New research out today suggests that for every person who receives unnecessary breast cancer treatment from screening, two other women's lives are saved. The research, partly funded by Cancer Research UK is published in the Journal of Medical Screening. This contradicts findings from Denmark which indicate that some women may be being overdiagnosed and overtreated.

Interviewed on the programme, Cancer Research UK's Professor Stephen Duffy said that the new research, which involved 80,000 women, indicated that rather than overdiagnosing patients, "we were early diagnosing them".

But Karsten Jorgensen, of the Nordic Cochrane Centre (NCC) in Copenhagen, argued that the case for screening was not so clear-cut and that money used to provide screening "could have been spent better".

More than 45,000 women are diagnosed with breast cancer each year in the UK, and more than 12,000 die from the disease. Women aged 50 to 70 are invited for NHS breast screening every three years across the UK. In England from 2012 screening will be extended to women aged from 47 to 73.