Simple SummaryThe aim of this study was to evaluate the diagnostic effectiveness of pro-gastrin-releasing peptide (ProGRP) and chromogranin A (CgA) in the diagnosis of neuroendocrine neoplasms of the lung (LNENs), (290 cases) and compared these results with controls (54 cases). The median ProGRP levels in LNEN patients were higher compared to controls (136.4 pg/mL vs. 6.5 pg/mL). The majority of the LNEN was well-differentiated tumors (262) (typical and atypical carcinoid). Based on the results ( sensitivity, specificity, and area under the curve) of ProGRP in LNENs vs. controls, we can conclude that ProGRP should be considered as an effective marker for the diagnosis of LNEN patients.AbstractThere is a lack of effective biomarkers for diagnosing lung neuroendocrine neoplasms (LNENs). A known small cell lung cancer (SCLC) biomarker is a pro-gastrin-releasing peptide (ProGRP), but not for all LNENs, especially for bronchopulmonary carcinoids. This study aimed to evaluate the diagnostic value of ProGRP and chromogranin A (CgA) in diagnosing LNENs. The ProGRP and CgA levels in 290 cases of LNENs and 54 healthy controls (HCs) were measured. The median ProGRP concentration in the group of LNEN patients was 136.4 pg/mL, higher than that of HCs at 6.5 pg/mL. Most of the LNEN cohort was well-differentiated tumors (typical and atypical carcinoids,n= 262, 91.7% of all LNENs). The sensitivity, specificity, and area under the curve (AUC) of ProGRP when distinguishing LNENs vs. HCs were 94.8%, 100%, and 0.995. CgA (AUC = 0.375) could not determine LNENs vs. HCs. Therefore, based on these results, ProGRP may be considered as an effective marker for diagnosing LNENs.