Mammograms in younger women yield low rates of cancer detection and have low accuracy, according to a study published in the Journal of the National Cancer Institute 2010 May 3 [Epub ahead of print]).
To determine the accuracy of screening tests and their cancer detection rates, researchers from the University of North Carolina at Chapel Hill followed 117,738 women who had their first mammogram between 18 and 39 years old for a year. Researchers analyzed data for both screening mammograms and diagnostic mammograms and found that screening mammograms had poor accuracy and high rates of recall for additional tests among women 35 to 39 years old. In addition, the cancer detection rate in this group was 1.6 per 1,000 women.
The authors concluded that in a theoretical population of 10,000 women having a screening mammogram between 35 and 39 years, 1,266 would be called back for further testing, 16 cancers would be detected, and, therefore 1,250 women would have false positives. “Our findings support a need for serious discussion about the appropriateness of mammography in women without the presence of symptoms,” the authors wrote.
According to background information provided by the authors, although screening mammograms are not generally recommended before age 40 years, about 29% of women in their 30s reported having had one.
“The study is a powerful reminder that we must continue to strive for better tests and better treatments,” said Ned Calonge, MD, of the Colorado Department of Public Health and Environment, who was not involved in the study. “Furthermore, we should not be satisfied with better detection rates alone. We need evidence that early detection of these cancers translates to improvements in important health outcomes.”