Risk of reactivation of a recent invasive fungal infection in patients with hematological malignancies undergoing further intensive chemo-radiotherapy. A single-center experience and review of the literature.

BACKGROUND Patients with hematologic malignancies and a history of an invasive fungal infection are considered to be at high risk of suffering reactivation of the infection during subsequent intensive chemotherapy. PATIENTS AND METHODS From January 1993 to September 1996, nine patients with a hematologic malignancy and previous invasive pulmonary aspergillosis (IPA) or Pseudallescheria boydii pneumonia and five with invasive candidiasis received further intensive chemotherapy (n = 3) or a bone marrow or peripheral blood stem cell transplant (n = 11) four days to 13 months (median three months) from the start of therapy for the fungal infection. Five patients with IPA and all five with invasive candidiasis showed complete or good partial radiologic resolution of the infection with the primary antifungal therapy given, which was continued before, during and after the period(s) of subsequent neutropenia. RESULTS Twelve of the 14 patients showed no signs of progression or reactivation of the fungal infection during therapy, while two patients with active IPA died with progressive aspergillosis shortly after an allogeneic transplant. A review of the literature revealed that in both types of infections the risk of reactivation and dissemination appears low after achieving clinical and radiologic signs of response, which takes several weeks or months before proceeding to further antileukemic therapy. INTERPRETATION AND CONCLUSIONS Despite lack of definite evidence, administration of an active antifungal drug before, during and after the period of neutropenia appears to be useful. In IPA, residual masses, nodules or cavities in the lung usually contain viable invasive fungal elements and should be resected whenever possible. On the other hand, the risk of reactivation and progression of an active fungal infection during intensive chemoradiotherapy is very high, and novel therapeutic strategies appear warranted in this setting.