VTE Risk Continues Long After Bladder Cancer Surgery
The cumulative incidence of venous thromboembolism following radical cystectomy was nearly 6.7% over 10 years.
|The following article is part of conference coverage from the 2017 American Urological Association meeting in Boston. Renal and Urology News' staff will be reporting live on medical studies conducted by urologists and other specialists who are tops in their field in kidney stones, prostate cancer, kidney cancer, bladder cancer, enlarged prostate, and more. Check back for the latest news from AUA 2017.|
BOSTON — The incidence of venous thromboembolism (VTE) peaks at 20 days after radical cystectomy (RC), according to new study findings presented at the American Urological Association 2017 annual meeting. Bladder cancer patients, however, continue to be at risk for VTE long after surgery.
Previous studies examining the perioperative period or just 6 months after RC likely underestimated VTE rates, according to the investigators. “The incidence of VTE continues to rise long after the date of surgery. However, the vast majority occur in the first year following surgery,” Christopher J.D. Wallis, MD, PhD, of the University of Toronto in Toronto, Canada, told Renal & Urology News.
Using data from the Ontario Cancer Registry (OCR), Ontario Health Insurance Plan (OHIP), and Canadian Institute for Health Information (CIHI), Dr Wallis and his colleagues analyzed VTE occurrence among all 3623 bladder cancer patients in the province undergoing RC from 2002 to 2014. These RC patients are more susceptible to pulmonary embolism and deep vein thrombosis because cancer, surgery, and immobility are each risk factors. The cohort included 433 patients who had preoperative and 695 who had postoperative chemotherapy.
The 10-year cumulative incidence of VTE was 6.68%, the investigators reported. VTE occurred a median of 216 days and an average of 527 days after surgery. They observed, however, the highest VTE rate at 20 days post-surgery.
“The peak in VTE incidence at 20 days is in keeping with previous data which has shown that a significant burden of VTE events occur following hospital discharge,” Dr Wallis said. “Extended, post-discharge prophylaxis is likely warranted.”
Patients treated preoperatively with chemotherapy appeared to have a 32% lower incidence of VTE compared with those not receiving chemotherapy, but perioperative chemotherapy did not show any significant associations on multivariate analysis. Given the observational design of the study, the investigators could draw no definitive conclusions.
Patients with a previous VTE had 5.1 times higher risk of VTE after RC. Other factors, including age, comorbidity score, diversion type (continent vs ileal conduit), academic treatment center, gender, locale, and treatment year, had no effect on risk. "A prior history of VTE before bladder cancer diagnosis is the strongest risk factor for subsequent VTE after cystectomy,” Dr Wallis stated. “Physicians should consider these patients at high risk and undertake prophylaxis accordingly.”
Previous research found an association between post-RC VTE and a 25%–65% increased risk of mortality at 5 years. “This may represent patients with more aggressive tumors or other adverse factors,” Dr Wallis commented.
The newly released European Association of Urology guidelines on thromboprophylaxis in urologic surgery are a good resource for care, he said.
Wallis CJD, Magee D, Satkunasivam R, and Nam RK. Long term incidence of venous thromboembolic events following cystectomy: a population-based analysis. [abstract] J Urol 2017;197(4S):e42-e43. Poster presented at the American Urological Association annual meeting in Boston on May 12, 2017. Poster MP04-02.