Thrombosis in leukemia: incidence, causes, and practical management.

In patients with acute leukemia (AL), coagulation disorders, which include both thrombotic and hemorrhagic events, are part of the clinical spectrum both at diagnosis and during its evolution. The incidence of these events has been reported by several authors in the range of 1-36 %. This heterogeneity appears to be related to the type of patients included, the study design, and patient-related factors as well as the treatment used. The pathophysiology of thrombosis in AL is complex and multifactorial and includes a myriad of factors that contribute to cancer procoagulant state: synthesis of procoagulant factors by circulating blasts, cellular microparticles, use of endovascular devices (catheters), type of chemotherapy used (L-asparaginase) to name a few. Currently, treatment relies in the use of heparin, followed by vitamin K antagonists for 3 to 6 months. However, randomized controlled studies are required in patients with AL and thrombosis to confirm its safety, duration, and effectiveness.

Incidence of thrombosis in adults with acute leukemia: a single center experience in Mexico.

BACKGROUND: Acute leukemias are hematopoietic malignancies that may be accompanied by hemostatic abnormalities. In general, information on the frequency of thrombotic events, their clinical characteristics and survival in adult patients with acute leukemia is still scarce and controversial. OBJECTIVES: To describe the frequency of thrombotic events, their clinical characteristics and survival of adult patients with acute leukemia at the Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico City. MATERIAL AND METHODS: A patient cohort, diagnosed and treated between October 2003 and December 2009, was retrospectively analyzed in terms of thrombotic events, frequencies and survival curves. RESULTS: We analyzed 181 patients with a median age of 33 years, 80 were female (44.2%). Fifteen cases with thrombosis (8.3%) were documented and in 53.3% of cases, they were related to the use of a central venous catheter. The median time to development of thrombosis was 92 days; 33.3% of events occurred during the first 30 days after diagnosis. The incidence of thrombosis in patients receiving L-asparaginase was 15%. Of the 15 patients with thrombosis, 27% were alive and without evidence of disease at last follow-up, and 73% had died; disease progression was the most common cause of death (81.8%). None of the thrombotic events had an impact on mortality. Median overall survival (OS) was 349 days. CONCLUSIONS: The incidence of thrombosis in this adult acute leukemia population is comparable to that reported in the literature. Only a third of cases occurred during the first month after diagnosis; however, 93.3% of patients developed a thrombotic event during the first year after the diagnosis of acute leukemia. All cases were symptomatic and central venous catheter-related thrombosis was the most frequent presentation in this group. Survival curves comparing patients with and without thrombosis were similar. Prospective studies are necessary in order to assess the risk factors fostering thrombosis in adult patients with acute leukemia.