Clinicopathologic features and prognostic analysis of 240 patients with gastric neuroendocrine neoplasms

Objective: To investigate clinicopathological features and prognostic factors of gastric neuroendocrine tumors (G-NEN). Methods: Clinical and pathological data of patients with G-NEN diagnosed by pathological examination in Chinese PLA General Hospital from January 2000 to June 2018 were retrospectively analyzed in this case-control study. Patients with complicated visceral lesions, other visceral primary tumors, mental disorders and incomplete clinicopathological data were excluded. Finally, 240 hospitalized patients who met the inclusion criteria were enrolled. Physical examination information, tumor characteristics and pathological characteristics of patients were summarized. The Cox regression models were used to analyze the risk factors affecting G-NEN and the survival conditions were described by Kaplan-Meier survival curves and log-rank test. Results: In 240 patients with G-NEN, the mean age was (60.3+/-10.1) years; 181 were male (75.4%) and 59 females (24.6%); mean tumor diameter was (4.2+/-2.8) cm; 51 cases (21.2%) were neuroendocrine tumor (NET), 139 cases (57.9%) neuroendocrine carcinoma (NEC), 50 cases (20.8%) mixed neuroendocrine carcinoma (MANEC); 28 cases (11.7%) were G1 low grades, 34 cases (14.2%) G2 medium grades, and 178 cases (74.2%) G3 high grades; tumor infiltration depth T1 to T4 were 44 cases (18.3%), 27 cases (11.2%), 60 cases (25.0%) and 109 cases (45.4%) respectively; 163 cases (67.9%) developed lymphatic metastasis and 46 patients (19.2%) distant metastasis; tumor stage from stage I to stage IV were 55 cases (22.9%), 42 cases (17.5%), 94 cases (39.2%) and 53 cases (22.1%) respectively. Of the 240 G-NEN patients, 223 cases (92.9%) were followed up. The median survival time of the patients was 39.2 (95% CI: 29.1 to 47.5) months. Univariate survival analysis showed that age >/= 60 years, tumor diameter >/= 4.2 cm, tumor grade G3, lymphatic metastasis, distant metastasis, and tumor stage III-IV were risk factors for G-NEN patients. Multivariate survival analysis revealed that lymphatic metastasis (HR=1.783, 95%CI: 1.007-3.155, P=0.047) and distant metastasis (HR=2.288, 95% CI: 1.307-4.008, P=0.004) were independent risk factors of the prognosis. Further analysis of the G3 subgroup of G-NEN showed that the 5-year survival rate of NET-G3 was 76.19%, which was significantly higher than that of NEC-G3 and MANEC-G3 (15.60% and 24.73%, P=0.012). Conclusions: Most G-NEN patients are in advanced stage at diagnosis. Lymphatic metastasis and distant metastasis indicate poor prognosis. The prognosis of high proliferation NET-G3 patients is better as compared to those of NEC-G3 and MANEC-G3. This classification is worth further attention.