Impact of the revised (2008) EORTC/MSG definitions for invasive fungal disease on the rates of diagnosis of invasive aspergillosis.

Diagnosis of invasive aspergillosis (IA) remains a challenge as the clinical manifestations are not specific, and a histological diagnosis is often unfeasible. The 2002 European Organization for Research and Treatment of Cancer (EORTC) and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (MSG) criteria for classification of cases into possible, probable or proven were revised in 2008. Our objective was to analyze the impact of these revisions on the diagnosis of IA. A retrospective analysis of 589 high risk patient-episodes revealed that 125 of 155 'possible' (81%) and 12 of 16 'probable' (75%) cases of IA should be changed to 'non-classifiable' when the new criteria were applied. We concluded, as expected, that the 2008 EORTC/MSG revised definitions reduced the number of cases classified as 'possible' IA, but additionally, there has been a dramatic reduction in 'probable' cases. These changes have significant implications on the interpretation of clinical trial data based on EORTC/MSG classifications.