Patterns and predictors of thromboembolic events among patients with gastric cancer.

Patients with gastric cancer are at higher risk for venous thromboembolic events (VTE). Majority of such patients are treated in ambulatory settings where thromboprophylaxis is not routinely offered. In this study, we report on VTE rates and search for predictors that may help identify patients at higher risk to justify VTE-prophylaxis in ambulatory settings. Patients with pathologically-confirmed gastric adenocarcinoma were retrospectively reviewed for VTE detected by imaging studies. Clinical and pathological features known to increase the risk of VTE were studied. Khorana risk assessment model was applied on patients receiving chemotherapy. A total of 671 patients; median age 55 years, were recruited. VTE were diagnosed in 150 (22.4%) patients, including 42 (28.0%) pulmonary embolism and 18 (12.0%) upper extremity deep vein thrombosis (DVT). Majority (> 80%) developed VTE while in ambulatory settings and none had been on thromboprophylaxis. Rate was higher (27.1%) among 365 patients with metastatic compared to 16.7% among 306 patients with nonmetastatic disease, p = 0.001. Patients with metastatic disease who received multiple lines of chemotherapy (n = 85) had significantly higher rate of VTE compared to those who received a single line; 48.2% versus 19.4%, p < 0.001. Among the whole group, Khorana risk score, age, gender, smoking and obesity had no impact on VTE rates. Patients with metastatic gastric cancer, especially when treated with multiple lines of chemotherapy, are at a significantly higher risk of VTE. Khorana risk score had no impact on VTE rates. Thromboprophylaxis in ambulatory patients with metastatic gastric cancer worth studying.