Systematic review of resection of primary midgut carcinoid tumour in patients with unresectable liver metastases

Surgical and Oncologic Outcomes of Primary Tumor Resection in Patients with Small Intestinal Neuroendocrine Tumors: Results from a Single-Center Series Over a 15-Year Period

BACKGROUND

The role of prophylactic primary tumor resection (PTR) in patients with small intestinal neuroendocrine tumors (SI-NETs) and unresectable liver metastases is a matter of debate.

OBJECTIVE

We aimed to evaluate outcomes in patients with SI-NETs who underwent PTR, according to the presence of metastasis and symptoms from primary.

MATERIAL AND METHODS

Data from patients who underwent PTR for SI-NETs from a single referral center (2007-2023) were prospectively collected. Patients were divided into three groups: non-metastatic (M0) and metastatic with primary tumor-related symptoms (MS) or metastatic asymptomatic (MA). Kaplan-Meier curves for overall survival (OS) and event-free survival (EFS) were generated and compared by group. Univariate and multivariable Cox regression analyses were performed to assess the significance of risk factors.

RESULTS

Of 147 patients, 53 were M0, 23 were MS, and 71 were MA. Median follow-up was 26 months. The 5- and 10-year OS estimates were 100% and 100% in M0 patients, 82 and 21% in MS patients, and 89 and 80% in MA patients, respectively (p < 0.001). Median EFS was 91 months overall and 43,126 months and not reached for the MS, MA, and M0 groups, respectively (p < 0.001). In multivariable analysis, MS (hazard ratio [HR] 3.92, 95% confidence interval [CI] 1.71-9.52), functioning tumors (HR 1.98, 95% CI 1.03-3.81), and G2 grade (HR 3.20, 95% CI 1.64-6.85) were associated with a shorter EFS.

CONCLUSIONS

In this large retrospective series, the MS group had a significantly worse OS and EFS compared with M0 and MA. This finding suggests that prophylactic PTR might benefit SI-NET patients with unresectable liver metastases, as symptom development could impair long-term prognosis after surgery.

Surgical Management of Neuroendocrine Tumor Liver Metastases

Patients with neuroendocrine tumor liver metastases (NETLMs) may develop carcinoid syndrome, carcinoid heart disease, or other symptoms from overproduction of hormones. Hepatic resection and cytoreduction is the most direct treatment of NETLMs in eligible patients, and cytoreduction improves symptoms, may reduce the sequelae of carcinoid syndrome, and extends survival. Parenchymal-sparing procedures, such as ablation and enucleation, should be considered during cytoreduction to maximize treatment of multifocal tumors while preserving healthy liver tissue. For patients with large hepatic tumor burdens, high-grade disease, or comorbidities precluding surgery, liver-directed and systemic therapies can be used to palliate symptoms and improve progression-free survival.

[Gastroenteropancreatic neuroendocrine neoplasms-Surgery in a multimodal concept]

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) are mainly found in the small intestine and pancreas. The course of the disease in patients is highly variable and depends on the degree of differentiation (G1-G3) of the neoplasm. The potential for metastasis formation of GEP-NEN is high even with good differentiation (G1). Lymph node metastases and, in many cases, liver metastases are also often found. Less common are bone metastases or peritoneal carcinomas. The treatment of these GEP-NENs is surgical, whenever possible. If an R0 resection with removal of all lymph node and liver metastases is successful, the prognosis of the patients is excellent. Patients with diffuse liver or bone metastases can no longer be cured by surgery alone. The long-term survival of these patients is nowadays possible due to the availability of drugs (e.g., somatostatin analogues, tyrosine kinase inhibitors), peptide receptor radionuclide therapy (PRRT) and liver-directed procedures, with a good quality of life.

The Clinicopathological Characteristics and Surgical Treatment of Gastrointestinal Neuroendocrine Neoplasm-A 10-Year Single-Center Experience

Background: Gastrointestinal neuroendocrine neoplasms (GI-NENs) represent a diverse group of tumors, with surgical resection being the gold standard for treatment. Materials and Methods: A retrospective analysis was conducted on 63 patients (32 women, 31 men) who underwent surgery for GI-NENs at the Department of Digestive Tract Surgery from January 2013 to June 2023. Tumors were classified by stage (localized, regionally advanced, metastatic). Results: Clinical symptoms were reported by 42 (66.7%) patients, with abdominal pain being the most common symptom, affecting 28 (44.4%) patients. The majority of tumors (44, 69.8%) originated in the midgut. The most frequently performed surgery was right hemicolectomy, carried out on 33 (52.4%) patients. Radical tumor resection was performed in 35 (55.6%) patients. Postoperative complications occurred in 12 (19%) patients, with male gender identified as an independent predictive factor for complications (p = 0.04). Non-functioning tumors were more common (33, 52.4%), and most tumors were classified as grade 1 histopathologically (49, 77.8%). Distant metastases were present in 29 (46%) patients. The overall two-year survival rate was 94.9%, with a five-year survival rate also estimated at 94.9%. Conclusions: GI-NENs are often diagnosed at advanced stages, frequently with distant or lymph node metastases, and predominantly arise in the midgut. Despite low postoperative morbidity and mortality, male gender may be a predictor of postoperative complications. Overall, the prognosis for GI-NENs is favorable, reflected in high overall survival rates.

Emerging Treatment Options for Neuroendocrine Neoplasms of Unknown Primary Origin: Current Evidence and Future Perspectives

Among neuroendocrine neoplasms (NENs), a non-negligible proportion (9-22%) is represented by sufferers of NENs of unknown primary origin (UPO), a poor prognostic group with largely unmet clinical needs. In the absence of standard therapeutic algorithms, current guidelines suggest that the treatment of UPO-NENs should be based on tumor clinical-pathological characteristics, disease burden, and patient conditions. Chemotherapy represents the backbone for the treatment of high-grade poorly differentiated UPO-NENs, usually providing deep but short-lasting responses. Conversely, the spectrum of available systemic therapy options for well-differentiated UPO-NENs may range from somatostatin analogs in indolent low-grade tumors, to peptide receptor radioligand therapy, tyrosine kinase inhibitors (TKIs), or chemotherapy for more aggressive tumors or in case of high disease burden. In recent years, molecular profiling has provided deep insights into the molecular landscape of UPO-NENs, with both diagnostic and therapeutic implications. Although preliminary, interesting activity data have been provided about upfront chemoimmunotherapy, the use of immune checkpoint inhibitors (ICIs), and the combination of ICIs plus TKIs in this setting. Here, we review the literature from the last 30 years to examine the available evidence about the treatment of UPO-NENs, with a particular focus on future perspectives, including the expanding scenario of targeted agents in this setting.

Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic Well-Differentiated Small Bowel Neuroendocrine Tumors

BACKGROUND

The benefit of primary tumor resection in distant metastatic small bowel neuroendocrine tumors (SBNETs) is controversial, with treatment-based morbidity not well-defined. We aimed to determine the impact of primary tumor resection on development of disease-specific complications in patients with metastatic well-differentiated SBNETs.

