HER2-low and HER2-zero in breast cancer between prognosis, prediction and entity.

A new editorial paper published in Oncotarget discusses the role of HER2 in breast cancer. HER2 is a prognostic and predictive factor in breast cancer, associated with a poor prognosis but also offering the chance of improved survival with targeted therapies like trastuzumab. The majority of breast tumors are considered HER2-negative, but recent trials with trastuzumab-based antibody-drug conjugates have challenged this view. The paper explores the implications of these findings. [Extracted from the article]