Initial Treatment of Unresectable Neuroendocrine Tumor Liver Metastases with Transarterial Chemoembolization using Streptozotocin: A 20-Year Experience

Liver-Directed Locoregional Therapies for Neuroendocrine Liver Metastases: Recent Advances and Management

Neuroendocrine tumors (NETs) are a heterogeneous class of cancers, predominately occurring in the gastroenteropancreatic system, which pose a growing health concern with a significant rise in incidence over the past four decades. Emerging from neuroendocrine cells, these tumors often elicit paraneoplastic syndromes such as carcinoid syndrome, which can manifest as a constellation of symptoms significantly impacting patients' quality of life. The prognosis of NETs is influenced by their tendency for metastasis, especially in cases involving the liver, where the estimated 5-year survival is between 20 and 40%. Although surgical resection remains the preferred curative option, challenges emerge in cases of neuroendocrine tumors with liver metastasis (NELM) with multifocal lobar involvement, and many patients may not meet the criteria for surgery. Thus, minimally invasive and non-surgical treatments, such as locoregional therapies, have surfaced. Overall, these approaches aim to prioritize symptom relief and aid in overall tumor control. This review examines locoregional therapies, encompassing catheter-driven procedures, ablative techniques, and radioembolization therapies. These interventions play a pivotal role in enhancing progression-free survival and managing hormonal symptoms, contributing to the dynamic landscape of evolving NELM treatment. This review meticulously explores each modality, presenting the current state of the literature on their utilization and efficacy in addressing NELM.

Chemoembolization Beyond Hepatocellular Carcinoma: What Tumors Can We Treat and When?

Liver metastases are the most common malignancy found in the liver and are 20 to 40 times more common than primary hepatic tumors, including hepatocellular carcinoma. Patients with liver metastases often present with advanced disease and are not eligible for curative-intent surgery or ablative techniques. The unique hepatic arterial blood supply of liver metastases allows interventional radiologists to target these tumors with transarterial therapies. Transarterial chemoembolization (TACE) has been studied in the treatment of liver metastases originating from a variety of primary malignancies and has demonstrated benefits in terms of hepatic progression-free survival, overall survival, and symptomatic relief, among other benefits. Depending on the primary tumor from which they originate, liver metastases may have different indications for TACE, may utilize different TACE regimens and techniques, and may result in different post-procedural outcomes. This review offers an overview of TACE techniques and specific considerations in the treatment of liver metastases, provides an in-depth review of TACE in the treatment of liver metastases originating from colorectal cancer, neuroendocrine tumor, and uveal melanoma, which represent some of the many tumors beyond hepatocellular carcinoma that can be treated by TACE, and summarizes data regarding when one should consider TACE in their treatment algorithms.

Management of neuroendocrine tumor liver metastases

BACKGROUND

Neuroendocrine Tumors (NETs) are a group of tumors that arise from neuroendocrine cells, and are increasing in incidence worldwide. These tumors often metastasize to the liver, and management of these neuroendocrine tumor liver metastases (NELMs) requires a multi-disciplinary approach. We aim to provide a comprehensive update for treatment of NELMs.

METHODS

We completed a comprehensive systemic review of papers involving the diagnosis, treatment, and outcomes of NELMs. We identified 1612 records via Scopus database literature search. Two independent authors reviewed these records, with 318 meeting criteria for inclusion in the final systemic review.

RESULTS

Primary tumor resection with resection of liver metastases is the treatment of choice for patients with NELMs. Liver-directed therapies and liver transplantation can be considered for patients with unresectable liver metastases. Systemic medical therapy is used for managing tumor burden and symptoms caused by NELMs.

CONCLUSIONS

Advancement in liver-directed and targeted systemic therapies provide improved options for patients with unresectable tumors. Given the complexity of NELMs, management of NELMs necessitates multidisciplinary teams at comprehensive health centers.

Conventional Transarterial Chemo embolization Using Streptozocin in Patients with Unresectable Neuroendocrine Liver Metastases

BACKGROUND

The purpose of this study was to evaluate the clinical, biological and radiological responses to, and tolerability of, conventional transarterial chemoembolization (cTACE) using streptozocin for unresectable neuroendocrine liver metastases.

