Background: The diagnostic sensitivity and specificity of serum Pro-gastrin-releasing peptide (ProGRP) in benign or malignant diseases remains controversial.
Methods: The clinical data of 6,948 patients who were examined for ProGRP from February 2015 to January 2017 in the Zhongshan Hospital of the XiaMen University, were collected. The clinical data of the different groups were analyzed by statistical methods.
Results: The ProGRP reference levels were 68.50 pg/mL. The percentages of abnormal ProGRP levels were 23.87%, 26.14%, 22.87%, 84.56%, 16.1%, 15.59% and 43.75% for the pneumonia, cardiovascular disease, cerebral vascular disease, renal failure, small cell lung cancer (SCLC), colorectal cancer, and prostate cancer groups, respectively. The 95th percentile of the serum ProGRP concentration levels in the renal failure group was 364.22 pg/mL. The ProGRP cutoff levels for SCLC group were 162.90 pg/mL and the area under the receiver-operating characteristic curve (AUC) was 0.940 (95% CI, 0.892 to 0.987). The parameters sensitivity, specificity, PLR (positive likelihood ratio), NLR (negative likelihood) and Kappa value for the SCLC group with the exclusion of the renal failure group were 81.10% (95% CI: 38.19% - 89.71%), 99.51% (95% CI: 99.31% - 99.66%), 167.59 (95% CI: 116.06 - 241.99), 0.19 (95% CI: 0.11 - 0.32), and 0.6830 (Sig: 0.000), respectively. In the SCLC group, significantly higher concentrations of serum ProGRP of M1 were observed compared with M0. All esophageal neoplasms with high-level ProGRP were identified as small cell neoplasms.
Conclusions: The ProGRP levels were increased in a variety of benign and malignant diseases and were considered a putative marker for SCLC with the exception of the renal failure group. It may be suggested that the high ProGRP levels originated from patients with neuroendocrine tumor.