Neuroendocrine gastroenteropancreatic tumors: ESMO clinical recommendation for diagnosis, treatment and follow-up

Neuroendocrine Tumor Therapy Response Assessment

Peptide receptor radionuclide therapy has become an integral part of management of neuroendocrine neoplasms. Gallium-68- and lutetium-177-labeled somatostatin receptor analogues have replaced yttrium-90- and 111-indium-based tracers. Several newer targeted therapies are also being used in clinical and research settings. It is imperative to accurately evaluate the response to these agents. The characteristics of NENs and the response patterns of the targeted therapies make response assessment in this group challenging. This article provides an overview of the strengths and weaknesses of the various biomarkers available for response assessment.

Peptide receptor radionuclide therapy implementation and results in a predominantly gastrointestinal neuroendocrine tumor population: A two-year experience in a nonuniversity setting

Neuroendocrine tumors (NETs) are rare, but the incidence and prevalence of NETs are increasing in the United States. While surgery is the preferred treatment for NETs, it is not a viable option for metastatic disease. Lutathera (177Lu-DOTATATE) is approved by the United States Food and Drug Administration and the European Medicines Agency for the treatment of gastroenteropancreatic (GEP)-NETs in adults. There is limited information on GEP-NET treatment responses to Lutathera.Our institution launched a peptide receptor radionuclide therapy (PRRT) service line using Lutathera with involvement from a multidisciplinary team and complete collaboration between hospital administration and clinical providers. A prospective registry study was also established in order to collect patient demographics and clinical data regarding the treatment of GEP primary NETs with Lutathera.Between August 2018 and July 2020, 35 GEP-NET patients were treated with Lutathera, of which 65.71% received 4 complete cycles and 25.71% received 3 cycles; 5.71% and 2.86% received 2 and 1 cycles of PRRT, respectively. Most adverse events during the course of our study were low grade using the common terminology criteria for adverse events system. Of the patients who completed all 4 cycles: 22% showed partial response to Lutathera, 44% showed stable disease, and 13% showed disease progression based on a qualitative assessment of positron emission tomography/computed tomography imaging.From our experience, Lutathera was well tolerated in patients with GEP-NET. Additional studies are needed to examine long-term clinical and patient-reported outcomes associated with GEP-NET treatment as well as financial considerations for hospitals embarking on a PRRT program.

The Role of Conventionally Fractionated Radiotherapy and Stereotactic Radiotherapy in the Treatment of Carcinoid Tumors and Large-Cell Neuroendocrine Cancer of the Lung

The occurrence of neuroendocrine tumors among the diagnosed neoplasms is extremely rare and is associated with difficulties in undertaking effective therapy due to the histopathological differentiation of individual subtypes and the scarce clinical data and recommendations found in the literature. The choice of treatment largely depends not only on its type, but also on the location and production of excess hormones by the tumor itself. Common therapeutic approaches include surgical removal of the tumor, the use of chemotherapy, targeted drug therapy, peptide receptor radionuclide therapy, and the use of radiation therapy. This article reviews the current knowledge on the classification and application of radiotherapy in the treatment of lung NETs. Case reports were presented in which treatment with conventional radiotherapy, radical and palliative radiochemotherapy, as well as stereotactic fractionated radiotherapy in the treatment of typical (TC) and atypical (AT) lung carcinoids and large cell neuroendocrine carcinoma (LCNC) were used. We hope that the solutions presented in the literature will allow many radiation oncologists to make the best, often personalized decisions about the therapeutic qualifications of patients.

The overriding role of surgery and tumor grade for long-term survival in patients with gastroenteropancreatic neuroendocrine neoplasms: A population-based cohort study

Background

Gastroenteropancreatic neuroendocrine neoplasms (GEP‐NENs) comprise a heterogeneous disease group. Factors that affect long‐term survival remain uncertain. Complete population‐representative cohorts with long‐term follow‐up are scarce.

Aim

To evaluate factors of importance for the long‐term survival.

