Predicting bacteraemia following chemotherapy administration in patients with hematological cancer (HC)

Abstract

19543 Background: Infections cause important morbidity and mortality in patients undergoing treatment for cancer. The type and the intensity of chemotherapy play an important role in the risk of infection which manifests itself most often as febrile neutropenia (FN) but regimen-specific risks are not well defined. Since bacteraemia is associated with increased mortality, we tried to determine predictors of it and to validate a classification of aggressiveness of a given chemotherapy regimen (CR) to be used in a risk prediction model in patients with HC. Methods: Patients older than 16 years, diagnosed with HC of any type were prospectively enrolled and followed at the “Institut Jules Bordet” and at the “Cliniques Universitaires Saint-Luc (UCL)” between 2001–2005. Out of the 266 patients, 22.9%, 43.6% and 33.5% were followed respectively during one cycle, 2 to 4 cycles and more than 4 cycles, totalizing 1053 cycles. Relevant patient’s information were collected at the beginning of the first cycle. Before each cycle, the CR score was computed, a blood examination performed and the temperature measured. Bacteraemia was defined according to IDSA criteria. FN was defined as a neutrophil count < 500/μl and fever. Generalized Estimating Equations (GEE) was used for the analysis. Results: Among 1017 evaluable cycles, 148 (14.5%) were followed by an episode of bacteraemia. Among the cycles with FN, 35.5% had bacteraemia. In the final model, adjusted for antimibrobial prophylaxis (R2=0.22), the CR score was the most important predictor of bacteraemia (OR 4.2 [95% CI, 2.3–7.6]), for patients given an aggressive regimen compared to the others. The other predictors associated with bacteraemia were: underlying disease (3.2 [1.9–5.2]), a baseline monocytopenia (<150/μL) (2.7 [1.6–4.3]), a baseline CRP >10 mg/L (2.1 [1.2–3.7]), the first cycle of patient’s treatment (0.3 [0.2–0.7]) and the administration of immunosuppressive agents (2.2 [1.2–4.0]). Conclusions: Bacteraemia was frequent in patients with HC undergoing myelosuppressive chemotherapy, especially in patients with FN. The CR plays an important role but further studies are needed to investigate yet unidentified additional risk factors. Grant given by the FNRS in Belgium (“Fonds National pour la Recherche Scientifique”) No significant financial relationships to disclose.