Does the severity of neutropenia affect mortality in bacteremic cancer patients?

Concurrent bacteremia in febrile neutropenia is associated with increased mortality, but there is limited data regarding the impact of neutropenia severity on patient outcomes.

A retrospective cohort study was conducted among adults (age > 18) with hematologic or solid malignancies who developed neutropenic bacteremia and received definitive cefepime treatment for > 48 h. Those who had severe neutropenia (absolute neutrophil count [ANC] 100-500 cells/µL) or profound neutropenia (ANC < 100 cells/µL) were included in the analysis. Cox proportional hazards model was used to determine the independent predictors of 30-day mortality.

The study included 200 bacteremias with an overall mortality rate of 13.5%. There was no difference in mortality between the profound and severe neutropenia groups (11.3% vs. 20.0%; P = 0.121). After adjusting for the confounding factors, profound neutropenia was not associated with 30-day mortality (adjusted hazard ratio [aHR] 0.73; 95% CI, 0.31-1.75; P = 0.484). Major predictors of 30-day mortality were pneumonia as the infection source (aHR 3.81; 95% CI, 1.23-11.78), higher Pitt bacteremia scores (aHR 1.26 per point), and increased Charlson comorbidity index (aHR 1.27 per point). Notably, patients with solid tumors had significantly higher 14-day mortality compared to those with hematologic malignancies (16.9% vs. 7.0%; P = 0.029). A relatively longer length of stay was observed in the profound neutropenia group (P = 0.096).

In patients with neutropenic bacteremia treated with appropriate antibiotics, the severity of neutropenia is not associated with 30-day mortality. Our findings suggest that the potential risk associated with profound neutropenia may be mitigated by the appropriate antimicrobial therapy.