Procalcitonin (PCT) as a diagnostic and prognostic marker in patients with solid tumors and febrile neutropenia

Abstract

8037 Background: Cancer patients with febrile neutropenia (FN) are currently assessed on clinical grounds only. Procalcitonin (PCT) is a pro-hormone that demonstrated significant sensitivity and specificity as a marker of severe infection in patients with hematologic malignancies and FN. This study prospectively evaluated the efficacy of baseline PCT in the detection of bacteremia and in the prediction of outcome in patients with solid tumors and FN. Methods: PCT was determined at baseline and every 48 hours in 104 patients undergoing chemotherapy that developed fever and grade 4 neutropenia. Results: Median baseline PCT values were significantly higher in patients with microbiologically documented infections (MDI) compared with patients with clinically documented infections (CDI) or fever of unknown origin (FUO) (1.30 vs. 0.24 vs. 0.21 ng/mL, P <.01). Accordingly, a cut-off value of PCT of 0.5 ng/mL was more frequently reached in patients with MDI than in those with CDI or FUO (68.7% vs. 12.5%, P <.001). Furthermore, this threshold was also associated with an increased likelihood of treatment failure (70.0% vs 14.9%, P <.001). All four septic patients and all five patients that ultimately died presented baseline PCT values 5 to 10-fold over the median. An increment of at least 50% from baseline PCT values was observed in 45.5%, 19.0% and 12.0% of patients with MDI, CDI, and FUO (P = .034). Also, an increment of at least 50% from baseline PCT values was observed in 71.4%, 18.2% and 12.5% of patients experiencing treatment failure, success with modifications, and success without modifications (P < .001). Baseline PCT had an equivalent sensitivity and specificity in the detection of severe infection and treatment failure than standard clinical risk scales. Clinical evaluation in combination with baseline PCT appeared to improve clinical risk evaluation alone. Conclusions: Baseline PCT is higher in febrile neutropenic patients with bacteremia compared with those with a CDI or FUO. PCT identifies patients with microbiological infections and those at higher risk of treatment failure, and may constitute a complementary tool in their initial assessment. No significant financial relationships to disclose.