Background and Aims: Since 1981, Japan Pancreas Society (JPS) and National Cancer Center jointly organized nationwide registry of pancreatic tumors. Since pancreatic endocrine tumors are rare, national registry greatly helps to analyze the clinical behaviors of endocrine tumors statistically.
Patients and Methods: Online submission of detailed record with more than 350 clinicopathological parameters was integrated into a database. Since 2001, the pathological subtypes of endocrine tumors were recorded while all endocrine carcinoma was registered as one entity before 2001. Conclusive JPS staging and UICC staging were determined by the latest versions of classifications for pancreatic cancer. Survival rate was calculated with actuarial method and tested with generalized Wilcoxon method.
Results: Out of 28,646 cases experienced until the end of 2004, there are 484 cases of endocrine tumors. Of 177 cases from 2001 to 2004, there were 45 cases (25.4%) of insulinoma, 5 cases (2.8%) of gastrinoma, 7 cases (4.0%) of glucagonoma 1 case (0.6%) of Somatostatinoma, 5 cases (2.8%) of endocrine tumors associated with MEN-1 syndrome, and 100 cases (56.5%) of non-functioning islet cell tumor and 14 cases (7.9%) of other type of endocrine tumors. There were 37 (7.9%) patients with multiple tumors, 12 of whom had tumors in whole area of the pancreas. There were 137 cases with UICC Stage IV disease of whom 96 patients(70.1%) underwent reductive pancreatectomy. Most of the cases with UICC Stage III or less disease underwent pancreatectomy. The median survival time (MST) of patients with UICC Stage Ia is more than 10 years and significantly better than that of patients with UICC Stage Ib, IIa, IIb disease. There was no significant difference between the MST of patients with UICC Stage III (63.3M) and IV (45.3M) disease. Within these 24 years, the overall survival of the patients in 1990s and 2000s was significantly better than that of the patients in 1980s. However, the survival after pancreatectomy for disseminated disease is not improving during these three decades.
Discussion: For the first time, the UICC Stage was shown to be reliable in large cohort of patients with pancreatic endocrine tumors. The survival rate is far better than that of the patients with ordinary pancreatic cancer. Although debulking surgery is widely performed, development of new treatment modalities for disseminated disease is awaited.