Background Several anatomic staging systems are used for pancreatic neuroendocrine tumors (pNETs), but their comparative prognostic performance in a common surgical cohort remains uncertain. We compared the American Joint Committee on Cancer (AJCC) Version 9, European Neuroendocrine Tumor Society (ENETS), modified ENETS (mENETS), and modified AJCC (mAJCC) staging systems. Methods This retrospective multicenter cohort included 891 patients who underwent pNET resection between 2000 and 2023 and had an assignable stage under all 4 systems. Performance was assessed using homogeneity, monotonicity, Harrell’s concordance index (C-index), Akaike information criterion (AIC), and integrated time-dependent area under the curve (iAUC). C-index uncertainty and optimism were evaluated with 1000 bootstrap resamples. Overall survival (OS) was the primary outcome. Results All 4 systems stratified OS (all log-rank P <.001). In the final common comparable cohort, the estimated 3-, 5-, and 10-year OS rates were 91.8%, 87.7%, and 67.5%, respectively. ENETS had the highest likelihood-ratio χ² value (26.90), mENETS had the highest linear-trend χ² value (22.10), and mAJCC had the highest apparent C-index (0.681; bootstrap 95% CI, 0.616–0.742). AJCC Version 9 had the lowest AIC (1126.65) and the highest iAUC (0.652). Bootstrap-corrected C-indices were 0.666 for AJCC Version 9, 0.654 for ENETS, 0.647 for mENETS, and 0.661 for mAJCC; their CIs overlapped. The equal-weight composite ranked AJCC Version 9 first as a descriptive summary. Conclusion All 4 systems provided prognostic stratification, and no system dominated every evaluation domain. AJCC Version 9 had the most balanced descriptive profile, but the small differences do not establish clinical superiority or independently direct treatment or surveillance decisions.
