Artificial intelligence (AI) could help detect fast-growing, hard-to-treat breast cancers earlier and reduce the burden on overstretched doctors, according to new findings from a large Swedish breast screening trial.
The study, published in The Lancet, analyzed nearly 100,000 women aged 40 to 80 who participated in Sweden’s national breast screening program between April 2021 and December 2022.
Addressing “Interval Cancers”
Mammography is widely recognized as the most effective method for early breast cancer detection and mortality reduction, with European guidelines recommending scans be reviewed independently by two radiologists. Despite this, researchers note that 20 to 30 percent of breast cancers are diagnosed between routine screenings. These “interval cancers” often grow faster, are more advanced at diagnosis, and are harder to treat.
How the Trial Worked
In the study, participants were randomly assigned to either standard screening with two radiologists or an AI-supported approach, in which AI flagged suspicious areas on mammograms while a radiologist made the final decision.
Results showed that the AI-assisted group had 11 fewer interval cancers over two years—a 12 percent reduction compared to standard screening—and detected more cancers during routine screenings.
Jessie Gommers, a researcher at Radboud University Medical Centre, emphasized that the AI acted as a support tool rather than a replacement. “The AI highlighted suspicious areas in a mammogram that helped radiologists during interpretation,” she explained. “The final recall decision was still made by the radiologists.”
Reducing Radiologist Workload
Because only one radiologist reviewed AI-supported scans, the system also significantly reduced workload. Earlier trial data showed a 44 percent decrease in radiologist workload, which could be particularly valuable in healthcare systems facing staff shortages.
Gommers noted the significance of reducing interval cancers: “You want to have as few of those interval cancers because they are known to be more aggressive and lead to poorer patient outcomes.”
Breast Cancer: A Global Challenge
Breast cancer is the most common cancer among women, with one in 20 women diagnosed during their lifetime. In 2022, an estimated 2.3 million women were diagnosed globally, resulting in around 670,000 deaths. Europe alone recorded nearly 558,000 new cases, according to the World Health Organization (WHO).
AI Is Not a Replacement for Doctors
While AI-assisted mammography is being introduced in parts of Sweden and Denmark, researchers stress that human oversight remains essential. Dr. Olga Oikonomidou, principal investigator and breast cancer research lead at the University of Edinburgh Cancer Centre, cautioned that the trial primarily assessed whether AI could help radiologists work “quicker and more efficiently,” not replace them.
She added that AI systems vary widely, must be rigorously tested like medicines, and should not be seen as a low-cost alternative.
