A Google artificial intelligence system proved as good as expert radiologists at detecting which women had breast cancer based on screening mammograms and showed promise at reducing errors, researchers report.
The study, published in the journal Nature, is the latest to show that artificial intelligence (AI) has the potential to improve the accuracy of screening for breast cancer, which affects one in eight women globally.
Radiologists miss about 20 percent of breast cancers in mammograms, the American Cancer Society says, and half of all women who get the screenings over a 10-year period have a false positive result.
The findings of the study, developed with Alphabet's DeepMind AI unit which merged with Google Health in September, represent a major advance in the potential for the early detection of breast cancer, said Mozziyar Etemadi, one of its co-authors from Northwestern Medicine in Chicago.
The team, which included researchers at Imperial College London and Britain's National Health Service, trained the system to identify breast cancers on tens of thousands of mammograms.
They then compared its predictions to the actual results from a set of 25,856 mammograms in the UK and 3097 from the US.
The study showed the AI system could identify cancers with a similar degree of accuracy to expert radiologists, while reducing the number of false positive results by 5.7 percent in the US-based group and by 1.2 percent in the British-based group.
It also cut the number of false negatives, where tests are wrongly classified as normal, by 9.4 percent in the US group, and by 2.7 percent in the British group.
These differences reflect the ways in which mammograms are read.
In the United States, only one radiologist reads the results and the tests are done every one to two years. In Britain, the tests are done every three years, and each is read by two radiologists. When they disagree, a third is consulted.
In a separate test, the group pitted the AI system against six radiologists and found it outperformed them at accurately predicting breast cancers.
Although computers have not been "super helpful" so far, "what we've shown at least in tens of thousands of mammograms is the tool can actually make a very well-informed decision," Etemadi said.
The study has some limitations. Most of the tests were done using the same type of imaging equipment, and the US group contained a lot of patients with confirmed breast cancers.
More studies will be needed to show that when used by radiologists, the tool improves patient care, and it will require regulatory approval, which could take several years.