Methods and results

An Observational population‐based study on consecutive GEP‐NEN patients diagnosed from 2003 to 2013, managed according to national guidelines. Univariable and multivariable survival analyses were performed to evaluate overall survival (OS) and to identify independent prognostic factors. One hundred ninety eligible patients (males, 58.9%) (median age, 60.0 years; range, 10.0–94.2 years) were included. The small bowel, appendix, and pancreas were the most common tumor locations. The World Health Organization (WHO) tumor grade 1–3 distributions varied according to the primary location and disease stage. Primary surgery with curative intent was performed in 66% of the patients. The median OS of the study population was 183 months with 5‐ and 10‐year OS rates of 66% and 57%, respectively. Only age, WHO tumor grade, and primary surgical treatment were independent prognostic factors for OS.

Conclusion

The outcomes of GEP‐NEN patients are related to several factors including age and primary surgical treatment. WHO tumor grading, based on the established criteria, should be routine in clinical practice. This may improve clinical decision‐making and allow the comparison of outcomes among different centers.

Outcomes of non-metastatic poorly differentiated gastroenteropancreatic neuroendocrine neoplasms treated with surgery: a real-world population-based study

OBJECTIVE

To assess the outcomes of non-metastatic poorly differentiated gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) treated with radical surgery.

METHODS

Surveillance, Epidemiology, and End Results (SEER) database (1998-2015) was accessed, and patients with non-metastatic poorly differentiated/undifferentiated GEP-NENs were reviewed. Multivariable Cox regression analysis was used to evaluate factors affecting overall survival (OS) and cancer-specific survival (CSS). Patients treated with radical surgery were matched to those who did not undergo surgery through propensity score matching and Kaplan-Meier survival estimates were used to evaluate the impact of surgery in the post-propensity cohort.

RESULTS

A total of 1517 patients were included. Within multivariable Cox regression models and compared to no surgery, radical surgery was associated with improved OS (HR: 0.41; 95% CI: 0.34-0.50) and CSS (HR: 0.37; 95% CI: 0.29-0.47). A total of 233 patients who underwent no surgery were then matched to 233 patients who underwent radical surgery. Within the post-propensity cohort, radical surgery was associated with improved OS (P < 0.001).

CONCLUSIONS

Radical surgery is associated with improved survival outcomes in patients with non-metastatic poorly differentiated GEP-NENs. Further studies are required to better identify the best timing of radical surgery within the context of multimodal management.

Validity of neuron-specific enolase as a prognostic tool in acute ischemic stroke in adults at Suez Canal University Hospital

Background

Biological markers of acute nerve cell damage can assist in the outcome of acute ischemic stroke, such as neuron-specific enolase (NSE) that have been tested for association with initial severity of stroke, extent of infarction, and functional outcome.

Objective

To determine short-term prognostic value of the biochemical marker neuron-specific enolase (NSE) in acute ischemic stroke.

Methods

A cohort study carried out on 37 patients with acute ischemic stroke. Data were gathered in a prepared data sheet. Initial serum NSE level was measured to the patients in the Emergency department within 6 h of the onset of stroke and another measurement after 48 h. National Institute of Health Stroke Scale (NIHSS) was held to the patients at presentation and after 28 days of stroke to determine short-term morbidity and mortality.

Results

Out of the 37 patients, 31 patients survived (no-death group) and 6 patients died (death group). The mean serum level of neuron-specific enolase at presentation and after 48 h was significantly higher in the death group than in the no-death group. There was a statistically significant positive correlation between neuron-specific enolase (NSE) serum level and clinical severity of stroke (NIHSS) among the patients at presentation (r = 0.737, p = 0.000).

Conclusion

Neuron-specific enolase (NSE) can be applied as single independent marker for prediction of mortality and short-term morbidity in ischemic stroke patients.

The efficacy of 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) in patients with metastatic neuroendocrine tumours: a systematic review and meta-analysis

PURPOSE

To evaluate the efficacy of ¹⁷⁷Lu-DOTA0-Tyr3-octreotate (¹⁷⁷Lu-DOTATATE) radionuclide therapy in patients with inoperable or metastatic neuroendocrine tumours (NETs), (PROSPERO ID CRD42019130755).

METHODS

All published clinical studies of NETs treated with ¹⁷⁷Lu-DOTATATE were identified based on systematic searches in the PubMed, EMBASE, Cochrane Library, Web of Science and ClinicalTrials.gov databases up to January 2019. Among these studies, only the reports evaluated with the "Response Evaluation Criteria in Solid Tumours (RECIST)" or "Southwest Oncology Group (SWOG)" criteria or both were included. We analysed the disease response rate (DRR) and disease control rate (DCR) of each group to evaluate the efficacy of ¹⁷⁷Lu-DOTATATE.

