In a new study of over 500 women who had digital breast tomosynthesis (DBT), researchers found that architectural distortion (AD), as a prominent or associated feature, was associated with over 70 percent of invasive ductal cancer cases.
For the retrospective study, recently published in the European Journal of Radiology, researchers reviewed breast ultrasound and DBT data for 537 women who had mentions of AD in the DBT reporting. For 307 cases, AD was indicated as the prominent feature and noted as an associated feature on DBT for 230 patients. Breast cancer occurred with 57 percent of the cohort, according to the study.
The researchers noted a 78 percent malignancy rate for cases involving masses or highly suspicious microcalcifications with associated AD on DBT.
For cases involving AD as a prominent finding on DBT, the presence of intermediate-risk microcalcifications was associated with a 68 percent malignancy rate and regional density cases had a 43 percent malignancy rate. Pure AD cases, on the other hand, had a 34 percent mortality rate, according to the study authors.
“The results showed that when AD was the associated feature accompanying other significant radiological findings, the cases were more likely to be malignant. Similarly, when AD was the prominent feature but accompanied by regional high-density or intermediate-risk microcalcifications, the malignancy rate was also higher than those presenting as pure AD,” wrote lead study author Jiejie Zhou, M.D., who is affiliated with the Department of Radiology at the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, China, and colleagues.
For cases involving prominent AD on DBT, the researchers pointed out that correlation with breast ultrasound findings doubled the malignancy rate (46 percent) in comparison to patients with no correlating findings on ultrasound (23 percent).
Out of 182 benign cases involving prominent AD on DBT, the study authors found that 38 patients had BI-RADS 2 or 3 presentations and 54 patients had no correlation of ultrasound findings.
“Therefore, about half of benign cases had low (ultrasound) BI-RADS scores or no abnormality, and many unnecessary biopsies could have been avoided with the supplementary (ultrasound),” posited Zhou and colleagues.
Three Key Takeaways
- High malignancy risk with associated findings. Architectural distortion (AD) on DBT, especially when associated with suspicious masses or microcalcifications, was linked to malignancy rates exceeding 70 percent.
- Ultrasound correlation improves risk stratification. For prominent AD cases, concurrent suspicious ultrasound findings doubled malignancy rates compared to those without ultrasound correlation, potentially helping to avoid unnecessary biopsies.
- Breast density influences detection. AD in fattier breasts (BI-RADS A/B) showed higher malignancy rates than in denser breasts, likely due to reduced tissue overlap and clearer visualization of pathology. However, researchers noted a lack of statistical significance with this study finding.
While noting a lack of statistical significance, the study authors noted a 15 percent higher malignancy rate in women with BI-RADS density A and B (55 percent) in contrast to those with BI-RADS density C and D (40 percent).
“In heterogeneously dense and extremely dense breasts, the tissue overlapping problem could obscure the assessment of AD. In contrast, when AD was identified in fattier breasts, it was more likely related to true pathological processes and had a higher malignant rate,” added Zhou and colleagues.
(Editor’s note: For related content, see “New Study Examines Impact of Mammography in Detecting Pregnancy-Associated Breast Cancer,” “Reducing the Interval Breast Cancer Rate of Screening DBT: Can AI Have an Impact?” and “A Closer Look at the Impact of Expanded Mammography Coverage in Missouri: An Interview with Amy Patel, MD.”)
Beyond the inherent limitations of a single-center retrospective study, the authors conceded the likelihood of high inter-observer variation in determining whether AD is a prominent or associated feature on DBT and acknowledged the lack of necessity for this determination in clinical practice. The researchers also did not assess whether ultrasound features correlated with DBT findings.
