Mutational status predicts the risk of thromboembolic events in lung adenocarcinoma

Introduction: Cancer is a well-known risk factor of thromboembolism (VTE) and lung adenocarcinoma is associated with an increased risk. Mutation analyses of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) identify subgroups of lung adenocarcinoma with different epidemiological and clinical features. How the mutational status affects the risk of VTE is still unknown. Aims: To evaluate the occurrence of VTE in patients with EGFR and ALK mutations compared with non-mutated lung adenocarcinoma. Material and Methods: A retrospective longitudinal design was used. Patients with lung adenocarcinoma diagnosed and/or treated at Karolinska University Hospital, Stockholm, Sweden between the years 2009-20015 were included. All patients underwent a predictive test, divided in 3 subgroups based on the predictive tests result (EGFR- or ALK-mutated, no detected mutation). Event-free time of patients by their mutation status and treatment was assessed using cox regression analysis. Results: 310 patients were included. A VTE occurred in 24.2% of the patients. Mutation of EGFR was associated with a decreased risk (HR 0.35, 95%CI 0.17-0.69, p=0.003) in similarity with ALK-mutated lung adenocarcinomas (HR 0.44, 95%CI 0.21-0.91, p=0.03). Treatment with thyrosin-kinase inhibitors (TKI) seems to further reduce the risk of VTE compared to other treatments (HR 0.18, 95%CI 0.06-0.49, p=0.001). Conclusions: The results of this study indicate that patients with adenocarcinoma bearing a EGFR or ALK mutation have a decreased risk of VTE compared with other patients with lung adenocarcinoma. Targeted therapy with TKI seems to be safer and to reduce risk of VTE compared to standard chemotherapy.