Emerging approaches in the management of patients with neuroendocrine liver metastasis: role of liver-directed and systemic therapies

Liver Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms

ABSTRACT

The incidence of neuroendocrine neoplasms (NENs) has gradually increased over the past few decades with the majority of patients presenting with metastases on initial presentation. The liver is the most common site of initial metastatic disease, and the presence of liver metastasis is an independent prognostic factor associated with a negative outcome. Because NENs are heterogenous neoplasms with variable differentiation, grading, and risk of grade transformation over time, accurate diagnosis and management of neuroendocrine liver lesions are both important and challenging. This is particularly so with the multiple liver-directed treatment options available. In this review article, we discuss the diagnosis, treatment, and response evaluation of NEN liver metastases.

Neuroendocrine Tumors: Genomics and Molecular Biomarkers with a Focus on Metastatic Disease

Neuroendocrine tumors (NETs) are considered rare tumors that originate from specialized endocrine cells. Patients often present with metastatic disease at the time of diagnosis, which negatively impacts their quality of life and overall survival. An understanding of the genetic mutations that drive these tumors and the biomarkers used to detect new NET cases is important to identify patients at an earlier disease stage. Elevations in CgA, synaptophysin, and 5-HIAA are most commonly used to identify NETs and assess prognosis; however, new advances in whole genome sequencing and multigenomic blood assays have allowed for a greater understanding of the drivers of NETs and more sensitive and specific tests to diagnose tumors and assess disease response. Treating NET liver metastases is important in managing hormonal or carcinoid symptoms and is imperative to improve patient survival. Treatment for liver-dominant disease is varied; delineating biomarkers that may predict response will allow for better patient stratification.

Ablative Therapy in Non-HCC Liver Malignancy

Surgical extirpation of liver tumors remains a proven approach in the management of metastatic tumors to the liver, particularly those of colorectal origin. Ablative, non-resective therapies are an increasingly attractive primary therapy for liver tumors as they are generally better tolerated and result in far less morbidity and mortality. Ablative therapies preserve greater normal liver parenchyma allowing better post-treatment liver function and are particularly appropriate for treating subsequent liver-specific tumor recurrence. This article reviews the current status of ablative therapies for non-hepatocellular liver tumors with a discussion of many of the clinically available approaches.

Patients with non-functional metastatic G2 pancreatic neuroendocrine tumor benefit from palliative surgery: A 20-year single-center retrospective analysis

Pancreatic neuroendocrine tumor (pNET) is the most common subset (31.5%) of gastroenteropancreatic neuroendocrine tumor in China. Based on real-world data from a single center, the present study aimed to evaluate the influence of clinical characteristics, medical treatment and surgery on the survival of non-functional metastatic G2 pNET. In total, 114 metastatic non-functional G2 pNET patients, who were treated and followed up in the Department of Medical Oncology, Peking Union Medical College Hospital (PUMCH) from 2001 until 2019, were analyzed retrospectively. The primary endpoint, overall survival (OS), was calculated from the date of diagnosis to the date of death. The second endpoint, progression-free survival (PFS), was calculated from the date of diagnosis to the date of disease progression. Statistical data were analyzed to evaluate the effects of a clinical characteristic, medical treatment and surgery on OS and PFS. Sixty-nine (60.5%) patients were male and 87 (76.3%) were aged < 60 years. The liver was the most common metastatic organ, with a total of 84 cases (73.7%). With respect to surgery, 32 (28.1%) patients underwent radical surgery and 37 (32.5%) underwent palliative surgery. Survival analysis showed that the 5-year and 10-year survival rates were 79.36% and 70.0%, respectively. Univariate and multivariate Cox regression analyses suggested that both radical (p < .001/.003) and palliative surgery (p < .001/.002) significantly prolonged OS, as revealed by the Kaplan-Meier test (p < .001). Subgroup analysis showed that palliative resection also significantly improves the prognosis in patients with multiple liver metastases. However, the first-line systemic anti-tumor therapy option showed no statistical differences in the present study. Overall, patients with non-functional metastatic G2 pNET receiving palliative or radical surgery demonstrated significantly better survival. Prospective clinical trials are suggested to validate our findings.

New frontiers in imaging including radiomics updates for pancreatic neuroendocrine neoplasms

OBJECTIVE

To illustrate the applications of various imaging tools including conventional MDCT, MRI including DWI, CT & MRI radiomics, FDG & DOTATATE PET-CT for diagnosis, staging, grading, prognostication, treatment planning and assessing treatment response in cases of pancreatic neuroendocrine neoplasms (PNENs).

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) are very diverse clinically & biologically. Their treatment and prognosis depend on staging and primary site, as well as histological grading, the importance of which is also reflected in the recently updated WHO classification of GEP NENs. Grade 3 poorly differentiated neuroendocrine carcinomas (NECs) are aggressive & nearly always advanced at diagnosis with poor prognosis; whereas Grades-1 and 2 well-differentiated neuroendocrine tumors (NETs) can be quite indolent. Grade 3 well-differentiated NETs represent a new category of neoplasm with an intermediate prognosis. Importantly, the evidence suggest grade heterogeneity can occur within a given tumor and even grade progression can occur over time. Emerging evidence suggests that several non-invasive qualitative and quantitative imaging features on CT, dual-energy CT (DECT), MRI, PET and somatostatin receptor imaging with new tracers, as well as texture analysis, may be useful to grade, prognosticate, and accurately stage primary NENs. Imaging features may also help to inform choice of treatment and follow these neoplasms post-treatment.

CONCLUSION

GEP NENs treatment and prognosis depend on the stage as well as histological grade of the tumor. Traditional ways of imaging evaluation for diagnosis and staging does not yet yield sufficient information to replace operative and histological evaluation. Recognition of important qualitative imaging features together with quantitative features and advanced imaging tools including functional imaging with DWI MRI, DOTATATE PET/CT, texture analysis with radiomics and radiogenomic features appear promising for more accurate staging, tumor risk stratification, guiding management and assessing treatment response.

Pancreatic neuroendocrine tumor with ectopic adrenocorticotropic hormone syndrome: a case report and 5-year follow-up

Pancreatic neuroendocrine tumors (P-NETs) secreting ectopic adrenocorticotropic hormones (ACTH) are rare and often delayed in diagnosis due to their atypical clinical characteristics. Here, we describe a case of P-NET in the pancreatic tail. The tumor had metastasized to the liver and secreted gastrin and ACTH. A 60-year-old female patient was diagnosed with gastrinoma in the pancreatic tail with liver metastases in 2015. After 3 months, the patient presented refractory hypokalemia and thyroid dysfunction. The final diagnosis was P-NET with ectopic ACTH syndrome (EAS). After cytoreductive surgery and the use of long-acting somatostatin analogs, plasma potassium levels and thyroid function were effectively corrected. Although Sandostatin LAR^® Depot and proton pump inhibitors (PPIs) were used throughout the follow-up period, the tumor relapsed 4 years later. After aggressive treatment, including right hepatectomy, microwave coagulation of the left liver, and cholecystectomy, the tumor returned 4 months later. Finally, the patient underwent three hepatic artery embolizations and 12 courses of CAPTEM regimen chemotherapy. The markers of disease were almost maintained in the normal ranges until now. We have followed up on this case for more than 5 years. A timely and comprehensive examination of hormones and immunohistochemistry is essential. The prognosis of P-NET is poor. Regular long-term follow-up and the application of combined therapies are helpful to control the disease and improve the prognosis.

