A new study finds that for patients with cancer and deep vein thrombosis (DVT), placement of an inferior vena cava (IVC) filter reduces the risk of pulmonary embolism.
Venous thromboembolism (VTE) poses a substantial problem for patients with cancer: it occurs four to seven times more frequently in this population, and it is the second overall leading cause of death for patients with known malignancies. Pulmonary embolism is a potentially deadly condition that can develop as a result of VTE, and patients with cancer and VTE have a twofold increased risk of fatal pulmonary embolism compared with patients without cancer who have VTE.
For patients with cancer and DVT who are at risk of pulmonary embolism, anticoagulation is the standard of care. However, for the many patients who are unable to receive anticoagulation because of the bleeding risk posed by this treatment, IVC filter placement is often used to reduce pulmonary embolism risk.
Data are limited on the efficacy of IVC filters, even though they are frequently used, and results have been mixed concerning their clinical benefit. In addition, very few studies have investigated the use of IVC filters in patients with cancer. Given the significant risk of IVC filter placement––the filters are thrombogenic and can lead to the development of new DVT or the spread of existing DVT––the authors of the study now published in JAMA Network Open felt that it was important to investigate whether IVC filter use was associated with the prevention of pulmonary embolism in patients with cancer and DVT.
For this population-based cohort study, administrative data from the state inpatient databases for California and Florida were obtained on 88,585 patients with cancer and acute lower extremity DVT, with patients from the California database having received treatment between 2005 and 2011 and patients from the Florida database having received treatment from 2005 to 2014. Patients in the study population had a variety of cancer types, of which the most frequent were lung cancer (18.2%), gastrointestinal tract cancers (14.3%), hematologic malignancies (12.6%), and prostate cancer (10.4%).
Of the overall study population, 38.1% underwent IVC filter placement, and 38.4% received systemic anticoagulation. Patients with IVC filter placement were more likely to have risk factors precluding the use of anticoagulation, such as upper gastrointestinal bleeding, intracranial hemorrhage, and coagulopathy. Patients who did not receive an IVC filter were more likely to use systemic anticoagulation (39.7% vs 29.0%). Patients were followed for a median of 479 days. Of the total study population, 5.1% developed a new pulmonary embolism following initial diagnosis of DVT, most within six months of DVT diagnosis.
"Patients who underwent IVC filter placement had worse overall in-hospital mortality compared with those who did not, reflecting the overall poorer status of patients who underwent IVC filter placement," write the investigators, led by first author Samyuktha Balabhadra, MD, a radiology resident at the University of Texas MD Anderson Cancer Center in Houston. "However, after accounting for mortality as a competing risk, there was a persistent improvement in the rate of pulmonary embolism development for patients who underwent IVC filter placement. Furthermore, after performing propensity score matching, this improvement in pulmonary embolism–free survival remained significant."
After propensity score matching, in which the investigators accounted for differences in bleeding risk factors, coagulopathies, and anticoagulation use, the risk of developing new DVT was 18.7% in patients who received IVC filters, compared with 22.1% for those who did not (P<0.001).
Inferior vena cava filter placement reduced pulmonary embolism risk in patients with very high-risk malignant neoplasms, such as pancreaticobiliary cancer; high-risk malignant neoplasms, such as lung cancer; and low-risk malignant neoplasms, such as prostate cancer. Placement of IVC filter significantly reduced the rate of new pulmonary embolisms for most cancer types, but not all. Cancer types that had no significant association included thyroid cancer (P=0.90), head or neck cancer (P=0.25), brain cancer (P=0.20), melanoma (P=0.10), neuroendocrine tumors (P=0.10), and sarcoma (P=0.07).
"These data suggest that IVC filter use in patients with cancer is of potential benefit in appropriately selected patients, and that further investigations into the appropriate use of these devices is warranted," conclude Dr. Balabhadra and colleagues.
For More Information
Balabhadra S, Kuban JD, Lee S, et al (2020). Association of inferior vena cava filter placement with rates of pulmonary embolism in patients with cancer and acute lower extremity deep venous thrombosis. JAMA Netw Open, 3(7):e2011079. DOI:10.1001/jamanetworkopen.2020.11079
Image credit: Baedr-9439