PATIENTS AND METHODS

A retrospective analysis was performed of patients diagnosed with metastatic well-differentiated jejunal/ileal SBNETs at a single tertiary care cancer center from 1980 to 2016. Outcomes were compared on the basis of treatment selected at diagnosis between patients who underwent initial medical treatment or primary tumor resection.

RESULTS

Among 180 patients, 71 underwent medical management and 109 primary tumor resection. Median follow-up was 116 months. Median event-free survival did not differ between treatment approaches (log-rank p = 0.2). In patients medically managed first, 16/71 (23%) required surgery due to obstruction, perforation, or bleeding. These same complications led to resection at presentation in 31/109 (28%) surgically treated patients. Development of an obstruction from the primary tumor was not associated with disease progression/recurrence (HR 1.14, 95% CI 0.75-1.75) with all patients recovering postoperatively. Ongoing tumor progression requiring secondary laparotomy was associated with worse mortality (HR 7.51, 95% CI 3.3-16.9; p < 0.001) and occurred in 20/109 (18%) primary tumor resection and 7/16 (44%) initially medically treated patients.

CONCLUSIONS

Rates of event-free survival among patients with metastatic SBNETs do not differ on the basis of primary tumor management. The development of an obstruction from the primary tumor was not associated with worse outcomes with all patients salvaged. Regardless of initial treatment selected, patients with metastatic SBNET should be closely followed for early signs of primary tumor complications.

Neuroendocrine liver metastases treated using transarterial radioembolization: Identification of prognostic parameters at 68Ga-DOTATATE PET/CT

PURPOSE

To identify prognostic clinical and imaging parameters for patients with neuroendocrine liver metastases (NELMs) undergoing transarterial radioembolization (TARE).

MATERIALS AND METHODS

Forty-seven patients (27 men; mean age, 64 years) with NELMs who received TARE, along with pre-procedure liver MRI and 68Ga-DOTATATE positron emission tomography/computed tomography were included. Apparent diffusion coefficient and standardized uptake value (SUV) of three liver metastases, normal spleen and liver were measured. SUVmax or SUVmean were used for the calculation of tumor-to-organ ratios (tumor-to-spleen and tumor-to-liver ratios) using all possible combinations (including SUVmax/SUVmax, SUVmax/SUVmean, and SUVmean/SUVmean). Clinical parameters (hepatic tumor-burden, presence of extra-hepatic metastases, chromograninA, Ki-67 and bilirubin levels) were assessed. Overall survival, progression-free survival (PFS) and hepatic progression-free survival (HPFS) were calculated using Kaplan-Meier curves.

RESULTS

Median overall survival, PFS and HPFS were 49.6, 13.1 and 28.3 months, respectively. In multivariable Cox regression analysis, low Ki-67 (≤ 5%), low hepatic tumor-burden (< 10%), absence of extrahepatic metastases, and increased Tmean/Lmax ratio were significant prognostic factors of longer overall survival and HPFS. High baseline chromograninA (> 1330 ng/mL) was associated with shorter HPFS. Tmean/Lmax > 1.9 yielded a median overall survival of 69 vs. 33 months (P < 0.04), and a median HPFS of 30 vs. 19 months (P = 0.09). For PFS, high baseline SUVmax of NELMs was the single significant parameter in the multivariable model. SUVmax > 28 resulted in a median PFS of 16.9 vs. 6.5 months, respectively (P = 0.001).

CONCLUSION

High preinterventional Tmean/Lmax ratios, and high SUVmax on 68Ga-DOTATATE positron emission tomography/computed tomography seem to have prognostic value in patients with NELMs undergoing TARE, potentially aiding patient selection and management alongside conventional variables.

Surgery Improves Patient-Reported Outcomes in Patients with Intestinal and Pancreatic NETs: A Prospective Analysis

BACKGROUND

Incorporation of patient-reported outcomes such as health-related quality of life has become increasingly important in the management of chronic diseases such as cancer. In this prospective study, we examined the effect of surgical resection on quality of life in patients with intestinal and pancreatic neuroendocrine tumors (NETs).

METHODS

Thirty-two patients underwent NET resection at our institution from January 2020 to January 2022. All patients completed the 12-item short-form quality-of-life survey prior to surgery, as well as at the 3-, 6-, and 12-month postoperative time points. The presence and severity of specific carcinoid syndrome symptoms (diarrhea, flushing, and abdominal pain) were also recorded during pre- and postoperative appointments.

RESULTS

Patients experienced significant increases in both mental and physical health after surgery. Mental health scores significantly increased at all three time points (baseline: 51.33; 3-month: 53.17, p = 0.02; 6-month: 57.20, p < 0.001; 12-month: 57.34, p = 0.002), and physical health scores increased at 6 and 12 months (baseline: 50.39; 6-month: 53.16, p = 0.04; 12-month: 55.02, p = 0.003). Younger patients benefited more in terms of physical health, while older patients had more significant increases in mental health. Patients with metastatic disease, larger primary tumors, and those receiving medical therapy had lower baseline quality-of-life scores and greater improvements after surgery. The vast majority of patients in this study also experienced alleviation of carcinoid syndrome symptoms.

CONCLUSIONS

In addition to prolonging survival, resection of intestinal and pancreatic NETs leads to significantly improved patient-reported quality of life.

Prognostic differences in grading and metastatic lymph node pattern in patients with small bowel neuroendocrine tumors

PURPOSE

Neuroendocrine tumors of the small intestine (si-NET) describe a heterogenous group of neoplasms. Based on the Ki67 proliferation index si-NET are divided into G1 (Ki67 < 2%), G2 (Ki67 3-20%) and rarely G3 (Ki67 > 20%) tumors. However, few studies evaluate the impact of tumor grading on prognosis in si-NET. Moreover, si-NET can form distinct lymphatic spread patterns to the mesenteric root, aortocaval lymph nodes, and distant organs. This study aims to identify prognostic factors within the lymphatic spread patterns and grading.

METHODS

Demographic, pathological, and surgical data of 208 (90 male, 118 female) individuals with si-NETs treated at Charité University Medicine Berlin between 2010 and 2020 were analyzed retrospectively.

RESULTS

A total of 113 (54.5%) specimens were defined as G1 and 93 (44.7%) as G2 tumors. Interestingly, splitting the G2 group in two subgroups: G2 low (Ki67 3-9%) and G2 high (Ki67 10-20%), displayed significant differences in overall survival (OS) (p = 0.008) and progression free survival (PFS) (p = 0.004) between these subgroups. Remission after surgery was less often achieved in patients with higher Ki67 index (> 10%). Lymph node metastases (N +) were present in 174 (83.6%) patients. Patients with isolated locoregional disease showed better PFS and OS in comparison to patients with additional aortocaval and distant lymph node metastases.

CONCLUSION

Lymphatic spread pattern influences patient outcome. In G2 tumors, low and high grading shows heterogenous outcome in OS and PFS. Differentiation within this group might impact follow-up, adjuvant treatment, and surgical strategy.

