Update on epidemiology of and preventive strategies for invasive fungal infections in cancer patients.

Changes in antineoplastic treatments and transplant practices are driving shifts in the epidemiology of invasive fungal diseases (IFDs). Patients with acute myelogenous leukemia (AML) and those undergoing bone marrow transplant (BMT) are at greatest risk for contracting IFDs. Unfortunately, there are few large population studies that can be used to track trends and help us to better understand why certain individuals within recognized high-risk groups are at greater risks than others for contracting IFDs. The growing use of antifungals in prophylaxis and treatment influences which species will cause an IFD as well as the resistance patterns of these fungi. On the one hand, antifungal prophylaxis has mitigated, but not eliminated, the threat of candidiasis. Furthermore, prophylaxis trials have shown trends of reduced aspergillosis in BMT patients; however, no survival benefits were seen, and 1 trial indicated a lower rate of aspergillosis and survival benefits in patients with AML. Future prophylaxis trials should reduce the heterogeneity of risk in study participants in order to better assess benefit; these trials should also incorporate fungal biomarkers into their design. The threat of emerging fungal resistance in prophylaxis strategies is real and must be monitored.