FIGURE 3.

Plot of receiver operating characteristic (ROC) curves for dichotomizing patients into those below and above the clinical threshold endoxifen concentration of 5.9 ng/mL (15.8 nM) based on CYP2D6 diplotype/AS. Bold squares depict the cutoff optimized by Youden index. ROC curves were calculated for all breast cancer patients (A) and for ethnic groups in Caucasian (B), Asian (C), and Middle-Eastern Arab (D) women. AS definitions were according to Gaedigk et al. (2008), except that EM/PM and IM/IM are distinguished assuming activities of 1 and 0.75, respectively (cf. Table 2).