Frequency, risk factors, and trends for venous thromboembolism among hospitalized cancer patients

BACKGROUND. Venous thromboembolism (VTE) contributes to morbidity and mortality in cancer patients and is a frequent complication of anticancer therapy. In the current study, the frequency, risk factors, and trends associated with VTE were examined among hospitalized cancer patients. METHODS. A retrospective cohort study was conducted using the discharge database of the University HealthSystem Consortium. This included 1,824,316 hospitalizations between 1995 and 2003 at 133 U.S. medical centers. RESULTS. Among 1,015,598 cancer patients, 34,357 (3.4%) were diagnosed with deep venous thrombosis and 11,515 with pulmonary embolism (PE) (1.1%) for an overall VTE rate of 4.1%. Subgroups of cancer patients with the highest rates included black ethnicity (5.1% per hospitalization) and those receiving chemotherapy (4.9%). Sites of cancer with the highest rates of VTE included pancreas (8.1%), kidney (5.6%), ovary (5.6%), lung (5.1%), and stomach (4.9%). Among hematologic malignancies, myeloma (5%), non-Hodgkin lymphoma (4.8%), and Hodgkin disease (4.6%) had the highest rates of VTE. The rate of VTE increased by 28%, secondary to a near-doubling of PE rates from 0.8% to 1.5% (P < .0001). Among patients receiving chemotherapy, the rates of VTE rose from 3.9% to 5.7%, an increase of 47% (P < .0001). In multivariate analysis, risk factors associated with VTE included age >= 65 years, female sex, black ethnicity, use of chemotherapy, primary site of cancer, presence of comorbidities, and year of admission. CONCLUSIONS. VTE, particularly PE, is an increasingly frequent complication of hospitalization in cancer patients. Patients with black ethnicity, specific sites of cancer, or those receiving chemotherapy are disproportionately at risk.