Survival rates in adolescent/young adult (AYA) patients with malignant diseases have improved with the introduction of pediatric-type
chemotherapy; however, the higher frequency of treatment-related complications, including
infections, remains a major challenge. We hypothesized that the efficacy of
antibiotics may differ between AYA and younger children. We aimed to evaluate differences in the efficacy of
antibiotics between them by retrospectively analyzing patients registered in previous first-line
antibiotic comparative studies on
febrile neutropenia (FN). Patients were classified into two groups: patients younger than 15 years of age (children group) and those aged 15 years or older (AYA group). The efficacy of
antibiotic therapy was compared between groups. Success of
therapy was defined as resolution of febrile episodes and clinical signs of
infection within 120 h of the initiation of
antibiotic therapy. A total of 818 febrile episodes in 204 patients were analyzed.
Antibiotic therapy success rates were lower in the AYA group than in the children group (53.8 vs. 63.7%, P = 0.028), even when patients were restricted to those with
bacteremia (11.8 vs. 41.4%, P = 0.025). However, mortality rates did not differ (0 vs. 0.5%, P = 1.000). The efficacy of first-line
antibiotic therapy for FN was poorer in AYA patients than in child patients.