Summary

Patients with cancer have an increased risk of venous thromboembolism (VTE).To further define the demographics, comorbidities, and risk factors of VTE in these patients, we analyzed a prospective registry of 5,451 patients with ultrasound confirmed deep vein thrombosis (DVT) from 183 hospitals in the United States. Cancer was reported in 1,768 (39%), of whom 1,096 (62.0%) had active cancer. Of these, 599 (54.7%) were receiving chemotherapy, and 226 (20.6%) had metastases. Lung (18.5%), colorectal (11.8%), and breast cancer (9.0%) were among the most common cancer types. Cancer patients were younger (median age 66 years vs. 70 years; p<0.0001), were more likely to be male (50.4% vs. 44.5%; p=0.0005), and had a lower average body mass index (26.6 kg/m2 vs. 28.9 kg/m2; p<0.0001). Cancer patients less often received VTE prophylaxis prior to development of DVT compared to those with no cancer (308 of 1,096, 28.2% vs. 1,196 of 3,444, 34.6%; p<0.0001). For DVT therapy, low-molecular-weight heparin (LMWH) as monotherapy without warfarin (142 of 1,086, 13.1% vs. 300 of 3,429, 8.7%; p<0.0001) and inferior vena caval filters (234 of 1,086, 21.5% vs. 473 of 3,429, 13.8%; p<0.0001) were utilized more often in cancer patients than in DVT patients without cancer. Cancer patients with DVT and neurological disease were twice as likely to receive inferior vena caval filters than those with no cancer (odds ratio 2.17, p=0.005). In conclusion, cancer patients who develop DVT receive prophylaxis less often and more often receive filters than patients with no cancer who develop DVT. Future studies should focus on ways to improve implementation of prophylaxis in cancer patients and to further define the indications, efficacy, and safety of inferior vena caval filters in this population.