European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for appendiceal neuroendocrine tumours (aNET)

[Clinical significance of neuroendocrine tumors : Incidence, symptoms, diagnosis, stage, and prognostic factors and their influence on disease management]

BACKGROUND

Neuroendocrine neoplasms (NEN) are heterogenous with an increasing incidence in recent years.

OBJECTIVES

Overview on incidence, symptoms, diagnostics, grading, imaging and prognostic determinants, including factors having an impact on therapeutic management.

METHODS

Review on current literature, including original articles, reviews, guidelines and expert opinions.

RESULTS

NEN are mainly located in the gastrointestinal tract and their incidence has increased in recent years, mainly due to improved diagnostics, e.g., cross-sectional imaging. Clinical characteristics include hormone excess syndromes (carcinoid syndrome). Laboratory markers such as chromogranin A are commonly used as part of routine diagnostics, followed by endoscopic and endosonographic procedures, which also allow biopsies to be obtained. Tumor spread can be determined by contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) or somatostatin receptor (SSRT)-PET/CT (positron emission tomography). Prognostic factors include Ki67 index, type, and grading. Resection with curative intent is the therapy of choice. In a metastasized setting, SSRT-directed treatment approaches are favored, while in dedifferentiated NEN, conventional chemotherapy is needed.

CONCLUSION

A broad diagnostic armamentarium can be offered to NEN patients and the improved diagnostic procedures have most likely caused a raising incidence in recent years. Among others, prognostic factors are Ki67 and NEN subtypes; these clinical determinants also have an impact on patient management.

[Current developments in the treatment of neuroendocrine tumors]

BACKGROUND

Well-differentiated neuroendocrine tumors (NET) are rare malignancies that are clinically very heterogeneous. Accordingly, their treatment is also complex and dependent on various factors. With currently available systemic therapies, the prognosis is often favorable.

OBJECTIVES

This article aims to provide an overview of current treatment strategies for NET, addressing the most important NET locations.

METHODS

The current European guidelines and further relevant literature on the treatment of NET were reviewed for this purpose.

RESULTS

The therapeutic spectrum for NET is extremely broad: For NET of the stomach/duodenum, appendix, and rectum, endoscopic or surgical resection is often sufficient, and metastatic tumors are rare. NET of the pancreas, small intestine and lung should also undergo potentially curative resection in the early stages. In the metastatic stage, locoregional treatments such as surgery and liver tumor embolization play a role. Major advances have been made in drug therapy, with somatostatin analogs (octreotide and lanreotide), an mTOR inhibitor (everolimus), and a tyrosine kinase inhibitor (sunitinib) being widely used. Peptide receptor radionuclide therapy (PRRT) is also an invaluable option. In some cases, classic chemotherapy is indicated.

CONCLUSIONS

Many effective therapies are now available for NET. It is important to select the right therapy at the right time for each patient through interdisciplinary management.

EndoBridge 2023: highlights and pearls

EndoBridge 2023 took place on October 20-22, 2023, in Antalya, Turkey. Accredited by the European Council, the 3-day scientific program of the 11th Annual Meeting of EndoBridge included state-of-the-art lectures and interactive small group discussion sessions incorporating interesting and challenging clinical cases led by globally recognized leaders in the field and was well attended by a highly diverse audience. Following its established format over the years, the program provided a comprehensive update across all aspects of endocrinology and metabolism, including topics in pituitary, thyroid, bone, and adrenal disorders, neuroendocrine tumors, diabetes mellitus, obesity, nutrition, and lipid disorders. As usual, the meeting was held in English with simultaneous translation into Russian, Arabic, and Turkish. The abstracts of clinical cases presented by the delegates during oral and poster sessions have been published in JCEM Case Reports. Herein, we provide a paper on highlights and pearls of the meeting sessions covering a wide range of subjects, from thyroid nodule stratification to secondary osteoporosis and from glycemic challenges in post-bariatric surgery to male hypogonadism. This report emphasizes the latest developments in the field, along with clinical approaches to common endocrine issues. The 12th annual meeting of EndoBridge will be held on October 17-20, 2024 in Antalya, Turkey.

Sequencing Treatments in Patients with Advanced Well-Differentiated Pancreatic Neuroendocrine Tumor (pNET): Results from a Large Multicenter Italian Cohort

