Sequencing Choices and Real-World Clinical Management in Advanced Grade 2/3 GEP-NET Treatment: The Emerging Role of PRRT.

Abstract

The prognosis of high-grade gastroenteropancreatic neuroendocrine tumors (GEP-NETs) is highly variable and reported median overall survival remains low. There is no established standard of care for patients with higher grade 2 (G2) (Ki-67 ≥ 10% and ≤ 20%) and grade 3 (G3) (Ki-67 ≥ 20% and ≤ 55%) GEP-NETs and most of the current treatment regimens, particularly for G3 NETs, are extrapolated from lower-grade GEP-NET treatments or based on data from small retrospective studies. Robust evidence to support treatment recommendations for high-grade NETs, especially in the first-line (1L) setting, is limited and the optimal treatment sequence has not been clearly defined. This review summarizes the latest literature on sequencing of therapies, identifies patient selection considerations for utilizing peptide receptor radionuclide therapy (PRRT), and offers data-driven expert opinions and clinical practice recommendations in high-grade GEP-NETs. As authors, we recommend that all patients with well-differentiated, higher G2 and G3 NETs are evaluated with [⁶⁸Ga]Ga-DOTA-peptide positron emission tomography (PET) for baseline somatostatin receptor expression and if positive, a 1L treatment option of PRRT should be considered, especially in clinically stable patients. Somatostatin analog therapy may benefit patients with low-volume, indolent disease, and chemotherapy is usually a better fit for patients in visceral crisis, in need of urgent treatment, or with no access to [⁶⁸Ga]Ga-DOTA-peptide PET. In complex cases, a robust discussion at a multidisciplinary NET tumor board can be beneficial.