Fall in mortality from breast cancer is due almost equally to screening and adjuvant therapy

Seven statistical models independently developed to investigate the reduction in death rates from breast cancer in the United States in 1975-2000 show that mammographical screening and adjuvant treatment have contributed almost equally (New England Journal of Medicine 2005;353:1784-92).

The proportion of the total reduction attributed to screening varied from 28% to 65% in the seven models (median 46%) with adjuvant treatment contributing the rest. The variability across models in the absolute contribution of screening was larger than it was for treatment, reflecting the greater uncertainty associated with estimating the benefit of screening.

The models were developed by the Breast Cancer Working Group of a consortium of investigators sponsored by the US National Cancer Institute (Cancer Intervention and Surveillance Modeling Network or CISNET). …