Screening mammography: proven benefit, continued controversy.

Screening mammography, despite its limitations, remains the best means for diagnosing breast cancer in asymptomatic women. Regarding the continuing controversies concerning the age at which screening should start, evidence supports beginning regular screening at age 40 in women at average risk . Similarly, evidence suggests that the screening interval should be yearly, especially in younger women. Rather than an arbitrary age at which screening should stop, the decision on screening elderly women should be made on an individual basis, taking into account level of health and life expectancy. More work needs to be done on determining the optimum screening strategies for high-risk women. As to the interpretation of screening mammography, a certain level of observer variability and of false-negative and false-positive readings are inherent in the process. These should be kept to a minimum through efforts by the interpreting radiologist to improve performance through auditing of individual results and continuing education. The impact of double reading and computer-aided detection in the interpretation of screening mammograms warrants further evaluation in terms of efficacy and cost-effectiveness. Despite these continuing controversies, mortality from breast cancer in the United States has been decreasing steadily for the past 25 years. The magnitude of the decrease has been reported to range from 8% to 25%. Although some of this decrease may be attributable to improvements in the treatment of breast cancer, early detection through screening mammography has undoubtedly played a role in this mortality reduction. The controversies that surround the issue of screening should not detract from the fact that screening mammography has proved to save lives.