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,

#4637 Non-functional retroperitoneal paraganglioma in a young patient: A case report

Introduction: Paragangliomas are neuroendocrine tumours arising in the parasympathetic nervous system, outside the adrenal gland. Retroperitoneal location is extremely rare. Non-functional paragangliomas often represent a diagnostic challenge.

Conference:

Presenting Author:

Authors: Aris H, Saidi M, Lahfa I,

Keywords: retroperitoneal paraganglioma, surgery, monitoring,

#4604 Germline predisposition to neuroendocrine tumours of the pancreas (pNEN) based on mutations in DNA repair genes – BRCA1, BRCA2, PALB2, CHEK2, MLH1, MSH2, MSH6, PMS2, EPCAM, APC, MUTYH, STK11

Introduction: Neuroendocrine tumours of the pancreas (pNEN) rank as the second most common epithelial neoplasms after pancreatic adenocarcinoma, with increasing prevalence and a mortality rate of 60%. Identifying germline mutations in DNA repair genes such as CHEK2, BRCA1/2, and MUTYH within pNEN cases may pave the way for personalised diagnostics and therapies.

Conference:

Presenting Author:

Authors: Jurecka Lubieniecka B, Ros-Mazurczyuk M, Oczko-Wojciechowska M, Cortez A, Handkiewicz-Junak D,

Keywords: pNEN, DNA repair genes,

#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,

#4590 Association of SST5TMD4 and SST5TMD5 expression with metastasis and poor prognostic markers in gastroenteropancreatic neuroendocrine tumours

Introduction: The expression of the somatostatin receptor isoform SST5TMD4 is linked to poorer prognosis in somatotropinomas, as well as in breast and thyroid cancers, and it is notably overexpressed in gastroenteropancreatic neuroendocrine tumours (GEP-NETs).

Conference:

Presenting Author: Pedraza-Arevalo S

Authors: Pedraza-Arévalo S, Díaz-Pérez J, Garcia-Carbonero R, Villabona C, Capdevila J,

Keywords: GEP-NET, somatostatin, truncated receptor, metastasis,