Intercal cancers, Breast density, Volpara Scorecard
Description
A recent study published in European Radiology found that interval cancers are not all the same. While most interval cancers occurred in dense breasts and were not visible at the time of screening, a smaller group was visible in hindsight and showed more aggressive tumor characteristics.
The findings highlight why reducing interval cancers may require more than one approach.
How was the study conducted?
This UK study looked at over 55,000 screening exams and used Volpara Scorecard to calculate breast density. Across that group, over 700 cancers were identified, including 260 interval cancers diagnosed between screening rounds.
Radiologists then retrospectively reviewed these cases as part of their standard quality check process and split them into two categories:
True interval cancers: those that weren't visible at the time of screening, accounting for about 87%.
Retrospectively missed cancers: those that were visible in hindsight but missed, making up 13%.
What did they learn about these interval cancers?
Density plays a key role in masking true interval cancers
About 72% of true interval cancers occurred in dense breasts, compared to 41% of the missed cancers.
In dense breast cases (BI-RADS C/D), there were also more instances where no mammographic signs were visible at all, meaning the cancers were effectively occult at screening and these patients might benefit from adjunctive screening.
Cancers visible in hindsight showed more aggressive features
Cancers that were visible in hindsight were more likely to be diagnosed sooner and showed more aggressive features, such as higher grade and lymph node involvement.
What do these findings mean?
This is a great reminder that not all interval cancers are the same and reducing them requires more than one approach.
And to be clear, the paper didn't test this, but it does provide a clear clinical basis for where AI could add value.
Density tools help flag masking risk, and detection tools can help surface subtle findings, working together to support different parts of the screening pathway.
Looking at the bigger picture
Improving screening means supporting the whole pathway.
At Lunit, we bring together density, detection, risk, and quality into one integrated approach.
If you're interested in how that looks in practice, you can learn more about Lunit's breast screening ecosystem on our website: Early Detection & Precision Oncology Medical AI Software | Lunit