Small bowel neuroendocrine tumours - casting the net wide

PURPOSE OF REVIEW

Our aim is to provide an overview of small bowel neuroendocrine tumours (NETs), clinical presentation, diagnosis algorithm and management options. We also highlight the latest evidence on management and suggest areas for future research.

RECENT FINDINGS

Dodecanetetraacetic acid (DOTATATE) scan can detect NETs with an improved sensitivity than when compared with an Octreotide scan. It is complimentary to small bowel endoscopy that provides mucosal views and allows the delineation of small lesions undetectable on imaging. Surgical resection is the best management modality even in metastatic disease. Prognosis can be improved with the administration of somatostatin analogues and Evarolimus as second-line therapies.

SUMMARY

NETs are heterogenous tumours affecting most commonly the distal small bowel as single or multiple lesions. Their secretary behaviour can lead to symptoms, most commonly diarrhoea and weight loss. Metastases to the liver are associated with carcinoid syndrome.

Lower gastrointestinal bleeding as an uncommon form of presentation in a small intestine neuroendocrine tumor

Neuroendocrine tumors (NETs) are rare, with an annual incidence of 10/100,000 inhabitants, with an increase in incidence in the last 30 years that probably is due to an improvement in diagnostic techniques 1. However, NETs the second neoplasia most prevalent advanced disease of the gastrointestinal tract due to its high survival. It´s way of presentation is usually with vague symptoms and often without an incidental diagnosis from the use of imaging techniques. A correct differential diagnosis will allow us its early diagnosis and its treatment. We present the case of a patient diagnosed with NET whose symptoms of presentation was lower gastrointestinal bleeding with a negative endoscopic study.

Defining a New Classification System for the Surgical Management of Neuroendocrine Tumor Liver Metastases

Although rarely curative, hepatic cytoreduction of neuroendocrine tumor liver metastases (NETLM) is associated with improved symptom control and prolonged survival. Preoperative 68Ga DOTATATE and gadoxetic acid-enhanced liver MRI can improve characterization of hepatic disease extent to improve surgical clearance, and resection of the primary tumor is associated with improved survival regardless of whether the liver metastases are treated. As parenchymal-sparing surgical techniques and the lowering of the debulking threshold have expanded the numbers of eligible NETLM patients for hepatic cytoreduction, we propose a new classification system to help guide surgical management. A multimodal approach that includes surgery, liver-directed therapies, and systemic therapies has improved outcomes and increased longevity for patients with well-differentiated metastatic NET.

Effectiveness and Prognostic Factors of Everolimus in Patients with Pancreatic Neuroendocrine Neoplasms

Objective The effectiveness of everolimus for the management of pancreatic neuroendocrine neoplasms (PNENs), including the G3/NEC types, remains unclear. We therefore investigated the effectiveness of the drug for the management of PNENs. Methods We analyzed the progression-free survival (PFS) and overall survival (OS) associated with everolimus and factors influencing the PFS and OS. Results One hundred patients were evaluated. The PFS associated with the G1/G2 types tended to be significantly longer than that associated with the G3/NEC types [hazard ratio (HR), 0.45; p=0.005]. A multivariate analysis showed that the significant factors influencing the PFS were age (<65 years old; HR, 0.44; p=0.002), grade (G1/G2; HR, 0.42; p=0.006), everolimus treatment line (≤2nd; HR, 0.55; p=0.031), and presence of treatment with metformin (yes; HR, 0.29; p=0.044). The median OS was 63.8 months. In the multivariate analysis, the significant factors influencing the OS were grade (G1/G2; HR, 0.21; p<0.001), volume of liver metastasis (≤25%; HR, 0.27; p<0.001), everolimus treatment line (≤2nd; HR, 0.27; p<0.001), and presence of primary tumor resection (yes; HR, 0.33; p=0.005). Conclusion The effectiveness of everolimus in the management of G3/NEC types and prognoses tended to be poorer than those associated with the G1/G2 types. Everolimus combined with metformin and early-line treatment with everolimus may be effective for managing advanced PNENs.

Survival of patients with small bowel neuroendocrine neoplasms in Auckland, Aotearoa New Zealand

Background

Small intestinal Neuroendocrine Neoplasms (SI‐NENs) are the most common primary malignancy of the small bowel. The aim of this study is to define the survival of patients with an SI‐NEN in Auckland, Aotearoa New Zealand (AoNZ).

Methods

A retrospective study of all patients diagnosed with a jejunal or ileal SI‐NEN in the Auckland region between 2000 and 2012 was performed. The New Zealand NETwork! Registry was searched to identify the study cohort. Retrospective data collection was performed to collect stage, survival and follow up data.

Results

One hundred and seven patients were included in the study. The mean age of patients was 62.8 years (SD 11.9). The 5 and 10‐year disease‐specific survival for all patients was 66.1% (95% CI 56.5–75.7%) and 61.8% (95% CI 51.8–71.8%), respectively. Ten‐year disease‐specific survival was 100% for stage I and II, 74% (95%CI 61.7–84.4%) for stage III and 33.9% (95%CI 16.9–35.6%) for stage IV SI‐NEN. Eleven of 40 (27.5%) patients with stage III disease had recurrence and 3 of 7 (42.8%) patients with stage IV disease had recurrence. In patients with stage IV disease, neither primary resection (HR 2.25, 95% CI 0.92–5.5) nor distant resection (HR 1.72, 95% CI 0.63–4.7) were significantly associated with a disease‐specific or overall survival benefit.

Conclusion

This study demonstrates that stage at SI‐NEN diagnosis is associated with survival, but resection of the primary or distant metastases in patients with stage IV disease is not. There was no recurrence in patients with stage I or II disease after complete resection.

Current status of surgical management of patients with gastroenteropancreatic neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) of the gastroenteropancreatic system are rare and heterogeneous tumours, yet with increasing prevalence. The most frequent primary sites are the small intestine, rectum, pancreas, and stomach. For a localized disease, surgical resection with local lymph nodes is usually curative with good overall and disease free survival. More complex situation is the treatment of locally advanced lesions, liver metastases, and, surprisingly, small asymptomatic tumours of the rectum and pancreas. In this review, we focus on the current role of surgical management of gastroenteropancreatic NENs. We present surgical approach for the most frequent primary sites. We highlight the role of endoscopic surgery and the watch-and-wait strategy for selected cases. As liver metastases pose an important clinical challenge, we present current indications and contraindications for liver resection and a role of liver transplantation for metastatic NENs.

[Importance of surgery in distant metastatic pancreatic neuroendocrine neoplasms]

The majority of patients with pancreatic neuroendocrine neoplasms (pNEN) already present with distant metastases at diagnosis. The heterogeneity of pNEN and the broad spectrum of treatment options make adequate patient selection and an evidence-based strategy essential. In metastatic pNEN both primary resection and resection of liver metastases have been shown to improve overall survival. Surgical treatment of liver metastases can also be carried out with palliative intent, especially for symptomatic pNEN and can have a positive effect on disease-free survival and overall survival. Classical hepatectomy techniques and innovative techniques (two-stage resections, liver transplantation) are available to the surgeon. In complex growth types of liver metastases, there is increasing evidence for a combination of surgery and ablative methods. Due to a relevant risk of recurrence following liver resection, pNEN patients need to be included in multimodal treatment concepts. Current areas of interest in the treatment of metastatic pNEN are the use of adjuvant/neoadjuvant chemotherapy and surgery in G3-NEN and G3-NEC patients. The aim of this review is to give an overview on the impact of surgery in the situation of distant metastatic NEN of the pancreas.

