Clinical significance of urinary plasminogen and fibrinogen gamma chain as novel potential diagnostic markers for non-small-cell lung cancer

•PLG and FGG could be detected in the urine.•PLG and FGG are up-regulated in urine and tissue of NSCLC patients comparing normal controls.•PLG and FGG could serve as a promising biomarker for the diagnosis of non-small cell lung cancer. Urinary proteins could be useful as markers for the detection of non-small-cell lung cancer (NSCLC). We investigated the levels of two different proteins in urine samples from NSCLC patients and assessed their diagnostic value. Urinary plasminogen (PLG) and fibrinogen gamma chain (FGG) levels in 112 NSCLC patients and 197 controls were detected using enzyme linked immunosorbent assay (ELISA). The expression of FGG and PLG in 20 NSCLC tissues and paired adjacent non-tumour tissues were detected through immunohistochemistry. The diagnostic value of FGG and PLG for NSCLC was evaluated through a receiver operating characteristic curve (ROC). PLG and FGG were significantly elevated in NSCLC tissues vs paired adjacent non-tumour tissues (p = 0.000) and in urinary samples from NSCLC patients vs healthy controls (p = 0.000). The expression level of PLG in urinary samples was related only to the histological type (p = 0.001). Further, ROC curve analysis revealed that PLG, FGG, and their combination could distinguish NSCLC and its subtypes from healthy controls with an AUC ranging from 0.827 to 0. 947. By comparing urine samples with matching plasma CEA from NSCLC stage I-IV patients (n = 81) and healthy controls (n = 31), the combination of CEA with PLG or FGG showed that the AUC was 0.889 and 0.806, respectively, which is superior to a single biomarker alone. These two urinary proteins could serve as potential markers for the diagnosis of NSCLC.