Sepsis detection in hematologic and solid tumor malignancies using quantitative inflammatory biomarker differences in a prospective single center study

Sepsis is a life-threatening condition triggered by a dysregulated immune response to bloodstream infection. Patients with solid and hematologic malignancies are at increased risk of severe infections and the onset of sepsis. Due to the limitations of blood cultures, particularly in culture-negative sepsis, multiple serological biomarkers, such as C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), white blood cells (WBC), lymphocytes (LYM), neutrophils (NEU), and monocytes (MON), are frequently used to diagnose infections. This prospective observational study aims to evaluate the efficacy of these biomarkers in distinguishing sepsis in patients with hematologic and solid tumors. It was observed that hematologic cancer patients exhibited significantly elevated IL-6, PCT, and MON levels, indicating their strong potential for sepsis detection. However, this difference was not statistically significant in patients with solid cancers and sepsis. Specifically, patients with blood cancer at the onset of sepsis have elevated levels of IL-6, PCT and MON, with AUCs exceeding 0.75, indicating strong predictive value. In contrast, patients with solid tumors had a moderate but not statistically significant increase in PCT (AUC = 0.693). Biomarker combinations enhanced the diagnostic power for hematologic cancers, but their performance in solid tumors remained limited. The findings underscore the need for cancer-specific sepsis diagnostic approaches, with a particular focus on the unique immune dynamics of hematologic versus solid tumors.