Surgery for hepatic neuroendocrine tumors: a single institutional experience in Japan

Currently available treatment options for neuroendocrine liver metastases

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

Neuroendocrine neoplasia of the gastrointestinal tract revisited: towards precision medicine

Over the past 5 years, a number of notable research advances have been made in the field of neuroendocrine cancer, specifically with regard to neuroendocrine cancer of the gastrointestinal tract. The aim of this Review is to provide an update on current knowledge that has proven effective for the clinical management of patients with these tumours. For example, for the first time in the tubular gastrointestinal tract, well-differentiated high-grade (grade 3) tumours and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are defined in the WHO classification. This novel classification enables efficient identification of the most aggressive well-differentiated neuroendocrine tumours and helps in defining the degree of aggressiveness of MiNENs. The Review also discusses updates to epidemiology, cell biology (including vesicle-specific components) and the as-yet-unresolved complex genetic background that varies according to site and differentiation status. The Review summarizes novel diagnostic instruments, including molecules associated with the secretory machinery, novel radiological approaches (including pattern recognition techniques), novel PET tracers and liquid biopsy combined with DNA or RNA assays. Surgery remains the treatment mainstay; however, peptide receptor radionuclide therapy with novel radioligands and new emerging medical therapies (including vaccination and immunotherapy) are evolving and being tested in clinical trials, which are summarized and critically reviewed here.

Predictive model for survival after liver resection for noncolorectal liver metastases in the modern era: a Japanese multicenter analysis

BACKGROUND

Survival benefit of liver resection for noncolorectal liver metastases (NCRLM) remains to be defined.

METHODS

This multicenter, retrospective cohort analysis included consecutive patients with NCRLM whose primary tumor and all metastases were treated with curative intent between 2000 and 2013. The primary endpoint was 5-year overall survival. Clinicopathological factors that affected prognoses were identified using multivariate Cox regression analyses and were included in a predictive model.

RESULTS

Data for 205 patients were analyzed. The three most common primary tumor sites were stomach (39%), pancreas (13%), and urinary tract (10%), with adenocarcinomas the main pathology (52%). R0 resection was achieved in 85%, and the overall survival at 5 years was 41%. In the multivariate analysis, synchronous liver metastases, R1/2 resection, and adenocarcinomas and other carcinomas (with gastrointestinal stromal tumors, neuroendocrine tumors G1/G2, and sarcomas set as the reference group) were independent negative indicators of overall survival. A predictive model effectively stratified the NCRLM patients into low-, intermediate-, and high-risk groups with overall 5-year survival rates of 63%, 38%, and 21%, respectively (P < 0.001).

CONCLUSIONS

Patients who underwent curative resection for metachronous disease and favorable tumor pathology are expected to have better survival in the NCRLM cohort.

The Impact of Extent of Liver Resection Among Patients with Neuroendocrine Liver Metastasis: an International Multi-institutional Study

BACKGROUND

Liver resection in patients with neuroendocrine liver metastasis (NELM) provides a survival benefit, yet the optimal extent of resection remains unknown. We sought to examine outcomes of patients undergoing non-anatomic (NAR) versus anatomic liver resection (AR) for NELM using a large international cohort of patients.

METHODS

Two hundred and fifty-eight patients who underwent curative intent liver resection from January 1990 to December 2016 were identified from eight institutions. Patients were excluded if they underwent concurrent ablation, had extrahepatic disease, underwent a debulking operation, or had mixed anatomic and non-anatomic resections. Overall (OS) and recurrence-free (RFS) survival were compared among patients based on the extent of liver resection (AR vs. NAR).

