Venous thromboembolism in hospitalized patients receiving chemotherapy for malignancies at Japanese community hospital: prospective observational study.

BACKGROUND: Although Asian population was recognized to have a lower risk of venous thromboembolism (VTE), its increasing prevalence and incidence remain unclear in patients with malignancies. We attempted to predict VTE development using activation markers of coagulation and fibrinolysis.

METHODS: We enrolled patients with malignancy admitted to Tonan Hospital between April and December 2014 to receive a new-for-them chemotherapy regimen. All patients were examined for VTE by computed tomography and whole-leg compression ultrasonography before chemotherapy and three months later. We also examined plasma levels of thrombin-antithrombin complex (TAT) and plasmin α2-plasmin inhibitor complex (PIC) before chemotherapy. The cut off values of TAT and PIC were set at 2.1 ng/mL and 1.8 μg/mL, respectively.

RESULTS: Of 97 patients, the majority (67%) had distant metastases. The most common malignancies were colorectal (26%), breast (23%), and stomach (19%) cancer. VTE was detected in 29 patients (31%); all were asymptomatic. VTE was newly developed in 12 patients in the three-month observation period, which means the incidence was 49 per 1000 person-years. Non-increased PIC with increased TAT was the only significant risk factor for both VTE prevalence and incidence in multivariate analysis, and the odds ratios were 3.0 (95% confidence interval, 1.1-8.2; P = 0.034) and 9.4 (95% confidence interval, 1.7-51.9; P = 0.011), respectively.

CONCLUSIONS: The prevalence and incidence of VTE were high in hospitalized Japanese patients receiving chemotherapy for malignancies. Non-increased PIC with increased levels of TAT may be an independent risk factor for VTE development.