PATIENTS AND METHODS

A total of 52 patients with predominant liver disease were treated with cTACE using an emulsion of streptozocin, Lipiodol and embolization particles. A sequential approach was favored in patients with high liver tumor burden. Clinical, biological and radiological responses were evaluated using carcinoid symptoms, biomarkers and mRecist criteria, respectively.

RESULTS

A total of 127 procedures were performed with a sequential approach in 65% of patients. All patients received streptozocin and Lipiodol. Carcinoid syndrome was improved in 69% of patients after treatment (p = 0.01). Post-embolization syndrome was reported in 78% of patients. At the end of all cTACE, objective response and non-progressive disease were 32% and 70%, respectively. Progression-free survival was 18.3 ± 13.3 months (median 14.9) and median overall survival (OS) from start of treatment was 74 months. The OS at 1 year, 2 years, 3 years and 5 years was 91% (IC = 84-99%), 84% (CI = 72-95%), 69% (CI = 53-84%) and 63% (C = 46-81%), respectively.

CONCLUSIONS

cTACE using streptozocin is an effective and well-tolerated palliative option for patients with neuroendocrine liver metastases, associated with prolonged survival and delayed time to progression.

A Comparison of the Outcomes of Transarterial Chemoembolization and Transarterial Radioembolization in the Management of Neuroendocrine Liver Metastases in Adults: A Systematic Review

The purpose of this article is to review the existing English scientific literature and determine the superior modality between transarterial chemoembolization (TACE) and radioembolization (TARE) in the treatment of neuroendocrine liver metastases (NELMs). To that end, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to search PubMed, the Cochrane Library, and Google Scholar. We identified 14 observational studies and no randomized controlled trials (RCTs) investigating the use of TACE or TARE to treat NELM. We used the Newcastle-Ottawa Scale to assess the risk of bias in these studies. We concluded that TACE and TARE appeared to have similar outcomes when comparing overall survival, progression-free survival, radiological response, symptomatic response, and the incidence of severe adverse events. Further large-scale RCTs are needed to identify the superior modality conclusively. We also identified several unique prognostic factors for overall survival, such as the neutrophil-lymphocyte ratio, volumetric multiparametric magnetic resonance imaging, serum albumin, alkaline phosphatase, and pancreastatin.

Surgery, Liver Directed Therapy and Peptide Receptor Radionuclide Therapy for Pancreatic Neuroendocrine Tumor Liver Metastases

Pancreatic neuroendocrine tumors (PNETs) are described by the World Health Organization (WHO) classification by grade (1–3) and degree of differentiation. Grade 1 and 2; well differentiated PNETs are often characterized as relatively “indolent” tumors for which locoregional therapies have been shown to be effective for palliation of symptom control and prolongation of survival even in the setting of advanced disease. The treatment of liver metastases includes surgical and non-surgical modalities with varying degrees of invasiveness; efficacy; and risk. Most of these modalities have not been prospectively compared. This paper reviews literature that has been published on treatment of pancreatic neuroendocrine liver metastases using surgery; liver directed embolization and peptide receptor radionuclide therapy (PRRT). Surgery is associated with the longest survival in patients with resectable disease burden. Liver-directed (hepatic artery) therapies can sometimes convert patients with borderline disease into candidates for surgery. Among the three embolization modalities; the preponderance of data suggests chemoembolization offers superior radiographic response compared to bland embolization and radioembolization; but all have similar survival. PRRT was initially approved as salvage therapy in patients with advanced disease that was not amenable to resection or embolization; though the role of PRRT is evolving rapidly

Minimizing the risk of small-for-size syndrome after liver surgery

BACKGROUND

Primary and secondary liver tumors are not always amenable to resection due to location and size. Inadequate future liver remnant (FLR) may prevent patients from having a curative resection or may result in increased postoperative morbidity and mortality from complications related to small-for-size syndrome (SFSS).

