ARTICLE ABSTRACT
KRASG12C is the most common KRAS mutation in primary lung adenocarcinoma. Phase I clinical trials have demonstrated encouraging clinical activity of KRASG12C inhibitors in the metastatic setting. We investigated disease-free survival (DFS) and tumor genomic features in patients with surgically resected KRASG12C-mutant lung adenocarcinoma.
Patients who underwent resection of stage I–III lung adenocarcinoma and next-generation sequencing (NGS) were evaluated. Exclusion criteria were receipt of induction therapy, incomplete resection, and low-quality NGS. Mutations were classified as KRAS wild-type (KRASwt), G12C (KRASG12C), or non-G12C (KRASother). DFS was compared between groups using the log-rank test; factors associated with DFS were assessed using Cox regression. Mutual exclusivity and cooccurrence, tumor clonality, and mutational signatures were assessed.
In total, 604 patients were included: 374 KRASwt (62%), 95 KRASG12C (16%), and 135 KRASother (22%). Three-year DFS was not different between KRAS-mutant and KRASwt tumors. However, 3-year DFS was worse in patients with KRASG12C than KRASother tumors (log-rank P = 0.029). KRASG12C tumors had more lymphovascular invasion (51% vs. 37%; P = 0.032) and higher tumor mutation burden [median (interquartile range), 7.0 (5.3–10.8) vs. 6.1 (3.5–9.7); P = 0.021], compared with KRASother tumors. KRASG12C mutation was independently associated with worse DFS on multivariable analysis. Our DFS findings were externally validated in an independent The Cancer Genome Atlas cohort.
KRASG12C mutations are associated with worse DFS after complete resection of stage I–III lung adenocarcinoma. These tumors harbor more aggressive clinicopathologic and genomic features than other KRAS-mutant tumors. We identified a high-risk group for whom KRASG12C inhibitors may be investigated to improve survival.
