Diagnostic accuracy of procalcitonin as an early predictor of infection after radical gastrectomy for gastric cancer: A prospective bicenter cohort study

To investigate the diagnostic accuracy of procalcitonin (PCT) as an early predictor of infection following radical gastrectomy to treat gastric cancer (GC). A prospective, observational, cohort study was conducted in two high-volume tertiary centers (registered under ClinicalTrials.gov). A total of 552 consecutive adult patients undergoing radical gastrectomy for GC from June 2018 to July 2019 were included. Routine blood tests (white blood cell count (WBC); neutrophil count; the neutrophil:WBC ratio, N%) and PCT were measured on post-operative day (POD) 3 and 5. Post-operative infection was recorded based on the criteria of the Center for Disease Control. The area under the curve (AUC) summarizing receiver-operating characteristic was calculated and compared for each biomarker measured. Ninety three adverse events occurred in 70 patients (12.7%), with infections being the most common (n = 37, 6.7%). With cutoff values of 0.695 ng/mL at POD 3 and 0.515 ng/mL at POD 5, specificity and negative predictive value for infections were 0.656 and 96.3%, 0.816 and 96.1%, respectively. PCT had a better AUC than the WBC and neutrophil count to detect post-operative complications, especially infections (AUC: 0.678, 0.600, 0.592, P = 0.028 and 0.017, respectively) at POD 3, but which were comparable at POD 5. Additionally, 4 of the 8 patients with PCT levels ≥3 ng/mL on POD 5 were confirmed to have an infection. PCT is a more reliable predictor than WBC and neutrophil count to detect infections following radical gastrectomy for GC. PCT levels <0.695 ng/mL at POD 3 and < 0.515 ng/mL at POD 5 makes post-operative infections very unlikely but extreme high PCT levels should alert the surgeon to the possibility of infections.