RESULTS

Fifteen studies were selected from 715 references. The pooled effect in the RECIST group (13 studies) was 27.58% (95% confidence interval (CI) 21.03-35.27%) for the DRR and 79.14% (95% CI 75.83-82.1%) for the DCR. In the SWOG criteria group (7 studies), the pooled effect was 20.59% (95% CI 10.89-35.51%) for the DRR and 78.28% (95% CI 74.39-81.72%) for the DCR. Therefore, the RECIST and SWOG groups showed similar DRRs and DCRs after¹⁷⁷Lu-DOTATATE treatment, indicating that ¹⁷⁷Lu-DOTATATE treatment has excellent efficacy with a control rate of approximately 78-79%. Moreover, adverse effects of ¹⁷⁷Lu-DOTATATE were minimal, including fatigue, nausea, vomiting and hormonal disorders.

CONCLUSIONS

For patients with inoperable or metastatic NETs, ¹⁷⁷Lu-DOTATATE is an effective treatment with minimal side effects.

Further Classification for Node-Positive Gastric Neuroendocrine Neoplasms

BACKGROUND

For gastric neuroendocrine neoplasms (GNEN), the current AJCC lymph node (N) stage classifies patients into N0/N1 disease (with/without locoregional nodal metastases); however, this does not account for the number of involved nodes. The objective of this study was to evaluate the prognostic significance of the number of involved locoregional nodes among resected GNEN.

METHODS

The National Cancer Database (2004-2014) was queried for GNEN patients who had undergone partial/total gastrectomy with known nodal status. Nearest-neighborhood grouping was used to identify survival clusters by number of metastatic nodes and to use these groupings to construct a new N classification (pN). External validation was performed using the SEER database. Kaplan-Meier analysis and Cox regression models were used to assess the prognostic strength of the pN classification.

RESULTS

One thousand two hundred seventy-five patients met study inclusion criteria. Patients with 1-6 positive nodes (pN1) demonstrated a distinct survival pattern from patients with > 6 positive nodes (pN2) as well as those with no positive nodes (N0) {5-year OS N0: 80% (95% CI 77-83%) vs. 65% (95% CI 61-69%) vs. 43% (95% CI 33-53%), p < 0.001}. On external validation, the pN classification demonstrated strong discriminatory ability for survival {5-year OS N0: 70% (95% CI 65-75%) vs. pN1:53% (95% CI 46-59%) vs. pN2:18% (95% CI 9-29%), p < 0.001}. On multivariable analysis, the pN classification remained an independent predictor of OS.

CONCLUSIONS

The number of metastatic lymph nodes is an independent prognostic factor in GNEN. Current AJCC N1 disease contains two groups of patients with distinctive prognoses, hence needs to be subclassified into pN1 (1-6 positive lymph nodes) and pN2 (> 6 positive nodes).

A New Robot-assisted Billroth-I Reconstruction: Details of the Technique and Early Results

BACKGROUND

Laparoscopic surgery for gastric tumor is considered a demanding procedure because of lymph node dissection and reconstruction. Billroth-I (B-I) reconstruction after laparoscopic distal gastrectomy is commonly performed extracorporeally because of the complexity of an intracorporeal procedure. Robotic surgery overcomes some limitations of laparoscopy, allowing to reproduce the basic maneuvers of open surgery. We describe a new technique to perform robotic B-I anastomosis.

METHODS

Between January 2012 and February 2015, 5 patients underwent distal gastrectomy with intracorporeal B-I-stapled anastomosis. Patient demographics, tumor characteristics, histopathologic features, and perioperative data were analyzed.

RESULTS

Median operative time was 170 minutes (145 to 180 min). There were no conversions. Contrast swallow was routinely performed on the third postoperative day. Median postoperative hospitalization was 7 days (range: 6 to 8). No major complications or mortality were observed.

CONCLUSIONS

Robotic distal gastrectomy with intracorporeal B-I anastomosis is a safe and promising technique in selected cases of gastric tumors.

