Breast screening from 40 may save hundreds of lives

SCREENING women for breast cancer from their 40s could prevent hundreds of deaths each year, a study suggests.

At present, women are not invited for breast screening until they reach 50, but researchers at Queen Mary University of London found that, by moving testing forward by a decade, death rates could be cut by 25 per cent in the first 10 years. The experts predict it could save between 300 and 400 more lives a year.

Prof Stephen Duffy, the lead researcher, said: “This is a very long-term follow-up of a study which confirms that screening in women under 50 can save lives.

“The benefit is seen mostly in the first 10 years, but the reduction in mortality persists in the long term at about one life saved per thousand women screened.”

He added: “We now screen more thoroughly and with better equipment than in the Nineties, when most of the screening in this trial took place, so the benefits may be greater than we’ve seen in this study.”

The results are based on a study of more than 160,000 women who were enrolled in the UK Breast Screening

Age Trial between 1990 and 1997, when they were aged between 39 and 41.

Researchers found early screening resulted in mortality dropping by one quarter in the first 10 years, with an estimated 620 total years of life saved, corresponding to 11.5 years saved per 1,000 women.

They estimated that 1,150 women would have to be screened in their 40s to prevent one death.

The results also suggest that any overdiagnosed cancers would be likely to be spotted at NHS screening from 50 years of age.

Shirley Hodgson, a professor of cancer genetics, St George’s, University of London, said: “The clear implication from this study is that screening from 40 does appear to save lives from breast cancer, particularly early stage (1 and 2). The fact that early screening involves annual screens, which at the time of the study were less sensitive than those done nowadays, indicates that the sensitivity of screening may be greater now, but possibly this could result in more false positive diagnoses.

However, Kevin Mcconway, emeritus professor of applied statistics at the Open University, said there was still a danger from overdiagnosis.

For every one woman whose life is saved by the current screening programme, three women are diagnosed with a cancer that would never threaten their lives.

“An earlier overdiagnosis does mean that a woman might have to live with the consequences of unnecessary treatment for longer,” Prof Mcconway said.

“It’s also the case, on the current screening programme, that most women whose mammogram shows something suspicious, so that they need further investigation, actually turn out not to have a cancer; currently that’s true for three out of every four women whose mammogram looks abnormal.”

The authors said they had not yet considered the cost-effectiveness of screening earlier.

The results were published in The Lancet Oncology.