Hemorrhage and thrombosis in adult patients with acute lymphoblastic leukemia: A comparative analysis between conventional vs pediatric-inspired induction regimens

Abstract Introduction: Acute lymphoblastic leukemia (ALL) in adults poses unique challenges, particularly during induction therapy. Differences between pediatric-inspired and conventional regimens may influence hematologic outcomes, especially the incidence of thrombosis and hemorrhage. Objectives: This study aims to compare the incidence of thrombosis (arterial and venous) and hemorrhage in adult patients with ALL treated with pediatric-inspired induction regimens versus HyperCVAD. Additionally, we sought to evaluate the relationship between these events, relapse, and overall survival (OS). Materials and Methods: A retrospective review was conducted on the records of 254 patients diagnosed with ALL between 2018 and 2023, of whom 195 met the inclusion criteria: diagnosis of ALL between ages 16 and 99, and induction with either HyperCVAD or a pediatric-inspired regimen during first-line therapy. Clinical, demographic, and risk variables for thrombosis and bleeding were analyzed. Incidence rates were calculated and compared using appropriate statistical analyses. Results: Among the 195 patients, 178 had B-cell lineage and 17 had T-cell lineage, with a median age of 31 years. Adolescents and young adults (AYA) represented 69.7% of the cohort, and 26.7% had obesity. The incidence of thrombosis during induction was 4.6%, with no significant difference between regimens (HyperCVAD 1.8% vs. pediatric inspired 5.8%, p=0.4504). At four months, the cumulative thrombosis rate was 9.2%, primarily venous events, including cerebral venous sinus thrombosis in the pediatric-inspired group. The overall hemorrhage rate was 10.8%, with a higher incidence in the HyperCVAD group (14.3%) compared to the pediatric group (9.4%), without statistical significance (p=0.3167). Bleeding sites included central nervous system (12 cases), gastrointestinal tract (5), ocular (3), and gynecologic (1). Hypofibrinogenemia, thrombocytopenia, hypertension, and age were associated with bleeding risk, while thrombotic events correlated with cardiovascular risk, acute kidney injury, red blood cell transfusions, and elevated D-dimer levels. Conclusions: No significant differences were observed in the rates of thrombosis or hemorrhage between conventional and pediatric-inspired induction regimens. Thrombotic and bleeding events during ALL induction appear to be more influenced by clinical and demographic factors rather than the type of regimen, underscoring the need for personalized therapeutic strategies based on individual patient characteristics rather than induction protocol alone.