Primary antifungal prophylaxis in oncohematological patients: who, when, and with what?

Invasive fungal infections (IFI) are among the main infectious complications in patients with hematological malignancies and with hematopoietic stem cell transplant (HSCT), causing high morbidity and mortality and significantly increasing the healthcare cost and hospital stay. The epidemiology of IFIs has changed in recent decades, with filamentous fungi, particularly Aspergillus spp., being the main etiological agents. There are multiple risk factors for having an IFI; however, the most important are profound and prolonged neutropenia and severe cellular immunodeficiency. For this reason, the population at greatest risk is made up of patients with acute leukemias, myelodysplasias and allogeneic HSCT with graft-versus-host disease (GVHD) treated with corticosteroids. Numerous randomized clinical trials and meta-analyses have shown that primary antifungal prophylaxis (AFP) significantly reduces the incidence of IFI, particularly those caused by Candida spp. and Aspergillus spp., IFI-related mortality, and overall mortality in some group of patients. Likewise, in high-risk patients, where a high incidence of IFI is expected, it is a cost-effective strategy. Several antifungals have demonstrated clinical benefit. They can be used as a AFP strategy in different settings, presenting advantages and disadvantages that must be taken into account in each case. For this, national and international scientific societies have issued recommendations for the indication of AFP. Aspects related to the different antifungals' clinical efficacy are analyzed considering the population at risk, the potential disadvantages, timing, and form of administration.