Epidemiology of neuroendocrine neoplasmas in Japan: based on analysis of hospital-based cancer registry data, 2009 – 2015

Purpose Neuroendocrine neoplasms are rare disease and could originate from throughout the body, however, there have been little epidemiological studies in Japan, especially the organ distribution. This study was to examine the epidemiological information of neuroendocrine neoplasms in the Japanese population using data from a hospital-based cancer registry. Methods Using data from the national database of hospital-based cancer registries, we examined the organ distribution, the stage and initial treatment of neuroendocrine neoplasms newly diagnosed and treated in designated and non-designated cancer care hospitals between 2009 and 2015. In the present study, neuroendocrine neoplasms consisted of neuroendocrine tumors and carcinoma. Results A total of 33,215 (17,485 neuroendocrine carcinomas and 15,730 neuroendocrine tumors) cases were diagnosed. The majority in neuroendocrine carcinoma occur in lung (31.1%) followed in decreasing frequency by stomach (12.9%), pancreas (7.5%), rectum (6.7%) and esophagus (5.8%). On the other hand, the half of neuroendocrine tumor originated rectum (50.9%) and followed by pancreas (13.9%), duodenum (9.0%), lung/bronchus (8.9%), and stomach (8.7%). Neuroendocrine carcinoma presented at more advanced stage and higher age than neuroendocrine tumors. Most cases of neuroendocrine tumors were treated surgically, while half of neuroendocrine carcinomas were treated with non-surgical therapy consisting of chemotherapy with or without radiotherapy. Conclusions Our results demonstrated that neuroendocrine neoplasms could originate from various organs and the site distribution was different between neuroendocrine carcinoma and tumor. The national database of hospital-based cancer registries in Japan is a valuable source for evaluating the organ distribution of the rare systemic disease.