Incidence, characteristics, and risk factors of venous thromboembolism in adolescent and young adult acute lymphoblastic leukemia patients receiving peg-asparaginase.

Abstract

e18520 Background: Venous thromboembolism (VTE) is common in acute lymphoblastic leukemia (ALL) patients (pts) receiving peg-asparaginase (ASNase) however there is limited data regarding the incidence of VTE and risk factors for VTE in adolescent and young adults (AYA) treated with ASNase. Methods: This is a single institutional retrospective analysis of AYA pts with ALL who received ASNase from January 2013 to December 2018. Time to VTE was calculated from date of starting treatment to onset of VTE or censored at last assessment date, treating death as a competing risk. The cumulative incidence of VTE was estimated and the Fine and Gray regression models accounting for competing risks were used to examine the association between risk factors and VTE. Results: Forty-six AYA ALL patients were included. Pt characteristics are shown in the Table. Twenty pts had a VTE following ASNase with the cumulative incidence rate of 35% (95% CI: 22-48%) at 100 days. The most common VTE sites were cerebral (n=6) and upper extremity (n=6). Nine pts (43%) had at least one recurrent VTE. After initial VTE, ASNase was continued in 13 pts (62%), stopped in 6 pts (29%), and dose reduced in 2 pts (10%). Nine pts (45%) of those who developed VTE received antithrombin. Out of the 6 pts with VTE who had ASNase discontinued or dose reduced, 2 (33%) had progression of ALL. The hazard ratios (HR) for risk of VTE from univariable regression models are listed in Table 1. Male sex was associated with increased VTE risk, with HR=3.33 (95% CI: 1.13-9.77). Conclusions: Our study estimated the incidence of VTE in the AYA cohort. Only male sex was identified as a risk factor for VTE. Additional studies are needed to assess VTE risk factors in AYA pts with ALL. Pt characteristics and hazard ratios for risk of VTE. [Table: see text]