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.

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Presenting Author:

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

Keywords: Merkel cell, skin, radiotherapy,

#4661 Comparison of preoperative chemotherapy and radio ligand therapy on prognosis after surgical resection for locally advanced or hepatic metastatic pancreatic neuroendocrine tumours

Introduction: The role of preoperative treatments in improving the rate of radical resection and survival of either locally advanced (LA) or hepatic metastatic (HM) pancreatic neuroendocrine tumours (panNETs) is unclear.

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Presenting Author:

Authors: Provinciali L, de Mestier L, Pontillo D, Guarneri G, Partelli S,

Keywords: adjuvant therapy, chemotherapy, event free survival, liver transplantation, RadioLigand Therapy,

#4625 Efficacy and safety of capecitabine-temozolomide (CAPTEM) regimen in patients with neuroendocrine neoplasms – A systematic review and experience from NETwerk, a Belgian ENETS Center of Excellence

Introduction: Current treatment guidelines remain inconclusive due to scarcity of data regarding the optimal systemic treatment for metastatic gastroenteropancreatic (GEP) neuroendocrine tumours (NET) grade 3 and aggressive GEP-NET grade 2. Similarly, for metastatic pulmonary typical (TC) and atypical carcinoids (AC), the indication for chemotherapy is unclear. Recent evidence highlights a promising role for CAPTEM, combining temozolomide (TEM) with capecitabine (CAP), showing encouraging antitumoural activity and safety profiles for these indications.

Conference:

Presenting Author: Chhajlani S

Authors: Chhajlani S, Lambrechts C, Islam O, de Weerdt C, Verbruggen L,

Keywords: capecitabine, temozolomide, CAPTEM, GEP-NET, pulmonary NEN, safety, efficacy, systematic review,

#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,

#4591 Efficacy of Trabectedin and Olaparib in homologous repair deficient neuroendocrine neoplasms – A subgroup analysis of the TOP-ART / PMO-1603 trial

Introduction: Genomic alterations resulting in homologous recombination deficiency (HRD) occur in a variety of cancers including neuroendocrine neoplasms (NEN). HRD-positive tumours are sensitive to PARP inhibitors such as olaparib. The DNA minor groove binder trabectedin leads to DNA double strand breaks and PARP activation. The combination of Trabectedin + Olaparib (TrO) may therefore have synergistic effects in HRD-positive tumours.

Conference:

Presenting Author: Apostolidis L

Authors: Apostolidis L, Ruebsam M, Teleanu M, Wagner S, Dorman K,

Keywords: Neuroendocrine Tumour, Neuroendocrine Carcinoma, targeted therapy, chemotherapy, HRD, olaparib, trabectedin, net, nec,