Abstract Library

#4666 Merkel cell neuroendocrine carcinoma of the skin: High response rates to short course palliative radiotherapy – Typical clinical scenarios

Introduction: Merkel cell carcinomas (MCC) are a rare, aggressive skin neuroendocrine carcinomas, with peak incidence in the elderly. MCC often presents as a firm, red/purple painless nodule with a short history of increasing size. Surgery is considered the 1st line treatment but elderly patients, in particular, have comorbidities which may preclude radical surgery requiring reconstruction. In advanced MCC, immunotherapy (IO) is 1st line systemic treatment. Chemotherapy is used 2nd line or if contraindications for IO but can be challenging in an elderly population. There may be an emerging role for PRRT due to the presence of somatostatin receptors on MCC. Radiotherapy (RT) can be used for non-surgical candidates, or those with unresectable or metastatic disease. Adjuvant post-operative irradiation (PORT) may provide additional benefit in risk reduction and improves local control.

Conference:

Presenting Author:

Authors: Saunders E, Sizer B, Collins J, Skelly R, Srinivasan G,

Keywords: Merkel cell, skin, radiotherapy,

#4662 A novel hormone based anti-SSTR anti-CD3 T-cell engager for the treatment of neuroendocrine tumours

Introduction: Somatostatin receptor 2 (SSTR2) is overexpressed in well-differentiated NETs.

Conference:

Presenting Author: Pelle E

Authors: Pelle E, Cives M, Chaoul N, d'Angelo G, Medina E,

Keywords: T-cell engager, immunotherapy, tumouroids,

#4638 Prognostic role of the kynurenine/tryptophan pathway and inflammatory cytokines in neuroendocrine tumour progression: A cross-sectional analysis

Introduction: Indoleamine-2,3-dioxygenase (IDO) converts L-tryptophan (T) to L-kynurenine (K) resulting in an immunosuppressive microenvironment.

Conference:

Presenting Author: Mancini C

Authors: Mancini C, Pecora G, Salerno G, Lionetto L, Visco V,

Keywords: Neuroendocrine Tumour, tryptophan, kynurenine, cytokines, immunotherapy, Indoleamine-2-3-dioxygenase,

#4601 Pembrolizumab combined with cisplatin or carboplatin and etoposide in treatment naïve advanced Merkel cell carcinoma (MCC): The phase II PANDORA Trial

Introduction: MCC is a rare and aggressive skin neuroendocrine tumour with high metastatic potential and mortality. Therapeutic options in metastatic/unresectable MCC are based on immunotherapy or platinum-based chemotherapy. However, a subgroup of patients (pts) has primary immunoresistance disease, so it would be important discover active upfront combinations. PANDORA trial [NCT 06086288] is an open-label, multicentre, single-arm phase II trial evaluating the activity and safety of pembrolizumab (PEM) combined with platinum-based chemotherapy as 1st line treatment in pts with metastatic, unresectable or recurrence MCC. Supported in part by a research grant from Investigator-Initiated Studies Program of MSD.

Conference:

Presenting Author: Oldani S

Authors: Oldani S, Morano F, Cingarlini S, Di Giacomo A, Borghesani M,

Keywords: Pembrolizumab, clinical trial, Merkel cell carcinoma, chemio-immunotherapy,

#4543 Single-cell transcriptomic landscape indicates the potential role of immunotherapy in metastatic pancreatic angiosarcoma

Introduction: Pancreatic angiosarcoma is a rare and highly aggressive tumour originated from lymphatic or vascular endothelial cells, with poor prognosis and few effective treatments. However, little is known about its tumour microenvironment and the mechanisms of its progression.

Conference:

Presenting Author: Yang Y

Authors: Yang Y, Chen L, Liu M, Lin X, Peng S,

Keywords: pancreatic angiosarcoma, single-cell RNA sequencing, immunotherapy, PD-L1, CD86,