Abstract Library

#3387 High tissue expression of Flt3L is linked to higher infiltration of immune cells in patients with high-grade GEP-NEN

Introduction: The clinical management of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) remains challenging due to disease heterogeneity. We have recently shown that mRNA expression of the immunostimulatory cytokine FMS-like tyrosine kinase 3 ligand (Flt3L) in tumor tissue is a prognostic biomarker in high-grade GEP-NEN patients. However, a direct link between Flt3L expression and the presence of proinflammatory immune cells in the tumor microenvironment (TME) of GEP-NEN is still missing.

Conference:

Presenting Author: Werner W

Authors: Werner W, Detjen K, Bruneau A, Wiedenmann B, Tacke F,

Keywords: NET, Flt3L, DC, dendritic cell, biomarker, immune response, immune microenvironment,

#3386 Peptide Radio Receptor Therapy induces immune activation in patients with neuroendocrine tumors and might sensitize to immunotherapy

Introduction: Peptide Radio Receptor Therapy (PRRT) is a standard treatment in patients with neuroendocrine tumors (NET), but treatment responses are limited and novel therapy combinations are needed. Since radiation induced cell death is considered immunogenic, patients might benefit from a combination of PRRT with immunotherapies, such as immune checkpoint inhibitors (ICI).

Conference:

Presenting Author: Büttner S

Authors: Büttner S, Detjen K, Galler M, Siefert J, Wiedenmann B,

Keywords: NET, PRRT, checkpoint inhibitors, immune response, PD1, flow cytometry,

#3259 Treatment outcomes of patients with G3 neuroendocrine neoplasms

Introduction: Extrapulmonary neuroendocrine carcinomas (NEC) and neuroendocrine tumors (NET) G3 are aggressive neoplasia that are associated with a limited prognosis.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Roderburg C

Authors: Jann H, Wiedenmann B, Tacke F, Roderburg C,

Keywords: NEN G3, chemotherapy, Cisplatin, Carboplatin,

#3244 Efficacy and safety of immune checkpoint inhibitors in patients with neuroendocrine neoplasia: Report of a case series from a large tertiary centre

Introduction: Immune checkpoint inhibitors (ICI) have changed our view on how to treat cancer. Despite their approved treatment of many different cancers, efficacy of ICI in neuroendocrine neoplasia is limited and poorly understood. Established treatment options of neuroendocrine tumors (NET) and carcinomas (NEC) are based on surgery, tumor-targeted medical treatments, peptide guided radioreceptor therapy (PRRT) and locoregional therapies. However, in many patients these treatments lose efficacy over time, and novel therapies are urgently needed.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Roderburg C

Authors: Özdirik B, Jann H, Tacke F, Wiedenmann B, Roderburg C,

Keywords: checkpoint inhibitor, neuroendocrine neoplasia, PD-L1,

#3195 Peptide Radio Receptor Therapy sensitizes to immunotherapy by increasing expression of checkpoint molecules in in patients with neuroendocrine tumors

Introduction: Peptide Radio Receptor Therapy (PRRT) represents a standard treatment in patients with well-differentiated neuroendocrine tumors (NET G1/G2). Nevertheless, a lack of response is observed in 1/3 of patients after PRRT, suggesting that combination of PRRT with other therapies might increase its efficacy. The combination of PRRT with immune checkpoint inhibitors (ICI) might be promising, since radiation induced cell death can trigger antigen release and lead to activation of the immune system.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Hammerich L

Authors: Büttne S, Wiedenmann B, Amthauer H, Tacke F, Roderburg C,

Keywords: neuroendocrine tumor, checkpoint blockade, PRRT, immunotherapy, spectral flow cytometry,