Cumulative incidence, risk factors and prognostic impact of venous thromboembolism in Japanese patients with advanced gastric cancer.

Background: A single-center retrospective cohort study was conducted to clarify the cumulative incidence, risk factors, and prognostic impact of venous thromboembolism in patients with advanced gastric cancer receiving first-line chemotherapy.Advanced gastric cancer (AGC) and systemic chemotherapy are some of the risk factors for venous thromboembolism (VTE). However, the cumulative incidence, risk factors and prognostic impact of VTE have not been evaluated in Japanese patients with AGC. Methods: This retrospective study included patients who received fluoropyrimidine-based first-line chemotherapy for AGC between September 2009 and July 2015 at our institution. VTE was diagnosed by computed tomography scan and was managed by anticoagulant therapy. The cumulative incidence of VTE was estimated by the Kaplan-Meier method. Multivariate analysis was performed to identify the risk factors and prognostic impact of VTE. Results: Of 283 patients, 37 (13.1%) developed VTE before or during chemotherapy. The cumulative incidence of VTE was 8.7% at 6 months and 13.6% at 1 year. The independent risk factors for VTE were body mass index (BMI) of >= 25 kg/m(2) (HR 3.38, 95% CI 1.72-6.65, P < 0.01) and presence of peritoneal metastasis (HR 2.01, 95% CI 1.00-4.00, P < 0.05). The median overall survival (OS) was 13.4 months for patients with VTE and 11.7 months for those without VTE (P = 0.58). After adjusting for other prognostic factors, the number of metastatic sites and metastases to the peritoneum and bone were independent prognostic factors for OS, but not for VTE (HR 0.89, 95% CI 0.62-1.28, P = 0.53). Conclusion: BMI >= 25 kg/m(2) and peritoneal metastasis could be the risk factors for VTE in Japanese AGC patients. VTE might have no negative impact on OS in AGC patients treated with chemotherapy.