Dynamic procalcitonin-guided antibiotic stewardship among cancer patients in the UK

Introduction. Procalcitonin has been recognized as a tool for effective antibiotic stewardship to reduce unnecessary antibiotic use; however, its effectiveness remains unknown in the oncology setting, where infections are common and antibiotics are frequently prescribed.Gap statement. The utility of procalcitonin for effective antibiotic stewardship in people with solid organ cancers is unknown.Aim. To evaluate the role of procalcitonin dynamics in solid organ cancer patients with suspected bacterial infections in predicting clinical outcomes and guiding antibiotic therapy decisions.Methodology. A single-centre evaluation was conducted at the Bristol Haematology and Oncology Centre, studying consecutive admissions of adult patients with solid organ cancer over a 3-month period. In a population in which serum procalcitonin levels were sporadically measured to guide antibiotic therapy, they were measured as standard care on admission and at 48 hours for patients admitted with a suspected bacterial infection. A threshold of 0.25 ng ml^-1 was used to distinguish between low and high procalcitonin levels. Cases that had persistently low procalcitonin levels were retrospectively analysed for the potential identification of patients who could have had their antibiotic treatment ceased 48 hours into the antibiotic course.Results. Seventy-seven cases with procalcitonin readings were recorded. Seventy (90.9%) cases received intravenous antibiotics during admission. Twenty-seven (35.1%) cases had persistently low procalcitonin, defined as <0.25 ng ml^-1 on consecutive measurements, interpreted as unlikely to have bacterial infection as suggested from previous literature. No objective microbiological evidence of bacterial infection was observed in these cases. Retrospective clinician reviews of the 27 cases showed antibiotic therapy for 16 of the 27 cases could have been stopped 48 h into the admission, equivalent to a total reduction of up to 83/778 (10.7%) antibiotic days.Conclusion. Procalcitonin could provide a helpful adjunct for clinicians to consider antibiotic stewardship and help reduce unnecessary antibiotic use in the oncology setting.