Analysis of acute leukemia complications in children at the disease onset and during induction

Abstract

Background. Despite the progress achieved in the treatment of acute leukemia (AL) in children, complications, both at the disease onset and those resulting from antitumor therapy, remain the main cause of early mortality, which varies from 3 to 20 %.Aim. To assess the frequency, severity, etiology, risk factors, and outcomes of AL complications in children at the disease onset and during induction chemotherapy (ICT).Results. The study analyzed 92 cases of AL in children aged from 5 months to 17 years. 75 patients had acute lymphoblastic leukemia (ALL), 17 had acute myeloid leukemia (AML). In 1 (1.3 %) patient with ALL and in 5 (29.4 %) with AML, a concomitant diagnosis was Down syndrome. At the AL onset, 34 (36.9 %) patients were diagnosed with infection, of which 27 (36 %) and 7 (41.2 %) patients had ALL and AML, respectively. In both cohorts, febrile neutropenia (55.5 %; n = 15 vs. 14.3 %; n = 1), pneumonia (25.9 %; n = 7 vs. 71.4 %; n = 5), enterocolitis (7.4 %; n = 2 vs. 14.3 %; n = 1) predominated in both cohorts for AML and ALL, respectively. Due to uncontrolled infection in 5 (29.4 %) patients with AML and 13 (17.3 %) with ALL, ICT was delayed until the condition stabilized and the infection was controlled. During ICT, the incidence of infectious complications was 81.3 % (n = 61) and 100 % (n = 17) in patients with ALL and AML, respectively. The most common types were enterocolitis (41.2 %; n = 7 vs. 34.4 %; n = 21), febrile neutropenia (29.4 %; n = 5 vs. 37.7 %; n = 23), pneumonia (47.1 %; n = 8 vs. 29.5 %; n = 18), catheter-associated bloodstream infection (11.8 %; n = 2 vs. 8.2 %; n = 4) in AML and ALL, respectively. By etiology, bacterial infections predominated, accounting for 32 % (n = 8) and 36.8 % (n = 35) in the AML and ALL groups, respectively. More cases of invasive mycoses were reported in AML patients – 23.5 % (n = 4) versus 14.8 % (n = 11). Non-infectious complications were diagnosed in 32.6 % (n = 30) of patients with a predominance in ALL group (34.6 %; n = 26 vs. 23.5 %; n = 4). Hyperleukocytosis at the leukemia onset caused such complications as leukostasis (11.8 %; n = 2) and acute tumor lysis syndrome (11.8 %; n = 2). The most common post-cytostatic complications in ALL were vincristine polyneuropathy (61.5 %; n = 16), hemorrhagic syndrome (15.4 %; n = 4), methotrexate-induced encephalopathy (15.4 %; n = 4), acute tumor lysis syndrome (11.5 %; n = 3). In AML cases, the most common type of non-infectious complications were hemorrhagic (75 %; n = 3). Induction mortality in the ALL group was 2.6 % (n = 2), in the AML group it was higher – 11.8 % (n = 2), however, it should be noted that all deaths were registered in children with Down syndrome. The main cause of mortality in both groups was severe infections secondary to chemotherapy-induced hematopoietic aplasia. There were no deaths associated with non-infectious complications or chemotherapy-induced toxicity.Conclusion. The main type of toxicity in children at the AL onset and during ICT remains infectious complications of various etiologies, while in AML patients a higher frequency of invasive mycoses is registered (23.5 % vs. 14.8 %). Despite the high incidence of chemo-induced toxicity, the mortality rate in ALL remains low, amounting to 2.6 % in our cohort. In the AML group, mortality was higher – 11.8 %, but it should be noted that all cases occurred in patients with Down syndrome. There were no deaths due to non-infectious complications in any of the study cohorts.