Molecular profiling of pancreatic neuroendocrine tumors (pNETS) and the clinical potential

Pancreatic neuroendocrine tumors (pNETs) represent a small part of pancreatic neoplasms, and the knowledge about their indolent clinical course remains a subject of investigation. They occur sporadically or as part of familial cancer syndromes and are classified by WHO in 3 categories. There is ongoing research to understand their molecular profiling and leading mutations. Areas covered: The aim of this review is to clarify the overall aspects of tumorigenesis, to expose the latest developments in understanding the course of the disease and the possible therapeutic implications of these. The review also discusses functional and non-functional pNETs and associated inherited syndromes as well as pNET molecular profiling and its possible guidance in the use of targeted therapy. Expert commentary: In the next decade, a more extensive application of new technologies will help improve quality of life and survival, individualizing treatment protocols and identifying which therapeutic strategy is more suitable for each kind of NET.

Molecular challenges of neuroendocrine tumors

Neuroendocrine tumors (NETs) are a very heterogeneous group that are thought to originate from the cells of the endocrine and nervous systems. These tumors develop in a number of organs, predominantly in the gastrointestinal and pulmonary systems. Clinical detection and diagnosis are reliable at the late stages when metastatic spread has occurred. However, traditional conventional therapies such as radiation and chemotherapy are not effective. In the majority of cases even surgical resection at that stage is unlikely to produce promising reusults. NETs present a serious clinical challenge, as the survival rates remain low, and as these rare tumors are very difficult to study, novel approaches and therapies are required. This review will highlight the important points of accumulated knowledge covering the molecular aspects of the role of neuroendocrine cells, hormonal peptides, the reasons for ectopic hormone production in NET, neuropeptides and epigenetic regulation as well as the other challenging questions that require further understanding.

Incidence and clinical characteristics of gastroenteropancreatic neuroendocrine tumor in Korea: a single-center experience

BACKGROUND/AIMS

Neuroendocrine tumors (NETs) may originate from heterogeneous neuroendocrine cells. The incidence is increasing worldwide, and World Health Organization (WHO) updated its classification in 2010. We investigated clinical characteristics of gastroenteropancreatic NETs in a single center.

METHODS

Clinicopathologic characteristics of patients with pathologically confirmed gastroenteropancreatic NET in Seoul St. Mary Hospital from March 2009 to August 2011 were retrospectively analyzed. The grade and stage were determined according to WHO 2010 classification and TNM Staging System for Neuroendocrine Tumors (7th ed., 2010) of American Joint Committee on Cancer.

RESULTS

One hundred and twenty-five patients (median age, 50; male, 61.3%) were analyzed. Among 100,000 patients who visited the hospital, incidence was 24.1. Only two patients (1.6%) had a functional NET. The rectum (n = 99, 79.8%) was most common primary site and found in early stage. The prevalence by stages was 84.7% stage I, 8.9% stage IV, 4.8% stage II, and 1.6% stage III. The pathology grading was 74.5% grade 1, 12.7% grade 2, and 12.7% grade 3. Tumor stage correlated positively with pathologic grade (Spearman's rank correlation coefficient, 0.644).

CONCLUSIONS

Wide range of clinicopathological features of Korean gastroenteropancreatic NETs were demonstrated using WHO 2010 classification. Rectal NET was most frequent and found in early stage.

ACR Appropriateness Criteria Radiologic Management of Hepatic Malignancy

Management of primary and secondary hepatic malignancy is a complex problem. Achieving optimal care for this challenging population often requires the involvement of multiple medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and loco-regional therapies, such as thermal ablation and transarterial embolization techniques. This article provides a review of treatment strategies for the three most common subtypes of hepatic malignancy treated with loco-regional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

New horizons for targeted treatment of neuroendocrine tumors

Neuroendocrine tumors (NETs) are rare and heterogeneous tumors and there is a paucity of randomized clinical trials evaluating the different therapeutic strategies. Over recent years, some important molecular aspects have been investigated and multiple targeted therapies are currently available. One of the most promising targets for the therapy of NETs are the mTOR and angiogenic growth factor receptors. The advent of the inhibitors of the mTOR pathway, tyrosine kinase inhibitors and of somatostatin analogs have shown their efficacy in randomized clinical trials in terms of implementing clinical hormone-induced syndromes and progression-free survival of advanced NETs. This article summarizes the standard therapies and new perspectives in NET's treatment, which remains still very heterogeneous and little known entity.

