A prognostic nomogram of stage IV gastroenteropancreatic neuroendocrine neoplasms establishment based on the SEER database

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are highly heterogeneous neoplasms of the gastrointestinal tract and pancreas. The objective of this study was to develop and verify a prediction nomogram for determining the overall survival rate of stage IV GEP-NENs. Data from 2139 stage IV GEP-NENs patients between 2010 and 2017 were extracted from the SEER database. Concordance index (C-index), calibration curve analysis, receiver operating curve (ROC) analysis, and decision curve analysis (DCA) were used to evaluate and validate the predictive performance of the nomogram. The difference in survival rates between the low-risk and high-risk groups was analyzed using the Kaplan-Meier method. Ten risk factors were integrated into the prognostic nomogram. The C-index (0.7961 in the training set and 0.801 in the validating set) and calibration curve analysis exhibited an excellent consistency between the two groups. The AUC value was 0.879, 0.857, and 0.839, respectively, for nomograms predicting 1-, 3-, and 5-year overall survival in the training set. In the validation set, AUC values were 0.859, 0.844, and 0.831 for nomograms predicting 1-, 3-, and 5-year overall survival. According to the DCA analysis, the nomogram offered significant clinical benefits. The scatter plot of risk score demonstrated that with the increase in risk score, the proportion of death also increased. In both training and validation sets, the Kaplan-Meier analysis displayed that patients in the high-risk group with stage IV GEP-NENs had a worse overall survival rate than patients in the low-risk group. A prognostic nomogram of stage IV GEP-NENs was established by integrating age, sex, differentiation, primary site, tumor size, surgery, chemotherapy, and bone, brain, and lung metastases. With further verification, the nomogram with favorable specificity, sensitivity, and added clinical benefit could help clinicians assess prognosis and provide treatment guidance for stage IV GEP-NENs patients.