Multimodal Management of Grade 1 and 2 Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (p-NETs) are rare tumors with a recent growing incidence. In the 2017 WHO classification, p-NETs are classified into well-differentiated (i.e., p-NETs grade 1 to 3) and poorly differentiated neuroendocrine carcinomas (i.e., p-NECs). P-NETs G1 and G2 are often non-functioning tumors, of which the prognosis depends on the metastatic status. In the localized setting, p-NETs should be surgically managed, as no benefit for adjuvant chemotherapy has been demonstrated. Parenchymal sparing resection, including both duodenum and pancreas, are safe procedures in selected patients with reduced endocrine and exocrine long-term dysfunction. When the p-NET is benign or borderline malignant, this surgical option is associated with low rates of severe postoperative morbidity and in-hospital mortality. This narrative review offers comments, tips, and tricks from reviewing the available literature on these different options in order to clarify their indications. We also sum up the overall current data on p-NETs G1 and G2 management.

A Nomogram to Predict Individual Survival of Patients with Liver-Limited Metastases from Gastroenteropancreatic Neuroendocrine Neoplasms: A US Population-Based Cohort Analysis and Chinese Multicenter Cohort Validation Study

INTRODUCTION

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) with liver metastasis encompass a wide variety of clinical conditions with various prognosis, no statistical model for predicting the prognosis of these patients has been established. We sought to establish a more elaborative and individualized nomogram to predict survival of patients with liver-limited metastatic GEP-NENs. In addition, this nomogram was validated by both the Surveillance, Epidemiology, and End Results (SEER) database and a Chinese multicenter cohort.

METHODS

Patients diagnosed with GEP-NENs with liver-limited metastasis between 2010 and 2016 were identified from the SEER database. Kaplan-Meier survival analysis was performed to analyze survival outcomes. A nomogram was established based on the independent prognostic variables identified from univariate and multivariate Cox regression analyses. The nomogram was evaluated in both an internal validation SEER dataset and an external validation dataset composed of patients from the Chinese multicenter cohort.

RESULTS

A total of 1,474 patients from the SEER database and 192 patients from the multicenter cohort were included. Age, tumor size, differentiation, primary tumor resection, and liver metastasis resection were identified as independent prognostic factors by univariate and multivariate Cox analyses and were verified by Kaplan-Meier survival analysis (all p < 0.0001). A nomogram was developed and validated by calibration curves and areas under the curve of the external validation cohort, which showed good consistency and veracity in predicting overall survival.

CONCLUSION

A nomogram was developed for the first time to predict the survival of patients with liver-limited metastases from GEP-NENs. Both internal and external validation demonstrated excellent discrimination and calibration of our nomogram. Based on this prognostic model, clinicians could develop more personalized treatment strategies and surveillance protocols.

Relevant prognostic factors in patients with stage IV small intestine neuroendocrine neoplasms

There are few, but controversial data on the prognostic role of upfront primary tumour resection and mesenteric lymph node dissection (PTR) in patients with diffuse metastatic small intestinal neuroendocrine neoplasia (SI-NEN). Therefore, the prognostic role of PTR and other factors was determined in this setting. This retrospective cohort study included patients with stage IV SI-NETs with unresectable distant metastases without clinical and radiological signs of acute bowel obstruction or ischaemia. Patients diagnosed from January 2002 to May 2020 were retrieved from a prospective SI-NEN database. Disease specific overall survival (OS) was analysed with regard to upfront PTR and a variety of other clinical (e.g., gender, age, Hedinger disease, carcinoid syndrome, diarrhoea, laboratory parameters, metastatic liver burden, extrahepatic and extra-abdominal metastasis) and pathological (e.g., grading, mesenteric gathering) parameters by uni- and multivariate analysis. A total of 138 patients (60 females, 43.5%) with a median age of 60 years, of whom 101 (73%) underwent PTR and 37 (27%) did not, were included in the analysis. Median OS was 106 (95% CI: 72.52-139.48) months in the PTR group and 52 (95% CI: 30.55-73.46) in the non-PTR group (p = 0.024), but the non-PTR group had more advanced metastatic disease (metastatic liver burden ≥50% 32.4% vs. 13.9%). There was no significant difference between groups regarding the rate of surgery for bowel complications during a median follow-up of 51 months (PTR group 10.9% and non-PTR group 16.2%, p = 0.403). Multivariate analysis revealed age < 60 years, normal C-reactive protein (CRP) at baseline, absence of diarrhoea, less than 50% of metastatic liver burden, and treatment with PRRT as independent positive prognostic factors, whereas PTR showed a strong tendency towards better OS, but level of significance was missed (p = 0.067). However, patients who underwent both, PTR and peptide radioreceptor therapy (PRRT) had the best survival compared to the rest (137 vs. 73 months, p = 0.013). PTR in combination with PRRT significantly prolongs survival in patients with stage IV SI-NEN. Prophylactic PTR does also not result in a lower reoperation rate compared to the non-PTR approach regarding bowel complications.

Effect of primary tumour resection without curative intent in patients with metastatic neuroendocrine tumours of the small intestine and right colon: meta-analysis

Background

Patients with small intestinal neuroendocrine tumours (siNETs) usually present with advanced disease. Primary tumour resection without curative intent is controversial in patients with metastatic siNETs. The aim of this meta-analysis was to investigate survival after primary tumour resection without curative intent compared with no resection in patients with metastatic siNETs.

Methods

A systematic literature search was performed, using MEDLINE® (PubMed), Embase®, Web of Science, and the Cochrane Library up to 25 February 2021. Studies were included if survival after primary tumour resection versus no resection in patients with metastatic siNETs was reported. Results were pooled in a random-effects meta-analysis, and are reported as hazard ratios (HRs) with 95 per cent confidence intervals. Sensitivity analyses were undertaken to enable comment on the impact of important confounders.

Results

After screening 3659 abstracts, 16 studies, published between 1992 and 2021, met the inclusion criteria, with a total of 9428 patients. Thirteen studies reported HRs adjusted for important confounders and were included in the meta-analysis. Median overall survival was 112 (i.q.r. 82–134) months in the primary tumour resection group compared with 60 (74–88) months in the group without resection. Five-year overall survival rates were 74 (i.q.r. 67–77) and 44 (34–45) per cent respectively. Primary tumour resection was associated with improved survival compared with no resection (HR 0.55, 95 per cent c.i. 0.47 to 0.66). This effect remained in sensitivity analyses.

Conclusion

Primary tumour resection is associated with increased survival in patients with advanced, metastatic siNETs, even after adjusting for important confounders.

