Two experts normally examine mammograms
A computer plus one expert are as effective at spotting breast cancer as the two experts usually used to read a mammogram in the UK, research suggests.
Computer-aided detection found 198 out of 227 cancers, compared with 199 from double-reading, in the Cancer Research UK study involving 28,000 women.
NHS breast screening could be made more efficient, say the scientists in the New England Journal of Medicine.
Some women are not offered screenings by the NHS as regularly as they should.
Women aged 50 to 70 should be offered screenings every three years, but in some areas a lack of experts means they do not get screening invitations regularly enough.
The national programme screens over 1.7 million each year.
The NHS would like to see even more women offered screening by extending eligibility to include the ages 47 to 73.
Scanning these extra 200,000 women would increase workload by 30%.
More scans read
Computer-aided detection would mean the same number of experts could read more mammograms in a given period of time, say the researchers.
Professor Fiona Gilbert of the University of Aberdeen and lead author of the study published in the New England Journal of Medicine said: "We want to offer screening to a wider age group. This computer technology will help us achieve this."
She said the financial cost of the software to the NHS would not be astronomical. The researchers are now waiting to see if the NHS cancer screening programme will agree that it can be used in hospitals.
The study invited around 28,000 women to have their NHS mammograms read both in the conventional way by two radiologists and also by a single radiologist using the computer.
The proportion of cancers detected was 199 out of 227 (87.7%) for double reading and 198 out of 227 (87.2%) for single reading with computer-aided detection.
Professor Stephen Duffy, Cancer Research UK's professor of cancer screening, said earlier studies had conflicting results about the success of the computer-aided readings.
He said: "We can now say for certain that this system is as good at detecting breast cancer as the one used as standard practice."
Dr Lesley Walker, Cancer Research UK's director of information, said: "This is good news for women - particularly for those who live in areas where invitations for screening have been late in arriving."
He said there would always be a need for the human eye of an expert to read mammograms.
"In the rare instance when the computer is at odds with the radiologist the human interpretation takes precedence.
"But now we know that a computer can help give more accurate readings there is bound to be an improvement in the national screening programme which already saves 1,400 lives a year through early detection of breast cancer."
Dr Alexis Willett of Breakthrough Breast Cancer said further investigations were required to determine why the technique led to more women needing repeat screening and also to assess practical implications for the NHS.
"To support technology like this, it will also be vital that digital mammography, which captures mammograms electronically rather than on film, is in place.
"Breakthrough Breast Cancer wants to see the Government's existing commitment to the roll-out of digital mammography in England by 2010 is made a reality."
Maria Leadbeater, of Breast Cancer Care, said the system would have to be closely monitored if introduced into clinical practice.
"We know from supporting women with breast cancer or breast health concerns that delays in access to routine screening can cause great anxiety.
"Any measures which could reduce these delays would be very welcome."
In the US and some other European countries only a single expert reads mammograms. The researchers say computers could aid detection in these countries.
The results will be presented at the National Cancer Research Institute's annual conference in Birmingham.