VENOUS THROMBEMBOLISM: A FREQUENT COMPLICATION IN CHRONIC LYMPHOCYTIC LEUKEMIA

ABSSUB-3956

Background: Venous thromboembolism (VTE) is a major cause of morbidity and mortality in patients with malignant tumors. Increased risk of VTE is well described in a variety of hematologic malignancies , especially in myeloproliferative disorders, plasma cell malignancies, and lymphomas. However, data regarding risk of VTE in chronic lymphocytic leukemia (CLL) is very scarce. A recent study (Whittle et al., Leuk Res 2010) reported high incidence of TEN in CLL patients compared with the general population.

Aims: To evaluate the occurrence and risk factors of VTE in patients with CLL.

Methods: We retrospectively analyzed clinical and laboratory data of consecutive patients (pts) with CLL followed up at 4th Department of Internal Medicine – Hematology,  University Hospital, Hradec Kralove, diagnosed between 1999 and 2013. In all, 346 patients were analyzed (222 males; median age at diagnosis, 64 years;  low/intermediate/ high Rai modified risk in 41/47/12%).  Only patients with radiologically confirmed deep vein thrombosis (ultrasonography) or pulmonary embolism (computer tomography) developed after diagnosis of CLL were considered as having VTE.

Results: After a median follow-up of 72 months (range, 26-138), at least one episode of VTE occurred in 38 patients (11 %). Basic characteristics are listed in Table 1. VTE developed after with a median of 34 months since CLL diagnosis. There was a high proportion of unfavourable prognostic factors (advanced Rai stages, unmutated IgVH genes, unfavourable cytogenetics). There was no association of VTE with hyperleukocytosis or other parameters of blood count. An apparent precipitating factor for VTE was present in 4 patients (acute infection).  The presence of 0/1/2/3 risk factors  for VTE was identified in 2/16/14/6 patients. Seventeen pts were previously untreated for CLL; 14 cases of VTE occurred during treatment for CLL and 7 cases after CLL treatment. The most common risk factors for VTE besides age (n=24) were corticosteroid therapy (n=13), other malignancies (n=9) and obesity (n=7). Recurrence of VTE was diagnosed in 8 pts (21%). Overall survival of patients who developed VTE was not different from those without VTE.

Summary/Conclusion: Based on our results, VTE is a relatively frequent complication in patients with CLL. Although most patients had other known risk factors for VTE including treatment of CLL, 29% had no risk factors or only age≥ 65 years. These findings support the role of CLL in the development of VTE. Updated data will be presented.

Keywords: Chronic lymphocytic leukemia, Prognostic factor, Thrombosis

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