Venous Thrombosis in Cancer Patients: Insights from the FRONTLINE Survey

BACKGROUND: Venous thromboembolism (VTE) is a common complication in cancer patients and a significant cause of morbidity and mortality. However, little information is available on oncologists' perceptions of the risk of VTE and its management. The Fundamental Research in Oncology and Thrombosis (FRONTLINE) study is the first comprehensive global survey of thrombosis and cancer. The study was designed to collect data on the perceived risk and patterns of practice with regard to VTE in cancer patients undergoing surgical and medical management of their malignancy and to provide information on international and regional practice patterns, allowing for the design of research studies to answer the concerns of practicing clinicians. METHODS: Literature reviews were performed to provide a current evidence base against which to compare the findings, and a survey was developed under the guidance of an advisory board. A paper-based reply-paid questionnaire was distributed globally between July and November 2001 to clinicians involved in cancer care and was made available on a dedicated website. FINDINGS: A total of 3,891 completed responses were available for analysis. Brain and pancreatic tumors were considered to carry a high risk for VTE, and 80% of respondents considered the use of central venous lines to be associated with a high risk of VTE. Marked differences were seen in the use of thromboprophylaxis for surgical and medical cancer patients, with over 50% of surgeons reporting that they initiated thromboprophylaxis routinely, while most medical oncologists reported using thromboprophylaxis in less than 5% of medical patients. Low molecular weight heparin (LMWH) was the most popular method of thromboprophylaxis employed in both surgical and medical patients and was more favored by European than U.S. clinicians. Some 20% of respondents reported using aspirin for prophylaxis, despite there being no reliable evidence for this agent as effective in prevention in this population. For the treatment of VTE, LMWH was again the most common initial treatment, although, for the long-term, oral anticoagulation therapy was widely adopted. Many patients were treated for VTE on an outpatient basis, and secondary prevention of VTE was typically continued for 3 to 6 months after an episode of deep vein thrombosis or for longer in the case of pulmonary embolism. INTERPRETATION: The results of the FRONTLINE survey demonstrate a need for guidelines to direct clinical practice in line with evidence-based data concerning cancer and VTE. Oncologists need to be educated regarding the true risks of VTE associated with certain cancers and on strategies for prevention and treatment to reduce the morbidity and mortality associated with VTE in all cancer patients. The study has also helped identify areas for future research.