OUTCOME EVALUATION IN THE SURGICAL TREATMENT OF GASTROENTEROPANCREATIC NEUROENDOCRINE NEOPLASMS IN PATIENTS AT VIET DUC UNIVERSITY HOSPITAL FROM 2015 TO 2020

Abstract

Neuroendocrine neoplasms (NENs) consist of a spectrum of malignancies that can arise from neuroendocrine cells throughout the body and was first described and coined the term carcinoid (or “karzinoide”) by Oberndofer in 1907. These tumors are characterized by their ability to produce peptides that cause characteristic hormonal syndromes. Most are more indolent than other epithelial malignancies; however, they can be aggressive and resistant to therapy. Approximately two-thirds of NENs occur in the Gastroenteropancreatic (GEP) system1. Neuroendocrine neoplasms (NENs), specifically GEP-NENs, comprise a broad family of rare malignancies. Though, incidence and prevalence of GEP-NENs are increasing frequently and significantly: in a US commercially insured population, from 2011-2014, incidence increased from 47.4-67.0 to 58.2-79.1 cases per million person years (PMPY), as well as prevalence increased from 50.8-77.9 to 108.9-131.2 PMPY from 2009-20142. Ethnic differences in the risk of developing a NET are also apparent, with a higher incidence in African-American than Caucasian patients 3,4; the potential genetic factors are currently unknown5. Although authors have described the incidence of GEP-NENs and the racial, sex, and primary tumor site distributions and survival durations in patients with these tumors in the United States, the Netherlands, and the United Kingdom3,6,7, much about them remains unknown. For example, the prevalence of GEP-NENs in the general population has not been well described. Furthermore, International Classification of Diseases for Oncology (ICD-O-3) classification of NETs is complex. In particular, a significant number of NETs are not classified using the ICDO-3 codes associated with carcinoid tumors (8240- 8246 and 8249)8. Clinical awareness of the protean and intermittent symptoms of NETs (eg, sweating, flushing, diarrhoea, and bronchospasm) is critical for timely diagnosis; however, the classical carcinoid syndrome is relatively uncommon. The most useful diagnostic test for GEP-NENs is measurement of plasma chromogranin A (CgA) levels. Disease extent is assessed by both anatomical imaging, and nuclear imaging with radio-labelled somatostatin analogues9. Pathological evaluation comprises tumor–node–metastasis (TNM) classification, a minimum pathological dataset, CgA and synaptophysin immunostaining, as well as mitotic count or Ki-67 index (a marker of cell proliferation) to define grading. However, these diagnostic test and imaging remain quite uncommon and difficult to approach in developing countries. Nowadays, a quite large range of modern therapies has been discovered, which is led to improve survival for all NENs over time, especially for distant-stage GEP-NENs in particular. However, resection of the primary lesion and as much metastatic disease as possible remains the standard treatment, increases the efficacy of medical therapy. Other management strategies include hepatic embolization and peptide receptor radionuclide therapy. Patients with tumours expressing somatostatin receptors should be treated with somatostatin analogues. Depending on the tumour grade, other effective agents include cytotoxins, tyrosine kinase inhibitors, and antiangiogenics10. In Vietnam, NENs definition is still quite new as well as there were already few studies establishing discussing about this method. Recently, there were still some case reports announced by Trinh Hong Son et al. discussing about this method, as well as review and update newest knowledges in diagnosis and managements of this disease11,12. Clinical trials are rare for GEP-NENs and the international, as well as national guidelines are largely based on epidemiological and pathological aspects. Creating large registries will be an important method to improve our understanding of these tumors in different regions around the world, especially in Vietnam. So that, we perform this study with two targets: 1. Describing clinical and subclinical signs in Gastroenteropancreatic neuroendocrine neoplasms patients at Viet Duc University Hospital from 2015 to 2020. 2. Evaluating outcome in surgical treatment of Gastroenteropancreatic neuroendocrine neoplasms patients at Viet Duc University Hospital from 2015 to 2020