Clinicopathological features and prognosis of gastroenteropancreatic neuroendocrine tumors: analysis from a single-institution

BACKGROUND

The gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine neoplasm. We summarized data in our centre to investigate the clinicopathological features, diagnostic methods, therapeutic approaches and prognosis for this neoplasm to increase knowledge of this disease in Asian populations.

METHOD

A total of 122 patients treated at Sun Yet-san Memorial Hospital of Sun Yat-sen University between January 2000 and December 2011 were analyzed retrospectively.

RESULTS

Pancreas was the most common site of involvement (65/122, 53.3%); this disease has no special symptoms; positive rates of chromogranin A (CgA) and synaptophysin (Syn) were 81.1% and 87.7%, respectively. The positive rate of Syn had statistical difference among the three grades, but not CgA. Some 68 patients had G1 tumors, 32 G2 tumors and 22 G3 tumors, and Chi-square test showed that higher grading was correlated with worse prognosis (χ2=32.825, P=0.0001). A total of 32 patients presented with distant metastasis, and 8 cases emerged during following up. Cox proportional hazards regression modeling showed that the tumor grade (P=0.01), lymphatic metastasis (P=0.025) and distant metastasis (P=0.031) were predictors of unfavorable prognosis. The overall 5-year survival rate was 39.6%, the 5-year survival rate of G1 was 55.7%, and the G2 and G3 were 34.2% and 0%, respectively.

CONCLUSIONS

The incidence of gastroenteropancreatic neuroendocrine tumors has risen over the last 12 years. All grades of these diseases metastasize readily, and further research regarding the treatment of patients after radical surgery is needed to prolong disease-free survival.

A cause to consider for chronic unresolving diarrhea

A 36-year-old male who carried a diagnosis of irritable bowel syndrome presented with chronic watery diarrhea and was found to have hepatomegaly on physical exam. A computed tomography (CT) scan of the abdomen revealed hepatomegaly with lesions suspicious for metastatic disease. A colonoscopy revealed a polypoid lesion in the terminal ileum, which was biopsied, revealing a neuroendocrine tumor (NET). He was treated with palliative octreotide and chemoembolization of liver metastases until disease progression. The case highlights the importance of considering functional NETs, especially carcinoid syndrome, in patients with chronic unresolving diarrhea, since early diagnosis allows for further treatment options that can prolong survival.

Vascular endothelial growth factor (VEGF) pathway and neuroendocrine neoplasms (NENs): prognostic and therapeutic considerations

Neuroendocrine neoplasms (NENs) consist of a large heterogeneous group of epithelial tumors with neuroendocrine differentiation, as proved by immune reactivity for neuroendocrine markers. From the very first studies of vascular endothelial growth factor (VEGF) pathway, VEGF has been considered an important prognostic marker in NENs. Consequently, a number of preclinical experiences and clinical trials have examined the efficacy of VEGF-targeted therapeutics in NENs. Bevacizumab and sorafenib were clinically tested in NENs and they showed modest activity, while on the other hand, they present significant toxicity problems. More interesting in gastroenteropancreatic (GEP)-NENs seems to be the demonstrated efficacy of sunitinib. Preclinical as well as clinical sunitinib data in this regard provide a new hope in that direction. The use of other novel VEGF-targeted agents like aflibercept as well as VEGFR-TKI is being investigated in a number of phase II studies; the results of which are greatly awaited. Additionally, the use of potential biomarkers to select patients for VEGF-targeted therapy may be considered for further clinical evaluation. Thus, this article reviews the basic science as well as clinical data of VEGF signaling in advanced NENs with special emphasis on the different VEGF-targeting agents tested previously in this disease and the future prospective in that field.

Neuroendocrine tumors of the gastrointestinal tract: Case reports and literature review

Neuroendocrine tumors (NET) previously called carcinoid tumors are neoplasms of enterochromaffin/neuroendocrine cell origin which display neurosecretory capacity that may result in the carcinoid syndrome. The annual incidence of patients with NET is 8.4 per 100000; yet many NET remain asymptomatic and clinically undetected. A majority of NET follows a benign course; however, some will display malignant characteristics. NET most commonly occur in the gastrointestinal tract (67%) and bronchopulmonary system (25%). Gastrointestinal NET occur within the stomach, small intestine, liver, and rectum. We report a retrospective study of 11 subjects: Eight with benign carcinoid tumors: duodenal bulb (n = 2), terminal ileum (n = 1), sigmoid colon (n = 2), and rectum (n = 3); three with malignant carcinoid: liver (n = 1) and intra-abdominal site (n = 2). The diagnosis, endoscopic images, outcome, treatment and review of the literature are presented.

