Classification and survival analysis within estrogen receptor (ER)-positive samples. (A) Dot plot of the ER-positive classification (55 pairs of samples), illustrating the probability of metastasis plotted versus the tumor number (P = 1.1e-9). The dashed vertical line separates the patients with metastasis (left of the line) from the non-metastatic patients (right of the line). The horizontal line refers to the discriminating limit; hence, the upper left and lower right corners contain the correctly classified patients. (B) Kaplan-Meier survival curve of metastasis-free survival according to model-based prediction using the ER-positive classification. HR, hazard ratio.