Screening mammography for early diagnosis of breast cancer: Facts, controversies, and the implementation in Israel

Background: Breast cancer is the leading cancer among Israeli women. Mammography is the most widely used tool for early diagnosis of breast cancer. Eight published randomized controlled trials followed nearly 500,000 women over 7 to 18 years. Most trials found that screening mammography decreases breast cancer mortality by 20 to 40%. A recent study examined the methodology of the randomized clinical trials and found that most trials were flawed in the methodology of data collection and analysis in a way that might have influenced the results of those trials. Purpose: To review the studies, clarify the issues, and reach a conclusion regarding the utility of screening mammography in reducing breast cancer-related mortality in Israel. Methods: A review of the world literature, and analyses of the Israeli data. Results: Seven out of eight published randomized controlled trials found a significant decrease in breast cancer mortality among women who underwent screening mammography. A meta-analysis of the trials also supports the utility of screening mammography in decreasing breast cancer mortality. The criticism over the methodology of these trials does not necessarily invalidate their conclusions. Conclusions: The data indicate that screening mammography does indeed assist in early diagnosis, and most published studies show a significant reduction in breast cancer-related mortality in the screened population. Due to the high incidence of breast cancer in the Israel, especially among young women, the national screening program should continue. Moreover, consideration should be given to expanding it to women starting at age 45, instead of 50, as is practiced today.