Almost 4,000 women a year in the UK are having treatment for breast cancer they don’t need, according to new research. An independent panel of doctors called in to assess the UK’s breast screening programmes found some women are diagnosed with tumours that would never cause them any problems in their natural life span. But the doctors say screening also prevents more than 1,300 deaths a year, underlining the benefits of regular mammograms.

Cancer Research UK, which took part in the review, strongly recommends women turn up for screening. The charity’s chief executive Dr Harpal Kumar said: “Screening remains one of the best ways to spot the very early signs of breast cancer, at a stage when treatment is most likely to be successful.”

The review was ordered after European researchers had warned that screening may do more harm than good. The independent panel trawled through 11 studies involving thousands of women, in the hope of settling the controversy. According to results published in The Lancet medical journal, for every cancer death prevented three women will be over-diagnosed and may have surgery, chemotherapy or radiotherapy as a result.

National cancer director Professor Sir Mike Richards said leaflets explaining breast screening will be rewritten within four months to reflect the new information. “We have always said that there are some cancers that can be found that would not have caused problems in a woman’s lifetime,” he said. “What we can now do is put a number on that, to give an estimate. Women can make their individual choices based on good information.”

But Dr Deborah Cunningham, clinical director of breast services at Charing Cross Hospital in London, warned that some women could be put off screening. She told Sky News: “They already have difficult choices to make. This complicates it further. Screening won’t work if they dona��t turn up.”

Beverley Angell was diagnosed with breast cancer after a routine screening appointment earlier this summer. She has no doubt that the programme is worthwhile. “I could not feel the lump and I did not know it was there. It has saved my life.”