456P - ALK-rearranged may promote VTE by increasing the expression tissue factor (TF) in lung adenocarcinoma

Abstract

Background: Patients with lung cancer are at increased risk for venous thromboembolism (VTE). About 8-15% of patients with advanced non-small-cell lung cancer (NSCLC) experience a VTE in the course of their disease. However, the incidences of VTE in different molecular subtypes of NSCLC are rarely reported though they have big differentiation in clinical features and therapeutic effects. Tissue factor (TF) expressed in many solid tumors could bind and activate coagulation factor FVII and trigger the downstream coagulation cascade leading to thrombin generation and clot formation. Methods: Here we extracted retrospective data from electronic medical records at Henan Cancer Hospital in China between January 2015 and January 2016. Lung adenocarcinomas with ALK-rearranged, EGFR mutation and both-negative were classified. The incidence rate of VTE after diagnosed with lung adenocarcinoma was calculated and analyzed. Then we randomly selected ALK-rearranged and ALK-rearranged-negative lung adenocarcinoma tissues and detected TF expression in them with imunohistochemistry. Results: At a median follow-up of 19 months, 5.85% (30 in 513) patients with advanced lung adenocarcinoma experienced VTE. Patients with different molecular subtypes showeddifferent rates of VTE (P = 0.0021). Among them ALK-rearranged were more likely to experience VTE (6 in 29, 20.69%). EGFR and both-negative had lower rates of VTE and had no big difference between them (11 in 218, 5.05%; 13 in 266, 4.89%, respectively). The expression of TF performed similar feature. TF high expression in ALK-rearranged tissues is 41.67% (10 in 24), dramatically higher than that in ALK-rearranged negative tissues (11.54%, 3 in 26, P = 0.0152). Conclusions: The rate of VTE in the ALK-rearranged advanced lung adenocarcinoma cohort was about 4-fold higher than that in EGFR mutation and both-negative patients. ALK-rearranged may promote VTE by increasing TF expression. The mechanism warrants further research. Legal entity responsible for the study: The Affiliated Cancer Hospital of Zhengzhou University Funding: None Disclosure: All authors have declared no conflicts of interest.