DATA SOURCES

This comprehensive review analyzed the principles, mechanism and risk factors associated with SFSS and presented current available options in the evaluation of FLR when planning liver surgery. In addition, it provided a detailed description of specific modalities that can be used before, during or after surgery, in order to optimize the conditions for a safe resection and minimize the risk of SFSS.

RESULTS

Several methods which aim to reduce tumor burden, preserve healthy liver parenchyma, induce hypertrophy of FLR or prevent postoperative complications help minimize the risk of SFSS.

CONCLUSIONS

With those techniques the indications of radical treatment for patients with liver tumors have significantly expanded. The successful outcome depends on appropriate patient selection, the individualization and modification of interventions and the right timing of surgery.

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

Simple Summary

Tumor resistance, both primary and acquired, is leading to increased complexity in the nonsurgical treatment of patients with advanced panNENs, which would be greatly helped by reliable prognostic/predictive factors. The importance in identifying resistance is being contributed to by the increased array of possible treatments available for treating resistant advanced disease; the variable clinical course as well as response to any given treatment approach of patients within one staging or grading system, the advances in imaging which are providing increasing promising results/parameters that correlate with grading/outcome/resistance, the increased understanding of the molecular pathogenesis providing promising prognostic markers, all of which can contribute to selecting the best treatment to overcome resistance disease. Several factors have been identified that have prognostic/predictive value for identifying development resistant disease and affecting overall survival (OS)/PFS with various nonsurgical treatments of patients with advanced panNENs. Prognostic factors identified for patients with advanced panNENs for both OS/PFSs include various clinically-related factors (clinical, laboratory/biological markers, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors. Particularly important prognostic factors for the different treatment modalities studies are the recent grading systems. Most prognostic factors for each treatment modality for OS/PFS are not specific for a given treatment option. These advances have generated several controversies and new unanswered questions, particularly those related to their possible role in predicting the possible sequence of different anti-tumor treatments in patients with different presentations. Each of these areas is reviewed in this paper.

Abstract

Purpose: Recent advances in the diagnosis, management and nonsurgical treatment of patients with advanced pancreatic neuroendocrine neoplasms (panNENs) have led to an emerging need for sensitive and useful prognostic factors for predicting responses/survival. Areas covered: The predictive value of a number of reported prognostic factors including clinically-related factors (clinical/laboratory/imaging/treatment-related factors), pathological factors (histological/classification/grading), and molecular factors, on therapeutic outcomes of anti-tumor medical therapies with molecular targeting agents (everolimus/sunitinib/somatostatin analogues), chemotherapy, radiological therapy with peptide receptor radionuclide therapy, or liver-directed therapies (embolization/chemoembolization/radio-embolization (SIRTs)) are reviewed. Recent findings in each of these areas, as well as remaining controversies and uncertainties, are discussed in detail, particularly from the viewpoint of treatment sequencing. Conclusions: The recent increase in the number of available therapeutic agents for the nonsurgical treatment of patients with advanced panNENs have raised the importance of prognostic factors predictive for therapeutic outcomes of each treatment option. The establishment of sensitive and useful prognostic markers will have a significant impact on optimal treatment selection, as well as in tailoring the therapeutic sequence, and for maximizing the survival benefit of each individual patient. In the paper, the progress in this area, as well as the controversies/uncertainties, are reviewed.

Long Term Efficacy and Assessment of Tumor Response of Transarterial Chemoembolization in Neuroendocrine Liver Metastases: A 15-Year Monocentric Experience

Simple Summary

Neuroendocrine tumors (NET) are rare tumors, with long-term survival even for patients with liver metastases. Transarterial chemoembolization (TACE) is one of the most widely used treatments in this setting. The aim of the study was to assess the long-term efficacy of TACE in a large cohort of patients with NET liver metastases and to correlate imaging findings with survival. In our study including 202 patients with NET liver metastases and a mean follow-up of 8.2 years, TACE was effective to provide disease control for 26 months and a 5.3-year median overall survival (OS). Imaging responses using RECIST and mRECIST criteria were significantly correlated to OS: the median-OS was twice as long among mRECIST responders versus non-responders, with 80.5 months and 39.6 months respectively. These findings are of major importance for everyday practice as they confirm TACE’s effectiveness and usefulness of imaging evaluation to better tailor patient treatment and repeat TACE sessions whenever necessary.

