Fig. 2

A high proportion of patients demonstrate elevated HER2-specific antibody responses following treatment with trastuzumab. a shows the mean (±s.e.m.) RI, both pre- and post-treatment for Arm A (N = 22) and Arm B and C combined (N = 28). P values for Arms A and B were calculated using the paired Student’s t test. b is a scatter plot comparing baseline RI with treatment-induced changes (ΔRI, y-axis) for patients who received chemotherapy plus trastuzumab. Each dot represents a unique patient in Arms B or C. c is a scatter plot comparing the time of post-treatment serum sample collection (x-axis) and the post-treatment change (i.e., ΔR) in antibody levels from baseline (y = axis). The inset lines, R value, and P value in Panels B and C represent linear regression analysis. d shows a bar graph of the proportion of patients who demonstrated a positive antibody response (defined as RI ≥0.2) before (Pre) and after treatment (Post). P values were calculated with a Fisher’s exact test