High Incidence Of Venous Thromboembolic Events (Vte) In Patients With Diffuse Large B-Cell Lymphoma

Background Incidence of venous thromboembolic events (VTE) is higher among cancer patients, especially while on chemotherapy. Diffuse large B-cell lymphoma (DLBL) is the most common lymphoma. Studies that specifically evaluated the risk of VTE in patients with different kinds of lymphomas reported a risk ranged from 1.5% to 14.6%. In this study, we specifically address VTE in a unified lymphoma population. Methods Medical records and hospital databases were searched for patients with a diagnosis of DLBL and VTE. All patients were diagnosed, treated and followed up at our institution. The Khorana and “Throly” risk assessment models (RAM) were applied on all patients and known risk factors for VTE were studied. Results A total of 393 patients (52.4% males), median age: 49 (range: 18-90) years were included. At diagnosis, 163 (41.5%) were stage IV, 116 (29.5%) had bulky disease and 197 (50.1%) had high LDH. All patients were treated on a unified guidelines using R-CHOP chemotherapy; 285 (72.5%) achieved CR while 72 (18.3) had salvage chemotherapy. Venous thromboembolic events were reported in 57 (14.5%) patients. Pulmonary embolism (PE) with or without deep venous thrombosis (DVT) was reported in 24 (42.1%), 8 of them (33.3%) were incidental. Upper extremity DVT were seen in 18 (31.6%); only 4 (22.2%) were associated with a vascular device. Thrombosis was diagnosed in ambulatory sitting in 30 (52.6%) and majority of the VTE occurred while on active chemotherapy; 20 (35.1%) while on initial induction and 15 (26.3%) while on salvage chemotherapy, however, 19 (33.3%) occurred before the initiation of any chemotherapy. Among the 35 patients on active chemotherapy, only 6 (17.1%) had high Khorana risk score. In a multivariate analysis, significantly higher rates of thrombosis were associated with stage-IV disease, high LDH and high International Prognostic Index (IPI). Sex, age, BMI, and the Khorana risk score were not. Conclusions Incidence of VTE in patients with DLBL is high and majority of such events occurred in ambulatory setting were VTE prophylaxis is not offered. Upper extremity DVT and incidental PE were exceptionally high. Stage at diagnosis, IPI score and LDH are important in predicting the risk for thrombosis. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.