Asymptomatic deep vein thrombosis and superficial vein thrombosis in ambulatory cancer patients: impact on short-term survival.

Background: Asymptomatic venous thrombotic events (VTEs) are possible findings in ambulatory cancer patients. Data regarding the incidence and clinical impact of asymptomatic VTEs are conflicting. We therefore conducted a study to evaluate the occurrence of asymptomatic VTEs of the lower limbs in ambulatory cancer patients to further evaluate the association of these asymptomatic VTEs on survival during a 9-month follow-up period.

Methods: In our prospective cohort, we included 150 consecutive ambulatory cancer patients who were free of any clinical symptoms for VTEs. Compression ultrasound to detect deep vein thrombosis (DVT) and superficial venous thrombosis (SVT) of the lower limbs was performed by a vascular specialist in all patients at baseline. In case of pathological findings the patients were treated with low molecular weight heparin (LMWH) because of current established guidelines. The occurrence of death was investigated during a 9-month follow-up period.

Results: A total of 27 (18%) patients with VTEs were detected, which included 13 patients (8.7%) with a SVT and 16 patients (10.7%) showing a DVT. Two patients had both, a SVT and a DVT as well. During the 9-month follow-up period the occurrence of a VTE at baseline was associated with a 2.4-fold increased risk for death (HR 2.4 (1.2-5.3); P=0.03).

Conclusion: Asymptomatic VTEs of the lower limbs in ambulatory cancer patients are frequently occurring concomitant features and are associated with poor survival during a 9-month follow-up period despite anticoagulation with LMWH.