Hemoglobin A1c Is a Predictor of New Insulin Dependence After Partial Pancreatectomy: A Multi-Institutional Analysis

BACKGROUND

Pancreatic diseases have long been associated with impaired glucose control. This study sought to identify the incidence of new insulin-dependent diabetes mellitus (IDDM) after pancreatectomy and the predictive accuracy of hemoglobin A1c (HbA1c) or blood glucose.

METHODS

Patients who underwent partial pancreatectomy and had preoperative HbA1c available at two academic institutions were assessed for new IDDM on discharge in relation to complication rates and survival.

RESULTS

Of the 267 patients analyzed, 67% had abnormal HbA1c levels prior to surgery (mean 6.8%, glucose 135 mg/dL). Two hundred eight (77.9%) were not insulin-dependent prior to surgery, and 35 (16.8%) developed new IDDM after resection. On multivariable regression, increasing HbA1c and preoperative glucose were the only significant predictors for new IDDM. Optimal predictive cutoffs (HbA1c of 6.25% and glucose of 121 mg/dL) were determined in a discovery group (n = 143) and confirmed in a validation group (n = 124) with a diagnostic sensitivity of 72.7% and specificity of 84.8%. Patients with new IDDM after resection had higher rates of severe complications (OR 3.39), increased TPN at discharge (OR 4.32), and increased rates of discharge to nursing facilities (OR 2.57) (all P < 0.05). New IDDM was also associated with a decreased cancer-specific survival.

CONCLUSION

Preoperative HbA1c ≥ 6.25% and blood glucose ≥ 121 mg/dL can accurately identify patients at increased risk of IDDM. These diagnostics may help identify patients in a preoperative setting that may benefit from interventions such as diabetes education or enhanced glucose control preoperatively.

Younger Age Is Associated with Improved Survival in Patients Undergoing Liver Transplantation Alone for Metastatic Neuroendocrine Tumors

BACKGROUND

Neuroendocrine tumor (NET) metastases are a major cause of morbidity and mortality. The role of liver transplantation to treat unresectable metastases from NET is controversial.

METHODS

We evaluated outcomes of all patients undergoing "isolated" liver transplantation (LT) for metastatic NETs in the USA, from October 1988 through June 2018 using the UNOS dataset.

RESULTS

During the study period, 160,360 LTs were performed. Two hundred six adult patients underwent "isolated" LT for metastatic NETs. The mean (SD) age was 48.2 (11.7) years, ranging from 19 to 75 years; 117 (56.8%) patients were male. Overall 1-, 3-, 5-, and 10-year patient survival rates were 89.1%, 75.3%, 64.9%, and 46.1%, respectively. Tumor recurrence was seen in 70 of 206 patients who underwent LT (34%). The median time to recurrence was 28 months (range, 1 to 192 months) and median wait time for LT was 112 days. Tumor recurrence was significantly higher in transplanted patients waiting less than 6 months compared with those waiting more than 6 months (74.3% vs. 25.7%). Patients' age ≤ 45 years had significantly better survival compared with those > 45 years (p = 0.03). Younger patients with carcinoid tumors had better survival but this trend was not observed in the non-carcinoid group. On multivariable analysis, recipient age, donor age, cold ischemic time MELD score, and tumor recurrence were significant predictors of poor patient survival.

CONCLUSIONS

Waiting time longer than 6 months is associated to lower rates of tumor recurrence. Younger patients ≤ 45 years had significantly improved survival after LT for NET metastases.

A literature-based treatment algorithm for low-grade neuroendocrine liver metastases

BACKGROUND

The optimal timing of treatment of liver metastases from low-grade neuroendocrine tumors (LG-NELM) varies significantly due to numerous treatment modalities and the literature supporting various treatment(s). This study sought to create and validate a literature-based treatment algorithm for LG-NELM.

METHODS

A treatment algorithm to maximize overall survival (OS) was designed using peer-reviewed articles evaluating treatment of LG-NELM. This algorithm was retrospectively applied to patients treated for LG-NELM at our institution. Deviation was determined based on whether or not a patient received treatment consistent with that recommended by the algorithm. Patients who did and did not deviate from the algorithm were compared with respect to OS and number of treatments.

RESULTS

Applying our algorithm to a 149-patient cohort, 57 (38%) deviated from recommended treatment. Deviation occurred in the form of alternative (28, 49%) versus additional procedures (29, 51%). Algorithm deviators underwent significantly more procedures than non-deviators (median 1 vs. 2, p < 0.001). Cox model indicated no difference in OS associated with algorithm deviation (HR 1.19, p = 0.58) when controlling for age and tumor characteristics.

CONCLUSION

This literature-based algorithm helps standardize treatment protocols in patients with LG-NELM and can reduce cost and risk by minimizing unnecessary procedures. Prospective implementation and validation is required.

Operative Microwave Ablation for the Multimodal Treatment of Neuroendocrine Liver Metastases

Background and Purpose: Operative microwave ablation (MWA) is a safe modality for treating hepatic tumors. The aim of this study is to present our 10-year, single-center experience of operative MWA for neuroendocrine liver metastases (NLM). Methods: A single-institution retrospective review of patients who underwent operative MWA for NLM was performed (2008-2018). Demographics, primary tumor site, operative approach, combined surgical operations, and carcinoid symptoms were recorded. Clinical outcomes for major complications, readmission, and mortality were analyzed 30 days postoperatively. Postablation imaging was evaluated for incomplete ablation/missed lesions, and surveillance imaging reviewed for local, regional, and metastatic recurrence. Results: Of the 50 patients (166 targeted lesions) who received MWA for NLM, 41 (82%) were treated with a minimally invasive approach, and 22 (44%) underwent MWA concomitant with hepatectomy and/or primary tumor resection. Within the study cohort 70% of patients were treated with curative intent with a 77% (27/35) success rate. Carcinoid symptoms were reported in 40% (20/50) of patients preoperatively, and MWA treatment improved symptoms in 19/20 patients. Incomplete ablation occurred in 1/166 treated lesions. Recurrence-free survival at 1 and 5 years was 86% and 28%, respectively. Overall survival at 1 and 5 years was 94% and 70%, respectively (median follow-up 32 months, range 0-116 months). Conclusion: Operative MWA is a versatile modality, which can be safe and effectively performed alone or combined with hepatectomy for NLM, preferably using a minimally invasive approach, to achieve symptom control and possibly improve survival.

