Breast cancer is the most common cancer in Taiwanese women. Most of them were diagnosed in
relatively early stages. Only 700 metastatic breast cancer were registered in Official Cancer
Registration 2012, while more than11,305 were registered as early breast cancer. With broadly
application of aromatase inhibitors, hormonal-receptor-positive breast cancer patients can
survive longer and longer. However, there is no prevalence of metastatic breast cancer can be
available yet. NHIA database coverage is more than 90% population in Taiwan, thus it can be
an appropriate surrogate of prevalence. In this retrospective database analysis, we will
explore the real world experience on aromatase inhibitor use for breast cancer in Taiwan.