Claims of breast cancer screening success are dishonest, say critics

Plans to expand the national breast screening programme have been called into question amid fresh claims that women are being misled about the benefits.

Claims by the NHS Breast Screening Programme (NHSBSP) that screening reduces breast cancer deaths by a third and cuts the risk of mastectomy are dishonest, according to research published in the Journal of the Royal Society of Medicine. The claims are based on "cherry-picked" data while "inconvenient truths" about the greater impact of new treatments and increased awareness among women are ignored, claim scientists from the Nordic Cochrane Centre, an independent institution that specialises in analysing research data.

The paper calls into question the integrity of eminent UK scientists who insist that the programme saves hundreds of lives every year – even though similar improvements have occurred among women ineligible for screening. The accusations were last night dismissed by the NHSBSP as unfounded.

The paper is likely to reignite the heated scientific debate about the value of breast screening, which costs the NHS more than £80m a year. Critics say the programme's benefits have always been overstated.

Peter Gotzsche, professor of clinical research, design and analysis at the University of Copenhagen and the study's lead author, said: "Senior researchers who are affiliated with the UK screening programme continue to distort the facts even though we, and others, have pointed out their errors.

"I can only speculate why, but when you have believed in something for a long time and your career is built on that belief, it is very difficult to change. These people, in a scientific sense, are behaving outright dishonestly and doing women a great disservice."

A flurry of papers published in the last two years raised concerns about the harmful effects of scanning women due to high rates of over-diagnosis. From these studies, the new paper estimates that screening leads to 50 per cent over-diagnosis of breast cancers – tumours identified and treated needlessly as they would never actually have progressed or caused illness.

The authors criticise the NHSBSP information leaflet which they say plays down this risk. But supporters insist the public health benefits far outweigh the risks. Professor Julietta Patnick, director of the NHS Cancer Screening Programmes, said: "We know that 97 per cent of women with screen-detected cancers are alive five years later compared to just over 80 per cent of women diagnosed without screening, and screeninglowers a woman's risk of having a mastectomy."

Screening for younger and older women will be expanded over the next few years, costing an extra £12m a year. A Department of Health spokesperson said: "According to the vast majority of experts, breast screening reduces deaths from breast cancer... We are expanding the programme so that we save even more lives."