Possible reduction in interval breast cancer after tomosynthesis
A large German study found 24 per cent fewer invasive interval cancers, but the main difference was not statistically significant.
A randomised German study examined whether 3D breast imaging alongside mammography misses fewer breast cancers than standard mammography. After two years, the number of invasive interval cancers was lower, but the primary difference did not reach the threshold for statistical significance.
The TOSYMA study followed nearly 100,000 women aged 50 to 70 at 17 screening sites in Germany. One group received digital breast tomosynthesis with a synthesised two-dimensional image; the other group received standard digital mammography.
Among women whose initial screening showed no cancer, 70 interval cancers were diagnosed within 24 months in the tomosynthesis group and 92 in the mammography group. That equates to 14.2 versus 18.6 cases per 10,000 women.
The relative difference was 24 per cent. The researchers say this indicates that tomosynthesis may detect some cancers earlier that would otherwise only come to light between two screening rounds. However, the margin of uncertainty was wide and the difference was not statistically significant.
In the first 12 months, the difference was statistically significant: 4.5 cases per 10,000 women after tomosynthesis compared with 6.3 after standard mammography. According to the researchers, the effect was particularly visible among women who had previously taken part in screening; in the first screening round, the numbers were virtually identical.
The study was published in the peer-reviewed journal The Lancet Oncology. The researchers point out that the coronavirus pandemic reduced participation below the planned level. As a result, the study may have had less statistical power to demonstrate a convincing difference over two years.
The results do not mean that every woman would benefit from a different screening method or that standard mammography should be replaced. The study found better detection in certain analyses, but further research is still needed to establish whether the method also leads to fewer advanced tumours and better outcomes in the longer term.
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One story, several perspectives
What is established
- The study compared tomosynthesis with standard mammography.
- Over two years, there were numerically fewer interval cancers in the tomosynthesis group.
- The primary difference was not statistically significant.
- The study was conducted in Germany.
Left
Arguments New screening technologies should be assessed primarily on their health effects and accessibility, not just on efficiency or cost.
Values Prevention, equal access and public health.
Consequences Wider use may be worthwhile if further research confirms better outcomes, but additional examinations must not lead to greater inequality or overdiagnosis.
Centre
Arguments The results are promising, but not yet sufficient to change national policy immediately. Longer follow-up and assessment of costs, radiation exposure and overdiagnosis are needed first.
Values Evidence-based policy, proportionality and patient safety.
Consequences A phased introduction or further research could enable innovation without abruptly replacing existing screening.
Right
Arguments Healthcare policy should remain cautious as long as the main endpoint does not show a statistically convincing difference. New equipment should demonstrate clear added value before public funds are committed.
Values Efficiency, freedom of choice and responsible budgetary policy.
Consequences A wait-and-see approach avoids high costs and unnecessary diagnostics, but may delay the introduction of a useful technique.
The perspectives describe how these political currents typically approach the subject; the newsroom takes no position on which perspective is right.
Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The figures, percentages and limitations correspond to the publication and independent summaries. The text makes clear that the primary outcome was not statistically significant.
- confirmed The study included nearly 100,000 women at 17 German screening sites. — Description in PubMed and ASCO Post. source
- confirmed There were 70 versus 92 interval cancers, or 14.2 versus 18.6 per 10,000 women. — The figures appear in the study abstract. source
- confirmed The 24 per cent relative reduction was not statistically significant. — The study reports p=0.11 and a confidence interval that includes zero. source
- confirmed The study was published in the peer-reviewed journal The Lancet Oncology. — PubMed lists the journal and publication status. source
Editor's note
The research was peer-reviewed and randomised. The main outcome over 24 months was not statistically significant; the wording has therefore been kept cautious.Sources
- Invasive interval breast cancer rates after digital breast tomosynthesis plus synthesised mammography versus digital mammography screening — PubMed / The Lancet Oncology
- Impact of Digital Breast Tomosynthesis on Invasive Interval Breast Cancer Rate — The ASCO Post
- Tomosynthesis detects breast cancer more frequently during screening — Medical Xpress