Clinicopathologic characteristics and prognosis of gastroenteropancreatic neuroendocrine neoplasms: a multicenter study in South China

Abstract

Background: Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a heterogeneous group of rare tumors. Many issues in terms of epidemiologic features, pathogenesis, and treatment of GEP-NENs are still under discussion. Our study aimed to analyze the clinicopathologic characteristics and prognosis of Chinese patients with GEP-NENs.

Methods: Complete clinicopathologic data and survival information of 1183 patients with GEP-NENs treated between 2005 and 2015 were collected from five medical centers in Guangdong Province, China. Patient survival was estimated using the Kaplan-Meier method and analyzed using the log-rank test; prognostic factors were analyzed using the Cox proportional hazards model.

Results: The most common tumor location was the rectum (37.4%), followed by the pancreas (28.1%), stomach (20.7%), small intestine (7.2%), appendix (3.4%), and colon (3.3%). After initial definitive diagnosis, 1016 (85.9%) patients underwent surgery. The 1-, 3-, and 5-year overall survival (OS) rates for the entire cohort were 87.9%, 78.5%, and 72.8%, respectively. The 3-year OS rates of patients with G1, G2, and G3 tumors were 93.1%, 82.7%, and 43.1%, respectively (P < 0.001). The 3-year OS rates of patients with stage I, II, III, and IV tumors were 96.0%, 87.3%, 64.0%, and 46.8%, respectively (P < 0.001). Patients with distant metastasis who underwent palliative surgery had a longer survival than those who did not (P = 0.003). Similar survival benefits of palliative surgery were observed in patients with neuroendocrine tumor (P = 0.031) or neuroendocrine carcinoma (P = 0.046). In multivariate analysis, age, grade, N category, M category, and surgery were found to be independent prognostic factors.

Conclusions: Patients with GEP-NENs who are women, younger than 50 years old, have smaller tumor size, have lower tumor grade, have lower T/N/M category, and who undergo surgery can have potentially longer survival time. Our data showed that surgery can improve the prognosis of GEP-NEN patients with distant metastasis. However, randomized controlled trials need to be conducted to establish the optimal criteria for selecting patients to undergo surgery.

Keywords: China; Gastroenteropancreatic neuroendocrine neoplasms; Prognosis; Surgery.

Fig. 1

Overall survival (OS) curves stratified by different variables in 1183 patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). OS curves stratified by gender (a), age (b), tumor functionality (c), tumor location (d), tumor size (e), tumor grade (f), tumor type (g), T category (h), N category (i), M category (j), TNM stage (k), and surgery (l). OS was different among subgroups stratified by all variables (all P < 0.001) except tumor functionality (P = 0.093). NET neuroendocrine tumor, NEC neuroendocrine carcinoma, MANEC mixed adenoneuroendocrine carcinoma

Fig. 2

Patients with neuroendocrine neoplasms (NENs) who underwent surgery had longer OS than those who did not. a OS curves stratified by treatment in patients with M0 category NENs. b OS curves of patients with M1 category NENs. c OS curves of patients with M1 category NETs. d OS curves of patients with M1 category NECs. In the above subgroups, OS is always significantly longer in patients who underwent surgery than in those who did not (all P < 0.05)