Figure 5. First-line early tumor shrinkage was predictive of the efficacy of second-line treatment in all patients with KRAS exon 2 wild-type.

Kaplan-Meier curves for (A) progression-free survival and (B) overall survival among patients with KRAS exon 2 wild-type and who achieved early tumor shrinkage during first-line treatment; and for (C) progression-free survival and (D) overall survival among patients with KRAS exon 2 wild-type but who did not achieve early tumor shrinkage during first-line treatment. The curves compare continued cetuximab plus changed chemotherapy and changed chemotherapy only as second-line treatments. Cet.: Cetuximab; Chemo.: chemotherapy; ETS: early tumor shrinkage. P values were determined using the log-rank test.