Multi-institutional Development and External Validation of a Nomogram Predicting Recurrence After Curative Liver Resection for Neuroendocrine Liver Metastasis

OBJECTIVES

To establish and externally validate a novel nomogram to predict recurrence of patients undergoing curative liver resection for neuroendocrine liver metastasis (NELM).

METHODS

A total of 279 patients who underwent curative liver resection for NELM identified from an international multicenter database were utilized to develop a nomogram to predict recurrence; 98 cases from two different institutions were used to externally validate the nomogram.

RESULTS

Among 279 patients in the development cohort, median age was 57 years, and 50.5% were male. On multivariate analysis, primary tumor location (pancreatic vs nonpancreatic, HR 2.1, p = 0.004), tumor grade (Ref. well, moderate HR 1.9, p = 0.022; poor HR 1.6, p = 0.238), lymph node metastasis (positive vs negative, HR 2.6, p = 0.002), and extent of resection (major vs parenchymal-sparing resection, HR 0.3, p = 0.001) were independently associated with recurrence-free survival. The beta coefficients from the final multivariable model were utilized to develop a nomogram. The nomogram demonstrated good ability to predict risk of recurrence (training cohort, C-index 0.754; validation cohort, C-index 0.748). The calibrated nomogram predicted recurrence-free survival that closely corresponded to actual recurrence. Decision curve analysis demonstrated that the nomogram had a good net benefit for most of the threshold probabilities, especially between 20 and 60%, in both development and validation cohorts.

CONCLUSIONS

The externally validated novel nomogram predicted 3- and 5-year recurrence-free survival among patients with NELM. Prediction of individual recurrence risk may help guide personalized estimates of prognosis, as well as surveillance protocols and consideration of adjuvant therapies.

Resection of pancreatic neuroendocrine tumors: defining patterns and time course of recurrence

BACKGROUND

To define recurrence patterns and time course, as well as risk factors associated with recurrence following curative resection of pNETs.

METHOD

Patients who underwent curative-intent resection for pNET between 1997 and 2016 were identified from the US Neuroendocrine Tumor Study Group. Data on baseline and tumor-specific characteristics, overall survival (OS), timing and first-site of recurrence, predictors and recurrence management were analyzed.

RESULTS

Among 1020 patients, 154 (15.1%) patients developed recurrence. Among patients who experienced recurrence, 76 (49.4%) had liver-only recurrence, while 35 (22.7%) had pancreas-only recurrence. The proportion of liver-only recurrence increased from 54.3% within one-year after surgery to 61.5% from four-to-six years after surgery; whereas the proportion of pancreas-only recurrence decreased from 26.1% to 7.7% over these time periods. While liver-only recurrence was associated with tumor characteristics, pancreas-only recurrence was only associated with surgical margin status. Patients undergoing curative resection of recurrence had comparable OS with patients who had no recurrence (median OS, pancreas-only recurrence, 133.9 months; liver-only recurrence, not attained; no recurrence, 143.0 months, p = 0.499) CONCLUSIONS: Different recurrence patterns and timing course, as well as risk factors suggest biological heterogeneity of pNET recurrence. A personalized approach to postoperative surveillance and treatment of recurrence disease should be considered.

Radiographic characteristics of neuroendocrine liver metastases do not predict clinical outcomes following liver resection

Background

Previous research has demonstrated that specific radiographic criteria, including the presence of calcifications and the enhancement pattern on computed tomography (CT) imaging, correlates with clinicopathologic features and outcomes of patients with gastroenteropancreatic neuroendocrine tumors (NET). We sought to investigate whether these radiographic characteristics were prognostic among patients with neuroendocrine liver metastases (NELM) undergoing surgical resection.

Methods

The preoperative contrast-enhanced CT scans of all patients who underwent resection of NELM at a single institution between 2000-2015 were retrospectively reviewed. The presence of calcifications was determined on non-contrast phase imaging. Enhancement on the arterial phase scan was categorized as hyperenhancing, hypoenhancing, or mixed. Relevant clinicopathologic characteristics as well as recurrence-free survival (RFS) and overall survival (OS) were compared between groups.

Results

Among 82 patients who underwent resection of NELM, 57 had available data on calcifications while 51 had data available on arterial enhancement patterns. Among all patients, median age was 58 (IQR: 47-63) and the majority were female (N=48, 59.5%). The most common primary tumor locations were pancreas (N=25, 30.5%) and small bowel (N=27, 32.9%). The most commonly performed operations were right hepatectomy (N=29, 35.4%), bisegmentectomy (N=15, 18.3%), and segmentectomy (N=14, 17.1%). Median tumor number was 4 (IQR: 2-9), median Ki-67 was 5% (IQR: 2-10%), and median size of the largest liver metastasis was 4.5 (IQR: 2.8-7.7) cm. Twelve (21%) patients had tumor calcifications. Among patients with and without calcifications there were no differences in demographics, clinicopathologic characteristics, RFS (P=0.772) or OS (P=0.095). Arterial enhancement was hypoenhancing in 23 (45.1%), hyperenhancing in 10 (19.6%), and mixed in 18 (35.3%). Similarly, there were no differences between arterial enhancement groups in demographics, clinicopathologic characteristics, RFS (P=0.618) or OS (P=0.268).

Conclusions

Radiographic characteristics on contrast-enhanced CT are not associated with the outcomes of patients undergoing resection of NELM. Future investigations should evaluate the prognostic impact of functional neuroendocrine imaging.

Multimodality management, recurrence patterns, and long-term outcome of gastroenteropancreatic neuroendocrine neoplasms: Progress over 17 years

BACKGROUND

Many advances in the management of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) happened in the last two decades. This study highlights the progress in its management over 17 years, outcomes, recurrence patterns, and follow up protocols.

METHODS

This retrospective analysis of prospectively maintained database at a single tertiary center included GEP-NEN patients from January 2001 to August 2017. Management protocols were based on European Neuroendocrine Tumor Society guidelines. Recurrences were categorized as follows: localized nodal, regional, distant hepatic, or combined. Patients were divided into cohorts: cohort 1 (2001-2006), cohort 2 (2007-2011), and cohort 3 (2012-2017). Survival patterns were analyzed.

