Clinical and biological heterogeneity of grade 2 gastroenteropancreatic neuroendocrine neoplasms (GEP NENs): Prognostic significance of the 10% Ki-67 index cutoff and implications for treatment strategies

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Introduction: Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) are a diverse group of neoplasms with varying prognoses. Grade 2 (G2) tumours, with a Ki-67 index between 3%-20%, present management challenges due to their intermediate behaviour, with evidence suggesting distinct outcomes between Ki-67 <10% and ≥10%.

Aim(s): To assess clinical and biological differences between Grade 1 (G1) and G2 GEP NENs and the prognostic relevance of a 10% Ki-67 cutoff within G2 tumours.

Materials and methods: A combined retrospective and prospective analysis was conducted on patients with G1 and G2 GEP NENs managed at IRCCS San Gerardo Hospital in Monza, Italy, from 2000 to 2024. Data on demographics, tumour characteristics, treatment, and survival were analysed across G1, G2 with Ki-67 <10%, and G2 with Ki-67 ≥10%.

Conference:

Presenting Author: Massironi S

Authors: Massironi S, Coltro L, Gallo C, Preatoni P, Dell' Anna G,

Keywords: Neuroendocrine neoplasm, Ki-67 Index, Grade 2 Neuroendocrine Tumour, Neoplasm Grading, Tumour Heterogeneity, Progression-Free Survival (PFS), Peptide Receptor Radionuclide Therapy,