Screening for Breast Cancer: Systematic Evidence Review Update for the US Preventive Services Task Force [Internet]

Review
Rockville (MD): Agency for Healthcare Research and Quality (US); 2009 Nov. Report No.: 10-05142-EF-1.

Excerpt

Background: This systematic review is an update of new evidence since the 2002 U.S. Preventive Services Task Force recommendation on breast cancer screening.

Purpose: To determine the effectiveness of mammography screening in decreasing breast cancer mortality among average-risk women age 40–49 years and 70 years and older; the effectiveness of clinical breast examination (CBE) and breast self examination (BSE) in decreasing breast cancer mortality among women of any age; and harms of screening with mammography, CBE, and BSE.

Data Sources: The Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (through the fourth quarter of 2008), MEDLINE® searches (January 2001 to December 2008), reference lists, and Web of Science® searches for published studies and Breast Cancer Surveillance Consortium for screening mammography data.

Study Selection: Randomized, controlled trials with breast cancer mortality outcomes for screening effectiveness, and studies of various designs and multiple data sources for harms.

Data Extraction: Relevant data were abstracted, and study quality was rated by using established criteria.

Data Synthesis: Mammography screening reduces breast cancer mortality by 15% for women age 39–49 (relative risk [RR] 0.85; 95% credible interval [CrI], 0.75–0.96; 8 trials). Results are similar to those for women age 50–59 years (RR 0.86; 95% CrI, 0.75–0.99; 6 trials), but effects are less than for women age 60–69 years (RR 0.68; 95% CrI, 0.54–0.87; 2 trials). Data are lacking for women age 70 years and older. Radiation exposure from mammography is low. Patient adverse experiences are common and transient and do not affect screening practices. Estimates of overdiagnosis vary from 1–10%. Younger women have more false-positive mammography results and additional imaging but fewer biopsies than older women. Trials of CBE are ongoing; trials of BSE showed no reductions in mortality but increases in benign biopsy results.

Limitations: Studies of older women, digital mammography, and magnetic resonance imaging are lacking.

Conclusions: Mammography screening reduces breast cancer mortality for women age 39–69 years; data are insufficient for women age 70 years and older. False-positive mammography results and additional imaging are common. No benefit has been shown for CBE or BSE.

Publication types

  • Review

Grants and funding

This report is based on research conducted by the Oregon Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research and Quality (AHRQ), (Contract No. 290-02-0024). This project was funded by AHRQ for the U.S. Preventive Services Task Force (USPSTF). Additional support was provided by the Veteran’s Administration Women’s Health Fellowship (Dr. Tyne) and the Oregon Health & Science University Department of Surgery in conjunction with the Human Investigators Program (Dr. Naik). Data collection for some of this work was supported by the NCI-funded Breast Cancer Surveillance Consortium (BCSC) cooperative agreement (U01CA63740, U01CA86076, U01CA86082, U01CA63736, U01CA70013, U01CA69976, U01CA63731, U01CA70040). The collection of cancer incidence data used in this study was supported in part by several state public health departments and cancer registries throughout the United States. A full description of these sources is available at http://breastscreening.cancer.gov/work/acknowledgement.html.