Clinicopathologic Characteristics and Survival of Patients with Gastroenteropancreatic Neuroendocrine Neoplasm in a Multi-Ethnic Asian Institution

Background: Epidemiological evidence suggests there are differences in gastroenteropancreatic neuroendocrine neoplasm (GEPNEN) among population groups. We aimed to contribute to the current evidence by evaluating the clinicopathological characteristics of GEPNEN in a multi-ethnic Asian group. Materials and Methods: This was a retrospective chart review of patients diagnosed with GEPNEN at a tertiary medical institution at Singhealth Outram Campus, Singapore, between 1995 and 2015. Results: Two hundred ninety-five patients were included in the evaluation, comprising Chinese (74.6%), Malay (4.4%), Indian (9.5%) and other (11.5%) ethnic backgrounds. The median age at diagnosis was 59 years; 52.5% were males. Distribution of disease stage at diagnosis was: localised (42.4%), regional (15.3%) and distant (38.0%). The three most common primary tumour sites were located in the pancreas (38.6%), rectum (19.7%) and stomach (9.5%), which varied significantly with ethnic background and age at diagnosis. Malay patients were younger (median 42 years) at diagnosis than Chinese (60 years). Patients with an appendiceal neuroendocrine neoplasm (NEN) (48 years) were younger compared to oesophageal NEN (66 years). Disease stage correlated with primary tumour site and grade (p < 0.001). Median overall survival (OS) for all GEPNEN was 10.2 years. Age at diagnosis, disease stage and grading were prognostic factors of OS in multivariable analyses. Conclusion: Our findings correspond with other studies that focus on GEPNEN incidences in Asian countries, with the pancreas, rectum and stomach being the most common primary tumour sites. Our findings suggest racial differences in primary tumour site and age at diagnosis. Further prospective population-based registries are required to understand these epidemiological differences.