Breast cancer screening outcomes in women ages 40-49: clinical experience with service screening using modern mammography.

The several randomized controlled trials (RCTs) of breast cancer screening among women of ages 40 to 49 now collectively show a statistically significant reduction in breast cancer mortality. However, there have been numerous recent advances in mammography, such that it now is demonstrably better than when the RCTs were conducted. The use of surrogate measures of screening efficacy (tumor size, lymph node status, cancer stage), readily derived from modern service screening programs, demonstrates how the improved mammography of the 1990s should produce a greater degree of mortality reduction among women ages 40-49 than that already demonstrated in the RCTs. Indeed, these surrogate measures of mortality reduction are as favorable for women of ages 40-49 and 65+ as they are for women of ages 50-64, strongly suggesting that, since modern service screening is accepted as effectively reducing mortality among women of ages 50-64, it should also effectively reduce mortality among women in the 40-49 and 65+ age groups.