Objective: Serial procalcitonin (PCT) monitoring has been adopted to supplement clinical judgement and help guide antibiotic therapy as part of antimicrobial stewardship programs. PCT levels peak 24 to 48 h after infection onset and decline with infection resolution. We explored the role of PCT as an infection biomarker for guiding antibiotic therapy in cancer patients hospitalized for febrile neutropenia. Design: Prospective randomized study. Methods: Patients were enrolled between October 2021 and August 2023 and received empiric intravenous broad-spectrum antibiotics (IVBSA) for at least 48 h. PCT was measured at baseline and 48–72 h after IVBSA initiation. PCT drop 48–72 h after IVBSA initiation was defined as a reduction of 30% from baseline or a PCT level < 0.25 ng/mL. De-escalation was defined as a switch from IVBSA to oral or simplified once-daily IV therapy. Results: Of the 89 patients with available PCT levels, 53 (60%) had a PCT drop, most of whom (79%) underwent IVBSA de-escalation. Compared with patients without a PCT drop, patients with a PCT drop had a higher de-escalation rate at 72 h (71% vs. 45%; p = 0.003) and a shorter median antibiotic duration (55 h vs. 98 h; p = 0.004). Patients with bacteremia had a significantly higher median PCT level than those without bacteremia (2.35 ng/mL vs. 0.370 ng/mL, p = 0.013). Conclusions: In patients with cancer and febrile neutropenia, a PCT drop was associated with earlier therapy de-escalation and shorter antibiotic duration. PCT monitoring may be useful in antimicrobial stewardship initiatives in this patient population. Clinical trials identifier: NCT04983901.

Background: Invasive aspergillosis (IA) is a life-threatening fungal infection that primarily affects immunocompromised individuals and has high morbidity and mortality rates, necessitating timely diagnosis and treatment. This study aimed to evaluate the prognostic utility of serum and bronchoalveolar lavage (BAL) fluid galactomannan levels, as well as galactomannan kinetics, in patients with IA. Methods: We retrospectively reviewed the medical records of patients who were diagnosed with proven or probable IA from March 2016 to April 2024 at a tertiary cancer center. The collected data included patient characteristics, baseline and peak galactomannan levels in serum and BAL fluid, galactomannan trends, and clinical outcomes. Subgroup analyses were performed to assess the prognostic value of dual-source galactomannan positivity (positive serum and BAL fluid galactomannan levels). Results: Elevated baseline serum galactomannan levels independently predicted treatment non-response (p = 0.039) and 12-week all-cause mortality (p < 0.001). Peak serum and BAL fluid galactomannan levels were strongly associated with poor clinical outcomes (p < 0.01). Compared to single-source galactomannan positivity, dual-source galactomannan positivity was linked to reduced treatment response (22% vs. 43%, p = 0.01) and higher IA-attributable mortality (52% vs. 27%, p = 0.002). Patients with neutropenia had poorer outcomes compared to patients without neutropenia, but neutrophil recovery dramatically improved survival (25% vs. 69% mortality, p < 0.0001). Early galactomannan kinetics and malignancy type had limited prognostic value. Conclusions: Our findings highlight the potential role of galactomannan as a key biomarker for early prognostication for IA. The strong association between galactomannan levels and clinical outcomes suggests its utility in identifying high-risk patients who may benefit from more aggressive management. Further studies are needed to introduce a nuanced and context-specific use of galactomannan into clinical practice and assess its role as a prognostic biomarker.

Background: Invasive aspergillosis (IA) is a life-threatening fungal infection that primarily affects immunocompromised individuals and has high morbidity and mortality rates, necessitating timely diagnosis and treatment. This study aimed to evaluate the prognostic utility of serum and bronchoalveolar lavage (BAL) fluid galactomannan levels, as well as galactomannan kinetics, in patients with IA. Methods: We retrospectively reviewed the medical records of patients who were diagnosed with proven or probable IA from March 2016 to April 2024 at a tertiary cancer center. The collected data included patient characteristics, baseline and peak galactomannan levels from serum and BAL fluid, galactomannan trends, and clinical outcomes. Subgroup analyses were performed to assess the prognostic value of dual-source galactomannan positivity (positive serum and BAL galactomannan levels). Results: Elevated baseline serum galactomannan levels independently predicted treatment non-response (P = 0.039) and 12-week all-cause mortality (P < 0.001). Peak serum and BAL galactomannan levels were strongly associated with poor clinical outcomes (P < 0.01). Compared to single-source galactomannan positivity, dual-source galactomannan positivity was linked to reduced treatment response (22% vs. 42%, P = 0.009) and higher IA-attributable mortality (52% vs. 28%, P = 0.002). Patients with neutropenia had poorer outcomes compared to patients without neutropenia, but neutrophil recovery dramatically improved survival (25% vs. 69% mortality, P < 0.0001). Early galactomannan kinetics and malignancy type had limited prognostic value. Conclusion: Our findings highlight the potential role of galactomannan as a key biomarker for early prognostication for IA. The strong association between galactomannan levels and clinical outcomes suggests its utility in identifying high-risk patients who may benefit from more aggressive management. Further studies are needed to introduce a nuanced and context-specific use of galactomannan into clinical practice and assess its role as a prognostic biomarker.