Diagnostic value of serum ProGRP31-98 in patients with small-cell lung cancer

Objective: To explore the clinical significance of serum level of pro-gastrin-releasing peptide 31-98 (ProGRP31-98) for small-cell lung cancer (SCLC), in comparison with neuron-spectic enolase (NSE). Methods. Serum level of ProGRP31-98 and NSE was measured by ELISA respectively in 30 patients with SCLC, 30 with non-small cell lung cancer (NSCLC), 15 with benign lung diseases and 15 normal subjects, additionally, 10 SCLC patients after having treatment with chemotherapy were included. The receiver operating characteristic (ROC) curve was used to set the cut-off value and evaluate the diagnostic accuracy. Results. The serum level of ProGRP31-98 was higher in patients with SCLC than that in other groups. The SCLC patients with extensive disease had a higher value than the patients with limited disease. In SCLC patients with distant metastases, it was also higher than in those without. Increase in serum ProGRP31-98 and NSE was both seen in SCLC patients, but for the former one, the increase was of much greater compared to the normal controls. Given the cut-off value for ProGRP31-98 was 40ng·L^-1 and for NSE 8 μg·L^-1, their sensitivity of diagnosis in SCLC was 73% and 60%, respectively. The area under ROC curve of ProGRP31-98 was significantly larger than that of NSE. All patients responded to chemotherapy showed marked decrease in ProGRP31-98. Conclusion. ProGRP31-98 is a more specific and sensitive marker than NSE in the diagnosis of SCLC.