Fungal infections are common in patients with cancer.
Morbidity and mortality associated with fungal infection complicate cancer treatment outcomes.
Invasive candidiasis is the most common fungal infection in patients with cancer, requiring careful assessment for dissemination, selection of appropriate antifungal agent, removal of infected devices, and duration of therapy.
Invasive aspergillosis (IA) is the most common mold infection in patients with cancer, requiring vigilance to detect pulmonary or sinus infection, which may require resection or debridement in addition to aggressive antifungal therapy.
Rare molds that infect patients with cancer include Fusarium and Mucorales spp., typically affecting patients with hematologic malignancy, with recovery of neutrophils the most important factor in improving mortality.
Fungal infections remain a significant cause of morbidity and mortality in patients with cancer. In the United States, fungal infections were estimated to cost $7.2 billion in 2017, with $4.5 billion for 75,033 hospitalizations.1 Modern management of infections in cancer requires knowledge of the epidemiology, pathogenesis, treatment, and prevention of such infections. Fungal infections range from nosocomial infections with Candida spp. to endemic fungi acquired outside the hospital, such as Histoplasma capsulatum.1 Opportunistic fungi, especially molds, have emerged as a leading cause of death in patients with leukemia or hematopoietic stem cell transplant (HSCT).2 Candida auris, recently identified and disseminating throughout the globe, poses a unique risk, forming biofilm capable of surviving for prolonged periods on surfaces, exhibiting multidrug resistance, often to all approved antifungals, and with a mortality rates as high as 40% to 60%.3,4
Fungal infections pose a continuing challenge for oncology patients. Exposure to fungi is common, typically occurring from the natural environment. Patients with cancer are not only susceptible to new infection with endemic fungi (such as H. capsulatum) but also reactivation of latent infections. In addition to Aspergillus spp., other less opportunistic molds, such as Fusarium spp., Scedosporium spp., and Mucorales spp., cause devastating disease in hematologic patients. Cases of nosocomial infection caused by molds are reported in the setting of hospital construction, leading to routine air sampling and filtration. In contrast, Candida spp. are a common component of patients' and health care workers' endogenous microbial flora. Manifestations of infection may not present until the patient receives chemotherapy or undergoes HSCT. In this chapter, we describe the general approach to diagnosis and assessment of risk factors for fungal infection and discuss common and rare causes of fungal infections in patients with cancer.
Fungal infections may involve several organs, ranging from the skin, brain, lungs, kidneys, and spleen to the liver and other tissues. In addition, evidence of infection may be identified from blood samples, demonstrating active, via polymerase chain reaction (PCR) or antigen testing, or past infection, via antibody testing. In the past two decades, the focus, as with other infectious etiologies, has shifted from culture or other direct ...