RESULTS

Most primary tumors were located in the pancreas (n = 117, 45.4%) or the small intestine (n = 65, 25.2%). Liver resection consisted of NAR (n = 126, 48.8%) or AR (n = 132, 51.2%) resection. The overwhelming majority of patients who underwent NAR had an estimated liver involvement of < 50% (NAR 109, 97.3% vs. AR n = 82, 65.6%; P < 0.001). Patients who underwent NAR also had higher rates of primary tumor lymph node metastasis (NAR n = 79, 71.2% vs. AR n = 37, 33.6%; P < 0.001) and microscopically positive margins (R1) (NAR n = 29, 25.7% vs. AR n = 16, 12.5%; P = 0.009). After a median follow-up of 47.7 months, 48 (18.6%) patients died and 37.0% (n = 95) had evidence of disease recurrence. Patients who underwent AR had both longer median OS (not reached) and RFS (not reached) versus patients who underwent NAR (median OS 138.3 months; median RFS 31.3 months) (both P < 0.01). After controlling for patient and disease-related factors, extent of liver resection was independently associated with an increased risk of recurrence (HR 2.39, 95% CI 1.04-5.48; P = 0.04) but not death (HR 1.92, 95% CI 0.40-9.28; P = 0.42).

CONCLUSION

NAR was independently associated with a higher incidence of recurrence versus patients who undergo a formal anatomic hepatectomy among patients with NELM.

Surgical management of neuroendocrine tumor-associated liver metastases: a review

Liver metastasis is common among patients who suffer from neuroendocrine tumors (NETs). Radical surgery is the standard treatment whenever possible but there is still controversies concerning the treatment strategies such as resection of the primary, role of debulking surgery, liver transplantation (LT) and neoadjuvant or adjuvant therapies. This article aims to review the current evidence available, together with some latest updates, focusing on the surgical management.

Liver transplantation for unresectable pancreatic neuroendocrine tumors with liver metastases in an era of transplant oncology

Patients with pancreatic neuroendocrine tumors (pNETs) very often present with a metastatic disease at the first diagnosis. Liver transplantation (LT) for unresectable pNET with liver metastases (pNETLM) has been described to prolong survival in highly selected patients, although outcomes were worse than those of patients who underwent LT for gastrointestinal NETLM (GI-NETLM). In this review, several proposed criteria are described with their rationale and controversies. Most of the data used to establish these criteria do not reflect the recent improvements of non-surgical treatments that has changed the landscape of treatment for pNETs, including the development of peptide receptor radionuclide therapy and molecular-targeted agents (sunitinib and everolimus). Properly designed studies are necessary to define the role of down-staging and bridging therapy prior to LT incorporating systemic chemotherapy using these molecular-targeted agents. Also, given the indolent nature of low or intermediate grade pNETs, the best endpoint to compare the efficacy of each treatment option for patients with pNETLM has yet to be determined. Lastly, the definition of "unresectable" remains ambiguous. The indication of the conventional technique of two-staged liver resection with portal vein embolization or the new technique of associating liver partition and portal vein ligation for staged hepatectomy to expand the resectability of wide-spread metastatic liver tumors has been controversial. In an era of transplant oncology, LT should be the last resort for patients who are considered unresectable and otherwise untreatable after an exhaustive multidisciplinary team discussion by all experts in the field. In conclusion, although its long-term outcomes have been promising, the role of LT for unresectable pNETLM as a curative or palliative treatment remains unclear. A well-designed randomized control study is required to elucidate the clinical impact of LT for pNETLM.

Resection of liver metastasis from neuroendocrine tumors: evaluation of results and prognostic factors

OBJECTIVES

to determine the prognostic factors that may impact on morbidity and mortality and survival of patients undergoing surgical treatment of liver metastases from neuroendocrine tumors.

METHODS

We studied 22 patients undergoing liver resection for metastases from neuroendocrine tumors between 1997 and 2007. Epidemiological and clinical data were correlated with morbidity and mortality and overall and disease-free survivals.

