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.

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Presenting Author:

Authors: Aris H, Saidi M, Lahfa I,

Keywords: retroperitoneal paraganglioma, surgery, monitoring,

#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,

#4574 Long-acting somatostatin analogue injections for treating gastroenteropancreatic neuroendocrine tumours (GEP-NETs) and acromegaly: BackSOM – A patient preference study

Introduction: Long-acting somatostatin analogues, lanreotide and octreotide, are indicated for first-line treatment of GEP-NETs and acromegaly. Lanreotide was approved in 2007 in Europe, and is supplied as a prefilled, ready-to-use syringe (LAN-PF). In 2021, a generic form of lanreotide was released and supplied in a syringe requiring assembly (LAN-RA). To ensure patient compliance with treatment, it is important to understand their injection experiences.

Conference:

Presenting Author: Hernando Cubero J

Authors: Rodien-Louw C, Simo-Servat A, Dubois M, Sheppard J, McDonnell M,

Keywords: gastroenteropancreatic neuroendocrine tumour, GEP-NET, acromegaly, lanreotide, LA-SSA, somatostatin, patient preference,

#4572 Steroid dosing to prevent tumour flare reaction with 177Lu-DOTATATE

Introduction: Tumour flare reactions including increased pain and small bowel obstruction (SBO) have been reported in patients with somatostatin receptor (SSTR)-positive gastroenteropancreatic neuroendocrine tumours (GEP-NETs) receiving 177Lu-DOTATATE. Retrospective reviews report tumour flare reactions in 6 to 40 percent of high-risk patients receiving 177Lu-DOTATATE and report success with using corticosteroid prophylaxis to prevent tumour flare recurrence with subsequent doses of 177Lu-DOTATATE (Strosberg, et al., 2021; Salner, et al., 2020).

Conference:

Presenting Author:

Authors: Cass A, Skotte E, Wheless M, Stockton S, Ramirez R,

Keywords: 177Lu-DOTATATE, corticosteroid prophylaxis, tumour flare,