RESULTS

One hundred and ninety-two patients were included with 98 (51.04%) grade (G) 1, 64 (33.34%) G2, and 30 (15.63%) G3. One hundred and four (54.16%) underwent curative surgery (58 G1, 27 G2, and 19 G3). Overall follow up ranged from 3 to 276 months; 39 were lost to follow up. Ninety-six patients had recurrences: 44 regional + distant and 40 liver-limited recurrences. One-, 3-, and 5-year survivals show significant differences among different treatment groups (p < 0.05). Significant increase in curative resections, chemotherapy utilization, and reduced recurrences were noted in cohort 3. Curative (R0) resection offered 1- and 3-year overall survival of 93.3% and 66.7% in cohort 1; 95.8% and 83.1% in cohort 2; and 100% and 92.9% in cohort 3.

CONCLUSION

Curative resection is the most significant factor for improved survival. Debulking surgerical procedure have a role whereas upfront peptide receptor radionuclide therapy is questionable. Chemotherapy improves overall survival in inoperable/metastatic setting. Recurrence patterns indicate that a long-term follow up greater than 10 years is necessary.

Insights into the biology and treatment strategies of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are the second most common primary pancreatic neoplasms after pancreatic ductal adenocarcinoma. PNETs present with widely various clinical manifestation and unfavorable survival rate. The recent advances in next generation sequencing have significantly increased our understanding of the molecular landscape of PNETs and help guide the development of targeted therapies. This review intends to outline a holistic picture of the tumors by discussing current understanding of clinical presentations, up-to-date treatment strategies, novel mouse models, and molecular biology of PNETs. Furthermore, we will provide insight into the future development of more effective targeted therapies that are necessary to manage PNETs.

Surgery Provides Long-Term Survival in Patients with Metastatic Neuroendocrine Tumors Undergoing Resection for Non-Hormonal Symptoms

INTRODUCTION

Patients with metastatic neuroendocrine tumor (NET) often have an indolent disease course yet the outcomes for patients with metastatic NET undergoing surgery for non-hormonal (NH) symptoms of GI obstruction, bleeding, or pain is not known.

METHODS

We identified patients with metastatic gastroenteropancreatic NET who underwent resection from 2000 to 2016 at 8 academic institutions who participated in the US Neuroendocrine Tumor Study Group.

RESULTS

Of 581 patients with metastatic NET to liver (61.3%), lymph nodes (24.1%), lung (2.1%), and bone (2.5%), 332 (57.1%) presented with NH symptoms of pain (n = 223, 67.4%), GI bleeding (n = 54, 16.3%), GI obstruction (n = 49, 14.8%), and biliary obstruction (n = 22, 6.7%). Most patients were undergoing their first operation (85.4%) within 4 weeks of diagnosis. The median overall survival was 110.4 months, and operative intent predicted survival (p < 0.001) with 66.3% undergoing curative resection. Removal of all metastatic disease was associated with the longest median survival (112.5 months) compared to debulking (89.2 months), or palliative resection (50.0 months; p < 0.001). The 1-, 3-, and 12-month mortality was 3.0%, 4.5%, and 9.0%, respectively. Factors associated with 1-year mortality included palliative operations (OR 6.54, p = 0.006), foregut NET (5.62, p = 0.042), major complication (4.91, p = 0.001), and high tumor grade (11.2, p < 0.001). The conditional survival for patients who lived past 1 year was 119 months.

CONCLUSIONS

Patients with metastatic NET and NH symptoms that necessitate surgery have long-term survival, and goals of care should focus on both oncologic and quality of life impact. Surgical intervention remains a critical component of multidisciplinary care of symptomatic patients.

Unmet Medical Needs in Pulmonary Neuroendocrine (Carcinoid) Neoplasms

Pulmonary carcinoids (PCs) display the common features of all well-differentiated neuroendocrine neoplasms (NEN) and are classified as low- and intermediate-grade malignant tumours (i.e., typical and atypical carcinoid, respectively). There is a paucity of randomised studies dedicated to advanced PCs and management principles are drawn from the larger gastroenteropancreatic NEN experience. There is growing evidence that NEN anatomic subgroups have different biology and different responses to treatment and, therefore, should be investigated as separate entities in clinical trials. In this review, we discuss the existing evidence and limitations of tumour classification, diagnostics and staging, prognostication, and treatment in the setting of PC, with focus on unmet medical needs and directions for the future.

Early recurrence of well-differentiated (G1) neuroendocrine liver metastasis after curative-intent surgery: Risk factors and outcome

BACKGROUND

The objective of the current study was to identify the risk of early vs late recurrence of well-differentiated (G1) neuroendocrine liver metastasis (NELM) after curative-intent resection.

METHODS

Patients who underwent curative-intent resection for well-differentiated NELM were identified from a multi-institutional database. Clinicopathological details, as well as the long-term overall (OS) and recurrence free survival (RFS) were obtained and compared. The optimal cutoff value to differentiate early and late recurrence was determined to be 1 year based on trend curve analysis.

RESULTS

Among the 548 patients undergoing curative resection for NELM, 162 patients had a well-differentiated NELM. After a median follow-up of 69 months, 59 (36.4%) patients had tumor recurrence; 23 (39.0%) patients recurred within 1 year (early recurrence) after surgery, while 36 (61.0%) recurred after 1 year (late recurrence). Early recurrence was associated with worse outcome vs late recurrence (5-year OS, 72.4% vs 92.0%; P = 0.020) and no recurrence (5-year OS, 72.4% vs 100.0%; P < 0.001). In addition, postrecurrence survival was worse within 36 months after recurrence among patients who recurred early compared with patients who recurred late (survival after recurrence at 36 months: early recurrence, 71.6% vs late recurrence, 91.4%; P = 0.047), although survival was comparable at 60 months (early recurrence, 71.6% vs late recurrence, 70.0%; P = 0.304). On multivariable analysis, nonfunctional neuroendocrine tumors (hazard ratio [HR], 4.4; 95% confidence interval [CI], 1.2-16.7; P = 0.029) and lymph node metastasis (HR, 3.6; 95% CI, 1.1-11.1; P = 0.028) were independent risk factors for early recurrence, whereas lymph node metastasis (HR, 3.0; 95% CI, 1.2-7.8; P = 0.020) and R1 resection (HR, 3.9; 95% CI, 1.4-10.5; P = 0.008) were independently associated with late recurrence.

CONCLUSIONS

Roughly, one-third of patients with well-differentiated NELM experienced a recurrence following curative-intent surgery. Among patients who recurred, two out of five patients recurred within 1 year after surgery. Early recurrence of well-differentiated NELM was associated with the hormone functional status and lymph node metastasis.

Analysis of recurrence after the resection of pancreatic neuroendocrine tumors

BACKGROUND AND OBJECTIVES

Outcomes after recurrence of resected pancreatic neuroendocrine tumors (PNETs) are not well described. We aim to assess the rate and sites of recurrence, and its effect on clinical outcomes.

METHODS

Retrospective chart review of patients (n = 83) who underwent surgical resection of PNETs at 2 institutions. Patients were treated from September 2002 to July 2010.

