Defining prognostic parameters of well-differentiated gastric neuroendocrine tumors based on metastatic potential: a two-center experience


Kurtulan O., Turhan N., Gedikoglu G., Akyol A., Sokmensuer C.

ACTA GASTRO-ENTEROLOGICA BELGICA, vol.85, no.2, pp.339-345, 2022 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 85 Issue: 2
  • Publication Date: 2022
  • Doi Number: 10.51821/85.2.8601
  • Title of Journal : ACTA GASTRO-ENTEROLOGICA BELGICA
  • Page Numbers: pp.339-345
  • Keywords: gastric neuroendocrine tumors, grade, clinicopathologic classification, prognosis, CARCINOID-TUMORS, TYPE-1, EPIDEMIOLOGY, MANAGEMENT, NEOPLASIA

Abstract

Background: Gastric neuroendocrine tumors [gNETs] are heterogeneous tumors and we are still unable to predict the behavior of these tumors. We aim to define the prognostic parameters of well-differentiated gNETs based on metastatic potential and to evaluate the current classification systems. Patients and methods: We retrospectively retrieved 44 well differentiated gNET cases who underwent radical surgery between 2000-2015 at two tertiary-care centers. Results: Among the 44 well-differentiated gNET patients, 17 (38%) patients had metastatic disease to lymph nodes and/or distant sites, while 27 (62%) were confined to the stomach. Higher risk of metastasis was observed with increasing tumor size, grade, depth of invasion and with type-3 and solitary tumors. 30 (68%) patients had type-1 gNET and 14 (32%) had type-3 gNET. Majority of the type-1 cases (76,6%) were Grade 1 [G1] and type-3 cases (78,5%) were Grade 3 [G3]. Type-1 subgroup had no G3 tumor, and type-3 had no G1. Grade 2 [G2] tumors were more controversial, with metastatic and non-metastatic cases. G2 cases with a >10% Ki67 expression or type-3, had a worse prognosis. Although most of the type-1 gNETs had an indolent course, 6 of 30 (20%) patients had metastatic disease. Metastasizing type-1 gNETs were >10 mm in diameter or extended to/beyond the submucosa. Conclusion: Regarding our results, tumor type, grade, size, focality and depth of invasion are the prognostic parameters for gNETs, based on metastatic potential. Besides these parameters, a two-tiered grading system with a 10% Ki-67 proliferation index cut-off value could be considered for right treatment choice. (Acta gastroenterol. belg., 2022, 85, 339-345).