Abstract 19620: Impact of D-dimer for Prediction of Occult Cancer in Patients With Unprovoked Venous Thromboembolism

Introduction: Unprovoked venous thromboembolism (VTE) is related higher incidence of occult cancer. However, routine screening for cancer in this population is still controversial. D-dimer is a biomarker reflecting the activation of hemostasis and fibrinolysis. D-dimer is clinically used to exclude VTE, also related in patients with malignancy. Hypothesis: We aimed to explore the predictive value of d-dimer level for detecting occult cancer in patients with unprovoked VTE. Methods: We retrospectively analyzed 840 patients who diagnosed deep vein thrombosis or pulmonary thromboembolism. Among them, 175 (20.8%) patients who diagnosed with unprovoked VTE selected to participate in this study. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated for incidence of occult cancer as well as d-dimer level reference to patient without occult cancer. Results: During follow-up for 5.0±1.9 years, 30 of 840 patients diagnosed cancer in this population. The primary origin of tumor was 6 (20%) of stomach, 6 (20%) of lung, 4 (13%) of colon and others. Number of patients with metastatic cancer was 17 (57%). Log d-dimer was significantly higher in occult cancer group than unprovoked VTE without cancer (3.5 ± 0.5 vs. 3.2 ± 0.5, p=0.009). When the patients with unprovoked VTE were divided by d-dimer according to Youden index, high d-dimer (≥2432) was associated with higher prevalence of occult cancer (26.9% vs. 9.2%, p=0.002). In logistic regression analysis, d-dimer is independently associated with occult cancer (OR: 3.93, 95% CI: 1.46-10.54, p=0.007) after adjusted gender, age, type of VTE (i.e., deep vein thrombosis or pulmonary thromboembolism) and tumor markers. In addition, d-dimer is more significantly associated with patients who diagnosed cancer with distant metastasis (OR: 4.31, 95% CI: 1.16-15.99, p=0.029) Conclusions: High level of d-dimer concentrations are indicator of an increased risk of occult cancer in patients with unprovoked VTE.