Identification of risk factors for venous thromboembolism and validation of the Khorana score in patients with advanced lung cancer: based on the multicenter, prospective Rising-VTE/NEJ037 study data

Background Management of cancer-associated venous thromboembolism (VTE) is essential in cancer treatment selection and prognosis. However, currently, no method exists for assessing VTE risk associated with advanced lung cancer. Therefore, we assessed VTE risk, including driver gene mutation, in advanced lung cancer and performed a Khorana score validation. Methods The Rising-VTE/NEJ037 study was a multicenter prospective observational study that included patients with advanced lung cancer. In the Rising-VTE/NEJ037 study, the Khorana score was calculated for enrolled patients with available data on all Khorana score components. The modified Khorana score was based on the body mass index of >= 25 kg/m(2), according to the Japanese obesity standard. A multivariate logistic regression analysis, including patient background characteristics, was performed to evaluate the presence of VTE 2 years after the lung cancer diagnosis. Results This study included 1008 patients with lung cancer, of whom 100 (9.9%) developed VTE. From the receiver operating characteristic curve analysis, VTE risk could not be determined because both the Khorana score (0.518) and modified Khorana score (0.516) showed very low areas under the curve. The risk factors for VTE in the multivariate analysis included female sex, adenocarcinoma, performance status, N factor, lymphocyte count, platelet count, prothrombin fragment 1 + 2 and diastolic blood pressure. Conclusion The Khorana score, which is widely used in cancer-VTE risk assessment, was less useful for Japanese patients with advanced lung cancer. Prothrombin fragment 1 + 2, a serum marker involved in coagulation, was more suitable for risk identification.