The effect of absolute phagocyte count on hospitalization duration in pediatric patients with solid tumors admitted with febrile neutropenia diagnosis

Purpose: Febrile neutropenia is a common oncologic emergency in pediatric oncology patients undergoing treatment for cancer, requiring early diagnosis and treatment. The traditional approach involves hospitalization of patients presenting with febrile neutropenia and administering antibiotic therapy intravenously. The severity of the disease is associated with suppression of bone marrow and loss of number and function of defense cells. Reliable algorithms exist for adult oncology patients that can classify patients shortly after presentation into low and high risk for serious bacterial infection and infection-related complications, but a similar consensus algorithm has not been reached for children. Our study aims to investigate the effects of absolute phagocyte count on the duration of hospitalization, duration of fever, and presence of infectious agents in the blood, and to contribute to risk prediction for children. Materials and Methods: Pediatric patients aged 0-18 years diagnosed with solid tumors and followed up in the Pediatric Oncology Unit of Celal Bayar University Medical Faculty Hospital between 2017 and 2024 were included in our study. Patient data including gender, age, diagnosis, accompanying symptoms of fever (cough, abdominal pain, frequent/painful urination, diarrhea, etc.), type of infection (clinical, microbiological, fever of unknown origin), type of clinical infection (mucositis, pneumonia, gastroenteritis, typhlitis, soft tissue infection, sinusitis, tonsillitis), duration of fever, duration of hospitalization, culture results (blood, urine, stool), respiratory viral PCR test results, antibiotics used, antifungal drugs, antiviral drugs, some laboratory parameters (total leukocyte count, neutrophil count, hemoglobin, platelet count, monocyte count, CRP), additional imaging techniques, rehospitalizations, and mortality were retrospectively analyzed. Results: A total of 43 patients with 179 episodes of febrile neutropenia were retrospectively reviewed in our study. The mean age of the patients was 9.59±5.25 years, with a gender distribution of 53.6% male and 46.4% female. The most common diagnoses observed were lymphoma (n=36, 20.1%), Ewing sarcoma (n=34, 19.0%), and rhabdomyosarcoma (n=32, 17.9%). The duration of fever and hospitalization was significantly longer in patient groups with absolute neutrophil count (ANC) ≤100, absolute monocyte count (AMC) ≤100, and absolute phagocyte count (APC) ≤100 compared to those above 100 (p-values were <0.001, <0.001, <0.001, respectively). As expected, the rate of growth in blood cultures was higher in patients with ANC, AMC, and APC below 100 compared to those above 100. Among the three groups, it was found that 45.2% (n=38) of those with APC ≤100, and 25.3% (n=24) of those with APC >100 had bacteria in their blood cultures, and it was statistically significantly higher in those with APC ≤100 (p=0.005). There was no statistically significant difference between ANC and AMC values (p: 0.343, p: 0.110, respectively). Antibiotic modification was required in 30.2% of cases. The rate of antibiotic modification or addition was statistically significantly higher in patients with APC and ANC values below 100 compared to those above 100. There was no statistically significant difference in patients with AMC values below and above 100. Conclusion: In our study, the duration of fever and hospitalization in patients followed up with febrile neutropenia was significantly longer in those with ANC, APC, and AMC ≤100. Evaluation of blood culture growth showed that the rate of growth in patients with ANC and APC values ≤100 was significantly higher than in those with values above 100. The rate of modifying or adding empirically administered antibiotics was significantly higher only in the group with APC ≤100 compared to those with APC>100. The ANC and AMC values did not have an effect on antibiotic modification. We believe that evaluating the absolute phagocyte count alongside the absolute neutrophil count in cancer patients hospitalized with infection will be beneficial in treatment management and patient discharge.