Bevacizumab-based combination therapy for advanced gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs): a systematic review of the literature

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) consist of a large heterogeneous group of epithelial tumors with neuroendocrine differentiation that arises in gastrointestinal tract and pancreatic tissues. Advanced GEP-NENs are considered distinct disease entity with limited approved treatment options and poor prognosis. So, we will explore in this systematic review the value of using bevacizumab-based combination in this subset of NENs.

METHODS

PubMed, Medline, the Cochrane Library, trip database and Google Scholar were searched using the terms "GEP-NENs" OR "Gastroenteropancreatic neuroendocrine tumors" AND "systemic anticancer therapy" AND "Bevacizumab" and selecting only the English literature. Outcomes of interest included progression-free survival and overall survival (PFS and OS), tumor response and toxicities.

RESULTS

A total of 17 potentially relevant trials were identified, of which eight studies were excluded. Hence, nine trials involving 320 patients were included. Median PFS was reported in eight out of the nine studies ranging from 8.2 to 16.5 months. Median OS was reported in one study, and it was 33.3 months for the whole group. The disease control rate was reported in the seven studies, and it ranged from 80 to 96%. The overall response rate was reported in eight studies, and it ranged from 0 to 64%. Frequently reported grade 3/4 toxicities were gastrointestinal toxicities, mucocutaneous toxicities and hematologic toxicities (particularly leucopenia).

CONCLUSIONS

The current evidence from the available clinical trials suggests that bevacizumab in combination with some other anticancer agents (especially mTOR inhibitors and interferons) could be a more effective and tolerable treatment for advanced GEP-NENs in the future. However, such bevacizumab-based combination cannot be recommended outside the setting of clinical trials.

Classification, clinicopathologic features and treatment of gastric neuroendocrine tumors

Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient’s survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.

New insights into the role of chronic inflammation and cytokines in the etiopathogenesis of gastroenteropancreatic neuroendocrine tumors

Although previously considered rare, recent epidemiological studies have revealed that the incidence (3.6/100,000) and prevalence (35/100,000) of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased over the past few decades. Despite the progress in the understanding of GEP-NET molecular biology, there is still little advance in the early diagnosis due to lack of specific tumor markers. As the tumors are mostly detected in their late stage, they are not well controlled by either biotherapy or conventional chemotherapy, and thus represent a significant clinical issue. Chronic inflammation has been implicated in the development of GEP-NETs. This review presents recent findings that link pro-inflammatory cytokines to the molecular basis of GEP-NET tumorigenesis, leading to a more personalized approach to disease management and therapy.

In Reply

Neuroendocrine tumors exhibit diverse clinical outcomes, and several recent studies have demonstrated that tumor histology, which incorporates assessments of tumor differentiation, tumor grade, mitotic rate, and proliferative index, can be associated with clinical outcomes and overall survival.

ACR Appropriateness Criteria radiologic management of hepatic malignancy

Management of hepatic malignancy is a challenging clinical problem involving several different medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and locoregional therapies, such as thermal ablation and transarterial embolization. The authors discuss treatment strategies for the 3 most common subtypes of hepatic malignancy treated with locoregional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Chromogranin A is a sensitive marker of progression or regression in ileo-cecal neuroendocrine tumors

OBJECTIVE

The correlation between plasma Chromogranin A concentrations and changes in tumor size evaluated by computed tomography (CT) - as a gold standard - was evaluated.

MATERIAL AND METHODS

One hundred and sixteen patients with CgA-producing ileo-cecal neuroendocrine tumors were evaluated by events, which were recorded when a CT was followed by another CT 1 - 12 months later. Change in tumor size was defined as regression, progression, or stable disease using RECIST criteria 1.1. Of 426 events, there were 97 with progression, 279 with stable disease, and 50 with regression. Based on the ROC curves a cutoff value of 25% change was selected to discriminate between increased, decreased, or unchanged CgA concentrations in plasma, using a sensitive radioimmunoassay with well-defined epitope specificity.

