‘Personalized Medicine’ is the ERA Shifting from ‘Molecular Treatment’ to ‘Molecular Diagnosis’; Experience from Breast Cancer

ABSTRACT Recent progress of molecular targeting drugs provided variety range of chance of response and survival to breast cancer patients. However, these benefits arising from rigid evaluation of drug target in the tumor sample. Success of trastuzumab development in HER2-positive breast cancer mostly depends on the correct evaluation of HER2 expression which developed during phase I-II clinical trials. Without HerceptestⓇ, trastuzumab has never come to the patients. Opposite case of example might be bevacizumab, lack of evaluation system about VEGF related molecules during early clinical development made it difficult to use this drug in effective way. Obviously, targeting drug should be developed with rigid molecular diagnostic tool from early stage. Roche's acquisition to VentanaⓇ and taking over attempt to IlluminaⓇ would be the case in same line strategy. Since DNA mutation may not be the major evaluation target in breast cancer, quantitative determination tools are still most important for us. Molecular diagnostic tools such as OncotypeDXⓇ and MammaprintⓇ have been already used in clinical situation in some part, and these are such of highly reproducible quantitative determination tools. In this session, we would discuss about current situation of these issues in breast cancer field.