RESULTS

twelve patients were male and ten female, with a mean age of 48.5 years. Bilobar disease was present in 17 patients (77.3%). In ten patients (45.5%) the primary tumor originated in the pancreas, terminal ileum in eight, duodenum in two, rectum in one and jejunum in one. Complete surgical resection (R0) was achieved in 59.1% of patients. Eight patients (36.3%) developed complications in the immediate postoperative period, one of them dying from septicemia. All patients undergoing re-hepatectomy and/or two-stage hepatectomy had complications in the postoperative period. The overall survival at one and five years was 77.3% and 44.2%. The disease-free survival at five years was 13.6%. The primary pancreatic neuroendocrine tumor (p = 0.006) was associated with reduced overall survival. Patients with number of metastatic nodules < 10 (p = 0.03) and asymptomatic at diagnosis (p = 0.015) had higher disease-free survival.

CONCLUSION

liver metastases originating from pancreatic neuroendocrine tumors proved to be a negative prognostic factor. Symptomatic patients with multiple metastatic nodules showed a significant reduction in disease-free survival.

A Novel Nomogram to Predict the Prognosis of Patients Undergoing Liver Resection for Neuroendocrine Liver Metastasis: an Analysis of the Italian Neuroendocrine Liver Metastasis Database

Even though surgery remains the only potentially curative option for patients with neuroendocrine liver metastases, the factors determining a patient's prognosis following hepatectomy are poorly understood. Using a multicentric database including patients who underwent hepatectomy for NELMs at seven tertiary referral hepato-biliary-pancreatic centers between January 1990 and December 2014, we sought to identify the predictors of survival and develop a clinical tool to predict patient's prognosis after liver resection for NELMs. The median age of the 238 patients included in the study was 61.9 years (interquartile range 51.5-70.1) and 55.9 % (n = 133) of patients were men. The number of NELMs (hazard ratio = 1.05), tumor size (HR = 1.01), and Ki-67 index (HR = 1.07) were the predictors of overall survival. These variables were used to develop a nomogram able to predict survival. According to the predicted 5-year OS, patients were divided into three different risk classes: 19.3, 55.5, and 25.2 % of patients were in low (>80 % predicted 5-year OS), medium (40-80 % predicted 5-year OS), and high (<40 % predicted 5-year OS) risk classes. The 10-year OS was 97.0, 55.9, and 20.0 % in the low, medium, and high-risk classes, respectively (p < 0.001). We developed a novel nomogram that accurately (c-index >70 %) staged and predicted the prognosis of patients undergoing liver resection for NELMs.

Liver-directed surgery of neuroendocrine metastases: What is the optimal strategy?

INTRODUCTION

Neuroendocrine tumors (NETs) frequently metastasize to the liver. Operative debulking offers symptomatic relief and improved survival; however, the frequent presence of multifocal, bilobar disease and high recurrence rates introduces doubt regarding their optimal management. Parenchyma-sparing debulking (PSD) procedures (ablation, enucleation, wedge resections) may offer similar survival improvements as resection while minimizing morbidity and preserving functional liver tissue.

METHODS

Clinicopathologic variables from 228 patients with small bowel or pancreatic NETs managed operatively at one institution were collected. Liver-directed surgery was carried out when substantial debulking was deemed feasible. Survival was assessed by use of the Kaplan-Meier method.

RESULTS

A total of 108 patients with pancreatic NET or small bowel NET underwent liver-directed surgery with primarily PSD procedures. Nearly two-thirds of patients achieved 70% cytoreduction and 84% had concurrent resection of their primary. The median number of lesions treated was 6 (range, 1-36). There were no 30-day operative mortalities. The 30-day major complication rate was 13.0%. Patients who achieved 70% cytoreduction enjoyed improved progression free (median 3.2 years) and overall survival (median not reached).

CONCLUSION

PSD procedures are safe and can achieve significant cytoreduction, which is associated with improved survival. Lowering the debulking target threshold to 70% may benefit NET patients by increasing eligibility for cytoreduction.

