Portland, Ore.

OHSU review says benefit of mammogram extended to younger women

A newly published analysis on the use of mammograms for breast cancer screening shows that the number of breast cancer deaths can be decreased through mammogram detection for women ages 40 and older. Because breast cancer is more common as women age, the balance between benefits and harms becomes more favorable as women get older, beginning at age 40 and increasing steadily until age 70.

The research summary, published today in the Annals of Internal Medicine, was prepared as background evidence for the U.S. Preventive Services Task Force. After reviewing the draft report last February, the Task Force issued a recommendation advising women 40 and older to have mammograms every 1-2 years. U.S. Health and Human Services Secretary Tommy Thompson used the recommendation to offer guidance to women and their clinicians that early detection of breast cancer can save lives.

"Because breast cancer is the second leading cancer killer of women, the debate over prevention and screening for the disease is very important," said Linda Humphrey, M.D., M.P.H., co-author of the analysis, along with Mark Helfand, M.D., M.P.H., at the Oregon Health & Science University Evidence-based Practice Center. "An in-depth analysis of the evidence on mammography shows it is effective at preventing deaths, but it's not a procedure without risks, including false-positive results and accumulated radiation exposure. Women need to know where they fall on the scale of risk versus benefit."

The Task Force, which is sponsored by the Agency for Healthcare Research and Quality -- the federal agency that funded the study -- suggested that women who are at increased risk for breast cancer (e.g., those with a family history of breast cancer in a mother or sister, a previous breast biopsy revealing atypical hyperplasia, or first childbirth after age 30) are more likely to benefit from regular mammograms than women at lower risk.

Another important aspect of the analysis was that clinical breast examinations by health care providers, in combination with regular mammograms, were not found to reduce breast cancer mortality more than regular mammograms alone. The Task Force also concluded that the evidence is insufficient to recommend for or against teaching or performing routine breast self-examinations.

The U.S. Preventive Services Task Force, the leading independent panel of private-sector experts in prevention and primary care, conducts rigorous, impartial assessments of all the scientific evidence for a broad range of preventive services. Its recommendations are considered the gold standard for clinical preventive services. To access the Task Force recommendation, visit: http://www.ahrq.gov/clinic/3rduspstf/breastcancer/

OHSU faculty title:
Mark Helfand, M.D., M.P.H., associate professor of medicine (general internal medicine and medical informatics and outcomes research) in the OHSU School of Medicine and director of the Evidence-based Practice Center at OHSU
Linda Humphrey, M.D., M.P.H., associate professor of medicine (general internal medicine and geriatrics) in the OHSU School of Medicine