Clinical outcomes of KRAS-mutant non-small cell lung cancer under untargeted therapeutic regimes in the real world: a retrospective observational study

BACKGROUND: Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation seemingly suffered less effective therapeutic regimens in the absence of widely-accepted targeted drugs compared with other mutation types in non-small cell lung cancer (NSCLC). However, whether these non-selective therapy schedules for KRAS mutation matters is still under debate. Correspondingly, we aimed to compare the long term expectancy of indicated therapeutic regimes and further explore the optimal schemes of KRAS mutated NSCLC in the absence of targeted drugs in this retrospective study cohort. METHODS: We conducted a single-center retrospective analysis among 66 patients diagnosed with KRAS-mutant advanced NSCLC from November 2018 to December 2020. These enrolled cases were divided into different subgroups in light of mutant isotypes, pathological characteristics, and therapeutic regimes to uncover indicated long-term survival benefits. Additionally, clinical outcomes of treatment schedules and interventional lines to KRAS-mutant NSCLC were described in detail. RESULTS: This cohort enrolled 8 patients with stage IIIB (12.1%) and 58 patients with stage IV (87.9%) with the median age 62 years, ranging from 32 to 91 years old. Genetically, G12C conducted as the most common KRAS mutation type, accounting for 30.3%. Pemetrexed combined with platinum chemotherapy seemed to be a priority (72.7%), and chemotherapy combined with immunotherapy became an alternative (15.2%) in clinic. Performing further analysis of long-term survival of patients receiving different treatment methods indicated that the median overall survival (mOS) in first-line therapy with antiangiogenesis or untreated was 13 and 12 months, respectively (P=0.79). In the first-line regimen, median survival was 17 months for patients who received combined immune checkpoint inhibitors and 12 months for those who did not (P=0.34). The mOS was 20 months for those who had used immune checkpoint inhibitors and 12 months for those who had not (P=0.11). Survival analysis results of NSCLC patients with different KRAS mutation types showed the median survival time of patients with G12C mutation type and patients without with nonG12C mutation type was 19 and 12 months, respectively (P=0.37). CONCLUSIONS: In the absence of KRAS targeted drugs, available treatment plans failed to benefit KRAS mutant sufferers regardless of isotypes, making the KRAS-targeted drugs urgent.