Breast screening with 3D mammograms increases the detection rate of tumours by a third, a study has found.

Scientists compared the results of ordinary 2D scans with a combination of 2D and 3D screening.

Two-thirds of the cancers detected, a total of 39, were found by both types of scan. But a third only came to light when 3D screening was added.

3D mammograms work in a similar way to a CT scan, by taking multiple X-rays to build up a three-dimensional picture.

They are said to be more sensitive, but have been criticised for increasing the radiation exposure of patients.

In the new study, researchers also found that including a 3D scan in screening resulted in fewer false positives – suspicious abnormalities that turn out to be false alarms.

The findings are published online in the journal The Lancet Oncology.

Lead researcher Professor Nehmat Houssami, from the University of Sydney, Australia, said: “Although controversial, mammography screening is the only population-level early detection strategy that has been shown to reduce breast cancer mortality in randomised trials. Irrespective of which side of the mammography screening debate one supports, efforts should be made to investigate methods that enhance the quality of, and hence potential benefit from, mammography screening.

“We have shown that integrated 2D and 3D mammography in population breast cancer screening increases detection of breast cancer and can reduce false-positive recalls depending on the recall strategy. Our results do not warrant an immediate change to breast screening practice, instead they show the urgent need for randomised controlled trials of integrated 2D and 3D versus 2D mammography.”