Liver-directed therapy for neuroendocrine liver metastases

Abstract: 

Neuroendocrine tumors are relatively uncommon neoplasms presenting with a wide spectrum of clinical behavior. Many patients may present with or develop liver metastases from neuroendocrine tumors, which significantly influences prognosis and the potential for symptoms. Data suggest that some patients may have symptomatic relief and oncologic benefit from liver-directed therapy for neuroendocrine tumor metastases. Surgical resection, tumor ablation, transarterial therapy such as bland embolization, chemoembolization and radioembolization, as well as liver transplantation have been studied as liver-directed therapies. Data continue to emerge to help guide selection of treatment modality for an individual patient. The spectrum of behavior of neuroendocrine metastases and heterogeneity in the literature are a challenge to arriving at cohesive recommendations for all patients.

When should a liver resection be performed in patients with liver metastases from neuroendocrine tumours? A systematic review with practice recommendations

AIM

To determine the benefits and risks of hepatic resection versus non-resectional liver-directed treatments in patients with potentially resectable neuroendocrine liver metastases.

METHODS

A systematic review identified 1594 reports which alluded to a possible liver resection for neuroendocrine tumour metastases, of which 38 reports (all retrospective), comprising 3425 patients, were relevant.

RESULTS

Thirty studies reported resection alone, and 16 studies reported overall survival (OS). Only two studies addressed quality-of-life (QoL) issues. Five-year overall survival was reported at 41-100%, whereas 5-year progression-free survival (PFS) was 5-54%. We identified no robust evidence that a liver resection was superior to any other liver-directed therapies in improving OS or PFS. There was no evidence to support the use of a R2 resection (debulking), with or without tumour ablation, to improve either OS or QoL. There was little evidence to guide sequencing of surgery for patients presenting in Stage IV with resectable disease, and none to support a resection of asymptomatic primary tumours in the presence of non-resectable liver metastases.

CONCLUSION

Low-level recommendations are offered to assist in the management of patients with neuroendocrine liver metastases, along with recommendations for future studies.

Curative versus palliative surgical resection of liver metastases in patients with neuroendocrine tumors: a meta-analysis of observational studies

BACKGROUND

The role of surgical therapy in patients with liver metastases from neuroendocrine tumors (NETs) is unclear. In this study, the results obtained with curative or palliative resection, by reviewing recent literature and performing a meta-analysis, were examined.

MATERIALS AND METHODS

A systematic review and meta-analysis of observational studies published between January 1990 and October 2013 were performed. Studies that evaluated the different survival between patients treated by curative or palliative surgical resection of hepatic metastases from NETs were considered. The collected studies were evaluated for heterogeneity, publication bias, and quality. To calculate the pooled hazard ratio (HR) estimate and the 95% confidence interval (95% CI), a fixed-effects model was applied.

RESULTS

After the literature search, 2,546 studies were found and, among 38 potentially eligible studies, 3 were considered. We did not find a significant longer survival in patients treated with curative surgical resection of hepatic metastases when compared to palliative hepatic resection HR 0.40 (95% CI: 0.14-1.11). In one study, palliative resection of hepatic metastases significantly increased survival when compared to embolization.

CONCLUSIONS

Curative and also palliative surgery of NETs liver metastases may improve survival outcome. However, further randomized clinical trials are needed to elucidate this argument.

Surgical resection of hepatic metastases from neuroendocrine neoplasms: a systematic review

BACKGROUND

Neuroendocrine tumours (NET) most commonly metastasize to the liver. Hepatic resection of NET hepatic metastases (NETHM) has been shown to improve symptomology and survival.

METHODS

A systematic review of clinical studies before September 2010 was performed to examine the efficacy of hepatic resection for NETHM. As a secondary end-point, the impact of treatment on safety and symptomology were determined and prognostic variables were identified. The quality of each study was also assessed using predefined criteria incorporating 9 characteristics. Clinical outcome was synthesized through a narrative review with full tabulation of results of all included studies.

