Risk factors and mortality associated with venous thromboembolism in elderly patients with non-Hodgkin lymphoma

Abstract Risk factors and mortality associated with venous thromboembolism in elderly patients with non-Hodgkin lymphoma Ambarina S. Faiz MD PhD1, Ashwin Sridharan MD1, Shuang Guo MD1, Claire S. Philipp MD1 1Department of Medicine, Rutgers Robert Wood Johnson Medical School Introduction: Venous thromboembolism (VTE) is a common complication in patients with non-Hodgkin lymphoma (NHL), but data are limited for the risk of VTE in elderly patients. The risk factors for VTE are reported to be different in lymphoma patients than the risk factors associated with VTE in solid tumors. In addition, the impact of VTE on mortality is also not known in elderly NHL patients. For our study, we propose to examine the risk factors for VTE and VTE associated mortality in elderly patients with non-Hodgkin lymphoma. Methods: The United States SEER-Medicare database (2000 to 2019) was used for patients ≥65 years with non-Hodkin lymphoma. Sociodemographic characteristics and data for malignancy were abstracted from the SEER files and data for comorbid medical conditions were abstracted from the inpatient and outpatient Medicare claim files. Logistic regression was used to examine unadjusted and adjusted Odds Ratios (ORs) for the risk of VTE. Cox proportional hazard regression was used to evaluate unadjusted and adjusted Hazard Ratios (HRs) for the effect of VTE on mortality in elderly patients with non-Hodgkin lymphoma. Results: There were 276,296 elderly (≥65 years) non-Hodgkin lymphoma patients in the cohort. VTE was diagnosed in 40,296 (14.6%) NHL patients, 12.2% patients had a diagnosis of deep vein thrombosis, and 4.9% patients had a diagnosis of pulmonary embolism. The mean age of NHL patients was 75.8 years (±6.6), with 91% White patients, 5% Black patients and 4% Asian patients. VTE was more common in patients ≥75 years, females, Blacks and in patients with comorbid medical conditions and with chemotherapy treatment (p <0.01). In a multivariate analysis, after adjusting for sociodemographic characteristics, comorbid medical conditions, and chemotherapy, risk of having VTE was higher for patients ≥75 years (OR=1.05, 95% CI, 1.02-1.08) than younger patients, in females (OR=1.15, 95% CI, 1.12-1.18), and in patients with chemotherapy treatment (OR=1.73, 95% CI, 1.68-1.78). Black patients had a higher risk of VTE (OR=1.59, 95% CI, 1.02-2.48) but Asian patients had a lower risk of VTE (OR=0.59, 95% CI, 0.54-0.63) compared to White patients. There were variations in the effect estimates but the risk of VTE was higher in the presence of medical comorbid conditions. The risk of VTE was 1.87 (95% CI, 1.79-1.95) with hypertension and 1.61 (95% CI, 1.56-1.66) with heart failure. VTE was associated with a higher risk of death in patients with NHL and the risk persisted (HR=1.20, 95% CI, 1.18-1.21) after adjusting for sociodemographic characteristics, comorbid medical conditions and chemotherapy. Conclusion: Our data suggest racial differences in the risk of VTE in elderly patients with non-Hodgkin lymphoma and a higher risk of death in non-Hodgkin lymphoma patients who had a diagnosis of VTE.