Background: The optimal treatment sequencing for advanced, well-differentiated pancreatic neuroendocrine tumors (pNETs) is unknown. We performed a multicenter, retrospective study to evaluate the best treatment sequence in terms of progression-free survival to first-line (PFS1) and to second-line (PFS2), and overall survival among patients with advanced, well-differentiated pNETs. Methods: This multicenter study retrospectively analyzed the prospectively collected data of patients with sporadic well-differentiated pNETs who received at least two consecutive therapeutic lines, with evidence of radiological disease progression before change of treatment lines. Results: Among 201 patients, 40 (19.9%) had a grade 1 and 149 (74.1%) a grade 2 pNET. Primary tumor resection was performed in 98 patients (48.8%). First-line therapy was performed in 128 patients with somatostatin analogs (SSA), 35 received SSA + radioligand therapy (RLT), 21 temozolomide-based chemotherapy, and 17 SSA + targeted therapy. PFS was significantly longer in patients with grade 1 pNETs compared to those with grade 2, in patients who received primary tumor surgery, and in patients treated with RLT compared to other treatments. At multivariate analysis, the use of upfront RLT was independently associated with improved PFS compared to SSA. Second-line therapy was performed in 94 patients with SSA + targeted therapy, 35 received chemotherapy, 45 SSA + RLT, and 27 nonconventional-dose SSA or SSA switch. PFS was significantly longer in patients treated with RLT compared to other treatments. At multivariate analysis, the type of second-line therapy was independently associated with the risk for progression. OS was significantly longer in patients who received primary tumor surgery, with Ki67 < 10%, without extrahepatic disease, and in patients who received SSA-RLT sequence compared to other sequences. Conclusions: In this large, multicenter study, RLT was associated with better PFS compared to other treatments, and the SSA-RLT sequence was associated with the best survival outcomes in patients with pNETs with Ki67 < 10%. Primary tumor surgery was also associated with improved survival.

Lymph node metastases are more frequent in paediatric appendiceal NET ≥1.5 cm but without impact on outcome - Data from the German MET studies

BACKGROUND

Paediatric appendiceal neuroendocrine tumours (appNET) are very rare tumours, mostly detected incidentally by histopathological evaluation after appendectomy. Treatment recommendations are based on adult data considering high-risk NET as defined by European Neuroendocrine Tumour Society (ENETS) guidelines for completion right-sided hemicolectomy (RHC). Recent data suggest that less aggressive therapy may be justified.

PROCEDURE

Analysis of children and adolescents with appNET prospectively registered with the German Malignant Endocrine Tumour (MET) studies between 1997 and 2022.

RESULTS

By December 2022, 662 patients (64.7% females, 35.3% male) had been reported. Median age was 13.3 years [4.5-17.9], median duration of follow-up 2.2 years [0-10.9]. No distant metastases were reported. Tumour size was <1 cm in 63.5%, 1-2 cm in 33.2%, and >2 cm in 3.2% of patients. WHO grade 1 and 2 tumours were diagnosed in 76.9% and 23.1% of patients, respectively. Lymphovascular invasion and lymph node metastases were associated with tumour size ≥1.5 cm. 27.0% of patients presented with high-risk NET according to ENETS criteria. Of those, only 55.9% underwent secondary oncological right hemicolectomy. Neither distant metastases, nor recurrences or disease-related deaths occurred in patients with appendectomy only as well as in patients with completion RHC. Overall and event-free survival were both 100%.

CONCLUSIONS

Internationally harmonized consensus recommendations on treatment of children and adolescents with appendiceal NET are urgently needed to avoid completion RHC in high-risk patients.

ASO Practice Guidelines Series: Surgical Management of Gastrointestinal (Midgut) Neuroendocrine Neoplasms

Gastrointestinal midgut neuroendocrine neoplasms (NENs) are a heterogeneous group of uncommon malignancies. For well-differentiated NENs, known as neuroendocrine tumors (NETs), surgery is a cornerstone of management in localized and metastatic disease. Because of heterogeneous tumor behaviour, association with endocrine syndrome, and prognosis, the management of NETs must be individualized to all these factors in addition to the primary site. With the fast pace of advancement in the field, both for therapies and understanding of tumoral etiology and behaviour, it is important for surgical oncologists to remain updated on guidelines recommendations and suggested treatment pathways. Those guidelines provide important guidance for management of NETs but are largely based on expert opinions and interpretation of retrospective evidence. This article reviews highlights of most recent practice guidelines for midgut (gastric, duodenal, small intestinal, and appendiceal) NETs.

Appendiceal Neuroendocrine Neoplasms: an Update for 2023

PURPOSE OF REVIEW

To summarize the literature from the last 5 years on treatment of appendiceal neuroendocrine neoplasms (aNEN). Furthermore, to evaluate the prognostic significance of lymph node metastases, indications for adjuvant treatment, and challenges of the current follow-up regimen.

RECENT FINDINGS

Simple appendectomy is sufficient in tumors < 1 cm while extended surgery is indicated in tumors > 2 cm. In a multicenter study of aNENs measuring 1-2 cm, extended surgery offered no significant prognostic advantage and is now limited to incomplete tumor resection or high-grade G2 or G3 aNEN. Follow-up remains debatable, as the use of imaging and biomarkers lacks validation. While surgical procedure is well established in aNEN tumors < 1 cm and > 2 cm, the need for extended surgery in aNEN tumors 1-2 cm is questionable. Future studies should address the prognostic impact of lymph node metastases and the optimal design and duration of follow-up.