Epidemiological and outcome data in Japanese patients with deep vein thrombosis with and without malignancy

There are very few epidemiological studies on Japanese patients with deep vein thrombosis (DVT). In particular, mortality rate differences in Japanese DVT patients with and without malignancy have rarely been evaluated. To elucidate these differences, we enrolled 211 patients who had been diagnosed with de-novo acute DVT of the pelvis or lower extremities between January 2012 and December 2015. The clinical characteristics, treatment information, and follow-up data were retrospectively assessed. We compared these variables in patients with (n = 120) and without (n = 91) concomitant malignancies. The median age of patients was 67 years, 33.7% were male, and 82.9% patients were treated with oral anticoagulants including direct oral anticoagulants. The clinical characteristics and treatment provided were almost identical in the two groups with some exceptions. Three-year survival rates of the total population, patients with malignancy, and patients without malignancy were 80.6, 67.6, and 97.6%, respectively (log-rank p < 0.001). Multivariable Cox regression analysis demonstrated that malignancy was independently associated with high risk of 3-year all-cause mortality with an adjusted hazard ratio of 9.1 (95% confidence interval; 2.1–39.0, p = 0.003). Bootstrap validation demonstrated an acceptable index corrected slope of 0.766 without significant overfitting in a multivariable model. In conclusion, we analyzed epidemiological data on Japanese patients with DVT. Malignancy was independently associated with increased 3-year all-cause mortality.