AI-supported mammography detected more clinically relevant cancers and reduced interval cancer diagnoses by 12 per cent compared with standard screening.
Women screened with AI were less likely to develop aggressive or advanced breast cancer in the following two years.
The use of AI reduced radiologists’ reading workload by 44 per cent while maintaining similar false-positive rates.
Use of artificial intelligence in Sweden's national breast cancer screening programme has revealed that AI-supported mammography screening is more effective than standard mammography, according to full results from a 2023 trial published in The Lancet journal.
AI-supported breast cancer screening identified more women with clinically relevant cancers without a higher rate of false positives, the results show.
Researchers from Lund University and other institutes in Sweden, Norway, Denmark and the Netherlands, also found that women who underwent AI-supported screening were less likely to be diagnosed with more aggressive and advanced breast cancer in the following two years.
In August 2023, interim results from the Mammography Screening with Artificial Intelligence (MASAI) showed that use of AI resulted in the detection of 20 per cent more cancers compared with standard screening.
The team also found that screen-reading workload for radiologists reduced by 44 per cent.
The full results now show that AI-supported mammography also reduces cancer diagnoses in the years following a breast cancer screening appointment by 12 per cent - a key test of screening programme effectiveness, the researchers said.
"Our study is the first randomised controlled trial investigating the use of AI in breast cancer screening and the largest to date looking at AI use in cancer screening in general," lead author Dr Kristina Lang, a breast radiologist and clinical researcher from Lund University, Sweden, said.
She added, "AI-supported screening improves the early detection of clinically relevant breast cancers which led to fewer aggressive or advanced cancers diagnosed in between screenings." Between April 2021 and December 2022, over 1,05,900 women were randomly assigned to either AI-supported mammography screening or to standard double reading by radiologists without AI.
The AI system was trained, validated, and tested with more than two lakh examinations from multiple institutions across more than ten countries.
During the follow-up period of two years, 1.55 interval cancers per 1,000 women (82/53,043) were detected in the AI-supported mammography group, compared to 1.76 interval cancers per 1,000 women (93/52,872) in the standard double reading group -- a 12 per cent reduction in interval cancer diagnosis for the AI arm.
An interval cancer is a malignancy detected between scheduled screening tests, after a prior negative result and before the next routine check-up.
Further, 81 per cent of cancer cases (338/420) in the AI-supported mammography group were detected at screening, compared to 74 per cent of cancer cases (262/355) in the standard reading group -- a nine per cent increase.
Rates of false positives were similar for both the groups -- 1.5 per cent in the AI-assisted mammography reading and 1.4 per cent in the standard reading group.
"Widely rolling out AI-supported mammography in breast cancer screening programmes could help reduce workload pressures amongst radiologists, as well as helping to detect more cancers at an early stage, including those with aggressive subtypes," Lang said.
