Objectives Patients with advanced cancer may develop bacterial infections (BI) as their general condition worsens, but general blood tests often find it difficult to distinguish them from non-bacterial infections (NBI). The present prospective study was undertaken to investigate the effectiveness of serum procalcitonin levels in distinguishing between BI and NBI in patients with advanced urological cancer.

Methods This study prospectively evaluated patients diagnosed with locally advanced or metastatic or recurrent urological cancer in our department from September 2013 to December 2019. Body temperature was measured in the axilla and the measurement results were recorded. Febrile episodes of ≥38.0°C were analysed, and written patient consent was obtained at the onset of the fever.

Results Of 75 patients enrolled in the present study, 90 febrile episodes were analysed. A total of 34 of 90 febrile episodes were regarded as BI, and the remaining 56 febrile episodes as NBI. The median procalcitonin value was significantly higher in the BI group (p=0.0015), while no significant difference was found between the two groups for white blood cell count and C reactive protein. Additionally, a white blood cell count of less than 1.0×10ˆ9/L resulted in BI in all cases. The procalcitonin receiver operating characteristic area under the curve was 0.710 (95% CI 0.586 to 0.83), excluding cases with white blood cell counts of <1.0 × 10³/μL.

Conclusions Procalcitonin is a rapid and affordable marker for differentiation between BI and NBI in patients with advanced urological cancer.