RESULTS

Twenty-nine included reported survival outcomes with a median 3-, 5- and 10-year overall survival of 83% (range, 63-100%), 70.5% (range, 31-100%), and 42% (range, 0-100%), respectively. The median progression-free survival (PFS) was 21 months (range, 13-46 months) and median 1-,3-,5- and 10-year PFS of 63% (range, 50-80 %), 32% (range, 24-69%), 29% (range, 6-66%) and 1% (range, 0-11%), respectively. Poor histologic grade, extra-hepatic disease and a macroscopically incomplete resection were associated with a poor prognosis. Studies reported a median rate of symptomatic relief from surgery in 95% of patients (range, 50-100%).

CONCLUSION

Hepatic resection for NETHM provides symptomatic benefit and is associated with favourable survival outcomes although the majority of patients invariably develop disease progression.

Surgical treatment of neuroendocrine liver metastases

Management of Neuroendocrine liver metastases (NELM) is challenging. The presence of NELM worsens survival outcome and almost 10% of all liver metastases are neuroendocrine in origin. There is no firm consensus on the optimal treatment strategy for NELM. A systematic search of the PubMed database was performed from 1995-2010, to collate the current evidence and formulate a sound management algorithm. There are 22 case series with a total of 793 patients who had undergone surgery for NELM. The overall survival ranges from 46-86% at 5 years, 35-79% at 10 years, and the median survival ranges from 52-123 months. After successful cytoreductive surgery, the mean duration of symptom reduction is between 16-26 months, and the 5-year recurrence/progression rate ranges from 59-76%. Five studies evaluated the efficacy of a combination cytoreductive strategy reporting survival rate of ranging from 83% at 3 years to 50% at 10 years. To date, there is no level 1 evidence comparing surgery versus other liver-directed treatment options for NELM. An aggressive surgical approach, including combination with additional liver-directed procedures is recommended as it leads to long-term survival, significant long-term palliation, and a good quality of life. A multidisciplinary approach should be established as the platform for decision making.

Radioembolization of symptomatic, unresectable neuroendocrine hepatic metastases using yttrium-90 microspheres

PURPOSE

To evaluate safety, efficacy, and symptom-control of radioembolization in patients with unresectable liver metastases from neuroendocrine tumors (NETLMs).

MATERIALS AND METHODS

Forty-two patients (mean age of 62 years) with treatment-refractory NETLMs underwent radioembolization using yttrium-90 ((90)Y) resin microspheres. Posttreatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST) and tumor-marker levels. Laboratory and clinical toxicities and clinical symptoms were monitored.

RESULTS

The median activity delivered was 1.63 GBq (range 0.63-2.36). Imaging follow-up using RECIST at 3-month follow-up demonstrated partial response, stable disease, and progressive disease in 22.5, 75.0, and 2.5% of patients, respectively. In 97.5% of patients, the liver lesions appeared hypovascular or partially necrotic. The mean follow-up was 16.2 months with 40 patients (95.2%) remaining alive. The median decrease in tumor-marker levels at 3 months was 54.8% (chromogranin A) and 37.3% (serotonin), respectively. There were no acute or delayed toxicities greater than grade 2 according to Common Terminology Criteria for Adverse Events [CTCAE (v3.0)]. No radiation-induced liver disease was noted. Improvement of clinical symptoms 3 months after treatment was observed in 36 of 38 symptomatic patients.

CONCLUSION

Radioembolization with (90)Y-microspheres is a safe and effective treatment option in patients with otherwise treatment-refractory NETLMs. Antitumoral effect is supported by good local tumor control, decreased tumor-marker levels, and improved clinical symptoms. Further investigation is warranted to define the role of radioembolization in the treatment paradigm for NETLMs.