Role of Resection of the Primary in Metastatic Well-Differentiated Neuroendocrine Tumors

OBJECTIVE

Resection of the primary (RP) in metastatic neuroendocrine tumor (NET) is controversial. The aim was to evaluate survival outcomes for RP in metastatic NET patients.

METHODS

Data were obtained from US hospitals at the National Cancer Database between 2004 and 2014. χ2, analysis of variance tests, univariate, and multivariate cox proportional hazards models were evaluated. Kaplan-Meier curves and log-rank tests conducted to compare the survival difference of patient characteristics.

RESULTS

A total of 2361 patients were identified. The mean age was 62.1 years (standard deviation, 13 years), male-to-female ratio 1:1; 33% were small intestine, 26.3% pancreas, and 24.4% lung; 69.6% were well-differentiated; and 42.5% underwent RP. The 5-year overall survival (OS) was significantly improved for patients who underwent RP in small intestine (5-year OS, 63.9% vs 44.2%), lung (5-year OS, 65.4% vs 20.2%), and pancreas tumors (5-year OS, 75.6% vs 30.6%). On multivariate analysis, RP (hazard ratio, 0.46; 95% confidence interval, 0.29-0.73; P < 0.001), female, year of diagnosis 2010-2014, margin, Charlson-Deyo score less than 2, and age less than 51 years, were associated with better OS.

CONCLUSIONS

Resection of the primary in metastatic well-differentiated NET is associated with improved OS compared with no RP.

Health-related quality of life and treatment effects in patients with well-differentiated gastroenteropancreatic neuroendocrine neoplasms: A systematic review and meta-analysis

Introduction

Gastroenteropancreatic neuroendocrine neoplasms (GEPNENs) are often diagnosed in an advanced stage. As the optimal sequence of therapy remains largely unclear, all treatment‐related outcomes, including health‐related quality of life (HRQoL) prospects, should be assessed according to patients' preferences.

Methods

A targeted search was performed in PubMed and EMBASE to identify studies on treatment effect and HRQoL, measured using the EORTC QLQ‐C30 tool, in patients with advanced, well‐differentiated GEPNENs. Study quality was assessed, and meta‐analyses were performed for global health status/QOL and tumour response.

Results

The search yielded 1,322 records, and 20 studies were included, examining somatostatin analogues (SSA), peptide receptor radionuclide therapies (PRRT), chemotherapy, SSA‐based combination therapies, and targeted therapies. Global HRQoL was stable, and rates for disease stabilisation were moderate to high across all treatments. Meta‐analyses for global health status/QOL after SSA treatment were not significant (mean difference: –0.3 [95% CI: −1.3 to 0.7]). The highest pooled overall tumour response rate was 33% (95% CI: 24–45%) for PRRT. The highest pooled clinical benefit rate was 94% (95% CI: 65–99%) for chemotherapy.

Conclusion

All treatments appeared beneficial for disease stabilisation while maintaining stable global health status/QOL. High‐quality HRQoL reporting was lacking. HRQoL should be a central outcome next to well‐established outcomes.

Prior Resection of the Primary Tumor Prolongs Survival After Peptide Receptor Radionuclide Therapy of Advanced Neuroendocrine Neoplasms

OBJECTIVE

The aim of the study was to compare impact on survival after resection of primary tumors (PTs) after peptide receptor radionuclide therapy (PRRT).

BACKGROUND

PRRT is a highly effective therapeutic option to treat locally advanced or metastatic neuroendocrine neoplasms (NENs).

METHODS

We retrospectively analyzed the data of 889 patients with advanced NEN (G1-G3, stage IV) treated with at least 1 cycle of PRRT. In 486 of 889 patients (55%, group 1), PT had been removed before PRRT. Group 2 constituted 403 patients (45%) with no prior PT resection. Progression-free survival (PFS) and overall survival (OS) was determined by 68Ga SSTR-PET/CT in all patients applying RECIST and EORTC.

RESULTS

Most patients had their PT in pancreas (n = 335; 38%) and small intestine (n = 284; 32%). Both groups received a mean of 4 cycles of PRRT (P = 0.835) with a mean cumulative administered radioactivity of 21.6 ± 11.7 versus 22.2 ± 11.2 GBq (P = 0.407). Median OS in group 1 was 134.0 months [confidence interval (CI): 118-147], whereas OS in group 2 was 67.0 months (CI: 60-80; hazard ratio 2.79); P < 0.001. Likewise, the median progression-free survival after first PRRT was longer in group 1 with 18.0 (CI: 15-20) months as compared to group 2 with 14.0 (CI: 15-18; hazard ratio 1.21) months; P = 0.012.

CONCLUSIONS

A previous resection of the PT before PRRT provides a significant survival benefit in patients with NENs stage IV.

How to Manage Small Intestine (Jejunal and Ileal) Neuroendocrine Neoplasms Presenting with Liver Metastases?

PURPOSE OF REVIEW

Small intestinal neuroendocrine neoplasms (siNENs) are slowly growing tumours with a low malignant potential. However, more than half of the patients present with distant metastases (stage IV) and nearly all with locoregional lymph node (LN) metastases at the time of surgery. The value of locoregional treatment is discussed controversially.

RECENT FINDINGS

In stage I to III disease, locoregional surgery was currently shown to be curative prolonging survival. In stage IV disease, surgery may prolong survival in selected patients with the chance to cure locoregional disease besides radical/debulking liver surgery. It may improve the quality of life and may prevent severe local complications resulting in a state of chronic malnutrition and severe intestinal ischaemia or bowel obstruction. Locoregional tumour resection offers the opportunity to be curative or to focus therapeutically on liver metastasis, facilitating various other therapeutic modalities. Risks and benefits of the surgical intervention need to be balanced individually.

ASO Author Reflections: Indolent Growth and Small Bowel Neuroendocrine Tumor Management

Surgical treatment is central to management of small bowel neuroendocrine tumors (SBNETs). Current controversies include whether to resect asymptomatic primary tumors in the setting of unresectable metastases, the role of minimally invasive surgery, and how best to incorporate/sequence medical treatments. Low SBNET incidence, long event-times, and variability in disease burden, surgical technique, and institutional treatment preferences remain obstacles to conducting randomized surgical trials for SBNETs. With increasing referral of these patients to high-volume centers, cooperation between experienced SBNET clinicians should allow design of high-quality randomized trials to test new treatments and answer key questions.

The Landmark Series: Management of Small Bowel Neuroendocrine Tumors

Surgical resection is the foundation for treatment of small bowel neuroendocrine tumors (SBNETs). Guidelines for surgical management of SBNETs rely on retrospective data, which suggest that primary tumor resection and cytoreduction improve symptoms, prevent future complications, and lengthen survival. In advanced NETs, improvement in progression-free survival has been reported in large, randomized, controlled trials of various medical treatments, including somatostatin analogues, targeted therapy, and peptide receptor radionuclide therapy. This review discusses important studies influencing the management of SBNETs and the limitations of current evidence regarding surgical interventions for SBNETs.

