AI mammography leads to fewer advanced breast cancers, study finds

AI mammography finds more cancers at screening and cuts diagnoses between screens by 12 per cent, a major trial has found.

The study involving over 100,000 Swedish women is described as the first randomised controlled trial investigating the use of AI in a national breast cancer screening programme.

Women who underwent AI-supported screening were less likely to be diagnosed with more aggressive and advanced breast cancer in the two years following, compared with standard mammography read by two radiologists.

The research was led by Lund University in Sweden.

Lead author Dr Kristina Lång 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.

“It finds that AI-supported screening improves the early detection of clinically relevant breast cancers which led to fewer aggressive or advanced cancers diagnosed in between screenings.

“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.

“However, introducing AI in healthcare must be done cautiously, using tested AI tools and with continuous monitoring in place to ensure we have good data on how AI influences different regional and national screening programmes and how that might vary over time.”

Between April 2021 and December 2022, women who were part of mammography screening at four sites in Sweden were randomly assigned to either AI-supported screening or standard double reading by radiologists without AI.

In the AI-supported group, a specialist system analysed the mammograms and triaged low-risk cases to single reading and high-risk cases to double reading performed by radiologists. AI was also used to highlight suspicious findings in the image.

During the two-year follow-up, there were 1.55 interval cancers per 1,000 women in the AI-supported group, compared with 1.76 per 1,000 women in the control group.

Interval cancers are those diagnosed after a negative screen and before the next scheduled appointment, and are often more aggressive than cancers detected during routine screening.

Additionally, there were 16 per cent fewer invasive cancers, 21 per cent fewer large cancers, and 27 per cent fewer aggressive sub-type cancers in the AI group. The rate of false positives was similar for both groups.

Jessie Gommers is first author and PhD student at Radboud University Medical Centre in the Netherlands, said:

Gommers said: “Our study does not support replacing healthcare professionals with AI as the AI-supported mammography screening still requires at least one human radiologist to perform the screen reading, but with support from AI.

“However, our results potentially justify using AI to ease the substantial pressure on radiologists’ workloads, enabling these experts to focus on other clinical tasks, which might shorten the waiting times for patients.

Dr Lång added: “Further studies on future screening rounds with this group of women and cost-effectiveness will help us understand the long-term benefits and risks of using AI-supported mammography screening.

“If they continue to suggest favourable outcomes for AI-supported mammography screening compared with standard screening, there could be a strong case for using AI in widespread mammography screening, especially as we face staff shortages.”