Advanced small-bowel well-differentiated neuroendocrine tumours: An international survey of practice on 3 rd -line treatment.

Background: Somatostatin analogues are an established first-line therapy for well differentiated small bowel neuroendocrine tumours (Wd-SBNETs), while and peptide receptor radionuclide therapy (PRRT) is frequently used as a second-line therapy. Adequate treatment selection of third-line treatment remains challenging due to the limited prospective data currently available on the best therapeutic sequence.
Aim: To understand current practice and rationale for decision-making by physicians in the 3 ^rd -line setting by building an online survey.
Methods: Weighted average (WA) of likelihood of usage between responders (1 very unlikely; 4 very likely) was used to reflect the relevance of factors explored.
Results: Replies from representatives of 28 centers were received (5/8/2020-21/9/2020); medical oncologist (53.6%), gastroenterologist (17.9%); United Kingdom (21.4%), Spain (17.9%), Italy (14.3%). Majority from European Neuroendocrine Tumor Society (ENETS) Centres of Excellence (57.1%), who followed ENETS guidelines (82.1%). Generally speaking, 3 ^rd -line treatment for Wd-SBNETs was: everolimus (EVE) (66.7%), PRRT (18.5%), liver embolization (LE) (7.4%) and interferon-alpha (IFN) (3.7%); chemotherapy (0%); decision was based on clinical trial data (59.3%), or personal experience (22.2%). EVE was most likely used if Ki-67 < 10% (WA 3.27/4) or age < 70 years (WA 3.23/4), in the 3 ^rd -line setting (WA 3.23/4); regardless of presence/absence of carcinoid syndrome (CS), rate of progression or extent of disease. Chemotherapy was mainly utilised only if rapid progression (within 6 mo) (WA 3.35/4), Ki-67 10%-20% (WA 2.77/4), negative somatostatin receptor imaging (WA 2.65/4) or high tumour burden (WA 2.77/4); temozolomide or streptozocin was used with capecitabine or 5-fluorouracil (5-FU) (57.7%), FOLFOX (5-FU combined with oxaliplatin) (23.1%). LE was selected if presence of CS (WA 3.24/4) or Ki-67 < 10% (WA 2.8/4), after progression to other treatments (WA 2.8/4). IFN was rarely used (WA 1.3/4).
Conclusion: Everolimus was the most frequently used therapeutic option in the third-line setting. The most important factors for decision-making included Ki-67, rate of progression, functionality and tumour burden; since this decision is based on multiple factors, it highlights the need for a multidisciplinary assessment.
Competing Interests: Conflict-of-interest statement: Dr Angela Lamarca received travel and educational support from Ipsen, Pfizer, Bayer, AAA, SirtEx, Novartis, Mylan and Delcath; speaker honoraria from Merck, Pfizer, Ipsen, Incyte and AAA; advisory honoraria from EISAI, Nutricia Ipsen, QED and Roche. Dr. Mauro Cives received travel support from Ipsen, Novartis, Pfizer and AAA; speaker honoraria from Ipsen, Novartis and AAA; advisory honoraria from AAA. Dr. Joakim Crona received educational honoraria from Novartis.
(©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.)