The incidence of venous thromboembolism and its effect on survival among patients with primary bladder cancer

BACKGROUND: The incidence, risk factors, time course, and impact on survival of venous thromboembolism (VTE) in a large, population-based study of patients with bladder cancer have not been identified previously. METHODS: The California Cancer Registry was merged with the California Patient Discharge Data Set to determine the incidence of VTE in patients with newly diagnosed bladder cancer within a 6-year period. Cox proportional hazards models were used to determine the risk factors for VTE and the effects of VTE on survival. RESULTS: Among 24,861 patients with bladder cancer, the 2-year incidence of VTE was 1.9%. The highest incidence of VTE occurred in the first 6 months regardless of age, sex, race, tumor stage, or histologic subtype. In a multivariate model, significant risk factors for the development of VTE included major surgery, advancing disease stage, and increasing number of comorbidities. Compared with the general population, the 1-year standardized incidence ratio for VTE in the bladder cancer cohort was 5.3 (95% confidence interval, 4.8-5.9). Among patients with bladder cancer, significant risk factors for death included advancing disease stage, increasing comorbidities, African-American race, nontransitional cell carcinoma histology, and the development of VTE. CONCLUSIONS: Patients with bladder cancer had a 1.9% 2-year incidence of VTE. Metastatic disease was the strongest predictor of both VTE and death. It was noteworthy that cancer-associated surgery was associated with a higher risk of VTE, which differed from the results reported from other studies in solid tumors. VTE was a significant predictor of death in the first 2 years.