The study aims to evaluate the occurrence, mortality, and risk factors for invasive mold infections (IMI) in children treated with chemotherapy for acute leukemia in Denmark. The study will be a retrospective nationwide survey study of all children who received first-line chemotherapy for acute leukemia from 2008 to 2022 in Danish pediatric oncology units. The study population includes 621 children under the age of 18. Data will be collected from medical records, hospital databases, and national databases. When the IMI subgroup has been identified, this will be compared to the leukemic group that did not develop IMI. Statistical analysis can then determine the occurrence, mortality rate, and possible IMI risk factors.

Chemotherapy can weaken children's immune system, making them vulnerable to infections, including invasive mold infections (IMI), caused mainly by Aspergillus spp. The at-risk population for IMI in children with acquired immunodeficiency is patients with prolonged granulocytopenia due to hematologic malignancies treated with chemotherapy or allogeneic hematopoietic stem cell transplantation (HSCT) recipients and children receiving long-term corticosteroid treatment. Incidences and mortality rates are often reported as high.

In a retrospective cohort study, we aim to obtain an epidemiological overview of IMI in children receiving first-line treatment for acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) in Denmark from 2008 to 2022 and identify possible risk factors, including treatment-related adverse effects.

Objectives

1. To determine and compare the incidence of IMI in childhood AML and ALL during first-line chemotherapy in Denmark.
2. To determine and compare the mortality of IMI in childhood AML and ALL during first-line chemotherapy in Denmark.
3. To explore risk factors for IMI in childhood AML and ALL during first-line chemotherapy in Denmark.

Inclusion Criteria:

• Age <18 years at the time of inclusion
• Received first-line treatment for ALL or AML
• Treatment at a Danish tertiary pediatric oncology unit (Rigshospitalet, Aarhus University Hospital, Odense University Hospital, and Aalborg University Hospital)
• Treatment initiation January 1st, 2008, to December 31st, 2022

Exclusion Criteria:

• Not meeting inclusion criteria

Any patient (<18 years) who initiated first-line chemotherapy against primary ALL or AML at any of the four Danish pediatric oncology departments from January 1st, 2008, to December 31st, 2022.

All individual participant data that underlie the results in a future publication will be made publicly available in an anonymized form.

The study protocol will be available before collecting participant data. The anonymized participant data will be made available as supplementary material simultaneously with the publication of the article.

All who have access to the article can access the participant data.