[Clinical features and prognostic factors of primary gastric neuroendocrine neoplasms]

Objective: To study the clinical characteristics and classification of gastric neuroendocrine neoplasm(NEN) and prognostic factors of mixed adenoneuroendocrine carcinoma (MANEC) and gastric neuroendocrine carcinoma(NEC). Methods: A total of 148 gastric NENs were divided into type Ⅰ, type Ⅱ and type Ⅲ based on the classification of European Neuroendocrine Tumor Society (ENETS). Kaplan-Meier test and Cox regression model were used in univariate and multivariate survival analysis in 108 cases with pathological G3 gastric NEN. Results: In this study, the percentages of type Ⅰ, type Ⅱ and type Ⅲ were 25.0%(37), 3.4%(5) and 71.6%(106) respectively. Among type Ⅰ patients, 28(75.7%) lesions were located in gastric fundus or body, 29(78.4%) had bumps. Lymph node involvement was found in 4 (10.8%) patients. Twenty-six (70.3%) patients received endoscopic treatment and 11 (29.7%) with surgery. All 5 type Ⅱ patients presented lesions in gastric fundus or body, including 4 with ulcers, who were all treated by endoscope. Three type Ⅱ patients had gastrinoma, and 2 combined with multiple endocrine neoplasmⅠ. In type Ⅲ patients, 56(52.8%) showed ulcerative lesions. The majority of patients (102, 96.2%) had a single lesion, 94(88.7%) with lymph node or other organ metastasis. In this study, no deaths were reported in gastric NEN with a pathological grade of G1 or G2. The mortality rate was 38.9%(42/108) in patients with G3 NEN. Survival analysis suggested that age, metastasis of tumor were associated with poor prognosis (P=0.041, 0.025). Conclusions: Patients with gastric NEN have heterogenous clinical presentations according to gender, age, endoscopic features, infiltration and metastasis, and pathological grade. Aging and metastasis are negative prognostic factors of G3 gastric NEN.