Identification of risk factors for venous thromboembolism and evaluation of Khorana venous thromboembolism risk assessment in Japanese lung cancer patients

Background The reported incidence of venous thromboembolism (VTE) in cancer patients is 4–20%. The Khorana VTE risk score (KRS) and the Vienna VTE risk score (VRS) have been proposed as scoring models for evaluation of cancer-associated VTE. However, the risk factors of VTE in Japanese lung cancer patients have not been clarified. Methods This retrospective study included 682 hospitalized Japanese patients with newly diagnosed lung cancer who were examined for VTE on admission between January 2014 and December 2016. Results Seventy-one (10.4%) of the 682 patients were diagnosed with VTE. Multivariate logistic regression analysis showed that body mass index (BMI) ≥25 kg/m 2 (OR, 2.02; 95% CI, 1.06–3.72), white blood cell (WBC) count >11 × 10 9 /L (OR, 2.31; 95% CI, 1.11–4.61), pre-chemotherapy serum D-dimer concentration ≥1.44 μg / mL (OR, 2.73; 95% CI, 1.49–4.99), and non-small cell lung cancer (OR, 3.13; 95% CI, 1.32–9.23) were significantly associated with VTE in these patients. The cut-off values for BMI, WBC count, and D-dimer concentration determined using receiver operating characteristic curves were 25.4 kg/m 2 , 11.2 × 10 9 /L, and 1.95 µg/mL, respectively. Conclusions In this study, we were able to identify four independent risk factors for cancer-associated VTE in Japanese lung cancer patients for the first time. Moreover, we showed that a cut-off level of ≥25 kg/m 2 for BMI was a risk factor for VTE in this cohort.