Impact of KRAS Mutations and Co-mutations on Clinical Outcomes in Pancreatic Ductal Adenocarcinoma

The relevance of KRAS mutation alleles to clinical outcome remains inconclusive in pancreatic adenocarcinoma (PDAC). We conducted a retrospective study of 803 PDAC patients (42% with metastatic disease) at MD Anderson Cancer Center. Overall survival (OS) analysis demonstrated that KRAS mutation status and subtypes were prognostic (p<0.001). Relative to patients with KRAS wildtype tumors (median OS 38 months), patients with KRAS(G12R) had a similar OS (median 34 months), while patients with KRAS(Q61) and KRAS(G12D) mutated tumors had shorter OS (median 20 months [HR: 1.9, 95% CI 1.2–3.0, p=0.006] and 22 months [HR: 1.7, 95% CI 1.3–2.3, p<0.001], respectively). There was enrichment of KRAS(G12D) mutation in metastatic tumors (34% vs 24%, OR: 1.7, 95% CI 1.2–2.4, p=0.001) and enrichment of KRAS(G12R) in well and moderately differentiated tumors (14% vs 9%, OR: 1.7, 95% CI 1.05–2.99, p=0.04). Similar findings were observed in the external validation cohort (PanCAN’s Know Your Tumor(®) dataset, n=408).