In a study of 3879 patients who underwent radical cystectomy to treat bladder cancer, 3.6% were diagnosed with a venous thromboembolism (VTE) - which occurs when a blood clot forms in a vein, potentially breaking loose and traveling to the lung - within 1 month of their surgical admission date. This increased to 4.7% at 2 months and 5.4% at 3 months. Fifty-five percent of VTE events occurred after hospital discharge, generally when patients are not treated prophylactically with drugs to decrease this risk.

There were very few factors found that could predict which patient would suffer from a VTE, other than those with longer length of stay in the hospital. For the first time, this study demonstrated that patients with VTE tended to die earlier from their bladder cancer.

"Although the findings in this population-based study confirmed some previous understanding of the frequency of VTE for this complex surgery, we were surprised at the number that were diagnosed after hospital discharge," said Dr. D. Robert Siemens, senior author of the BJU International study. "Furthermore, we were unable to identify strong predictive factors associated with VTE, suggesting to us that most all patients should receive prolonged VTE prophylaxis well beyond their hospital discharge." Dr. Siemens noted that the fact that a VTE was associated with lower cancer cure was also intriguing and suggests that this could represent a marker of more aggressive disease.