Venous Sonography for the Diagnosis of Asymptomatic Deep Vein Thrombosis in Patients with Cancer Undergoing Chemotherapy

Objective. Early detection of asymptomatic deep vein thrombosis by venous sonography may identify patients who may benefit from anticoagulant therapy and thus may prevent morbidity and mortality associated with deep vein thrombosis. The aim of this study was to examine the prevalence of deep vein thrombosis by venous sonography in asymptomatic ambulatory patients with cancer undergoing chemotherapy and to evaluate the correlation between procoagulant activity and asymptomatic deep vein thrombosis. Methods. The study population included 62 patients (32 with lung cancer and 30 with lymphoma) receiving chemotherapy with an ambulatory performance status and without clinical evidence of deep vein thrombosis. Bilateral venous sonographic studies of the lower extremities were performed, covering the femoropopliteal venous system. The D-dimer level and acquired activated protein C resistance were determined in the patients and in 30 healthy control subjects. Results. Sonographic evidence of deep vein thrombosis on the femoropopliteal axis was found in 0 (0%) of 62 patients (1-sided 95% confidence interval, 0%-4.8%). Acquired activated protein C resistance prevalence and D-dimer levels were increased in study patients compared with control subjects (34% versus 0%; P < .003; median, 0.72 versus 0.25 mg/L; P < .0001, respectively). Conclusions. Despite the procoagulant tendency, venous sonography did not detect asymptomatic deep vein thrombosis in patients with cancer undergoing chemotherapy. Thus, screening by venous sonography is not justified in this patient population.