Impact of fluconazole prophylaxis on fungal colonization and infection rates in neutropenic patients. The Canadian Fluconazole Study.

Fungal colonization profiles from four different anatomical sites were evaluated in 266 neutropenic cancer patients receiving intensive cytotoxic therapy for acute leukaemia or for autologous marrow transplantation. At the beginning of chemotherapy patients were allocated randomly to receive oral fluconazole 400 mg daily or an identical placebo until prophylaxis failure or marrow recovery. Candida albicans colonization was reduced from 30 to 10% in the fluconazole recipients while it increased from 32 to 57% in the placebo patients (P<0.001). By the end of prophylaxis, colonization with non-albicans Candida species increased from 7 to 21% and 8 to 18% in the fluconazole and placebo patients, respectively (P = 0.396). Although Candida glabrata was isolated more frequently at the end of the prophylactic period in the fluconazole patients than in the placebo patients (16 versus 7%), only one definite invasive C. glabrata infection was noted. Overall, definite invasive fungal infections were documented in 26 patients [four fluconazole versus 22 placebo patients (P< or =0.001)]. In 23 (92%) patients the infections were caused by persistently colonizing or newly acquired organisms. While probable invasive fungal infections were noted in five fluconazole patients, 10 placebo patients were also affected (P = 0.19). An end-of-prophylaxis colonization index >0.25 was 76% sensitive but only 69% specific for invasive fungal infection. However, a colonization index < or =0.25 at baseline had a negative predictive value of 88% for development of invasive fungal infection. Fluconazole prophylaxis decreased colonization by fungi and subsequent invasive fungal infections in neutropenic cancer patients.