Real-world retrospective study of KRAS mutations in advanced nonsmall cell lung cancer in the era of immunotherapy

Background: KRAS mutation-positive (KRAS-positive), advanced nonsmall-cell lung cancer (NSCLC) is characterized by a poor prognosis. KRAS mutations are extremely heterogeneous from a biologic point of view, and real-world data by mutation subtype in the era of immunotherapy are still incomplete. Methods: The objective of this study was to retrospectively analyze all consecutive patients with advanced/metastatic, KRAS-positive NSCLC who were diagnosed at a single academic institution since the advent of immunotherapy. The authors report on the natural history of the disease as well as the efficacy of first-line treatments in the entire cohort and by KRAS mutation subtypes as well as the presence/absence of co-mutations. Results: From March 2016 to December 2021, the authors identified 199 consecutive patients who had KRAS-positive, advanced or metastatic NSCLC. The median overall survival (OS) was 10.7 months (95% confidence interval [CI], 8.5-12.9 months), and there were no differences by mutation subtype. Among 134 patients who received first-line treatment, the median OS was 12.2 months (95% CI, 8.3-16.1 months), and the median progression-free survival was 5.6 months (95% CI, 4.5-6.6 months). At multivariate analysis, only an Eastern Cooperative Oncology Group performance status of 2 was associated with significantly shorter progression-free survival and OS. Conclusions: KRAS-positive, advanced NSCLC is characterized by a poor prognosis despite the introduction of immunotherapy. Survival was not associated with KRAS mutation subtype. Plain language summary: This study evaluated the efficacy of systemic therapies for advanced/metastatic nonsmall cell lung cancer harboring KRAS mutations, along with the potential predictive and prognostic role of mutation subtypes. The authors found that advanced/metastatic, KRAS-positive nonsmall cell lung cancer is characterized by a poor prognosis and that first-line treatment efficacy is not related to different KRAS mutations, although a numerically shorter median progression-free survival was observed in patients who had p.G12D and p.G12A mutations. These results underline the need for novel treatment options in this population, such as next-generation KRAS inhibitors, which are in clinical and preclinical development.