The incidence, risk factors and prognostic implications of venous thromboembolism in Asian patients with non-small cell lung cancer.

Abstract

1590 Background: The goal of this study was to describe the incidence, risk factors and prognostic implications of venous thromboembolism (VTE) in Asian patients with non-small cell lung cancer (NSCLC). The association between specific gene mutations and the risk of VTE was also evaluated. Methods: A total of 1998 consecutive patients with NSCLC were enrolled and analyzed retrospectively. To minimize potential confounding, we used propensity score-matching to compare overall survival between patients with and without VTE. Results: The 6-month and 2-year cumulative incidences of VTE were 4.2% and 6.4%, respectively. The risk of VTE increased 2.45-fold with each advancing stage in NSCLC (common hazard ratio [HR] 2.45; 95% CI 1.96–3.05; P<0.001). In multivariate analyses, the effects of therapeutic variables including surgery, chemotherapy, and radiotherapy on the development of VTE were modified by NSCLC stage. Therefore, we calculated stratum-specific HRs by performing stratified analyses for each stage. The independent predictors of VTE were advanced age, pneumonectomy (vs. lobectomy) and palliative radiotherapy (vs. no radiotherapy) in localized NSCLC and no surgery (vs. lobectomy) and palliative radiotherapy (vs. no radiotherapy) in locally advanced NSCLC. Adenocarcinoma histology (vs. squamous cell carcinoma) was the only independent risk factor for increased risk of VTE in metastatic NSCLC. EGFR mutation was independently associated with a 47% lower risk of VTE in adenocarcinoma compared to wild type (HR 0.53; 95% CI 0.29–0.99; P=0.045). Among both the entire and propensity score-matched cohorts, a significant survival difference was observed between patients with and without VTE in localized NSCLC, but not in locally advanced or metastatic NSCLC. The strong association we observed between VTE and the increased rate of recurrence (risk ratio 2.0; 95% CI 1.28–3.12; P=0.009) can explain the significant difference in survival in localized NSCLC. Conclusions: Approximately 6.4% of Asian patients with NSCLC developed VTE during a 2-year period. The association between VTE and decreased survival was limited to localized NSCLC.