Screening Women Aged 40-49 Years: Where Are We Today?

The fact that mammographic screening can reduce deaths from breast cancer is well established and is unarguably true for women aged 50-69 years (12)- While the unique value of mam-mography in the early detection of breast cancer is also well es-tablished, it is less certain if early detection results in similar mortality reductions for women diagnosed with breast cancer between the ages of 40 and 49 years compared with women aged 50 years and older. This uncertainty is, at the outset, the result of an inadequate base of scientific data. Specifically, no trial to date, with the exception of the Canadian National Breast Screening Study (NBSS-1), was designed to have adequate statistical power to test the hypothesis of a benefit from mam-mography for women aged 40^9 years, and the results are not universally accepted due to concerns about study methodology. While the majority of these trials suggest a benefit for wome