Conspicuity and imaging features of breast cancers on digital breast tomosynthesis according to molecular profile

Objective To describe BI-RADS features and evaluate conspicuity of breast cancer on digital breast tomosynthesis (DBT) according to their molecular profile. Materials and method Institutional review board was obtained for this retrospective study. Consecutive patients with histologically proven breast cancers who underwent digital breast tomosynthesis (DBT) with 2D synthetic mammography (SM) and digital mammography (DM) at the time of diagnosis were included. Morphological features and conspicuity of cancers on DM, SM and DBT were evaluated in consensus by two breast radiologists. Imaging features were compared across molecular subtypes (luminal, triple negative (TN) and HER2+) using Fisher’s exact test and between DBT and SM and DM using McNemar’s test. Conspicuity was compared between DBT and SM and DM using Wilcoxon matched pairs test and between each molecular subtype using the Wilcoxon test. Results One hundred and eleven consecutive patients were included. On DBT, TN cancers more frequently presented as masses with microlobulated margins (P = 0.04) while HER2 + cancers were more often associated with microcalcifications (P = 0.02). Greater conspicuity on DBT in comparison to DM was observed for cancers with low Ki67 (P = .015), less aggressive tumours (P = .005), positive ER (P = 0.005), positive PR (P = .005) or negative HER2 (P = .024), and for luminal molecular profiles (P = 0.012) while no difference was observed between the two techniques for TN (P = .73) and HER+ (P = .79) tumours. Conclusion DBT reveals specific features of breast cancers according to their molecular characteristics. In comparison with DM, DBT improves conspicuity of luminal subtype cancers and tumours demonstrating less aggressive features on pathology.