Abstract
BACKGROUND: To investigate the clinical implications of serum carcinoembryonic antigen (CEA), neuron specific enolase (NSE), and pro-gastrin-releasing peptide (ProGRP) in small cell esophageal carcinoma (SCEC). METHODS: Receiver operating characteristic (ROC) curves were used to determine the area under the curve (AUC), sensitivity, and specificity of serum markers for differentiating SCEC from patients with esophageal squamous carcinoma (ESCC), esophageal adenocarcinoma (EAC) and healthy subjects. RESULTS: The combination of ProGRP and NSE demonstrated significant diagnostic efficacy in distinguishing SCEC from ESCC, EAC, and healthy individuals. After treatment, serum levels of ProGRP, NSE, and CEA in SCEC patients with disease control decreased significantly compared to pre-treatment levels. Conversely, the serum levels of ProGRP and NSE in patients with disease progression after treatment were significantly increased compared to those before treatment. Compared with those in the follow-up phase, the levels of ProGRP, NSE, and CEA significantly increased after tumor progression in SCEC patients. This study further exhibited that serum levels of ProGRP above 45.15 pg/mL and NSE above 14.70 ng/mL during follow-up after first-line treatment in SCEC patients were associated with poor progression-free survival (PFS). Moreover, significant associations were observed between baseline serum concentrations of ProGRP, NSE, CEA and both PFS and cancer-specific survival (CSS) in SCEC patients. CONCLUSIONS: ProGRP and NSE have significant value in the diagnosis and differential diagnosis of SCEC, and are also associated with the clinical stage and prognosis of SCEC patients, as well as are effective indicators for evaluating therapeutic efficacy and disease recurrence.