The burden of venous thromboembolism in patients with cancer is higher than anticipated, according to research presented at the European Society for Medical Oncology Asia Congress in Singapore.
Among 507 ambulatory patients newly diagnosed with cancer between 2014 and 2015 at an Indian institute, 18.14% had venous thromboembolism as detected by bilateral lower limb venous Doppler or by imaging during staging. Of these cases, 12.22% were incidental while the remaining 5.91% were symptomatic.
Venous thromboembolism was observed in 86.6% of 15 patients with hepatocellular carcinoma and 75.0% of 12 patients with pancreatic cancer. By comparison, the incidence of venous thromboembolism was lower in individuals with gastric, lung and colorectal cancer, at 16.6% of 78, 12.9% of 62 and 14.5% of 48 patients, respectively.
Hepatocellular carcinoma patients also had the highest incidence of incidental venous thromboembolism, at a rate of 21.0%, followed by gastric and pancreatic cancer patients, with incidence rates of 16.1% and 11.3%, respectively.
Symptomatic venous thromboembolism, by contrast, was most common in lung and ovarian cancer patients, at a rate of 16.7% each.
The index event most commonly occurred at the femoropopliteal site (39.2%), followed by portal vein thrombosis (27.3%) and inferior vena cava thrombosis (19.6%), reported Radhakrishna Balambika, on behalf of the team from the Sri Venkateswara Institute of Medical Sciences in Tirupati, India.
Additionally, pulmonary thromboembolism, superior mesenteric vein thrombosis and splenic vein thrombosis each occurred in 4.4% of patients.
The presenting author highlighted that after the malignancy itself, venous thromboembolism is the second most common cause of death in cancer patients, but added that international guidelines do not routinely recommend the use of prophylaxis.
She concluded: “Though thromboprophylaxis in cancer patients is challenging in view of bleeding complications, screening for [venous thromboembolism] and primary prophylaxis in eligible patients might actually improve clinical outcomes.”
Mario Dicato, from Luxembourg Medical Center, who discussed the research, pointed out that the distribution of index venous thromboembolism cases – specifically, that 25 patients presented with portal vein thrombosis, 18 with inferior vena cava thrombosis, four with superior mesenteric vein obstruction and four with pulmonary embolism – is “very unusual”, especially so early in the presentation of disease.
He also noted that the reported incidence of venous thromboembolism as a whole was high, and that the rate of incidental cases was twice that of symptomatic cases, “which is not the observation in Western Europe or North America.”
The discussant highlighted the need for further confirmation and clarification of the data, such as evaluating the biological and laboratory characteristics as well as the tumour stage of patients with versus without venous thromboembolism, but he concluded that the differences in distribution across the world were interesting.
Balambika RG, Manickavasagam M, Silpa K, Pai A. Venous thromboembolism in cancer patients – an elephant in the room. Presented at:ESMO Asia 2015 Congress. Singapore; 18–21 December 2015; 368O