Mutant KRas-Gly12Cys and mutant KRas-Gly12Val and response in refractory non–small cell lung cancer (NSCLC). Kaplan–Meier plots of progression-free survival (PFS) for NSCLC patients in the BATTLE trial by tumor KRas mutation for (A) all treatments and (B) for sorafenib-treated patients. n = a/b indicates “a” total number of events in “b” patients in each category. Data were analyzed by the log-rank test. P values are two-sided. C) Cluster analysis of microarray data from patients treated in BATTLE trial of genes that most accurately define the differences between mutant KRas-Gly12Cys or mutant KRas-Gly12Val, and other mutant KRas tumors. The false discovery rate was chosen as 0.3. Red dots indicate genes known to be involved in cell cycle regulation. Panel A: The numbers at risk at 3, 6, and 12 months were 4, 1, 0 for Cys/Val; 10, 2, 0 for other; and 67, 29, 6 for wild-type KRas groups, respectively. The corresponding PFS (95% confidence intervals [CIs]) were 0.17 (95% CI = 0.07 to 0.41), 0.04 (95% CI = 0.01 to 0.28), and NA (not applicable) for the Cys/Val group; 0.53 (95% CI = 0.34 to 0.81), 0.11 (95% CI = 0.03 to 0.39), and NA for the other group; and 0.41 (95% CI = 0.34 to 0.49), 0.18 (95% CI = 0.13 to 0.25), and 0.05 (95% CI = 0.02 to 0.11) for the wild-type KRas group. Panel B: The numbers at risk at 3, 6, and 12 months were 2, 0, 0 for Cys/Val; 6, 1, 0, for other; and 29, 12, 1, for wild-type KRas groups, respectively. The corresponding PFS (95% CIs) were 0.18 (95% CI = 0.05 to 0.64), NA (NA) for the Cys/Val group; 0.67 (95% CI = 0.42 to 1.00), 0.11 (95% CI = 0.02 to 0.71), and NA for the other group; and 0.49 (95% CI = 0.38 to 0.63), 0.20 (95% CI = 0.12 to 0.33), and 0.04 (95% CI = 0.01 to 0.21) for the wild-type KRas group.