Breast screening women in their 40’s to save lives

A 23-year follow-up of a large UK trial found that screening women aged 40-49 led to a substantial and significant 25% reduction in breast cancer mortality in the first 10 years.

The UK, along with many other countries, has a breast cancer screening programme offering mammography to women aged 50–70 years every 3 years. However, uncertainty currently exists over whether to start screening at a younger age, including whether it might lead to over-diagnosis of breast cancer.

Between 1990 and 1997, the UK Breast Screening Age Trial randomised more than 160,000 UK women aged 39-41 to receive either annual mammography, or the usual National Health Service (NHS) breast screening which commences at age 50. The primary outcome was mortality from breast cancers diagnosed prior to first NHS breast screen.

In a new analysis, which presents the 23-year follow-up results of the trial, it was found that screening women aged 40-49 led to a substantial and significant 25% reduction in breast cancer mortality in the first ten years. The total years of life saved from breast cancer in the intervention group was estimated as 620, corresponding to 11.5 years saved per 1,000 women invited to earlier screening.