Phase II Trial of EVEROLIMUS ± Trastuzumab in Hormone-Refractory Metastatic Breast Cancer

Breast cancer is the most common type of invasive cancer in women, with more than 1 million cases and almost 600,000 deaths occurring worldwide annually. Breast cancer that has spread to other parts of the body (metastasized) is usually not curable. Patients with a type of metastatic breast cancer that has hormone receptors on the surface of the cancer cells are usually treated with the drug tamoxifen, which interferes with the function of these hormone receptors. However, the average survival time for these patients remains at around 36 months. In patients who no longer respond to tamoxifen (hormone-refractory breast cancer), the cancer drug trastuzumab (Herceptin), which acts on a protein called human epidermal growth factor receptor 2 (HER2), may have some activity. In addition, studies suggest that the drug everolimus, which acts on a pathway within cancer cells that is important for growth of the tumor, may make the cancer cells more sensitive to treatment with trastuzumab. Thus, the two drugs may act together to increase their anti-cancer potential.