RESULTS

In the 97 events showing tumor progression diagnostic sensitivity and specificity of an increased CgA concentration were 86% and 86%, respectively. The positive and negative predictive values were 64% and 85%, respectively. In the 279 events with unchanged tumor size the diagnostic sensitivity and specificity of an unchanged CgA concentration were 73% and 86%, and the positive and negative predictive values were 91% and 63%, respectively. In the 50 events showing tumor regression, diagnostic sensitivity and specificity of a decrease in CgA concentration were 78% and 91%, the positive and negative predictive values being 55% and 97%.

CONCLUSIONS

CgA concentrations in plasma have a high diagnostic accuracy in monitoring patients with ileo-cecal neuroendocrine tumors. In particular, an increase in plasma CgA concentration was useful to indicate tumor progression.

Pathology - grading and staging of GEP-NETs

Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) constitute a heterogeneous group of neoplasms. In the last few decades, due to a substantial rise in incidence and prevalence, GEP-NETs have been included among the most common tumours of the gastrointestinal tract. Diagnosis could be challenging and a significant number of patients present with metastatic or unresectable disease. The development of appropriate tools for standardised prognostic stratification and the introduction of effective target therapies have opened new horizons for planning tailored surgical or medical management and follow-up programs for these complex neoplasms. An overview on the GEP-NETs' diagnostic and prognostic criteria proposed by the recently published WHO classification and ENETS and UICC TNM staging systems is presented, focussing on their impact on the clinical and therapeutical approaches.

Acromegaly induced by ectopic secretion of GHRH: a review 30 years after GHRH discovery

Ectopic acromegaly is very rare and since the discovery of growth hormone-releasing hormone (GHRH), 30 years ago, only 74 cases have been reported in the literature. Except for a recent French series of 21 cases, most of them were case reports. The present review summarizes the current knowledge on clinical presentation, diagnosis and prognosis. Tumors secreting GHRH are neuroendocrine tumors, usually well differentiated and mainly from pancreatic or bronchial origin. They are usually large and easy to localize using TDM and somatostatin receptor scintigraphy. Clinical presentation is an acromegaly of variable intensity, whose features are similar to that of a somatotropic adenoma. Pituitary may be normal or enlarged at MRI which may be difficult to interpret especially in MEN1 patients where the association of a microprolactinoma to a pancreatic tumor secreting GHRH may be misleading. GHRH plasmatic measurement has an excellent specificity for the diagnosis, using a threshold of 250 to 300ng/L and is a good tool for follow-up of patients after treatment. These tumors have a good overall prognosis, even in metastatic forms which represent 50% of cases. Surgical approach is recommended and, when a complete tumoral resection is feasible, results, in most patients, in long-lasting remission. In such cases, GHRH concentration is normalized and its increase is an accurate indicator of recurrence. In uncured patients, somatostatin analogs control GH secretion but inhibit, only partially, GHRH secretion. MEN1 mutation should be systematically investigated in patients with a pancreatic tumor.

Potential synergies for combined targeted therapy in the treatment of neuroendocrine cancer

Well differentiated neuroendocrine tumours (WDNET) are a diverse group of cancers that are often advanced at the time of diagnosis and generally do not respond significantly to traditional chemotherapy. A number of intriguing therapeutic targets have emerged, including somatostatin receptors, insulin-like growth factor-1 (IGF-1) and its receptor (IGF-1R), the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, and vascular endothelial growth factor receptor. Functional somatostatin receptors and IGF-1R as well as dysregulated mTOR--a key pathway component for both growth factor signalling and protein synthesis--have been identified in human neuroendocrine tumour (NET) cell lines. Somatostatin analogues (SSA) and mTOR inhibitors have exhibited in vitro and in vivo antitumour activity against NET and have shown effects on the IGF-1 pathway in preclinical studies. SSA inhibit PI3K/Akt signalling upstream of mTOR, suggesting that the combination of an SSA and an mTOR inhibitor may have greater efficacy than either as single agents. Recent clinical trial experience has provided some encouraging findings and prompted the design of additional studies of this dual-targeted approach to treating advanced WDNET. Results of ongoing trials of dual-targeted therapy combinations will define future therapies for advanced WDNET.

