Can procalcitonin distinguish infectious fever from tumor-related fever in non-neutropenic cancer patients?

BACKGROUND: Procalcitonin (PCT) has been proposed as a marker of infection and was studied in neutropenic patients. This study investigated its role in non-neutropenic febrile cancer patients (NNCPs).
METHODS: Between July 2009 and July 2010, a total of 248 NNCPs with fever were studied. PCT was measured in plasma within 24 hours of fever onset and 4 to 7 days thereafter, using a Kryptor system with a lower limit of quantitation of 0.075 ng/mL. Patients' clinical, microbiological, and radiological data were reviewed to make the diagnosis and were correlated with PCT levels.
RESULTS: This study included 30 patients with bloodstream infection (BSI), 60 with localized bacterial infection, 141 with no documented infection, and 8 with tumor-related fever. Most patients (98%) were inpatients or admitted to the hospital during the study. Patients with BSI had significantly higher PCT levels than did those with documented localized infections (P = .048) and no documented infection (P = .011). PCT levels were significantly higher in septic patients than in those without sepsis (P = .012). Patients with stage IV disease or metastasis had significantly higher baseline PCT levels than did those with early stages of cancer (P < .05). PCT levels dropped significantly in patients with bacterial infections in response to antibiotics (P < .0001).
CONCLUSIONS: Baseline PCT levels are predictive of BSI and sepsis in NNCPs. They may be predictors of metastasis and advanced cancer. Subsequent decrease in PCT levels in response to antibiotics is suggestive of bacterial infection. Larger trials are needed to confirm the results of this pilot study.