Lymphoma and venous thromboembolism: Influence on mortality

Background The population-based incidence of acute venous thromboembolism (VTE) in adult patients diagnosed with non-Hodgkin's lymphoma has not been established, and the effect of VTE on survival is not clear. Aim To determine the incidence of acute VTE in California residents diagnosed with lymphoma, and to determine the effect of acute VTE on survival. Methods We used the California Cancer Registry coupled with the California Patient Discharge database to identify incident cases with lymphoma, 1991-1997, and the incidence of first-time VTE in these patients. Multivariable models were constructed to evaluate risk of developing acute VTE within 2 years, and a proportional hazard model was used to predict death within 2 years, using acute VTE as a time-dependent covariate. Results There were 16,755 patients diagnosed with non-Hodgkin's lymphoma; 29% had low-grade, 66% intermediate/aggressive grade and 5.6% had high-grade lymphoma. Acute VTE developed in 3.6% of the patients by year 1 and 4.0% by the end of year 2. Significant predictors of acute VTE included advanced stage lymphoma, number of chronic comorbidities and advancing age. Significant predictors of death within 2 years included diagnosis of acute VTE, advanced stage disease, increasing number of co-morbidities, age over 75 years and intermediate or high grade histopathology. The effect of acute VTE on death increased as the time between lymphoma diagnosis and VTE diagnosis increased (HR = 1.7 95%CI:1.5-1.9 for VTEs < 6 months; HR = 6.5 95%CI:4.7-8.9 VTEs 12-24 months). Conclusions Acute VTE developed frequently in patients with lymphoma, and VTE was a strong predictor of decreased survival.