Abstract

Background: transarterial chemoembolization (TACE) is an established treatment for neuroendocrine tumor (NET) liver metastases. The aim was to evaluate the long-term treatment efficacy of TACE for NET liver metastases, and correlate imaging response with survival. Methods: this IRB-approved, single-center, retrospective study evaluated all TACE procedures performed for NET liver metastases from 2003–2017 for imaging tumor response (RECIST and mRECIST), time to liver progression (TT_LP), time to untreatable progression with TACE (TTUP), and overall survival (OS). Patient, tumor, and treatment characteristics were analyzed as prognostic factors. Survival curves according to the Kaplan–Meier method were compared by Log-rank test. Tumor responses according to RECIST and mRECIST were correlated with OS. Results: 555 TACE procedures were performed in 202 NET patients (38% grade 1, 60% grade 2) with primary tumors originating from pancreas, small bowel, and lung (39, 26, and 22% respectively). Median follow-up was 8.2 years (90–139 months). Median TT_LP and TTUP were 19.3 months (95%CI 16.3–22.3) and 26.2 months (95%CI 22.3–33.1), respectively. Median OS was 5.3 years (95%CI 4.2–6.7), and was higher among mRECIST responders (80.5 months; 95%CI 64.6–89.8) than in non-responders (39.6 months; 95%CI = 32.8–60.2; p < 0.001). In multivariable analysis, age, tumor grade and liver involvement predicted worse OS, whereas administration of somatostatin analogs correlated with improved OS. Conclusion: TACE for NET liver metastases provides objective response and sustained local disease control rates. RECIST and mRECIST responses correlate with OS.

Management of Metastatic GEPNETs

The chief causes of death of patients with GEPNETs are liver failure from hepatic replacement by tumor in the majority and bowel obstruction in the remainder. Many patients are with liver metastases are actually eligible for hepatic cytoreductive operations, even if they have numerous bilobar metastases and extra-hepatic disease, provided that greater than 70% of the liver tumor volume can be removed. This can often be done by combinations of parenchyma-sparing enucleations, wedge resections and radio frequency ablations. Patients with higher liver tumor burden can be treated with intra-arterial therapies, such as embolization and chemoembolization. Patients with peritoneal carcinomatosis are recommended to undergo cytoreductive operations including peritoneal stripping and bowel resections. Consensus guidelines by experts recommend bisphosphonate therapy for patients with bone metastases, reserving surgical treatment for patients with mechanical issues and/or potential spinal cord compression. Radiation can be employed for isolated painful metastases. PRRT may be an emerging therapy for treatment of bone metastases.

Serotoninergic brain dysfunction in neuroendocrine tumor patients: A scoping review

INTRODUCTION

Neuroendocrine tumors (NETs) are rare and malignant neoplasms characterized by their potential to produce metabolically active substances with the capacity to bring about clinical syndromes. The clinical expression of serotonin-producing NETs is known as carcinoid syndrome (CS). The synthesis of serotonin in the brain is dependent on tryptophan availability. At the central level, serotonin is indispensable for mood, anxiety, and sleep regulation. In CS patients, around 60% of all tryptophan is reported to be consumed by tumor cells for the peripheral synthesis of serotonin, increasing the risk of a central deficiency and thus psychiatric disorders.

MATERIALS AND METHODS

This manuscript reviews the existing literature about psychiatric disorders associated with NETs and addresses the safety of psychiatric drugs in these patients. A systematic search of the biomedical literature was performed using the following databases: PubMed, Embase, CINAHL (EBSCO), PsycInfo (OVID), and Cochrane CENTRAL (Wiley). The database search included articles published between January 1965 and February 2021. Relevant information were charted using a calibrated charting-form.

