Figure 1

Boxplots of serum carcinoembryonic antigen (CEA) changes from baseline to the first response evaluation. (a) Whole cohort; (b) patients treated with chemotherapy plus anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb); (c) patients treated with chemotherapy alone; (d) patients treated with chemotherapy plus anti-vascular endothelial growth factor (VEGF) mAb.