PO32 | ANTICOAGULANT THROMBOPROPHYLAXIS IN AGGRESSIVE LYMPHOMAS PATIENTS: PREDICTIVE THROMBOTIC RISK SCORES AND RISK FACTORS

L. Gurgoglione¹, G. Gini¹, S. Rupoli¹, A. Poloni^1|2 | ¹Hematology, AOU delle Marche, Ancona; ²Università Politecnica delle Marche, Ancona, Italy

Introduction. Lymphoma patients have a well-known increased risk of thrombosis, which can cause therapy delays and increase mortality. The use of thromboprophylaxis in this setting could improve such odds, but there are no international guidelines for anticoagulant prophylaxis. The different scores used in cancer patients are mostly not developed in this specific subset, and they’ve not been validated.

Aim. We conducted a retrospective monocentric study to evaluate the predictive value of the most used risk score (Khorana, Conko, and Throly) in this setting, while also evaluating single risk factors. We also evaluated the safety and effectiveness of anticoagulant thromboprophylaxis.
Materials and Methods. We collected the data of 302 patients with a histological diagnosis of aggressive lymphomas (both new and relapsed) between 2021 and 2024 at AOU delle Marche. Anticoagulant prophylaxis with LMWH was administered according to clinical judgment. We collected the clinical and laboratory findings, risk factors, survival data, and the incidence of bleeding and thrombotic events. The relative risks were calculated with a 95% confidence interval.

Results. 86 patients received anticoagulant prophylaxis and 24 patients were already in full anticoagulant therapy. 54 patients (17.88%) had a thromboembolic event, 6 during thromboprophylaxis. All were treated and none were fatal. No risk score was able to predict the thrombotic risk in a statistically significant way (Figure 1). Among all the analyzed items, only ECOG >2 (RR 5.79 CI 2.59-12.97) (RR 2.01, CI 1.08-3.76) and a previous thrombotic event (RR 3.87, CI 1.08-13.87) (RR 2.94, CI 1.40-6.14) showed increased risk of thrombosis both at diagnosis and during treatment. Primary Mediastinal B-cell Lymphoma (RR 4.87, CI 1.71-13.87) showed an increased risk of thrombosis at the time of diagnosis. Anticoagulant prophylaxis decreased the risk of thrombosis (RR 0.20, CI 0.08-0.54), without an increased risk of bleeding (RR 1.03, CI 0.90-3.20).

Conclusions. Anticoagulant prophylaxis showed efficacy in preventing thromboembolic events without increased bleeding risk. However, patient selection for prophylaxis is still an unmet clinical need since there is still no reliable score. All scores analyzed in this study performed poorly, but we identified some new items that could be used for further development. New clinical studies are required to find new risk factors and to develop better scores in this setting.