RESULTS

There were 13 (16%) recurrences. The most common site of recurrence was the liver (9 patients, 9.6%). The most common treatment of recurrences was chemotherapy (5 patients, 36%). The 1-, 3-, and 5-year disease-free survival was 90.9%, 82.7%, and 72.5%, respectively. Median recurrence-free survival was 127 months. The median follow-up for all PNET patients was 25.8 months (range, 1-140 months). The 3-year survival was 97%. The median follow-up of patients after the diagnosis of a recurrence was 13.8 months. The overall survival for those with and without recurrence was 96.3% and 100%, respectively (P = .36). The age ( P = .002) and lymph node ratio ( P < .001) were predictors of recurrence on multivariate analysis.

CONCLUSIONS

Age and lymph node ratio are significant predictors of recurrence after the resection of PNETs with hepatic metastases being the most common. Survival of patients with recurrence is not significantly different from patients without recurrence.

Current treatment strategies for patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs)

Background

Neuroendocrine tumors (NETs) are rare neoplasms, with an estimated annual incidence of ~ 6.9/100,000. NETs arise throughout the body from cells of the diffuse endocrine system. More than half originate from endocrine cells of the gastrointestinal tract and the pancreas, thus being referred to as gastroenteropancreatic NETs (GEP NETs). The only treatment that offers a cure is surgery, however most patients are diagnosed with metastatic disease, and curative surgery is usually not an option.Since the majority of patients are not candidate for curative surgery, they can be offered long-term systemic treatment, for both symptomatic relief and tumor growth suppression. Evidence based treatment options include somatostatin analogues, everolimus (an mTOR inhibitor), sunitinib (a tyrosine kinase inhibitor), peptide receptor radionuclide therapy (PRRT), chemotherapy, etc., alone or combined with cytoreductive procedures (surgery or liver directed procedures). However, there is an increasing need for novel therapies. Other treatment options being investigated are immunotherapy and epigenetic assessment that may lead to more personalized interventions. Following first line therapy with somatostatin analogues, there is no clear information to date indicating a preferred treatment sequence, and therefore the treatment approach should be individualized based on each NET patient characteristics.

Conclusions

NET patients are increasingly diagnosed throughout the world, usually with metastatic disease and requiring systemic therapy. We believe that each patient should be therefore thoroughly evaluated and individually discussed by a multidisciplinary and dedicated NET-expert team, updated with all treatment options including ongoing clinical trials, and before selecting the proper treatment sequence.

Outcomes and toxicity following Yttrium-90 radioembolization for hepatic metastases from neuroendocrine tumors-a single-institution experience

Background

The prognosis of patients with hepatic metastases from neuroendocrine tumors (NET) is generally good, and radioembolization with Yttrium-90 microspheres is a locoregional therapy that is used in efforts to improve hepatic disease control and survival. This study aims to describe the survival outcomes and toxicities associated with radioembolization for hepatic-predominant metastatic NET in a large single-institution cohort.

Methods

A total of 59 patients underwent radioembolization for metastatic NET with hepatic predominant disease at a single academic center. Patient outcomes were analyzed by Kaplan-Meier survival analysis and toxicities were detailed and described. Ten patients within the cohort underwent post-treatment dosimetric analysis using PET-MRI and normal liver dosimetry was correlated with hepatic fibrosis and toxicity.

Results

Median overall survival from time of radioembolization in the patient cohort was 31 months, and the 1- and 2-year overall survival was 80.4% and 65.6% respectively. Median hepatic progression-free survival and overall progression-free survival were 18 and 13 months, respectively. Three patients died of hepatic failure that was possibly therapy-related. Ten patients underwent evaluation of post-treatment dosimetry following radioembolization. In patients who did not develop hepatotoxicity or hepatic fibrosis, mean dose to normal liver was 25.4 Gy, while the mean liver dose in patients who experienced toxicity (hepatic fibrosis in n=2 and death from hepatic failure in n=1) was 59.1 Gy.

Conclusions

Overall survival following radioembolization for hepatic metastases from NET is excellent; however, deaths that are potentially treatment-related have been observed. Preliminary data regarding dose to normal liver is suggestive of a relation between dosimetry and toxicity, however further work is required to further elucidate the mechanism, correlation with dosimetry, as well as additional patient and tumor factors that may predispose these patients to toxicity.

Neuroendocrine Liver Metastasis: Prognostic Implications of Primary Tumor Site on Patients Undergoing Curative Intent Liver Surgery

BACKGROUND

Neuroendocrine tumors typically arise from pancreatic (PNET) vs. gastrointestinal or thoracic origins (non-PNET). The impact of primary tumor site on long-term prognosis following resection of neuroendocrine liver metastasis (NELM) remains poorly defined. The objective of the current study was to define the association of primary tumor location on prognosis of patients undergoing curative intent liver resection for NELM.

METHODS

Between 1990 and 2014, 421 patients who underwent resection of NELM were identified from a multi-institutional database. Clinicopathological characteristics, operative details, and outcomes were stratified and analyzed by location of the primary tumor (PNET vs. non-PNET). A propensity score-matched analysis was utilized to assess the impact of primary tumor location on long-term survival.

RESULTS

Among the 421 patients, 197 (46.8%) patients had NELM from a PNET primary while 224 (53.2%) had a non-PNET primary (small bowel, n = 145; rectal, n = 10; bronchial, n = 22; other, n = 47). There were no differences in tumor burden and tumor site, while presence of extrahepatic disease was more common among patients with non-PNET NELM (extrahepatic disease, PNET NELM, n = 11 27.5% vs. non-PNET NELM, n = 29 72.5%; p = 0.010). Patients with PNET NELM were more likely to have non-functional disease compared with patients who had non-PNET NELM (non-functional, PNET NELM, n = 117 54.9% vs. non-PNET NELM, n = 96 45.1%; p = 0.011). On the final pathological specimen of the resected NELM, patients with PNET NELM were more likely to have a moderately differentiated tumor (59.3%), while patients with non-PNET NELM were more likely to have a poorly differentiated tumor (67.8%) (p = 0.005). Patients with PNET NELM had a worse 5-year DFS and 5-year OS compared with patients who had non-PNET NELM (DFS, PNET 36.2% vs. non-PNET 55.2%; p = 0.001 and OS, PNET 79.5% vs. non-PNET 83.4%; p = 0.008). After propensity score matching, both 5-year DFS and 5-year OS of the PNET and non-PNET groups were comparable (DFS, PNET 46.2% vs. non-PNET 55.9%; p = 0.22 and OS, PNET 81.5% vs. non-PNET 84.3%; p = 0.19).

CONCLUSION

PNET patients more often present with non-functional NELM and moderately differentiated tumors. On propensity-matched analysis, factors such as extrahepatic disease and tumor grade, but not primary tumor location, were associated with prognosis of patients undergoing curative intent liver surgery for NELM.

