Procalcitonin serum levels in patients with stage IV non-small cell lung cancer in first line of chemotherapy

Background: For healthy people, the basal procalcitonin (PCT) serum level is lower than 0.5 ng/ml. More sensitive and specific than C reactive protein (CRP) to differ inflammation from infection and viral cause from bacterial cause, PCT is used as a biological marker for infections. Very few data are available on PCT basal level for patients suffering from Non Small Cells Lung Cancer (NSCLC) without active infection. Objective: The aim of this study is to evaluate the basal PCT level for patient suffering from metastatic NSCLC. Methods: we performed a prospective cohort study with PCT and CRP dosage on 42 patients (76% of adenocarcinoma, PS lower than 2 in 93%) hospitalized for their first chemotherapy line (without clinical, biological et radiological signs of infection) between December 2014 and february 2016. Results: The mean PCT of the 42 patients was 0.27 ng/ml (median 0.15) with a mean CRP of 62 mg/L. PCT was higher than 0.5 ng/ml for 4 patients: one with infectious signs few days after the PCT dosage, 3 with liver metastasis.When we excluded the patient with infectious signs, the mean PCT was 0.25 with a mean PCT in patients without liver metastasis of 0.17 versus 0.40 in patients with liver metastasis (p=0.001). Conclusions: Except for patients with liver metastasis, the basal PCT of patients NSCLC stage IV without any infection was lower than 0.25 ng/ml. The next step will be the evaluation of PCT in diagnosis of infectious diseases in NSCLC under chemotherapy.