RESULTS

Twenty-two articles were included in the present review. The overall population size of the studies came to 3319 patients. All patients presented a confirmed diagnosis of NET. The information about the presence of CS was confirmed in 351 cases. The psychiatric symptoms reported included mood disturbances (including, depression and anxiety), psychoses, impulse control disorders and sleeping alterations. We also evaluated the presence of cognitive impairments in NET patients. Finally, we summarize the available data regarding the safety of psychiatric drugs in this setting.

CONCLUSIONS

Psychiatric disorders among NET patients are poorly recognized, and therefore have received very little research attention. As a result, no standardized algorithm is presently available. Our findings support detailed psychiatric evaluation in NET patients, especially in those presenting CS and symptoms suggestive of psychiatric involvement. Not only do cognitive impairment and psychiatry symptoms negatively impact health-related quality of life in cancer patients, they can also reduce survival rates.

Chemoembolization Versus Radioembolization for Neuroendocrine Liver Metastases: A Meta-analysis Comparing Clinical Outcomes

BACKGROUND

Studies have shown intra-arterial therapies to be effective in controlling neuroendocrine liver metastases (NELMs), but the evidence supporting the selection of specific methods is limited. This meta-analysis is the first to compare survival outcomes between transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) in the treatment of NELM.

METHODS

A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in PubMed and Embase databases was conducted in February 2020 for published studies comparing survival outcomes between TACE and TARE in the treatment of NELM.

RESULTS

Six eligible cohort studies with a total of 643 patients were identified. The TACE and TARE groups were similar in terms of age, sex, hepatic tumor burden, tumor grade, and Eastern Cooperative Oncology Group (ECOG) score. The patients treated with TACE had significantly better overall survival (odds ratio [OR], 1.92; 95% confidence interval [CI] 1.14-3.22, p = 0.014) than those treated with TARE. Overall survival ranged from 16.8 to 81.9 months with TACE and from 14.5 to 66.8 months with TARE. No significant differences in hepatic progression-free survival (OR, 1.01; 95% CI 0.75-1.35; p = 0.96) or tumor response were observed within the first 3 months (OR, 2.87; 95% CI 0.81-10.21; p = 0.10) or thereafter (OR, 0.98; 95% CI 0.12-7.86; p = 0.99). The complication rates were similar between the two groups, with 6.9% of the TACE patients versus 8.5% of TARE patients reporting major complications (OR, 1.16; 95% CI 0.54-2.48; p = 0.71) and respectively 44.6% and 58.8% of the TACE and TARE patients reporting minor adverse events (OR, 1.08; 95% CI 0.39-2.99; p = 0.88).

CONCLUSIONS

Despite similar tumor responses, an overall survival benefit was associated with TACE treatment of NELM compared with TARE treatment. Randomized controlled trials are warranted to confirm this finding and clarify whether certain subpopulations benefit from different transarterial methods.

Liver Embolisation for Patients with Neuroendocrine Neoplasms: Systematic Review

BACKGROUND

Liver embolisation is one of the treatment options available for patients diagnosed with neuro-endocrine neoplasms (NEN). It is still uncertain whether the benefits of the various types of embolisation treatments truly outweigh the complications in NENs. This systematic review assesses the available data relating to liver embolisation in patients with NENs.

METHODS

Eligible studies (identified using MEDLINE-PubMed) were those reporting data on NEN patients who had undergone any type of liver embolisation. The primary end points were best radiological response and symptomatic response; secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity.

RESULTS

Of 598 studies screened, 101 were eligible: 16 were prospective (15.8%). The eligible studies included a total of 5,545 NEN patients, with a median of 39 patients per study (range 5-214). Pooled rate of partial response was 36.6% (38.9% achieved stable disease) and 55.2% of patients had a symptomatic response to therapy when pooled data were analysed. The median PFS and OS were 18.4 months (95% CI 15.5-21.2) and 40.7 months (95% CI 35.2-46.2) respectively. The most common toxicities were found to be abdominal pain (48.8%) and nausea (48.1%). Outcome did not significantly vary depending on the type of embolisation performed.