Update in the Therapy of Advanced Neuroendocrine Tumors

OPINION STATEMENT

Neuroendocrine tumors (NETs) are rare neoplasms, with an estimated annual incidence of ~ 6.9/100,000. NETs arise throughout the body from cells of the diffuse endocrine system. More than half originate from endocrine cells of the gastrointestinal tract and the pancreas, thus being referred to as gastroenteropancreatic NETs (GEP-NETs). The only treatment that offers a cure is surgery; however, most patients are diagnosed with metastatic disease, and curative surgery is usually not an option. These patients can be offered long-term systemic treatment, for both symptomatic relief and tumor growth suppression. Evidence-based treatment options include somatostatin analogs, everolimus (a mTOR inhibitor), sunitinib (a tyrosine kinase inhibitor), and peptide receptor radionuclide therapy, alone or combined with cytoreductive procedures (surgery or liver-directed procedures). Other treatment options being investigated are immunotherapy and epigenetic assessment that may lead to more personalized interventions. We believe that each patient should be thoroughly evaluated and their case discussed by a multidisciplinary team that is up-to-date with all treatment modalities including ongoing clinical trials, before selecting the proper treatment option.

Early Recurrence of Neuroendocrine Liver Metastasis After Curative Hepatectomy: Risk Factors, Prognosis, and Treatment

BACKGROUND

Early tumor recurrence after curative resection typically indicates a poor prognosis. The objective of the current study was to investigate the risk factors, treatment, and prognosis of early recurrence of neuroendocrine tumor (NET) liver metastasis (NELM) after hepatic resection.

METHODS

A total of 481 patients who underwent curative-intent resection for NELM were identified from a multi-institutional database. Data on clinicopathological characteristics, intraoperative details, and outcomes were documented. The optimal cutoff value to differentiate early and late recurrence was determined to be 3 years based on linear regression.

RESULTS

With a median follow-up of 60 months, 223 (46.4%) patients developed a recurrence, including 158 (70.9%) early and 65 (29.1%) late recurrences. On multivariable analysis, pancreatic NET, primary tumor lymph node metastasis, and a microscopic positive surgical margin were independent risk factors for early intrahepatic recurrence. While recurrence patterns and treatments were comparable among patients with early and late recurrences, early recurrence was associated with worse disease-specific survival than late recurrences (10-year NELM-specific survival, 44.5 vs 75.8%, p < 0.001). Among the 34 (21.5%) patients who underwent curative treatment for early recurrence, post-recurrence disease-specific survival was better than non-curatively treated patients (10-year NELM-specific survival, 54.2 vs 26.3%, p = 0.028), yet similar to patients with late recurrences treated with curative intent (10-year NELM-specific survival, 54.2 vs 37.4%, p = 0.519).

CONCLUSIONS

Early recurrence after surgery for NELM was associated with the pancreatic type, primary lymph node metastasis, and extrahepatic disease. Re-treatment with curative intent prolonged survival after recurrence, and therefore, operative intervention even for early recurrences of NELM should be considered.

Timing of disease occurrence and hepatic resection on long-term outcome of patients with neuroendocrine liver metastasis

BACKGROUND AND OBJECTIVES

The objective of the study was to evaluate the impact of timing of disease occurrence and hepatic resection on long-term outcome of neuroendocrine liver metastasis (NELM).

METHODS

A total of 420 patients undergoing curative-intent resection for NELM were identified from a multi-institutional database. Date of primary resection, NELM detection and resection, intraoperative details, disease-specific (DSS), and recurrence-free survival (RFS) were obtained.

RESULTS

A total of 243 (57.9%) patients had synchronous NELM, while 177 (42.1%) developed metachronous NELM. On propensity score matching (PSM), patients with synchronous versus metachronous NELM had comparable DSS (10-year DSS, 76.2% vs 85.9%, P = 0.105), yet a worse RFS (10-year RFS, 34.1% vs 59.8%, P = 0.008). DSS and RFS were comparable regardless of operative approach (simultaneous vs staged, both P > 0.1). Among patients who developed metachronous NELM, no difference in long-term outcomes were identified between early (≤2 years, n = 102, 57.6%) and late (>2 years, n = 68, 42.4%) disease on PSM (both P > 0.1).

CONCLUSIONS

Patients with synchronous NELM had a higher risk of tumor recurrence after hepatic resection versus patients with metachronous disease. The time to development of metachronous NELM did not affect long-term outcome. Curative-intent hepatic resection should be considered for patients who develop NELM regardless of the timing of disease presentation.

Peptide Receptor Radionuclide Therapy Outcomes in a North American Cohort With Metastatic Well-Differentiated Neuroendocrine Tumors

OBJECTIVES

The objective of this study was to describe the outcomes of patients in the University of Iowa Neuroendocrine Tumor (NET) Database treated with peptide receptor radionuclide therapy (PRRT).

METHODS

One hundred thirty-five patients from the University of Iowa NET Database who received PRRT were analyzed, their characteristics were described, and survival was calculated.

RESULTS

The median age at diagnosis was 51 years, and 64% were men. The primary tumor was located in the small bowel (SBNET) in 37.8%, in the pancreas (PNET) in 26.0%, in the lung in 13.3%, in unknown primary in 9.6%, and in other sites in 13.3%. A radiographic response of any magnitude was observed in 65.8%, 11.1% had a mixed response, and 15.4% showed progression. The overall survival (OS) from the first PRRT was 40 months, and the median time to progression was 23.9 months. Higher pretreatment chromogranin A and pancreastatin levels predicted inferior OS.

CONCLUSIONS

Peptide receptor radionuclide therapy resulted in a relatively long OS and time to progression in heavily pretreated North American patients with advanced NETs. Elevated pretreatment chromogranin A and pancreastatin predicted shorter OS after therapy. Peptide receptor radionuclide therapy is a valuable treatment option in patients with advanced NETs, especially SBNETS.

Neuroendocrine liver metastasis: The chance to be cured after liver surgery

BACKGROUND AND OBJECTIVE

Neuroendocrine liver metastasis tumors (NELM) are a heterogeneous group of neoplasms with varied histologic features and a wide range of clinical behaviors. We aimed to identify the fraction of patients cured after liver surgery for NELM.

METHODS

Cure fraction models were used to analyze 376 patients who underwent hepatectomy with curative intent for NELM.

