Challenges in evaluating thromboembolic risk in acute leukemia: clinical profiling and limitations of current scoring systems

Background

Limited evidence is available on risk factors for thrombotic events in newly diagnosed acute leukemia (AL) patients, and predictive tools in this population need further validation.

Objectives

To evaluate the incidence of thrombosis in newly diagnosed AL patients and to validate known predictive scores.

Methods

We retrospectively included 421 patients between 2009 and 2022. Data on thrombotic events (venous and arterial) were collected from admission to 60 days of follow-up. The Khorana, International Society on Thrombosis and Haemostasis (ISTH) disseminated intravascular coagulation, and Siriraj Acute Myeloid/Lymphoblastic Leukemia scores were applied to the cohort.

Results

The cumulative incidence of thrombotic events within 60 days was 15.8%, being higher in the acute lymphoblastic leukemia subgroup (21%). Seventy-two percent of the events occurred within the first 30 days of diagnosis. Superficial vein thrombosis and catheter-related thrombosis comprised most events (38.2% and 19.1%, respectively), while arterial thrombosis represented 11.8%. Obesity and platelet count > 20 × 10⁹/L were associated with an overall risk of thrombosis in this cohort. In the acute myeloid leukemia subset, thrombotic event occurrence was associated with a higher peripheral blast percentage and elevated C-reactive protein levels. The Khorana, ISTH-disseminated intravascular coagulation, and Siriraj Acute Myeloid/Lymphoblastic Leukemia scores were not associated with thrombotic events in AL patients.

Conclusion

The incidence of thrombotic events is not negligible, being higher in the induction phase. Further studies and better tools to improve event prediction in this population, such as biomarker development, are needed.