Introduction to HER2-Positive Breast Cancer
HER2-positive breast cancer is characterized by the overproduction of the human epidermal growth factor receptor 2 protein, which promotes the growth of cancer cells. Historically, this subtype was associated with an aggressive disease course and a higher risk of recurrence. However, the landscape of treatment was transformed with the development of targeted anti-HER2 therapies, such as trastuzumab and pertuzumab. Today, the standard of care for stage II-III HER2-positive breast cancer typically involves neoadjuvant (pre-operative) chemotherapy combined with dual HER2 blockade. This intensive approach has led to high rates of pathological complete response (pCR), meaning no invasive cancer is visible in the tissue removed during surgery, and excellent long-term survival.