Management of fungal infections in neutropenic patients: more doubts than certainties?

An evidence based approach to prophylaxis and therapy of invasive fungal infections depends on the knowledge of epidemiology and of risk factors for these infections, as well as on the appreciation of merits and limitation of the available clinical trials. A progressive increase in the incidence of systemic fungal infections, most often caused by Candida and Aspergillus, in patients with cancer and neutropenia has been observed in recent years. This increase of systemic fungal infections recognizes a multifactorial origin, including host defense impairment and type of underlying disease. The various combinations of these different risk factors make the patients affected by systemic fungal infections a non-homogeneous population and, therefore, the transferability of the results of many clinical trials from one population to another is difficult. Clinical trials on prophylaxis and treatment of systemic fungal infections moreover have many limitations: they are often of small size, are frequently non-comparative, enrol population at different risk for infection, use different criteria to define success or failure of therapy. These limitations make the interpretation of the trial results difficult. As randomised clinical trials and metanalysis are considered the most valuable sources of information on new treatments, it dearly appears that the mentioned difficulties in interpreting available data from the literature may expose patients to an increased risk of receiving an inappropriate or non-optimal treatment. Better designed studies are needed to clarify the many controversial questions in antifungal prophylaxis and therapy.