London: The world’s biggest breast cancer charity has been accused of ‘Oscar-winning’ tactics that dupe women into being screened.

Experts said the charity — which invented the pink ribbon logo for breast cancer awareness — was overselling the benefits of X-ray checks and ignoring the potentially harmful effects.

Misleading statistics are persuading women to undergo mammography without knowing the full facts, it was claimed. Professor Lisa Schwartz and Steven Woloshin of the US Centre for Medicine and the Media at The Dartmouth Institute for Health Policy and Clinical Practice said women were being given false hope by ‘deceptive’ advertising.

They launched an attack on the British Medical Journal’s website bmj.com on advertising campaigning by the charity Susan G Komen for the Cure.

They said its campaign failed to acknowledge that survival rates are distorted by the process of screening, and further bias is created by overdiagnosis of cancers that would never have caused death.

“If there were an Oscar for misleading statistics, using survival statistics to judge the benefit of screening would win a lifetime achievement award hands down,” they said.

The criticisms will fuel the debate in the UK about whether or not breast cancer screening does more harm than good. An independent review is under way into the NHS breast cancer screening programme to investigate whether it remains worthwhile. It is expected to report by the end of the year.

In the US, there is growing awareness of a ‘fine balance’ between benefits and harms caused by screening. But you would not know that from charity adverts for screening which claim ‘early detection saves lives’, say the US professors.

The adverts say: “The five-year survival rate for breast cancer when caught early is 98 per cent. When it’s not? It’s 23 per cent.”

The actual benefit is small, they claim. Mammography results in a reduction in the chance that a woman in her 50s will die from breast cancer over the next ten years from 0.53 per cent to 0.46 per cent, a difference of 0.07 percentage points, they said.

In addition, harms are overlooked including false alarms requiring a biopsy and overdiagnosis — where women are treated for cancers that would have never have produced symptoms.

The US critics claim: “For every life saved by mammography, around two in ten women are overdiagnosed. Women who are overdiagnosed cannot benefit from unnecessary chemotherapy, radiation or surgery.’ Under the NHS screening programme, which cost £75 million last year, women are invited for three-yearly mammograms, or X-rays, between the ages of 50 and 70 years. The age limits are being extended to 47-73.

UK cancer charities said they hoped the outcome of the NHS review would provide clarity on the controversial screening issue. A Breast Cancer Care spokesman added: “Until then, we know that in the majority of cases, the sooner breast cancer is detected, the greater the chances of a better outcome.”

A Susan G Komen for the Cure spokesman said: “Everyone agrees mammography isn’t perfect, but it’s the best widely available detection tool we have.”

Critics of screening say programmes are bad for women because they lead to unnecessary investigations, over-treatment including mastectomies, and distress.

They claim the dramatic fall in breast cancer deaths in recent years is mostly due to changes in risk factors and improved treatment.

Above all, many experts are uneasy that women are not properly informed about the drawbacks when they are invited for an X-ray check — because they might say no. Danish researchers estimate that 7,000 British women a year needlessly go through the ordeal of diagnosis and treatment because of screening overdiagnosis.

Southampton University found women are more likely to undergo unnecessary surgery in the first decade of being screened.

But research from Holland found screening still saves women’s lives, reducing deaths by almost 16 per cent.