Grade Increases In Gastroenteropancreatic Neuroendocrine Tumor Metastases Compared to the Primary Tumor

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Introduction: The neuroendocrine tumor (NET) proliferation-based grading system (ENETS/WHO) has proved reliable for prognostic stratification of gastroenteropancreatic tumors (GEP). Although anecdotes have been published, no single study has evaluated whether grade changes between primary site and metastases.

Aim(s): The aim was therefore to evaluate grade changes between primary tumor and metastases.

Materials and methods: A total of 256 GEP-NETs (1993-2011) were identified from histopathology archives; 45 had tissue from the primary tumor and from local/distant metastases (28 synchronous; 8 metachronous). Grade was assigned on both primary and metastatic tumors and evaluated both as mitotic index and as proliferation index (by counting Ki-67 positive cells in 2000 neoplastic cells).

Conference: 11th Annual ENETSConcerence (2014)

Presenting Author: Grillo F

Authors: Grillo F, Brisigotti M, Albertelli M, Borra T, Mastracci L,

Keywords: neuroendocrine, grade, Ki-67,