The Role of Procalcitonin in Guiding Antimicrobial Therapy Duration in Cancer Patients with Sepsis or Bloodstream Infections

Background: Excessive antibiotics use leads to emergence of resistance and increase healthcare cost. Procalcitonin has been shown as an effective tool to guide antimicrobial therapy and shorten its duration in patients with respiratory tract infections and in critically ill patients. Similar studies in cancer patients are limited. We conducted this study to compare outcomes of cancer patients with an adequate PCT response according to their antimicrobial therapy duration.

 Methods: Our study includes febrile cancer patients with sepsis or bloodstream infections who have presented to the MD Anderson Cancer Center between July 2009 and July 2010. We measured PCT levels at presentation and at 4-7 days of intravenous antibiotics therapy. A procalcitonin response has been previously defined as a decrease from baseline of 80%. We included all those who had a PCT baseline level ≤ 0.25 ng/mL or who had a decrease in their PCT of 80% from baseline. We divided them into two groups: group 1 received 7 or less days of IV antibiotics and group 2 received more than 7 days of IV antibiotics. We then compared the outcomes of the 2 groups.

 Results: We screened a total of 189 cancer patients. Of those 60 had a low baseline PCT level or an adequate PCT response and received intravenous antibiotics. Twenty patients received ≤7 days of IV antibiotics and 40 patients received > 7 days. Patients' baseline characteristics including underlying disease and neutropenia were similar in the two groups. Analysis showed no significant difference in outcomes between patients receiving different durations of IV antibiotics, including microbiological eradication (85% vs 90%, p=0.62), relapse (8% vs 11%, p>0.99), deep seated infection (15% vs 15%, p>0.99) and infection-related mortality during the three months follow-up period (0% vs 5%, p>0.99).

 Conclusion: A longer duration of therapy beyond 7 days may not be necessary in cancer patients with sepsis and/or bloodstream infections who have a low baseline PCT or who respond with a substantial drop in their PCT level of ≥80%. PCT-guided therapy in the management of febrile neutropenic cancer patients is promising and may be a useful strategy to be implemented in an antimicrobial stewardship program.