With cancer, time is health. The earlier a tumor is detected, the better: the higher the chances of treatment and cure. Therefore, early detection tests have become an ally in increasing survival and tackling nascent tumors as soon as possible. For instance, scientific literature estimates that population-based screening by mammogram reduces breast cancer mortality by 20%, and this decline may be even more pronounced if screening tests and the analysis of results are refined. Artificial intelligence (AI) has already crept into this field and, according to a Swedish study involving 80,000 women published in The Lancet Oncology, breast cancer screenings that are supported by artificial intelligence systems have detected 20% more tumors than those that follow the traditional methodology, which involves a double review carried out by two radiologists. Preliminary results from the research, which is still ongoing, conclude that using AI to analyze mammograms is safe and nearly halves the workload of radiologists.

In breast cancer screening, mammography analysis is usually done by two independent radiologists, as recommended by European clinical guidelines. If they do not agree on the reading, they usually agree on the discrepancies or allow the most aggressive decision to prevail. For example, between not calling the patient or referring them for more tests, the second option is chosen. One study suggests that this double-read technique will detect 0.44 more tumors per 1,000 people screened than a single reading. However, the specialist’s eye is not infallible either: scientific literature estimates that up to 25% of mammographically visible cancers are still not detected in screening and there is already research suggesting that the accuracy of AI may be similar or even superior to that of radiologists.

To verify whether AI-assisted screening is indeed inferior to standard methodology, the Swedish study recruited more than 80,000 healthy women who participated in population-based breast cancer screening between April 2021 and July 2022. The researchers divided them into two groups: the control group, whose mammogram analysis was to follow the standard double-reading procedure; and the intervention group, which would have the initial help of an AI system to analyze the medical tests — and catalog their degree of risk — before being reviewed and interpreted by one or two radiologists (one, if the risk marked by the AI was low and two if the mammogram was at the high risk threshold).

“There were no false positives among that 20%. They are confirmed cases of cancer.”