed
in the context of new guidelines recommending annual MRIs for women at very high
risk of breast cancer.
SOURCE: The Journal of the American Medical Association, 2008;299:2151-2163
