Retrospective Data Analysis of Patients With Metastatic Lung Adenocarcinoma With or Without KRAS-Mutation or TTF1-Expression

INTRODUCTION: Patients with lung adenocarcinoma not expressing TTF1 and those with a KRAS mutation have worse prognosis. However, available data are limited and sometimes contradictory. Therefore, this retrospective cohort analysis aimed to clarify whether there was a difference in overall survival and progression-free survival between these groups of patients. METHODS: In total, data derived from 181 patients with metastatic lung adenocarcinoma treated at the Martha-Maria Halle-Dölau Hospital from 2016 to 2019 were analyzed. Kaplan-Meier curves were generated, and associated values, such as median survival and its confidence intervals, were determined using the log-rank test. RESULTS: A benefit in overall survival (OS) (8.4 vs 5.8 months; HR, .8; 95% CI, .53-1.19; P = .267) was associated with positive TTF1 expression, but this was not statistically significant. The same trend was shown with the progressive free survival (PFS) (6.5 vs 4.6 months; HR, .76; 95% CI, .51-1.20; P = .162). In patients with a KRAS mutation, there was no difference in OS compared to those with a wildtype KRAS. The median survival was almost identical at 7.5 months (KRAS mutation, 95% CI, 3.32-11.74) and 7.0 months (KRAS wildtype, 95% CI, 3.59-10.41). Additionally, in PFS, there was no difference between the 2 groups (5.8 vs 6.3 months). CONCLUSIONS: Our analysis did not show a worse prognosis in patients with a KRAS mutation or in those with missing TTF1 expression, which is most likely related to the new therapeutic options. As a result of the administration of immunotherapy in patients with a KRAS mutation and the change from a regimen containing pemetrexed to a regimen containing no pemetrexed, the corresponding patients no longer seem to have a worse prognosis.