Innovations therapy: mammalian target of rapamycin (mTOR) inhibitors for the treatment of neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare neoplasms that require a multidisciplinary approach for an optimal management. The lack of effectiveness of traditional DNA-damaging agents has led to the exploration of new targeted drugs in order to exploit phenotypical features of GEP-NET therapy. However, due to the orphan setting of these tumors, deeper characterization of molecular features and pathways that characterize cell growth, apoptosis, angiogenesis, and invasion are lacking, particularly genetic mutations or epigenetic alterations that generate oncogenic dependency or even addiction. The PI3K-AKT-mTOR pathway has been implicated as having a crucial role in GEP-NETs not only due to the overexpression of several growth factors and their receptors that finally activate this axis but also hereditary syndromes with constitutive activation of the mTOR pathway with high incidence of GEP-NETs. In this article, we aim to review the recent development of the main molecules that target mTOR complex and have showed promising activity in the treatment of GEPNETs.

Future perspectives on neuroendocrine tumors

In the last 30 years the incidence and prevalence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased substantially. This could be partly due to improvements in diagnostic imaging, which lead to the incidental diagnosis of asymptomatic cases. However, despite these improvements, patients typically experience long delays before they are diagnosed. In this review, we discuss both the limitations and advances in our understanding of the pathogenesis, molecular and cellular biology, diagnosis, classification, staging, and treatment of GEP-NETs in order to identify which factors could be contributing to the delay in diagnosis and timely treatment of these patients. Within this context, the results from the most relevant clinical trials the available targeted therapies for the treatment of GEP-NETs, such as the "RAD001 in Advanced Neuroendocrine Tumors," will be discussed.

[Familial adenomatous polyposis and liver metastases from a neuroendocrine tumor]

Familial adenomatous polyposis (FAP) is mainly characterized by the development of a large number of polyps in the gastrointestinal tract and by the risk of developing adenocarcinomas. We present the case of a woman diagnosed with FAP and liver metastases. Histological analysis revealed both diseases to be secondary to a neuroendocrine tumor. To date, only three cases showing the simultaneous occurrence of these two entities have been published. Currently, there is no genetic basis to explain the coexistence of these two diseases, both of which have a very low prevalence.

Phase II study of single agent capecitabine in the treatment of metastatic non-pancreatic neuroendocrine tumours

Background:

This study sought to determine the safety of single agent capecitabine, a pro-drug of 5FU, in patients with metastatic non-pancreatic neuroendocrine tumours (NETs).

Methods:

Multicentre phase II, first-line study design. Oral capecitabine was administered on days 1–14 of 3-week cycles.

Results:

Treatment was safe and well tolerated. Common toxicities were diarrhoea and fatigue.

Conclusion:

The study provides evidence to support the use of capecitabine as a substitute for infusional 5FU in the management of NETs.

Imaging of gastroenteropancreatic neuroendocrine tumors

Imaging of gastroenteropancreatic neuroendocrine tumors can be broadly divided into anatomic and functional techniques. Anatomic imaging determines the local extent of the primary lesion, providing crucial information required for surgical planning. Functional imaging, not only determines the extent of metastatic disease spread, but also provides important information with regard to the biologic behavior of the tumor, allowing clinicians to decide on the most appropriate forms of treatment. We review the current literature on this subject, with emphasis on the strengths of each imaging modality.

New pharmacologic therapies for gastroenteropancreatic neuroendocrine tumors

Successful treatment of unresectable and metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs) requires the thoughtful choice of systemic therapy as a component of a multidisciplinary therapeutic approach. The role of somatostatin analogues is established in symptom relief, but the efficacy of interferon and radiopeptide targeted therapy is not clear. The utility of a variety of tyrosine kinase and antiangiogenic agents is variable and under investigation, whereas the role of cytotoxic chemotherapy in poorly differentiated GEP-NETs is accepted. Overall, the ideal treatment of more indolent tumors is less certain. Reassessments of the GEP-NET pathology classification has provided improved logic for the role of a variety of agents, whereas the precise positioning of many new agents that target molecular pathways of angiogenesis and proliferation is under examination. This article describes the current options for systemic therapy for GEP-NETs within the framework of the current World Health Organization classification system.