Prevalence, Patterns, and Predictors of Venous Thromboembolic Events in Patients Undergoing Salvage Chemotherapy and Autologous Stem Cell Transplantation for Relapsed Lymphomas.

Background and objectives: Almost 25% of patients with lymphoma may have relapse or develop refractory disease, and a majority of such patients undergo salvage chemotherapy and autologous stem cell transplantation (ASCT). Data on venous thromboembolism (VTE) in this setting are scarce. This study aimed to investigate the prevalence and factors that may increase the risk of VTE in such patients.

Patients and methods: Adult patients who were diagnosed with lymphoma and received salvage chemotherapy and ASCT were included in the study, and the subgroup with radiologically confirmed VTE were identified. Correlations between different clinical and laboratory variables and VTE were evaluated.

Results: A total of 216 patients (median age, 31 [range, 19-60] years) were enrolled in the study. Most patients (n = 140, 64.8%) had Hodgkin's lymphoma, while 54 (25.0%) had diffuse large B-cell lymphoma. A total of 36 (16.7%) patients had VTE, mostly as upper extremity deep vein thrombosis (n = 28, 77.8%); 18 (50%) of the cases were related to central venous catheter insertion. Thrombosis rates were higher among patients with high lactate dehydrogenase (LDH) level (29.2% vs. 5.9%, p < 0.001), those with mediastinal involvement (25.9% vs. 11.5%, p = 0.025). and those with longer hospital stay (22.3% vs.9.5%, p = 0.036). In the multivariate analysis, high LDH level (odds ratio (OR), 6.53; p < 0.001), mediastinal involvement (OR, 2.70; p = 0.005) and hospital stay ≥24 days (OR, 2.71; p = 0.007) were all associated with significantly higher VTE rates.

Conclusion: Patients with relapsed lymphoma undergoing salvage chemotherapy and ASCT are at higher risk for VTE, especially in those with high LDH level, mediastinal involvement, and prolonged hospital stay. If no contraindications exist, thromboprophylaxis might be considered in these settings.