Neuroendocrine liver metastasis from the small intestine: Is surgery beneficial for survival?

BACKGROUND

Neuroendocrine neoplasia of the small intestine (siNEN) are frequently diagnosed with liver metastases. The impact of the presence of liver metastases on overall survival and the necessity of surgery for liver metastasis is discussed controversially. The aim of this study is to evaluate and compare the overall long-term survival of patients with siNENs with and without liver metastasis at initial diagnosis and the possible benefit of surgical treatment as compared to active surveillance of metastases. 123 consecutive patients with siNENs were treated between 1965 and 2016. All clinical and histological records were reevaluated including analysis of the proliferation rates in all specimens. The 1-, 5-, 10- and 20-year overall survival was estimated by Kaplan-Meier analysis for patients with and without liver metastasis and according to the type of treatment (surgical vs. surveillance) of liver metastases if present.

RESULTS

The 1-, 5-, 10- and 20-year overall survival rate was 89.0%, 68.4%, 52.8% and 31.0% in patients without and 89.5%, 69.5%, 33.2% and 3.6% in those with liver metastases. No statistically significant differences were observed comparing the two groups. Within the group of patients with liver metastases, the type of treatment (surgical vs. surveillance) was in favor of patients undergoing surgery. Multivariate analysis showed that the presence of liver metastases upon diagnosis was an individual risk factor associated with worse survival.

CONCLUSION

The presence of liver metastasis at initial diagnosis does not have a statistically significant influence on survival. Surgery for hepatic metastasis seems to show a benefit for overall survival and may be indicated especially in patients symptomatic due to high tumor burden and serotonin hypersecretion to reduce hormone activity.

Surgical Management of Neuroendocrine Tumor Liver Metastases

Patients with neuroendocrine tumor liver metastases (NETLMs) may develop carcinoid syndrome, carcinoid heart disease, or other symptoms from overproduction of hormones. Hepatic resection and cytoreduction is the most direct treatment of NETLMs in eligible patients, and cytoreduction improves symptoms, may reduce the sequelae of carcinoid syndrome, and extends survival. Parenchymal-sparing procedures, such as ablation and enucleation, should be considered during cytoreduction to maximize treatment of multifocal tumors while preserving healthy liver tissue. For patients with large hepatic tumor burdens, high-grade disease, or comorbidities precluding surgery, liver-directed and systemic therapies can be used to palliate symptoms and improve progression-free survival.

Intraindividual comparison of 18 F-FDOPA and 68 Ga-DOTATOC PET/CT detection rate for metastatic assessment in patients with ileal neuroendocrine tumours

INTRODUCTION

In patients with ileal neuroendocrine tumours (ileal NETs), head-to-head evaluation of diagnostic performances of ⁶⁸ Ga-DOTA-peptides and ¹⁸ F-fluorodihydroxyphenylalanine (¹⁸ F-FDOPA) positron emission tomography/computed tomography (PET/CT) has been performed in only few small patients' cohorts. The aim of this retrospective study was to compare ⁶⁸ Ga-DOTATOC and ¹⁸ F-FDOPA PET/CT for metastatic disease assessment in a homogeneous large series of patients with well-differentiated ileal NETs.

METHODS

All patients with ileal NETs who underwent both ¹⁸ F-FDOPA and ⁶⁸ Ga-DOTATOC PET/CT within a 3-month period and no therapeutic change between the two studies were retrospectively included. The detection rates of both modalities were calculated using per-patient, per-region and per-lesion analyses.

RESULTS

Forty one patients with ileal NETs were evaluated. ¹⁸ F-FDOPA and ⁶⁸ Ga-DOTATOC showed similar detection rates according to per-patient (97% for both) and per-region analyses (94% for ¹⁸ F-FDOPA vs 88% for ⁶⁸ Ga-DOTATOC, P = .35). For a total of 605 positive lesions, 458 (76%) were detected by both modalities, 122 (20%) exclusively by ¹⁸ F-FDOPA PET/CT, and 25 (4%) by ⁶⁸ Ga-DOTATOC PET/CT only. In a per-lesion analysis, ¹⁸ F-FDOPA PET/CT performed better than ⁶⁸ Ga-DOTATOC PET/CT (overall detection rates of 96% vs 80%; P < .001). ¹⁸ F-FDOPA PET/CT detected significantly more metastases than ⁶⁸ Ga-DOTATOC PET/CT in the liver, peritoneum, abdominal and supra-diaphragmatic lymph nodes.

CONCLUSION

¹⁸ F-FDOPA PET/CT seems not inferior than ⁶⁸ Ga-DOTATOC PET/CT for the delineation of metastatic spread of ileal NETs. Therefore, according to local expertise and technical availability, ¹⁸ F-FDOPA should be considered as a valid clinical diagnostic option for exhaustive metastatic assessment in patients with ileal NETs. Obviously, ⁶⁸ Ga-DOTATOC PET/CT remains mandatory for PRRT assessment. Further comparative studies are needed to determine the optimal approach in various clinical scenarios such as preoperative staging and primary tumour detection.

Comparative safety review of the current therapies for gastroenteropancreatic neuroendocrine tumors

Introduction: Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of neoplasms, whose management requires complex and individualized clinical decisions. Over the last decades the advent of novel medications and advanced diagnostic and therapeutic modalities, alongside our deeper understanding of the disease, revolutionized the landscape of their management, significantly improving both prognosis and quality of life of patients.Area covered: Treatment-related adverse events and safety concerns as demonstrated in clinical trials, as well as in real-world clinical practice.Expert opinion: The only true curative option for NENs remains surgery, whereas high-grade advanced neuroendocrine carcinomas should be primarily managed with platinum-based chemotherapy. For the remaining cases, that comprise the vast majority, the current armamentarium includes somatostatin analogs, interferon, telotristat ethyl, molecular targeted therapies, chemotherapy, peptide receptor radionuclide therapy, and locoregional treatment. The use of the aforementioned therapeutic options is associated with several and not uncommonly severe treatment-related adverse events. However, the benefits offered inclusive of improved prognosis, amelioration of symptoms, and better quality of life amidst others, by far outweighs any adverse event.

Surgical Principles in the Management of Small Bowel Neuroendocrine Tumors

OPINION STATEMENT

Small bowel neuroendocrine tumors (SB NETs) are increasing in frequency and becoming more common in surgical practice. It is often difficult to make the diagnosis of a SB NET at an early stage, as the primary tumor tends to be small and patients are asymptomatic until there is regional or distant metastasis, when they develop abdominal pain, partial obstruction, or bleeding and/or develop carcinoid syndrome. Despite this advanced presentation at the time of diagnosis, patients with metastatic SB NETs, as compared to other gastrointestinal malignancies, have favorable survival, which can be improved by appropriate surgical interventions. With the lack of randomized studies, there is reasonable controversy surrounding the optimal management of patients with SB NETs. As such, treatment of these patients is driven primarily by physician experience and available data based predominantly on retrospective studies. Based on this, current recommendations advocate for patients with SB NETs (localized or metastatic) to be managed at experienced centers by a multidisciplinary team. Eligible patients should undergo surgical resection of primary and regional disease as outlined in this article. Additionally, patients with metastatic disease should be evaluated on a case by case basis to evaluate surgical options that may mitigate bowel symptoms (i.e., pain, intestinal angina, obstruction) and carcinoid symptoms (flushing, diarrhea, hemodynamic instability) and prolong survival. Unlike other gastrointestinal malignancies, aggressive surgical management of these patients, even in the context of unresectable metastatic disease, can improve patients' symptoms and long-term survival. The principles outlined in this article are geared to guide appropriate management of SB NET patients with improvement in quality of life and overall survival outcomes.