RESULTS

The median and 5-year disease-free survival (DFS) were 4.5 years and 46%, respectively. The probability of being cured from NELM by liver surgery was 44%; the time to cure was 5.1 years. In a multivariable cure model, type of neuroendocrine tumor (NET), grade of tumor differentiation, and rate of liver involvement resulted as independent predictors of cure. The cure fraction for patients with well differentiated NELM from gastrointestinal NET or a functional pancreatic NET, and with <50% of liver-involvement was 95%. Patients who had moderately/poorly differentiated NELM from a non-functional pancreatic NET, and with <50% of liver-involvement was 43%. In the presence of all the three unfavorable prognostic factors (nonfunctional PNET, liver involvement >50%, moderately/poorly differentiation), the cure fraction was 8%.

CONCLUSIONS

Statistical cure after surgery for NELM is possible, and allow for a more accurate prediction of long-term outcome among patients with NELM undergoing liver resection.

Neuroendocrine tumor liver metastases treated with yttrium-90 radioembolization

OBJECTIVE

Yttrium-90 (Y-90) radioembolization is an emerging treatment option for unresectable neuroendocrine liver metastases (NELM). However, the data regarding this treatment are currently limited. This study evaluates the efficacy and tolerability of Y-90 radioembolization and identifies prognostic factors for radiographic response and survival.

METHODS AND MATERIALS

Thirty-eight patients underwent Y-90 radioembolization for NELM at our institution between April 2004 and February 2012. Patients were assessed radiographically (RECIST criteria, enhancement), serologically, and clinically at 1month, and then at every 3months after treatment for tumor response, toxicity, and survival outcomes.

RESULTS

Median length of follow-up was 17.0months (IQR, 9.0-37.0). Median survival was 29.2months. Three patients (9%) had a radiographic complete response to treatment, 6 (17%) had a partial response, 21 (60%) had stable disease, and 5 (14%) developed progressive disease. Two factors were significantly associated with a good radiographic response (complete/partial response): islet cell histological subtype (p=0.043) and hepatic tumor burden ≥33% (p=0.031). Multivariate analysis revealed that patients requiring multiple Y-90 treatments (HR 2.9, p=0.035) and patients who had previously failed systemic therapy with octreotide/chemotherapy (HR 4.4, p=0.012) had worse survival. Grade 3 serologic toxicity was observed in 2 patients (5%; hyperbilirubinemia, elevated alkaline phosphatase) after treatment. Grade 3 non-serologic toxicities included abdominal pain (11%), fatigue (11%), nausea/vomiting (5%), ascites (5%), dyspnea (3%), diarrhea (3%), and peripheral edema (3%). No grade 4 or 5 toxicity was reported.

CONCLUSIONS

Y-90 radioembolization is a promising treatment option for inoperable NELM and is associated with low rates of grade≥3 toxicity.

Diagnosis and management of gastrointestinal neuroendocrine tumors: An evidence-based Canadian consensus

The majority of neuroendocrine tumors originate in the digestive system and incidence is increasing within Canada and globally. Due to rapidly evolving evidence related to diagnosis and clinical management, updated guidance on the diagnosis and treatment of gastrointestinal neuroendocrine tumors (GI-NETs) are of clinical importance. Well-differentiated GI-NETs may exhibit indolent clinical behavior and are often metastatic at diagnosis. Some NET patients will develop secretory disease requiring symptom control to optimize quality of life and clinical outcomes. Optimal management of GI-NETs is in a multidisciplinary environment and is multimodal, requiring collaboration between medical, surgical, imaging and pathology specialties. Clinical application of advances in pathological classification and diagnostic technologies, along with evolving surgical, radiotherapeutic and medical therapies are critical to the advancement of patient care. We performed a systematic literature search to update our last set of published guidelines (2010) and identified new level 1 evidence for novel therapies, including telotristat etiprate (TELESTAR), lanreotide (CLARINET), everolimus (RADIANT-2; RADIANT-4) and peptide receptor radionuclide therapy (PRRT; NETTER-1). Integrating these data with the clinical knowledge of 16 multi-disciplinary experts, we devised consensus recommendations to guide state of the art clinical management of GI-NETs.

Impact of Chemotherapy and External-Beam Radiation Therapy on Outcomes among Patients with Resected Gallbladder Cancer: A Multi-institutional Analysis

BACKGROUND

Use of adjuvant chemotherapy (CTx) and chemoradiation therapy (cXRT) for the treatment of gallbladder cancer (GBC) remains varied. We sought to define the utilization and effect of adjuvant therapy for patients with GBC.

METHODS

Using a multi-institutional national database, 291 patients with GBC who underwent curative-intent resection between 2000 and 2015 were included. Patients with metastasis or an R2 margin were excluded.

RESULTS

Median patient age was 66.6 years. Most patients had a T2 (46.2 %) or T3 (38.6 %) lesion, and 37.8 % of patients had lymph node (LN) metastasis. A total of 186 (63.9 %) patients underwent surgery alone, 61 (21.0 %) received CTx, and 44 (15.1 %) patients received cXRT. On multivariable analysis, factors associated with worse overall survival (OS) included T3/T4 stage [hazard ratio (HR) 1.82], LN-metastasis (HR 1.84), lymphovascular invasion (HR 2.02), perineural invasion (HR 1.42), and R1 surgical margin status (HR 2.06); all P < 0.05). In contrast, receipt of CTx/cXRT was associated with improved OS (CTx, HR 0.38; cXRT, HR 0.26; P < 0.001) compared with surgery alone. Similar results were observed for disease-free survival (DFS) (CTx, HR 0.61; cXRT, HR 0.43; P < 0.05). Of note, only patients with high-risk features, such as AJCC T3/T4 stage (HR 0.41), LN metastasis (HR 0.45), and R1 disease (HR 0.21) (all P < 0.05) derived an OS benefit from CTx/cXRT.

CONCLUSIONS

Adjuvant CTx/cXRT was utilized in 36 % of patients undergoing curative-intent resection for GBC. After adjusted analyses, CTx/cXRT were independently associated with improved long-term outcomes, but the benefit was isolated to only patients with high-risk characteristics.

Elevated Alkaline Phosphatase Prior to Transarterial Chemoembolization for Neuroendocrine Tumors Predicts Worse Outcomes

INTRODUCTION

We hypothesized that an elevated preoperative alkaline phosphatase (AP) predicted worse outcomes for patients undergoing transarterial chemoembolization (TACE) for neuroendocrine tumor (NET) liver metastases.

METHODS

We reviewed all patients who underwent TACE for metastatic NET between 2009 and 2013. Survival was evaluated using preprocedure variables.

RESULTS

One hundred and nine patients underwent 210 TACE procedures. The average age was 57.7 years (range 20-78). Primary sites included pancreas (N = 20), other gastrointestinal (N = 52), lung (N = 9), and unknown (N = 28). The tumor was grade 1 in 68 (62 %), grade 2 in 21 (19 %), and grade 3 in 3 (3 %). Extrahepatic disease was present in 54 (50 %) and greater than 50 % hepatic tumor burden by imaging in 63 (58 %). Elevated bilirubin occurred in 8 (7 %), elevated AP in 22 (20 %), elevated ALT in 21 (19 %), and elevated AST in 41 (38 %). Univariate predictors included tumor grade (43 vs 27 vs 21 months, p = 0.015), hepatic tumor burden (59 vs 37 months, p = 0.009), and elevated AP (59 vs 23 months, p < 0.001). On multivariate analysis, only elevated AP (p = 0.001) predicted worse survival.

