Which tumor biomarker is associated with breast cancer?

HER-2, or Human Epidermal growth factor Receptor 2, is a tumor biomarker specifically associated with breast cancer. It is a member of the human epidermal growth factor receptor family and is overexpressed in approximately 15-20% of breast cancers. The presence of HER-2 is significant because it helps determine the course of treatment a patient may receive. HER-2 positive breast cancers tend to be more aggressive, and targeted therapies, such as trastuzumab (Herceptin), are available that specifically inhibit the HER-2 receptor, improving patient outcomes.

Other biomarkers mentioned, such as CEA (Carcinoembryonic Antigen), AFP (Alpha-Fetoprotein), and CA-125 (Cancer Antigen 125), are associated with other types of cancers. CEA is generally related to colorectal cancer, AFP is commonly linked to liver cancer and certain testicular cancers, and CA-125 is primarily used in the context of ovarian cancer diagnosis and monitoring. Understanding these distinctions is crucial in oncology, as they guide the diagnosis, prognosis, and treatment strategies for various cancer types.