Role of Primary Tumor Resection for Metastatic Small Bowel Neuroendocrine Tumors

While small bowel resection is well established as standard of care for curative-intent management of localized and loco-regional small bowel neuroendocrine tumors (SB-NETs), resection of the primary tumor in the setting of metastatic disease is debated. This review addresses the role of primary tumor resection for stage IV well-differentiated grade 1 and 2 SB-NETs. While survival benefits have been reported for primary tumor resection in the setting of metastatic disease, these studies are limited by selection bias and thus controversial. The main clinical benefits of primary tumor resection for stage IV disease involve the prevention of potentially debilitating complications associated with mesenteric fibrosis, including intestinal obstruction, mesenteric ischemia and angina, venous congestion, malabsorption, and malnutrition. Patients with metastases undergoing initial resection of the primary SB-NETs appear to have fewer episodes of care and re-intervention for loco-regional complications than those who do not undergo resection. As recommended by the NANETS and ENETS guidelines, resection of the primary tumor for stage IV SB-NETs should be strongly considered to avoid future loco-regional complications and potentially to improve survival. All patients with stage IV SB-NETs should be assessed by a surgeon experienced in the management of NETs to consider surgical therapies, including resection of the primary tumor despite metastatic disease.

[Gastroenteropancreatic neuroendocrine neoplasms-Heterogeneity, management and perspectives of treatment and research]

The term neuroendocrine neoplasms (NEN) encompasses a molecularly and biologically very heterogeneous group of tumors, which have in common their origin in neuroendocrine cells. The also very heterogeneous subgroup of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) is the best classified and investigated group. This article provides a systematic review of the current classification, diagnostics and treatment options of GEP-NEN. In order to achieve a better overview, it was consciously decided not to use an approach based on the primary localization. Instead, a thematic organization according to classification, clinical phenotype, diagnostics and treatment was chosen.

High-grade well-differentiated neuroendocrine tumour of the cecum diagnosed following incisional hernia repair: a case report

High-grade well-differentiated neuroendocrine tumour tumours (NETs) of gastrointestinal tract are rare; they can arise in any part of the digestive system and usually present in advanced stages. Low incidence and wide heterogeneity in the biological behaviour of such lesions pose a diagnostic and therapeutic challenge. Loco-regional NETs should be resected whenever feasible, potentially with a curative intent. Management of a metastatic disease is often more complex, primarily aimed at the alleviation of symptoms, prevention of further complications, and prolongation of survival. Current literature describing the optimal treatment plan for such patients is sparse and further studies are necessary to enhance our understanding of the disease. Here we present a case of high-grade well-differentiated cecal NET with an associated carcinoid syndrome that was diagnosed following the incisional hernia repair.

Primary Tumor Resection Offers Survival Benefit in Patients with Metastatic Midgut Neuroendocrine Tumors

BACKGROUND

Approximately 35% of patients with midgut neuroendocrine tumors (MNET) present with distant metastases. Although successful resection of these metastatic foci improves overall survival (OS), the role of primary tumor resection (PTR) in patients with unresectable metastatic disease is unclear. The aim of this study is to evaluate prevalence and survival impact of PTR in patients with unresectable metastatic MNET.

PATIENTS AND METHODS

A retrospective cohort study of patients with metastatic MNET was performed using the National Cancer Database (2004-2014). Demographic and clinicopathologic variables were compared between patients who did and did not undergo PTR. Survival analysis was performed using Kaplan-Meier and log-rank tests. Multivariable regression analysis was used to assess factors associated with PTR and all-cause mortality.

RESULTS

The cohort included 4076 patients; 2520 (61.8%) underwent PTR. Patients more likely to undergo PTR were younger and diagnosed earlier, underwent treatment at a nonacademic facility, lived on the West Coast or in the Central USA, and presented with smaller lower-grade small bowel primary tumors. Median OS was improved for patients who underwent PTR compared with those who did not (71 vs. 29 months, p < 0.001). On multivariable analysis, younger age, Black race, higher income, later year of diagnosis, treatment at an academic facility, private insurance, fewer comorbidities, small bowel primary, lower grade, and PTR (hazard ratio 0.63, 95% confidence interval 0.51-0.78, p < 0.001) were associated with lower mortality.

CONCLUSIONS

PTR was associated with improved OS. Further study is needed to understand how clinicians select patients for PTR.

Digestive Neuroendocrine Neoplasms (NEN): French Intergroup clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, GTE, RENATEN, TENPATH, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of digestive neuroendocrine neoplasms (NEN) published in February 2020 (www.tncd.org).

METHODS

All French medical societies involved in the management of NEN took part in this work. Recommendations were graded into four categories (A, B, C or D), according to the level of evidence found in the literature until May 2019.

RESULTS

The management of NEN is challenging because of their heterogeneity and the increasing complexity of diagnostic and therapeutic procedures. Pathological analysis is required for their diagnostic and prognostic characterization, which mainly relies on differentiation, grade and stage. The two main emergency situations are functioning syndromes and poorly-differentiated carcinoma. Chromogranin A is the main biochemical marker of NET, although of limited clinical interest. Initial characterization relies on morphological and isotopic imaging. The treatment of localized NET relies on watchful follow-up and local or surgical resection depending on its supposed aggressiveness. Treatment options for metastatic disease include surgery, somatostatin analogues, chemotherapy, targeted therapies, organ-driven locoregional therapies and peptide-receptor radionuclide therapy. As specific predictive factors of treatment efficacy are yet to be identified and head-to-head comparisons have not or only rarely been performed, the therapeutic strategy currently depends on prognostic factors. Cumulative toxicity and the impact of treatment on quality of life must be considered since survival is relatively long in most patients with NET.

CONCLUSION

These guidelines are proposed to achieve the most beneficial therapeutic strategy in clinical practice as the therapeutic landscape of NEN is becoming ever more complex. These recommendations are permanently being reviewed.

A novel stratification of mesenteric mass involvement as a predictor of challenging mesenteric lymph node dissection by minimally invasive approach for ileal neuroendocrine tumors

BACKGROUND AND OBJECTIVES

We classified the extent of mesenteric mass (MM) involvement that predicts challenging mesenteric lymph node dissection (mLND) by minimally invasive surgery (MIS) for ileal neuroendocrine tumors (i-NETs).