CONCLUSION

Liver embolisation provides adequate symptom relief for patients with carcinoid syndrome and is also able to reach partial response in a significant proportion of patients and a reasonable PFS. Quality of studies was limited, highlighting the need of further prospective studies to confirm the most suitable form of liver embolisation in NENs.

Interventional Liver-Directed Therapy for Neuroendocrine Metastases: Current Status and Future Directions

OPINION STATEMENT

Liver-directed therapy should be considered for patients with unresectable liver metastases from neuroendocrine tumor if symptomatic or progressing despite medical management. Our experience and current literature shows that the bland embolization, chemoembolization, and radioembolization are very effective in controlling symptoms and disease burden in the liver, and that these embolization modalities are similar in terms of efficacy and radiologic response. Their safety profiles differ, however, with recent studies suggesting an increase in biliary toxicity with drug-eluting bead chemoembolization over conventional chemoembolization, and a risk of long-term hepatotoxicity with radioembolization. For this reason, we tailor the type of embolotherapy to each patient according to their clinical status, symptoms, degree of tumor burden, histologic grade, and life expectancy. We do not recommend a "one-size-fits-all" approach. Our general strategy is to use bland embolization as first-line embolotherapy, and radioembolization for patients with high-grade tumors or who have failed other embolotherapy.

Transarterial Chemoembolization vs Radioembolization for Neuroendocrine Liver Metastases: A Multi-Institutional Analysis

BACKGROUND

Liver-directed hepatic arterial therapies are associated with improved survival and effective symptom control for patients with unresectable neuroendocrine liver metastases (NELM). Whether transarterial chemoembolization (TACE) or transarterial radioembolization (TARE) with yttrium-90 (y-90) are associated with improved short- or long-term outcomes is unknown.

STUDY DESIGN

A retrospective review was performed of all patients with NELM undergoing transarterial therapies, from 2000 to 2018, at 2 academic medical centers. Postoperative morbidity, radiographic response according to response evaluation criteria in solid tumors (RECIST) criteria, and long-term outcomes were compared between patients who underwent TACE vs TARE.

RESULTS

Among 248 patients with NELM, 197 (79%) received TACE and 51 (21%) received TARE. While patients who underwent TACE were more likely to have carcinoid syndrome, larger tumors, and higher chromogranin A levels, there was no difference in tumor differentiation, primary site, bilobar disease, or synchronous presentation. Nearly all TARE treatments (92%) were performed as outpatient procedures, while 99% of TACE patients spent at least 1 night in the hospital. There were no differences in overall morbidity (TARE 13.7% vs TACE 22.6%, p = 0.17), grade III/IV complication (5.9% vs 9.2%, p = 0.58), or 90-day mortality. The disease control rate (DCR) on first post-treatment imaging (RECIST partial/complete response or stable disease) was greater for TACE compared with TARE (96% vs 83%, p < 0.01). However, there was no difference in median overall survival (OS, 35.9 months vs 50.1 months, p = 0.3) or progression-free survival (PFS, 15.9 months vs 19.9 months, p = 0.37).

CONCLUSIONS

In this retrospective multi-institutional analysis, both TACE and TARE with Y-90 were safe and effective liver-directed therapies for unresectable NELM. Although TARE was associated with a shorter length of hospital stay, TACE demonstrated improved short-term DCR, and both resulted in comparable long term outcomes.

Non-Pharmacological Therapeutic Options for Liver Metastases in Advanced Neuroendocrine Tumors

The incidence of liver metastasis in digestive neuroendocrine tumors is high. Their presence appears as an important prognostic factor in terms of quality of life and survival. These tumors may be symptomatic because of the tumor burden itself and/or the hormonal hyper-secretion induced by the tumor. Surgery is the treatment of choice for resectable tumors and metastasis. Nevertheless, surgery is only possible in a small number of cases. The management of non-resectable liver metastasis is a challenge. The literature is rich but consists predominantly in small retrospective series with a low level of proof. Thus, the choice of one technique over another could be difficult. Local ablative techniques (radiofrequency) or trans-catheter intra-arterial liver-directed treatments (hepatic artery embolization, chemo-embolization, and radio-embolization) are frequently considered for liver metastasis. In the present review, we focus on these different therapeutic approaches in advanced neuroendocrine tumors, results (clinical and radiological), and overall efficacy, and summarize recommendations to help physicians in their clinical practice.

