Trastuzumab is primarily used for treating which subtype of cancer?

Trastuzumab is a targeted therapy that specifically addresses cancers that express the HER2 (human epidermal growth factor receptor 2) protein. In breast cancer, HER2 positivity is a key factor that determines treatment options and prognosis. Cancers that overexpress HER2 are more aggressive and tend to have poorer outcomes if left untreated.

Trastuzumab works by binding to the HER2 protein on cancer cells, inhibiting their growth and proliferation. It is primarily used in the treatment of HER2-positive breast cancer, which accounts for a significant subset of breast cancer cases. This targeted approach has proven to be effective in improving the survival rates of patients with this specific subtype of breast cancer.

The other listed cancer types do not benefit from trastuzumab in the same way. Triple-negative breast cancer, while a challenging subtype, lacks the HER2 expression; instead, it is characterized by the absence of estrogen receptors, progesterone receptors, and HER2, thus making trastuzumab ineffective for those patients. Prostate cancer generally is treated with hormonal therapies or chemotherapy. Similarly, endometrial cancer treatment typically does not include trastuzumab, as it is not indicated for cancers not expressing HER2.