Objective:Quality assurance is crucial for oncological surgical treatment assessment.For rare diseases,single-quality indicators are not enough.We aim to develop a comprehensive and reproducible measurement,called the“Textbook Outcome”(TO),to assess the quality of surgical treatment and prognosis of gastric neuroendocrine carcinoma(G-NEC)patients.Methods:Data from patients with primary diagnosed G-NEC included in 24 high-volume Chinese hospitals from October 2005 to September 2018 were analyzed.TO included receiving a curative resection,≥15 lymph nodes examined,no severe postoperative complications,hospital stay≤21 d,and no hospital readmission≤30 d after discharge.Hospital variation in TO was analyzed using a case mix-adjusted funnel plot.Prognostic factors of survival and risk factors for non-Textbook Outcome(non-TO)were analyzed using Cox and logistic models,respectively.Results:TO was achieved in 56.6％of 860 G-NEC patients.TO patients had better overall survival(OS),disease-free survival(DFS),and recurrence-free survival(RFS)than non-TO patients(P＜0.05).Moreover,TO patients accounted for 60.3％of patients without recurrence.Multivariate Cox analysis revealed non-TO as an independent risk factor for OS,DFS,and RFS of G-NEC patients(P＜0.05).Increasing TO rates were associated with improved OS for G-NEC patients,but not hospital volume.Multivariate logistic regression revealed that non-lower tumors,open surgery,and＞200 mL blood loss were independent risk factors for non-TO patients(P＜0.05).Conclusions:TO is strongly associated with multicenter surgical quality and prognosis for G-NEC patients.Factors predicting non-TO are identified,which may help guide strategies to optimize G-NEC outcomes.