PURPOSE: Patients with cancer are especially susceptible to deep vein thrombosis (DVT).
METHODS: In a prospective registry of 5,451 consecutive patients with ultrasound-confirmed DVT at 183 U.S. sites, we studied the epidemiology of cancer patients newly-diagnosed with acute DVT.
RESULTS: We identified 1,096 (20.1%) patients with active cancer, 672 (12.3%) with inactive cancer, and 2,807 (51.5%) with no history of cancer; 876 (16.1%) had unknown cancer status. Fewer active cancer patients had received DVT prophylaxis compared with noncancer patients: 308 (28%) vs. 1196 (35%); (p<0.0001). In multivariable regression analysis, immobility within 30 days (Odds ratio (OR) =2.5; 95% confidence interval (CI)=1.7-3.6), surgery within 3 months (OR=2.0; 95% CI 1.4-3.0), and history of venous thromboembolism (VTE) (OR=1.9; 95% CI 1.2-2.8) were independent predictors of receiving VTE prophylaxis. Low molecular weight heparin as monotherapy without warfarin was used more often in cancer patients than in noncancer patients: 142 (13.1%) vs. 300 (8.7%); p<0.0001. Active cancer patients were more likely to receive an inferior vena cava filter (IVCF) than noncancer patients: 234 (21.6%) vs. 473 (13.8%) (p <0.0001). In multivariable regression analysis, neurological disease (OR=2.2; 95% CI 1.3-3.7), hospitalization within 30 days (OR=1.7; 95% CI 1.1-2.7), and presence of an indwelling central venous catheter (OR=1.6; 95% CI 1.0-2.6) were independent predictors of receiving an IVCF.
CONCLUSION: Cancer patients comprise a large proportion of those with DVT. The low rate of VTE prophylaxis among active cancer patients is surprising because of the known hypercoagulability of cancer. One of every five patients with active cancer and DVT underwent insertion of an IVCF. We conclude there is an unsolved paradox: infrequent use of routine VTE prophylaxis predisposes to acute DVT that is managed aggressively with a high rate of IVCF insertion.
CLINICAL IMPLICATIONS: In active cancer patients, VTE prophylaxis is underutilized, and IVCF insertion rates are high. Future studies should focus on implementing safe and effective pharmacological prophylaxis in cancer patients and on assessing the long-term efficacy and safety of IVCF.
DISCLOSURE: Ali Seddighzadeh, No Product/Research Disclosure Information; Grant monies (from industry related sources) This study was funded, in part, by Sanofi Aventis.