Semi-quantitative visual assessment of hepatic tumor burden can reliably predict survival in neuroendocrine liver metastases treated with transarterial chemoembolization

OBJECTIVES

To evaluate the accuracy and reproducibility of semi-quantitative visual assessment of hepatic tumor burden (HTB) on MRI and to investigate its prognostic value in predicting overall survival (OS) in neuroendocrine liver metastases (NELMs) treated with transarterial chemoembolization (TACE).

METHODS

Three independent readers blinded to the quantitative HTB measurement reviewed baseline MRI in 111 NELM patients treated with TACE. Readers visually assessed and semi-quantitatively categorized HTB using the European Neuroendocrine Tumor Society (ENETS) guidelines. Quantitative HTB measured by manual segmentation was used as the reference standard. Agreements between quantitative and semi-quantitative measurement of HTB, as well as intra- and inter-reader reproducibility, were evaluated using weighted kappa coefficient and intraclass correlation coefficient (ICC). Survival analysis included the Kaplan-Meier curves and Cox regression. Harrell C-index was calculated to evaluate the prognostic value of semi-quantitative HTB for predicting OS.

RESULTS

According to quantitative HTB, 41, 29, 25, and 16 patients were categorized into ≤ 10%, 11-25%, 26-50%, and > 50% groups, respectively. Agreements between quantitative and semi-quantitative measurement of HTB by each reader (weighted kappa, 0.82-0.96), intra-reader agreement (weighted kappa, 0.95), and inter-reader agreements (weighted kappa, 0.84-0.91; ICC, 0.98) were at least substantial to almost perfect. Semi-quantitative HTB was an independent prognostic factor in NELMs treated with TACE (multivariate Cox regression, p < 0.001), with prognostic value comparable to that of quantitative HTB (Harrell C-index, 0.735 for both semi-quantitative and quantitative HTB in multivariate regression).

CONCLUSION

Semi-quantitative visual assessment of HTB using MRI is accurate and reproducible and could reliably predict OS in NELMs treated with TACE.

KEY POINTS

• Semi-quantitative visual assessment of HTB using MR imaging is considerably accurate, reproducible, and efficient. • Visually assessed semi-quantitative HTB serves as an independent predictor of OS in NELMs treated with TACE.

Neutrophil Lymphocyte Ratio and Transarterial Chemoembolization in Neuroendocrine Tumor Metastases

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) has been shown to be predictive of outcomes in various cancers, including neuroendocrine tumors (NETs), and cancer-related treatments, including transarterial chemoembolization (TACE). We hypothesized that NLR could be predictive of response to TACE in patients with metastatic NET.

METHODS

We reviewed 262 patients who underwent TACE for metastatic NET at a single tertiary medical center from 2000 to 2016. NLR was calculated from blood work drawn 1 d before TACE, as well as 1 d, 1 wk, and 6 mo after treatment.

RESULTS

The median post-TACE overall survival (OS) of the entire cohort was 30.1 mo. Median OS of patients with a pre-TACE NLR ≤ 4 was 33.3 mo versus 21.1 mo for patients with a pre-TACE NLR >4 (P = 0.005). At 6 mo, the median OS for patients with post-TACE NLR > pre-TACE NLR was 21.4 mo versus 25.8 mo for patients with post-TACE NLR ≤ pre-TACE NLR (P = 0.007). On multivariate analysis, both pre-TACE NLR and 6-mo post-TACE NLR were independent predictors of survival. NLR values from 1-d and 1-wk post-TACE did not correlate with outcome.

CONCLUSIONS

An elevated NLR pre-TACE and an NLR that has not returned to its pre-TACE value several months after TACE correlate with outcomes in patients with NET and liver metastases. This value can easily be calculated from laboratory results routinely obtained as part of preprocedural and postprocedural care, potential treatment strategies.

