EGFR and neoplasm: Specifically, in patients with left-sided RAS wild-type metastatic CRC, the hazard ratios for early tumor shrinkage–positive cases compared with early tumor shrinkage–negative cases in the anti-EGFR antibody group were as follows: overall survival, 0.47 (95% confidence interval [CI] = 0.40 to 0.55); PFS, 0.49 (95% CI = 0.42 to 0.57); and postprogression survival, 0.52 (95% CI = 0.42 to 0.64).