METHODS

Patients who underwent surgery for i-NETs were retrospectively reviewed. MM involvement was classified as region-0: no MM; region-1: >2 cm from the origins of the ileocolic artery/vein; region-2: ≤2 cm from the origins; and region-3: more proximal superior mesenteric artery/vein. Logistic regression analysis was used to evaluate the predictive value of MM regions for gross positive mesenteric margin (mR2) and/or conversion among the MIS cohort. The open surgery cohort was used as a reference for mR2 rates.

RESULTS

Of 108 patients, 83 patients (77%) underwent MIS. MMs in region-2 and region-3 were independent risk factors for mR2 and/or conversion (odds ratio [95% confidence interval]: 4.25 [1.17-16.4] and 8.51 × 10⁷ [11.0-], respectively, against regions-0 and 1]. mR2 rates of MIS and open surgery cohorts per region did not differ significantly (4% and 7% for regions-0 and 1; 17% and 25% for region-2; and 100% and 83% for region-3).

CONCLUSIONS

The novel stratification of MM regions was predictive of challenging mLND by MIS. Surgeons should have a low threshold for conversion for MMs in proximal regions.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.

Risk factors for short recurrence-free survival after resection of pancreatic neuroendocrine tumor (PanNET) liver metastases: which patients should undergo resection?

Background: In the treatment of metastatic pancreatic neuroendocrine tumors (PanNETs), surgical resection is the first choice if curative resection is expected. However, most patients develop recurrence after resection of liver metastasis. Because one of the benefits of resection is to gain a tumor-free period for the patients, it is important to identify which patients achieve longer recurrence-free survival (RFS) by resection. In this study, the clinicopathological factors associated with RFS after resection of metastatic PanNETs in the liver were evaluated to identify the patient group that is suitable for resection.Methods: Consecutively diagnosed patients with PanNET liver metastasis with resection at our hospital from January 2000 to July 2019 were evaluated. A total of 26 metastatic PanNET patients with primary liver resections were evaluated. The median follow-up time was 48.3 months.Results: There were 18 NET recurrences of the total 26 resections, with a median RFS of 17.9 months. Independent risk factors for short RFS were a high Ki67 index (p = .009) and the number of resected tumors (p = .045). When the cut-off value for the Ki67 index was 5.0% and that for the number of resected tumors was 6, Ki67 > 5.0% tumors had shorter RFS (4.9 months vs. 38.2 months p = .006), and patients with tumors > = 7 tumors had shorter RFS (4.7 months vs. 27.5 months p = .001).Conclusions: These findings indicate that good candidates for resection of metastatic tumors of PanNETs could be patients with low Ki67 tumors and a small number of metastatic tumors.

Resection of the Primary Gastrointestinal Neuroendocrine Tumor Improves Survival With or Without Liver Treatment

OBJECTIVE

The aim of this study was to determine outcomes of primary tumor resection in metastatic neuroendocrine tumors across all primary tumor sites.

BACKGROUND

Primary tumor resection (PTR) may offer a survival benefit in metastatic gastrointestinal neuroendocrine tumors (GI-NETs); however, few studies have examined the effect of primary site and grade on resection and survival.

METHODS

This is a retrospective study of patients with metastatic GI-NETs at presentation between 2005 and 2011 using the California Cancer Registry (CCR) dataset merged with California Office of Statewide Health Planning and Development (OSHPD) inpatient longitudinal database. Primary outcome was overall survival (OS). Univariate and multivariate (MV) analyses were performed using the Pearson Chi-squared tests and Cox proportional hazard, respectively. OS was estimated using the Kaplan-Meier method and log-rank test.

RESULTS

A total of 854 patients with GI-NET metastases on presentation underwent 392 PTRs. Liver metastases occurred in 430 patients; 240 received liver treatment(s). PTR improved OS in patients with untreated metastases (median survival 10 vs 38 months, P < 0.001). On MV analysis adjusted for demographics, tumor stage, grade, chemotherapy use, Charlson comorbidity index, primary tumor location, or treatment of liver metastases, PTR with/without liver treatment improved OS in comparison to no treatment [hazard ratio (HR) 0.50, P < 0.001 and 0.39, P < 0.001, respectively]. PTR offered a survival benefit across all grades (low-grade, HR 0.38, P = 0.002 and high-grade, HR 0.62, P = 0.025) CONCLUSION:: PTR in GI-NET is associated with a better survival, with or without liver treatment, irrespective of grade. This study supports the resection of the primary tumor in patients with metastatic GI-NETs, independent of liver treatment.

Neuroendocrine Neoplasms of the Small Bowel and Pancreas

The traditionally promulgated perspectives of neuroendocrine neoplasms (NEN) as rare, indolent tumours are blunt and have been outdated for the last 2 decades. Clear increments in their incidence over the past decades render them increasingly clinically relevant, and at initial diagnosis many present with nodal and/or distant metastases (notably hepatic). The molecular pathogenesis of these tumours is increasingly yet incompletely understood. Those arising from the small bowel (SB) or pancreas typically occur sporadically; the latter may occur within the context of hereditary tumour predisposition syndromes. NENs can also be associated with endocrinopathy of hormonal hypersecretion. Tangible advances in the development of novel biomarkers, functional imaging modalities and therapy are especially applicable to this sub-set of tumours. The management of SB and pancreatic neuroendocrine tumours (NET) may be challenging, and often comprises a multidisciplinary approach wherein surgical, medical, interventional radiological and radiotherapeutic modalities are implemented. This review provides a comprehensive overview of the epidemiology, pathophysiology, diagnosis and treatment of SB and pancreatic NETs. Moreover, we provide an outlook of the future in these tumour types which will include the development of precision oncology frameworks for individualised therapy, multi-analyte predictive biomarkers, artificial intelligence-derived clinical decision support tools and elucidation of the role of the microbiome in NEN development and clinical behaviour.

Quand et avec quelles conséquences opérer une tumeur neuroendocrine du pancréas ou du grêle ?

Les tumeurs neuroendocrines (TNE) sont des tumeurs rares et peuvent survenir dans tout le tube digestif. On distingue les tumeurs fonctionnelles associées à des symptômes secondaires à l’activité sécrétoire de la tumeur et les tumeurs non fonctionnelles. Tout patient présentant une TNE doit être discuté en RCP RENATEN. Concernant les TNE duodénopancréatiques sporadiques, la chirurgie est nécessaire devant une TNE fonctionnelle ainsi que devant une TNE non fonctionnelle de plus de 2 cm, associées ou non à un retentissement canalaire. Pour les tumeurs supposées peu ou pas agressives, il sera toujours privilégié une stratégie d’épargne parenchymateuse afin d’éviter l’insuffisance pancréatique endocrine et exocrine. Concernant les TNE du grêle, la chirurgie doit être systématiquement envisagée, y compris en cas de métastases ou de carcinose associée afin d’éviter une complication mécanique telle qu’une occlusion. Un curage ganglionnaire comportant au minimum huit ganglions doit être effectué. Ce curage doit être large tout en préservant une vascularisation suffisante afin d’éviter la survenue d’un syndrome de grêle court.