In our series, more than half of the patients achieved long term OS with AHSCT. Less toxic conditioning regimens or more intensive GVHD prophylaxis could lead to better results in some children.

Background and Aims: Worldwide, the incidence of COVID-19 is lower in children than in adults and symptoms are less severe. So far, few studies from Latin America have been published on the behavior of COVID-19 in children with cancer. Purpose: To characterize the epidemiology, clinical course, morbidity, and mortality in children with cancer and COVID-19. Methods: All patients registered in the Argentine National Pediatric Cancer Registry (ROHA) with diagnosis of SARS-CoV-2 between December 4, 2020, and May 3, 2022 were included. Variables analyzed were: sex, age at COVID-19 diagnosis, clinical presentation at diagnosis, symptom severity, tumor type, intensive care requirement, specific treatment for COVID-19, vital status, and cause of death. Mortality was analyzed comparing the three main waves. Results: Overall, 888 children with cancer and COVID-19 infection were registered (484 females); 437 (49.2%) had leukemia, followed by central nervous system tumors (CNS-T) 120 (13.5%). Of the children, 57.2% (n=508) were symptomatic; 75% were febrile, and 37% (n=210) had neutropenia; 17.1% (n=152) were diagnosed within one month of cancer diagnosis. A total of 154 children had severe or critical symptoms (17%). In this study, 112 deaths were reported, 105 (94%) due to disease progression, sepsis, comorbidities, or treatment complications. Seven patients (0.8%) died from COVID-19, all diagnosed with leukemia/lymphoma. No association of deaths was found between the three waves analyzed. Conclusions: Based on the ROHA data, we may conclude that in pediatric cancer patients, contrary to what was initially expected, morbidity and mortality due to COVID-19 were not increased.