[Japanese Subgroup Data in Global Clinical Trials for Breast Cancer]

Number of the approved drugs for breast cancer with global clinical trials including Japanese subjects is increasing. Attending to global clinical trials could shorten the drug lag period, which is expected to contribute to the implementation of best clinical practice. It is well known that some ethnic factors and the number of the subjects included in the trials may influence the interpretations of the efficacy and safety of drugs in regional subgroup data. In this article, we review the cases of interpretations of Japanese subgroup data in breast cancer global clinical trial results. We also refer to the potential ethnic factors in breast cancer clinical practice in Japan.