Screening mammography is the most effective method for early detection of breast cancer (National Institutes of Health Consensus Development Panel, 1997). Strong evidence from randomized, controlled trials conducted around the world shows that regular screening mammograms can reduce breast cancer mortality by about 30 percent for women in their 50s and by 17 percent for women in their 40s (Hendrick et al., 1997; Berry, 1998). Thus, regular screening mammography is now recommended by most medical organizations for women age 40 and older (see, e.g., American Cancer Society, 2001; Eastman, 1997). Controversy remains, however, fueled most recently by a Lancet meta-analysis (Olsen and Gatzsche, 2001) that found no benefit from mammography for women of any age. However, reviews of this report have been conducted by the National Cancer Institute, the American Cancer Society, and other organizations. Despite the announcement that the U.S. Preventive Services Task Force will recommend regularly scheduled mammography for women age 40 and over, there is not widespread agreement among medical organizations that regular mammography should be recommended for women in that age group. Major efforts to promote screening mammography have been underway since 1987, with lead roles played by the American Cancer Society, National Cancer Institute, Centers for Disease Control and Prevention, associations of health professionals, and consumer advocacy groups, such as the Susan G. Komen Foundation and the National Alliance of Breast Cancer Organizations.

Since 1987, the proportion of women age 40 and over who report receiving regular mammograms has increased dramatically. The proportion of women age 40 and older who had a mammogram in the previous 2 years increased from 29 percent in 1987 to 68 percent in 1998. For women ages 50 to 64, the proportion increased from 34 percent to slightly over 75 percent during the same time interval (Breen et al., 2001). Data for 1998 show that