ASCO, NCCN and others call for improving thromboprophylaxis in patients with cancer

Consensus statement recommends thromboprophylaxis in all hospitalized patients with cancer; lists areas that require further research.

Experts from international medical organizations, including the National Comprehensive Cancer Network and the American Society for Clinical Oncology, recently published a call to action and consensus statement stressing the need for thromboprophylaxis in hospitalized patients with cancer and prolonged prophylaxis in high-risk surgical patients.

The European Society of Medical Oncology, the Italian Association of Medical Oncology, the French National Federation of the League of Centers against Cancer, ASCO and NCCN have all recently published guidelines on the use of VTE prophylaxis in patients with cancer.

In the consensus statement, published in The Journal of Clinical Oncology, a group of representatives from these organizations called for “a sustained research effort” to investigate the outstanding clinical issues to “reduce the burden of venous thromboembolism and its consequences in patients with cancer.”

“The consensus statement is a call to action to increase awareness of the risk for thrombosis in cancer patients; enhance appropriate clinical management including adherence to clinical practice guidelines; and to encourage further research into improved identification of patients with cancer at increased risk for venous thromboembolism who might benefit from prophylaxis, such as the use of low–molecular-weight heparin,” Gary H. Lyman, MD, MPH, FRCP(Edin), of Duke University School of Medicine in Durham, N.C., and chair of the ASCO guidelines, told HemOnc Today.

The group did not recommend prophylaxis for ambulatory patients with cancer with the exceptions of those patients receiving thalidomide- (Thalomid, Celgene) or lenalidomide- (Revlimid, Celgene) based therapy. However, they acknowledged that the prophylaxis recommendations for ambulatory patients may change with use of the thrombosis risk assessment tool, developed by Alok A. Khorana, MD, of the University of Rochester School of Medicine and Dentistry in Rochester, N.Y., and colleagues.

Published in Blood in 2008, this validated model should lead to randomized trials of venous thromboembolism prophylaxis in high-risk patients, the researchers wrote. When each organization updates its guidelines, their panels will also consider results from large, randomized clinical trials, such as the PROTECHT study, which demonstrated a benefit for prophylaxis in this setting.

Right now, the guidelines recommend pharmacologic thromboprophylaxis, including low-dose unfractionated heparin, low–molecular-weight heparin or fondaparinux (Arixtra, GlaxoSmithKline), in those patients without contraindications, and all of the organizations’ guidelines agree that low–molecular-weight heparins are preferred for long-term treatment of venous thromboembolism.

“Overall, compliance with prophylaxis has been slowly improving, and we hope that this clear statement will further advocate for thromboprophylaxis, specifically for patients with cancer in high-risk settings,” Khorana, who was also an author of the consensus statement, told HemOnc Today.

Khorana also said that the working group hoped to use the consensus statement as an opportunity to identify areas where additional research is necessary. Two areas in particular include “thromboprophylaxis in outpatients with cancer where several studies are ongoing, and a better understanding of ‘incidental’ venous thromboembolism, which is becoming an increasing problem for practitioners,” Khorana said.

Areas that require further research include prophylaxis in the ambulatory setting, the risk/benefit ratio of prophylaxis for hospitalized patients with cancer, an understanding of incidental venous thromboembolism and the impact of anticoagulation on survival. – by Tina DiMarcantonio

Khorana AA et al. J Clin Oncol. 2009;doi:10.1200/JCO.2009.22.3214.

In recognition of the morbidity and mortality associated with venous thromboembolic events in cancer patients, several medical societies have issued clinical practice guidelines for the appropriate anticoagulant management and prophylaxis in this high-risk population. Despite these guidelines put forth by ASCO, the American College of Chest Physicians, and others, it is estimated that only one in four patients with cancer receive adequate thromboprophylaxis during hospitalization (Amin A. J Thromb Haemost. 2007;5:1610-1616). The consensus statement by Khorana et al presents a more uniform message that again stresses the importance of thromboprophylaxis in high-risk patients with cancer (ie, those who are hospitalized or undergoing surgery). Although there remain areas where appropriate prophylactic strategies continue to be evaluated, establishing a consensus position will hopefully provide the clinician a clearer guidance to those clinical scenarios where the benefit of thromboprophylaxis is most pronounced.

– Jeffrey Zwicker, MD

Instructor in Medicine
Beth Israel Deaconness Medical Center, Harvard University

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