Surgical management of liver metastases from gastrointestinal endocrine tumors

Liver metastases from endocrine tumors can reduce 5-year survival from 90% to 40% and, in cases of functional gastrointestinal endocrine tumors, lead to a carcinoid syndrome. Complete resection of cancerous disease should be considered in all cases. Indeed, after hepatectomy, prolonged survival (41-86% at five years) can be achieved, with low rates of surgery-related mortality (0-6.7%). Extended liver resection is required in most cases. Percutaneous portal embolization increases the volumetric feasibility of resection, and sequential hepatectomy techniques enable a two-stage resection of both bilobar metastases and the primary tumor. For carcinoid syndrome that does not respond to medical therapy, incomplete resection of liver metastases, by reducing tumor volume, may be indicated to reduce symptoms and halt the progression of carcinoid heart disease. In cases of non-resectable liver metastases in selected patients, liver transplantation can lead to 5-year survival rates as high as 77%.

Reoperative surgery for the Zollinger-Ellison syndrome

It is clear that a properly performed initial operation is the key to success in the management of a patient with ZES. However, reoperation is frequently a consideration in the management of patients with ZES because high rates of persistent and recurrent disease are manifest even with modern imaging and surgical approaches. In carefully selected patients, reoperation can result in durable biochemical cure and improved survival and should be considered. A thorough knowledge of the natural history of the sporadic form of ZES and ZES in the context of MEN-1, patterns of presentation, and sites of metastases are necessary to achieve the best outcome in patients with this unusual disease.

Hepatic cytoreductive surgery for neuroendocrine cancer

Patients with gut-based metastatic neuroendocrine tumors (NET) often present late in the course of their slowly progressive disease, when cancer has extended beyond the point of reasonable expectation for surgical cure. At this stage of disease, the tumor's overwhelming hormonal production often significantly impairs the patient's quality of life. Unlike patients with other malignancies that might involve a heavy burden of hepatic metastatic disease, many patients with metastatic NET continue to live for a long time despite escalating hormone-related symptoms. This establishes the justification and rationale for cytoreduction, a noncurative surgical intervention that reduces tumor burden and hormonal burden and thereby can significantly increase symptom-free survival in the setting of an often slow but inevitable disease progression.

Radioembolization for unresectable neuroendocrine hepatic metastases using resin 90Y-microspheres: early results in 148 patients

PURPOSE

The use of 90Y-microspheres to treat unresectable liver metastases originating from a variety of neuroendocrine tumors was reviewed.

MATERIALS AND METHODS

This is a retrospective review from 10 institutions of patients given 90Y-microsphere therapy for neuroendocrine hepatic metastases. Physical, radiographic, biochemical, and clinical factors associated with treatment and response were examined. All patients were followed with laboratory and imaging studies at regular intervals until death, or censured whether other therapy was given after brachytherapy. Toxicities (acute and late) were recorded, and survival of the group determined.

RESULTS

A total of 148 patients were treated with 185 separate procedures. The median age was 58 years (26-95 years) at treatment with median performance status of Eastern Cooperative Oncology Group (0). The median activity delivered was 1.14 GBq (0.33-3.30 GBq) with a median of 99% of the planned activity able to be given (38.1%-147.4%). There were no acute or delayed toxicity of Common Terminology Criteria for Adverse Events v3.0 grade 3 in 67% of patients, with fatigue (6.5%) the most common side effect. Imaging response was stable in 22.7%, partial response in 60.5%, complete in 2.7% and progressive disease in 4.9%. No radiation liver failure occurred. The median survival is 70 months.

CONCLUSION

Radioembolization with 90Y-microspheres to the whole liver, or lobe with single or multiple fractions are safe and produce high response rates, even with extensive tumor replacement of normal liver and/or heavy pretreatment. The acute and delayed toxicity was very low without a treatment related grade 4 acute event or radiation induced liver disease in this modest-sized cohort. The significant objective response suggests that further investigation of this approach is warranted.