Carcinoid-syndrome: recent advances, current status and controversies

PURPOSE OF REVIEW

To review recent advances and controversies in all aspects of carcinoid-syndrome.

RECENT FINDINGS

Over the last few years there have been a number of advances in all aspects of carcinoid syndrome as well as new therapies. These include new studies on its epidemiology which demonstrate it is increasing in frequency; increasing insights into the pathogenesis of its various clinical manifestations and into its natural history: definition of prognostic factors; new methods to verify its presence; the development of new drugs to treat its various manifestations, both initially and in somatostatin-refractory cases; and an increased understanding of the pathogenesis, natural history and management of carcinoid heart disease. These advances have generated several controversies and these are also reviewed.

SUMMARY

There have been numerous advances in all aspects of the carcinoid-syndrome, which is the most common functional syndrome neuroendocrine tumors produce. These advances are leading to new approaches to the management of these patients and in some cases to new controversies.

Liver transarterial embolizations in metastatic neuroendocrine tumors

The management of patients with well-differentiated neuroendocrine tumors (NET) and non-resectable liver metastases is challenging. Liver-directed transarterial embolization (TAE), transarterial chemo-embolization (TACE) and selective internal radiation therapy (SIRT) have a place of choice among other treatment modalities. However, their utilization relies on a low level of proof, due to the lack of prospective data, the absence of comparative studies and considerable heterogeneity between local practices. TAE and TACE generally achieve average symptomatic, biological and radiological responses of 75%, 56% and 50%, with progression-free survival of 12-18 months, with acceptable tolerance. Although not clearly demonstrated, TACE may be more effective than TAE in pancreatic NET, but not in small-intestine NET. SIRT has been developed more recently and may achieve similar results, with improved tolerance, but decreased cost-effectiveness, although no prospective comparison has been published to date. There is currently no strong argument to choose between TAE, TACE and SIRT, and they have not been compared to other treatment modalities. The evaluation of their efficacy has mostly relied on criteria based on size variations, which do not take into account tumor viability and metabolism, and thus may not be relevant. These techniques may be especially effective when performed as first-line therapies, in patients with non-major liver involvement (<75%) and with hypervascular metastases. Finally, studies exploring their combination with systemic therapies are ongoing.

Antineoplastic effects of histone deacetylase inhibitors in neuroendocrine cancer cells are mediated through transcriptional regulation of Notch1 by activator protein 1

Notch signaling is minimally active in neuroendocrine (NE) cancer cells. While histone deacetylase inhibitors (HDACi) suppress NE cancer growth by inducing Notch, the molecular mechanism underlying this interplay has not yet been defined. NE cancer cell lines BON, H727, and MZ-CRC-1 were treated with known HDACi Thailadepsin-A (TDP-A) and valproic acid (VPA), and Notch1 mRNA expression was measured with RT-PCR. Truncated genomic fragments of the Notch1 promotor region fused with luciferase reporter were used to identify the potential transcription factor (TF) binding site. The key regulatory TF was identified with the electrophoretic mobility shift assay (EMSA). The effect of HDACi on Notch1 level was determined before and after silencing the TF. TDP-A and VPA induced Notch1 mRNA in a dose-dependent manner. A functional DNA motif at -80 to -52 from the Notch1 start codon responsible for the HDACi-dependent Notch1 induction was identified. Mutation of this core sequence failed to induce luciferase activity despite HDACi treatment. EMSA showed the greatest gel shift with AP-1 in nuclear extracts. Knockdown of AP-1 significantly attenuated the effect of HDACi on Notch1 induction. Interestingly, AP-1 transfection did not alter Notch1 level, suggesting that AP-1 is necessary but insufficient for HDACi activation of Notch1. Therefore, AP-1 is the TF that binds to a specific transcription-binding site within the Notch1 promotor region to trigger Notch1 transcription. Elucidating the HDACi activation mechanism may lead to the development of novel therapeutic options against NE cancers and facilitate the identification of clinical responders and prevent adverse effects.