VPB0945 - Poor Performance Status and Elevated Factor VIII Levels Increase Thrombotic Risk in Lymphoma and Multiple Myeloma Patients

Background: Venous thromboembolism (VTE) is an important cause of morbimortality in cancer,resulting from a combination of genetic and acquired conditions. Thrombosis incidence in lymphoma is variable (1,5-59,5%), being higher in non-Hodgkin lymphoma (NHL) than in Hodgkin disease (6,5 vs.4,7%), and in aggressive compared to indolent NHL (16,3 vs.3,8%). VTE incidence in multiple myeloma (MM) is 15,2%. Despite the demonstrated thrombotic risk in these patients, thromboprophylaxis is largely underutilized. Recently,new thrombotic risk assessment models (RAMs) have been developed.

Aims: To identify risk factors for thrombosis and explore thrombotic RAMs in lymphoma and MM patients.

Methods: This prospective, observational study includes 63 patients diagnosed with lymphoma/MM between February 2020 and June 2021 at our centre. The variables recorded were: thrombosis characteristics; clinical, treatment and laboratory variables(including acquired and genetic-Thrombo inCode- thrombophilia testing at cancer diagnosis).Approval by the local medical ethics committee and patients’ informed consent were obtained.

Results: Median age at cancer diagnosis was 64 (IQR:51-72). MM was diagnosed in 16 (25,4%) patients and lymphoma in 47 (74,6%), the majority being NHL (87,2%). At a median follow-up of 9,1 months (IQR:5,1-12), 6 (9,5%) patients developed VTE (2 deep venous thrombosis,2 pulmonary embolisms,1 catheter-related,1 internal jugular vein thrombosis); median time to VTE was 36 days(IQR:4-92). Thrombosis was more common in patients with ECOG2 or more(28,6% vs.4,1%;p=0,019). Baseline median factor VIII was higher in VTE (393%;IQR 246-344) than in non-VTE group (211%;IQR 157-241)(p=0,005). Other risk factors appear in Table 1. Table 2 shows thrombotic risk according to different RAMs.

Conclusion(s): Thrombosis incidence in our population is similar to previously described, with impaired ECOG and elevated factor VIII increasing VTE risk. Existing thromboprophylaxis didn't significantly reduce thrombosis,and RAMs stratification showed no association with thrombosis; this may be due to the small population analyzed. Improved RAMs combining clinical, laboratory and genetic variables are needed to prevent thrombosis in lymphoma and MM.