Agency for Healthcare Research and Quality.

Background This systematic review is an update of evidence since the 2002 U.S. Preventive Services Task Force (USPSTF) recommendation on breast cancer screening. Purpose To determine the effectiveness of mammography screening in decreasing breast cancer mortality among average-risk women age 40 to 49 and 70 and older; the effectiveness of clinical breast examination (CBE) and breast self examination (BSE); and harms of screening. Data Sources Cochrane Controlled Trials Registry and Database of Systematic Reviews (4th Quarter 2008), MEDLINE® (January 2001 to December 2008), reference lists, and Web of Science® for published studies; Breast Cancer Surveillance Consortium for screening mammography data. Study Selection Randomized controlled trials with breast cancer mortality outcomes for screening effectiveness; multiple study designs and data sources for harms. Data Extraction Investigators abstracted relevant data and rated study quality using established criteria. Data Synthesis Mammography screening reduces breast cancer mortality by 15% for women age 39 to 49 (relative risk 0.85; 95% CrI 0.75 to 0.96; 8 trials); data are lacking for age ≥70. Radiation exposure from mammography is low. Patient adverse experiences are common, transient, and do not impact screening practices. Estimates of overdiagnosis vary from 1% to 10%. Younger women have more false positive mammograms and additional imaging, but fewer biopsies than older women. Trials of CBE are ongoing; for BSE, trials showed no reductions in mortality but increased benign biopsies. Limitations Studies of older women, digital mammography, and MRI are lacking. Conclusions Mammography screening reduces breast cancer mortality for women age 39 to 69; data are insufficient for older women. False positive mammograms and additional imaging are common. No benefit has been shown for CBE or BSE.

Agency for Healthcare Research and Quality.

Agency for Healthcare Research and Quality.