Screening women for breast cancer from their 40s rather than their 50s could save lives without adding to the diagnosis of harmless cancers, a UK study has found.
The research was based on 160,000 women from England, Scotland and Wales, followed up for around 23 years.
Lowering the screening age could save one life per 1,000 women checked, the scientists say.
But experts caution there are many other considerations, including cost.
Cancer Research UK says it is still "not clear if reducing the breast screening age would give any additional benefit compared to the UK's existi