Digital breast tomosynthesis findings may be different in HER2 positive breast cancer patients according to hormone receptor status

To The Editor,

I want to congratulate Lee and colleagues for their article¹ in which they evaluated imaging features of breast cancers on digital breast tomosynthesis (DBT) according to molecular subtype. All of the study cases were classified into three major subtypes using hormone receptor (HR) and HER2 status: HR+ (i.e. ER or PR positive and HER2 negative), HER2+ (i.e. ER and PR may be positive or negative) and TNBC (i.e. ER, PR, and HER2 negative). The most common DBT findings were irregular spiculated masses for HR-positive cancer; fine pleomorphic or linear branching calcifications for HER2-positive cancer; and irregular masses with circumscribed margins for TNBC (p < 0.001). However, authors did not evaluate imaging features of HER2 subtypes according to HR status. Interestingly, another study investigated the association between breast cancer subtype and radiological findings in the Chinese population.² The molecular subtypes of breast cancer were classified into four types: luminal A, luminal B (including HR-positive and HER2-positive patients), HER2 overexpressed (HER2) and basal-like breast cancer. They found that luminal A and B subtypes showed different radiological findings compared to patients with HER2 overexpressed tumours at all. Therefore, it would be interesting to know whether DBT findings are different according to hormonal receptor status in HER2-positive patients in the current study.