Introduction: Although in our analysis high-dose AZA was not associated with infection, it is noteworthy that due to common practice of reducing AZA dose following infection, patients experiencing one infectious event tend to receive low doses in subsequent cycles. Additionally, some physicians are reluctant to prescribe a full dose AZA to octogenarian patients.
Purpose: We therefore analyzed only the first cycle prescribed to 184 patients, comparing infection frequency following a full 7-day cycle of 75 mg/m2 (7∗75) versus a 5-day cycle of therapy (5∗75).
Materials and Methods: Even lower AZA doses were prescribed to nine patients and the information regarding the prescribed dose was missing for two patients. Among the remaining 173 patients, 106 received a full 7∗75 dose and 67 received a 5∗75 dose.
Results: Characteristics of these two groups were compared and patients’ age, sex, platelets, neutrophils and hemoglobin counts, number of previous blood transfusions, cytogenetics and percentage of blasts in bone marrow appeared to be similar in both groups (Table 1). Infectious events were reported in 36/106 (34%) and 10/67 (14.9%) in groups of 7∗75 and 5∗75 doses, respectively (p=0.008). Multivariate analysis identified standard AZA dose and platelets count of less than 20,000 as the only significant predictors of infections during the first cycle of therapy.
Conclusions: No specific factor that drove physicians to use a reduced dose was recognized. However, infection risk was doubled following the 7∗75 compared to 5∗75 dose. Although AZA dose was not identified as a risk factor in the previous study, current analysis raises concern regarding recommended first cycle AZA dose. Impacts of first cycle dose should be prospectively studied. Currently, reducing dose based on patient’s age alone is not justified but a low platelet count should be considered as a hazard for infection.