Utility of procalcitonin as a predictor of bloodstream infections and supportive modality requirements in critically ill cancer patients

•Procalcitonin is predictive of BSI in critically ill cancer patients.•The association of elevated PCT with BSI was stronger in neutropenic patients.•PCT was associated with need for vasopressors but not mechanical ventilation.•Although PCT predicts BSI, it should not replace clinical decision making. We evaluated the diagnostic utility of procalcitonin (PCT) in predicting bacterial bloodstream infections (BSI) in critically ill cancer patients with and without neutropenia. We also investigated the role of PCT as a prognostic marker of supportive modalities (vasopressors, invasive mechanical ventilation, and renal replacement therapy (RRT)) in the intensive care unit (ICU). We retrospectively analyzed 2200 PCT and blood cultures from adult cancer patients with suspected sepsis. Primary outcome was BSI, defined by positive blood culture, collected within 72 h of PCT collection. Median PCT values were higher in encounters with BSI (3.2 vs 0.5 ng/ml, p 2.0 ng/ml was significantly associated with greater likelihood of BSI and this effect was significantly stronger for neutropenic (OR 9.09, 95%CI: 4.39, 18.79) compared with non-neutropenic patients (OR 4.00 (95% CI: 3.13, 5.10), interaction p = 0.036). PCT > 2.0 was associated with vasopressor requirement on ICU admission (OR 1.82 (95% CI 1.31, 2.53), p 2.0 ng/ml was significantly more likely to require vasopressors and RRT in the ICU.