What cancer is treated with trastuzumab?

Trastuzumab, also known as Herceptin, is specifically designed to target and inhibit the human epidermal growth factor receptor 2 (HER2). This protein is overexpressed in a subset of breast cancers, known as HER2-positive breast cancer. The presence of high levels of HER2 can lead to aggressive tumor growth, and trastuzumab has been shown to improve outcomes in patients whose tumors express this receptor.

Treating HER2-positive breast cancer with trastuzumab has become a standard approach because it can significantly reduce the risk of recurrence and improve overall survival when used alone or in combination with chemotherapy. The drug works by binding to the HER2 receptors on cancer cells, causing them to stop growing and dividing, and also marking them for destruction by the immune system.

In contrast, triple-negative breast cancer lacks HER2 expression and does not benefit from trastuzumab treatment. Similarly, ovarian and lung cancers do not routinely use trastuzumab as a therapeutic intervention since their pathophysiology does not involve the HER2 receptor in the same manner as HER2-positive breast cancer. Therefore, trastuzumab's effectiveness is specifically linked to HER2-positive breast cancer, making the identification of this cancer type paramount in the context of the treatment