Results of a prospective multicenter neuroendocrine tumor registry reporting on clinicopathologic characteristics of Greek patients.

Background: The rare incidence of neuroendocrine neoplasms (NENs) has contributed to a paucity of large epidemiologic studies of patients with this condition. We investigated the occurrence and clinicopathologic features of NENs in Greece.

Methods: Between October 2010 and November 2012 we collected data on 246 newly diagnosed patients from a broad-based multi-institutional registry that comprises eight academic and hospital sites in Greece. The WHO 2010 pathologic classification and the 7th AJCC Staging system was applied in all cases.

Results: Of all patients 94 % had a sporadic and 6 % a multiple endocrine neoplasia tumor; 63.4 % were gastroenteropancreatic-(GEP)-NENs, 17.9 % Head & Neck NENs, 9.8 % NENs of Unknown Primary, 6.5 % Lung NENs and 2.4 % Pheochromocytomas. Gastric and pancreatic NENs were the most common primary sites. Poorly differentiated neuroendocrine carcinomas (NEC) were 9.3 %, all sporadic. Fifteen percent of patients were asymptomatic at presentation, 24 % had a first symptom of the disease related to endocrine syndrome and 61 % had symptoms related to locally advanced or metastatic disease. Metastatic disease was established in 25 % of tumors most frequently in the GEP NEN group. Findings are presented according to Ki-67 distribution. MRI had a higher diagnostic positive yield than Octreoscan. Somatostatin analogs, lanreotide and octreotide acetate, were prescribed at 38.5 & 61.5 % of NEN patients respectively and were found to be equally effective at providing symptomatic relief.

Conclusions: This is to our knowledge the first study of a Greek tumor registry and one of the few European Registries providing information regarding clinicopathologic characteristics and therapies in patients with neuroendocrine tumors of various origin sites, beyond GEP NENs.