Asymptomatic deep vein thrombosis in advanced cancer patients: the value of venous sonography.

ABSTRACT

PURPOSE: Although guidelines for venous thromboembolism prevention are available, the implementation of anticoagulant prophylaxis in patients with advanced cancer has yet to be more clearly defined. We aim to determine the incidence of lower extremity deep vein thrombosis (DVT) diagnosed by Doppler sonography (USD) in asymptomatic nonambulatory patients with advanced cancer. METHOD: In a prospective study, 44 nonambulatory cancer patients with grade 3-4 World Health Organization performance status, asymptomatic for lower extremity DVT, underwent bilateral venous USD studies of the lower extremities. Different risk factors and laboratory data were registered and correlated with the incidence of DVT. RESULT: Asymptomatic DVT was detected in 15 of 44 patients (34%, 95% CI, 0.21-0.49). Twenty-three percent of all patients had isolated deep calf vein thrombi and 11% of all patients had thrombi in the proximal veins. The only significant risk factor was the number of metastatic sites. DVT was found in 4 of 23 (17.4%) patients with one metastatic site as opposed to 11 of 21 (52.3%) with two or more sites (p < 0.01). CONCLUSION: USD of the lower extremities detected asymptomatic DVT in 34% of advanced nonambulatory cancer patients and may serve as an additional decision-making tool in the consideration of anticoagulant therapy for this specific population.