First results of gastroentero- pancreatic neuroendocrine tumors (GEP-NET) multi-institutional registry in Latvia

Background. Recent epidemiological studies show an increasing trend in the incidence of GEP-NET [1], [2]. How-ever, the site of origin, pathological features, distribution of stage may vary in different populations.The aim of this study was to show first data from Latvian registry of GEP-NET from two University Hospitals.Materials and Methods. Patients with a histopathological diagnosis of GEP-NET treated at Riga East Clinical Univer-sity Hospital and Pauls Stradins Clinical University Hospital between 2006 and 2016 were registered in EUROCRINE, an international Endocrine Surgical Registry funded by the EU, and included in our study. Clinical, pathological features and treatment results were analyzed. Results: In total, 172 patients were included. The median age of the patients was 60 (IQR 52–70) years and 120 (69.8%) predominantly were female. The most frequent primary site was the pancreas (n = 50; 29.1%), followed by stomach (n = 46; 26.7%), small intestine (n = 35; 20.3%), appendix (n = 12; 7.0%), rectum (n = 8; 4.7%), colon (n = 8; 4.7%), caecum (n = 6; 3.5%), sigmoid colon (n = 4; 2.3%) and Ca of unknown primary site (n = 3; 1.7%). In 84.3% (n = 145) tumors were hormonally non-functional. Metastases at diagnosis were found in 51 patients (29.7%), however in Latvia we were not able to use PET-CT till 2016. The majority of patients 80.2% (n = 138) under-went an operation with curative intent. According to Ki-67 distribution, G1 tumors were 36.6% (n = 63), G2 33.1% (n = 57), G3 13.4% (n = 23), in 16.7% (n = 29) correct grading was difficult to obtain. Chemotherapy was adminis-tered in 13.4% (n = 23) and biological targeted therapy was administered only in 8.1% (n = 14) of patients. At the time of the analyses 42 deaths were documented, corresponding to 24.4% of the registry population.Conclusion. Collection and critical analysis of GEP-NET data in accordance to European level can serve as a solid background for improvement of surgical and non-surgical treatment thus influencing long term results in the future.