Yearly Mammograms Starting at 40 Saves More Lives

A new study questions current breast cancer screening recommendations with data that shows starting at a younger age and screening more frequently results in many more lives saved.

Researchers at the University of Colorado School of Medicine (Aurora, CO, USA) and the University of Michigan Comprehensive Cancer Center (UMCCC; Ann Arbor, MI, USA) conducted a study to examine the scientific evidence considered by the United States Preventive Services Task Force (USPSTF; Rockville, MD, USA) in recommending against screening mammography in women 40-49 years old, and against annual screening mammography in women 50 and older.

To do so, they used the same evidence made available to the USPSTF to estimate the benefits and harms of screening mammography in women 40 years old and older. They then used six model scenarios of screening mammography created by the Cancer Intervention and Surveillance Modeling Network to compare lives saved by different screening scenarios, and the summary of evidence prepared for the USPSTF to estimate the frequency of harms of screening mammography by age. They also compared task force guidelines to the American Cancer Society (Atlanta, GA, USA) guidelines.

The researchers found that when averaged over the six models, screening mammography shows greatest benefit from annual screening of women 40-84 years old. This screening regimen saves 71% more lives than the USPSTF-recommended regimen of biennial screening of women 50-74 years old, which had a 23.2% mortality reduction. According to these results, for US women currently aged 30-39 years old, annual screening mammography starting at 40 years would save 99,829 more lives than USPSTF recommendations (if all women complied). Potential harms of a screening examination in women 40-49 years old, on average, consist of a false-positive mammogram once every 10 years; recall for more tests once every 12 years, and a false-positive biopsy once every 149 years. The study was published in the February 2011 issue of the American Journal of Roentgenology.

"The task force overemphasized potential harms of screening mammography, while ignoring the proven statistically significant benefit of annual screening mammography starting at age 40,” said coauthor R. Edward Hendrick, PhD, a clinical professor of radiology. "In addition, the panel ignored more recent data from screening programs in Sweden and Canada showing that 40% of breast cancer deaths are averted in women who get regular screening mammography.”

"Task force guidelines have created confusion among women, leading some to forego mammography altogether,” added coauthor Mark Helvie, MD, director of breast imaging at the UMCCC. "Mammography is one of the few screening tools that has been proven to save lives, and our analysis shows that for maximum survival, annual screening beginning at 40 is best.”

Related Links:
University of Colorado School of Medicine
University of Michigan Comprehensive Cancer Center
United States Preventive Services Task Force
American Cancer Society