Screening by breast digital tomosynthesis does not find more cancers than conventional mammography, according to the results from the first randomised controlled trial comparing the two.

Norwegian researchers were surprised to find that 3D mammography detected breast cancer in only 0.66% of women aged 50-69 years old, a result that was not statistically different from the 0.61% detection rate using conventional mammography.

They had expected cancers to be found in about 0.88% of women screened using the new 3D technology in a trial that included more than 29,400 women taking part in Norway’s national two-yearly screening program, they wrote in the Lancet Oncology.

The results raised “the question of whether this is the beginning of the end for digital breast tomosynthesis screening, or whether we should consider these results in context and learn from them,” wrote Professor Sophia Zackrisson, of Lund University in Sweden, in an accompanying editorial.