The Department of Health has ordered an independent review into breast screening following research that suggests the harm of mammograms may outweigh the benefits.

Professor Sir Mike Richards, national cancer director at the Department of Health, initiated the review after academics called into question the worth of the screening programme.

According to scientists from the Nordic Cochrane Centre in Denmark, as many as 30% of women are “over-diagnosed” following a screening, with benign lumps or that require no treatment often mistaken for cancer.

Once diagnosed, the woman is set on a path of treatment, often radiotherapy, chemotherapy and even surgery that may not be necessary.

The Danish researchers also argue that women - more than 50 million undergo screening in Britain every three years – should be better informed about the potential harms as well as the benefits of mammograms.

Professor Susan Bewley, consultant obstetrician at King's College, London, praised the research. In an open letter to Richards, published in the British Medical Journal, she said the NHS leaflets on breast screening "did not spell out the risks".

"The oft-repeated statement that '1,400 lives a year are saved' has not been subjected to proper scrutiny,” she added. “Even cancer charities use lower estimates."

"I am not convinced that you have challenged your experts competently and mercilessly, rather than hidden behind them. Thus I support the calls for an independent review of the evidence - a review that will not be kicked into the long grass, whose findings will be widely and properly disseminated, and that will adjust screening policy appropriately and will lead to proper pursuit of the research implications."

In response, Richards published his own letter. He said: “screening programmes should be based on the best available evidence," which currently indicates that mammograms save lives.

The NHS claim that over a decade, for every 400 women screened one life is saved. However, the Nordic Cochrane Centre research disputes those figures, claiming that it is closer to one life for every 2,000 screenings over a decade. They say that during that time, 200 women will have to go through further unnecessary test and 10 will have been unnecessarily operated on.

Speaking in The Independent, GP Margaret McCartney said: “We should be honest about the problems and women should be left to choose whether or not to be screened.”

Should the independent review conclude that the balance of harms outweighs the benefits of breast screening, Richards said he “will have no hesitation in referring the findings to the UK National Screening Committee and then ministers."

Speaking on Sky News, Richards said that women that have been recently invited for a mammogram “should go to the screening.”

Speaking to The Huffington Post UK, Harpal Kumar, Chief Executive of Cancer Research UK, said: “Over the last few years a growing controversy has emerged surrounding the benefits and potential harms of breast screening. Some of the controversy surrounds whether women are being given appropriately balanced information.

"It is clear that information can and should be improved. However, at the heart of the debate lie two deceptively simple-sounding and more fundamental questions – how many lives does breast screening save? And how much harm does it cause? We need to reach a consensus on the answers to these questions in order to guide the future of breast screening."

Dr Emma Pennery, clinical director at Breast Cancer Care, told The Huffington Post UK that conflicting opinions about screening can be confusing for people and adds to their anxiety. As such, she welcomed the review, adding:

“We know that prompt detection of breast cancer can lead to more effective outcomes so we encourage all women, including those outside of screening age, to be breast aware – getting to know what is normal for them so they can spot and report any unusual changes to their GP immediately."

The results of the review are expected next year.

On Monday, Downing Street was bathed in pink light to celebrate Breast Cancer Awareness Day on Friday 28th.