Improving Breast Cancer Screening
Reported May 15, 2008
(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