New findings that highlight the challenges of managing thromboembolic events in patients being treated for cancer were released at the ESMO 2012 Congress of the European Society for Medical Oncology in Vienna.

Venous thromboembolism causes symptoms in about 3 to 4% of cancer patients whose chemotherapy drugs are delivered via a central venous catheter, comments Dr. Fausto Roila, from Medical Oncology Department, Terni, Italy, Chair of the ESMO 2012 Supportive Care Track. "When asymptomatic patients are considered, these events affect about 12-18% of patients who have central venous catheters."

Efficacy of anticoagulation for cancer patients suggests guidelines should be reconsidered

Anticoagulants are effective for preventing deep vein thrombosis in cancer patients who have a central venous catheter in place for the delivery of chemotherapy, the results of a new French study reveal.

The risk of deep vein thrombosis (DVT) is higher among cancer patients than among the general population. Furthermore, patients undergoing chemotherapy often have central venous access devices implanted. These devices are associated with deep vein thrombosis, which can lead to a pulmonary embolism and in some cases, death. But whether an anticoagulant prophylaxis is needed for patients with cancer with a central venous catheter is a controversial subject.

Dr Sandrine Lavau-Denes, from Centre Hospitalier Universitaire à Limoges, and colleagues performed a phase III prospective, randomized trial in 407 patients and found that anticoagulation significantly reduced the incidence of catheter-related DVT.

"The current guidelines of the American Society of Clinical Oncology, American College of Chest Physicians, and the French National Federation of the League of Centers against Cancer do not recommend prophylactic anticoagulant treatment for cancer outpatients," Dr Lavau-Denes says. "In recent studies and meta-analyses, results are still contradictory, perhaps because of the heterogeneity of the screened patients. We think that these new results should lead to a new reflection."

Dr Fausto Roila, who was not involved in the study, said: "The incidence of CVC-related thrombosis was significantly lower with the two anticoagulant drugs [8.1% (22/272) versus 14.8% (20//135), respectively]." Dr. Roila noted however that the study has some limitations, among these the fact that it is a single-centre study requiring 11 years to be completed. Therefore, "the results of this study should be confirmed by other double-blind, randomized clinical trials, before changing the actual recommendations".

Related studies presented at ESMO 2012

Real-world analysis shows risks and costs of venous thromboembolic events with chemotherapy

For patients with breast and prostate cancer, the risk of venous thromboembolism within the first months after initiation of chemotherapy is about 4% and almost doubles at 12 months, a new US analysis shows. The study used the US IMPACT claims database to retrospectively identify 34,144 patients with breast and prostate cancer.

Almost 20% of patients receiving cisplatin-based chemotherapy experience thromboembolic events

A retrospective analysis of 141 cancer patients treated with cisplatin-based chemotherapy finds that 19.1% experienced a thromboembolic event, including deep vein thrombosis, pulmonary embolism and arterial thrombosis. Patients with gastric and pancreatic cancers had the highest incidence of events. It is important to carry out randomized studies to conclude the need for prophylaxis of thromboembolic events in these patients, authors say.