Low HER2 expression is associated with clinical benefit for metastatic breast cancer patients that receive trastuzumab deruxtecan, a HER2-targeting antibody drug conjugate, but its prognostic value for earlier-stage cancers is unknown.

Researchers led by Clinton Yam, MD, and Debu Tripathy, MD, evaluated the significance of low HER2 expression in 367 patients with early-stage triple-negative breast cancer receiving neoadjuvant therapy.

They found that low HER2 expression was associated with increased expression of the androgen receptor and genes associated with both fatty acid and steroid hormone metabolism.

Further analysis showed different potential causes of resistance to neoadjuvant chemotherapy between HER2-low and HER2-zero tumours, which may influence personalised treatment for patients with early-stage triple-negative breast cancer.

The poster will be presented on December 7.

Source: University of Texas MD Anderson Cancer Centre