Invasive Fungal Infections in Acute Promyelocytic Leukemia Patients. Results of a Prospective Multicenter Study in Italy

OBJECTIVES

Aim of this prospective study was to evaluate the risk of invasive fungal infection (IFI) in patients (pts) with acute promyelocytic leukemia (APL) and to compare APL pts with patients affected by non promyelocytic acute myeloid leukemia (npAML) in order to evaluate factors potentially linked to IFI in these two subsets of acute myeloid leukemia.

PATIENTS AND METHODS

From January 2010 to April 2012 all pts with newly diagnosed AML were registered in 33 Italian participating centers. A minimum follow up of 90 days after 1^st induction chemotherapy was requested for all pts. A prolonged follow up until June 2014 was made only for APL. Data were collected about age, gender, AML subtype, treatment and also about post chemotherapy risk factors for IFI (duration of neutropenia, mucosal damages, vomiting, diarrhea, presence of medical devices), antifungal prophylaxis, onset of IFI, level of certainty (possible/probable/proven), and antifungal treatment. Only for APL the survey was prolonged for at least 3 months in order to analyze if these pts have an IFI risk during other than first induction phases.

RESULTS

1,192 consecutive newly diagnosed adult AML pts (npAML:1,086/APL:106) were enrolled in the study.

Among npAML pts, those receiving low dose chemotherapy and/or palliative treatment were excluded from the analysis; in the remaining 881 pts 214 cases (24%) of IFI were recorded.

Considering APL, 3 pts were excluded from the analysis due to early death (1 pt) or bad performance status (2 pts). The remaining 103 pts received APL treatment according to local protocols: all trans retinoic acid (ATRA) plus chemotherapy (90 pts) or ATRA plus arsenic trioxide (ATO)(13 pts). Only 8 (8%) APL pts developed an IFI after the induction phase: 1 proven, 3 probable and 4 possible IFI. All cases were caused by molds. All APL were followed for a median follow up of 36 months (range 3-54). During this time only 2 other cases of IFI were observed: 1 possible IFI during consolidation at 16 weeks from APL diagnosis and 1 probable aspergillosis in a rare case of APL relapse at 132 weeks from APL diagnosis. All the IFI occurred in pts treated with ATRA plus chemotherapy.

IFI was fatal in only 1 case (cerebral aspergillosis), all the other pts recovered after antifungal treatment.

A comparison between npAML and APL was made in order to analyze the risk of IFI within 90 days after induction treatment among these 2 groups of patients (see table). A significantly lower number of overall IFI and systemic antifungal treatment was observed in the APL group, in spite of the fact that systemic anti mold prophylaxis was significantly less frequently utilized.

Comparing APL among them in order to identify parameters that could be correlated to IFI presentation, no significant factors were identified.

DISCUSSION

In our prospective study we specifically analyzed the incidence and the type of IFI in APL during a prolonged follow-up. Only 10 cases of IFI were documented and in most cases (6 pts) the infection was only possible. Comparing APL to npAML a lower incidence of overall IFI was observed despite less use of mold active drugs as prophylaxis. It could be attributed to the different chemotherapy (less aggressive in APL) and to lower duration of deep neutropenia. No yeast infection was observed in APL. On the basis of this study, APLs may be considered at low risk of IFI so probably the use of a mold active antifungal prophylaxis could be omitted.