Gastric neuroendocrine carcinoma (G-NEC) and mixed adenoneuroendocrine carcinoma (G-MANEC) are rare pathological types of gastric cancer, and there is a lack of multicenter studies comparing the prognosis and recurrence patterns of G-NEC, G-MANEC and gastric adenocarcinoma (G-AC).
Patients with resectable G-NEC and G-MANEC at 23 hospitals in China from January 2006 to December 2016 were identified. In addition, 2,785 patients with G-AC were selected as controls. Propensity score-matched analysis was used to match stage among the different pathological types, and disease-free survival (DFS), postrecurrence survival (PRS) and patterns of recurrence were examined.
We reviewed 3,689 patients: 503 of with G-NEC, 401 with G-MANEC and 2,785 with G-AC. After propensity score matching, the DFS and PRS of G-NEC and G-MANEC were significantly worse than those of G-AC (all P<0.05). Multivariable analyses revealed that G-NEC and G-MANEC (vs. G-AC) were independent risk factors for DFS and PRS (all P<0.05). Compared with G-AC patients, G-NEC and G-MANEC patients were more likely to have distant recurrence (P<0.05). On multivariate analysis, G-NEC and G-MANEC were independent predictors for distant recurrence (both P<0.001). Additionally, T3-T4 stage and lymph node metastasis were independent risk factors for distant recurrence of G-NEC and G-MANEC (both P<0.05).
G-NEC and G-MANEC have worse prognoses and are more prone to distant recurrence than G-AC. Thus, different follow-up and treatment strategies should be developed for G-NEC and G-MANEC, especially patients with tumors penetrating into the subserosa or deeper layers and with lymph node metastasis.
The authors.
Scientific and Technological Innovation Joint Capital Projects of Fujian Province.
All authors have declared no conflicts of interest.