CONCLUSIONS

Elevated AP prior to TACE for metastatic NET portends a worse survival outcome, even more so than tumor grade or extent of hepatic disease.

Quality of life after treatment of neuroendocrine liver metastasis

BACKGROUND

A large subset of patients with neuroendocrine liver metastasis (NELM) is symptomatic at the time of presentation. In addition to improving survival, treatment of NELM seeks to provide palliation of symptoms. However, data on health-related quality of life (QoL) are uncommon. We sought to define patient-reported QoL after treatment of NELM.

METHODS

Patients who underwent treatment of NELM at Johns Hopkins Hospital between 1998 and 2013 and who were alive as of March 2014 were identified (n = 125). These patients were invited to complete a QoL survey designed using validated assessment tools, to assess their physical, mental, and general health before treatment, after the most recent treatment and at the time of the study. Clinicopathologic data were collected and correlated with QoL data.

RESULTS

The response rate was 68.0% (n = 85). Median patient age was 55 y and most were male (59.2%). Most patients had a pancreatic (24.7%) or a small bowel (37.7%) primary tumor; the overwhelming majority had multiple NELM (83.5%). Patient-reported symptoms before any treatment included diarrhea (41.1%), flushing (34.1%), fatigue (36.5%), and osteoarticular pain (18.8%). Initial treatment of NELM consisted of surgery in 55 patients (64.7%) and nonsurgical treatment in 30 patients (35.3%). Many patients reported an overall improvement in physical health and mental health. Specifically, the proportion of patients reporting diarrhea (before any treatment, 41.1% versus currently, 25.9%; P = 0.019) and flushing (before any treatment, 34.1% versus currently, 10.5%; P < 0.001) tended to decrease over time and a lower proportion of patients reported to be currently sad about being ill (before any treatment, 31.8% versus currently, 23.2%; P = 0.009). Patients with a very poor QoL at the time of the diagnosis were more likely to experience an improvement in QoL after treatment. Interestingly, there was no difference in the improvement in overall QoL whether the initial treatment for NELM was surgical or nonsurgical; however, a lower proportion of patients were dissatisfied with surgery versus nonsurgical therapy (5.4% versus 9.4%; P = 0.001).

CONCLUSIONS

Less than one-fourth of patients experienced a significant improvement in QoL after treatment of NELM. The patients who benefit the most of treatment were those who were more symptomatic before any treatment.

Liver transplantation for metastatic neuroendocrine tumors

Neuroendocrine tumors are a heterogeneous group of rare epithelial tumors. Most of them are metastatic at the time of initial diagnosis. Liver transplantation (LT) has been proposed in selected patients with diffuse liver involvement. Rationale for LT in this indication is based on the frequently indolent nature of neuroendocrine tumors, the propensity for liver-only metastasis and the high rate of intrahepatic recurrence after resection. However, indications for LT for neuroendocrine liver metastases remain controversial, and patient selection criteria is still a matter of debate. The aim of this review is to summarize data regarding LT for neuroendocrine liver metastases by answering frequently asked questions about this issue.

Expanded criteria for carcinoid liver debulking: Maintaining survival and increasing the number of eligible patients

BACKGROUND

Cytoreduction of carcinoid liver metastases typically aims for ≥ 90% debulking in patients without extrahepatic disease. Data on the impact of less-restrictive resection criteria and other clinical and tumor-specific factors on outcomes are limited.

METHODS

Records of carcinoid patients undergoing liver debulking from 2007 to 2011 were reviewed. Debulking threshold was 70%, extrahepatic disease did not preclude cytoreduction, and positive margins were allowed. Kaplan-Meier liver progression-free (PFS) and disease-specific (DSS) survival were calculated and compared by log-rank analysis and statistical significance of differences in distributions of factors between patient groups was determined by chi-squared analysis.

RESULTS

Fifty-two patients were identified. Complete resection of intrahepatic and extrahepatic gross disease was achieved in 12 patients. All primaries reviewed were low grade, but one third of patients had at least one intermediate-grade metastasis. Fifteen patients (29%) had liver progression; median PFS was 72 months. Five-year DSS was 90%, with all deaths from liver failure. Only age was an important prognostic factor for PFS and DSS. Five-year DSS for patients <50 years was 73% and was 97% for patients 50 or older (P = .03).

CONCLUSION

The use of expanded criteria for debulking resulted in 90% 5-year DSS. Although younger age portends a poorer prognosis, the favorable PFS and DSS justify also using expanded criteria in this subgroup.

Modern technical approaches in resectional hepatic surgery

Techniques in liver surgery have improved considerably during the last decades, allowing for liver resections with low morbidity and mortality. Preoperative patient selection, perioperative management, and intraoperative blood-sparing techniques are the cornerstones of modern liver surgery. Multimodal treatment of colorectal liver metastases has expanded the group of patients who are potential candidates for liver resection. Adjunctive techniques, including preoperative portal vein embolization and staged hepatectomy, have facilitated the safe performance of extensive liver resection. This article provides an overview of indications for liver resection and a systematic description of the technical approach to the most commonly performed resections.

Role of surgery and transplantation in the treatment of hepatic metastases from neuroendocrine tumor

Neuroendocrine tumors (NET) are a heterogeneous group of cancers, with indolent behavior. The most common primary origin is the gastro-intestinal tract but can also appear in the lungs, kidneys, adrenals, ovaries and other organs. In general, NET is usually discovered in the metastatic phase (40%-80%). The liver is the most common organ involved when metastases occur (40%-93%), followed by bone (12%-20%) and lung (8%-10%).A number of different therapeutic options are available for the treatment of hepatic metastases including surgical resection, transplantation, ablation, trans-arterial chemoembolization, chemotherapy and somatostatin analogues. Recently, molecular targeted therapies have been used, usually in combination with other treatment options, to improve outcomes in patients with metastases. This article emphasizes on the role of surgery in the treatment of liver metastases from NET.

Outcomes following liver transplantation for metastatic neuroendocrine tumors

INTRODUCTION

Metastatic disease is generally considered as an absolute contraindication for liver transplantation. However, due to relatively low aggressiveness and slow progression rates, liver metastases from neuroendocrine tumors (NETs) form an exception to this rule. Given the scarcity of available data, the purpose of this study was to evaluate long-term outcomes following liver transplantation for NET metastases.

MATERIAL AND METHODS

There were 12 primary liver transplantations in patients with NET metastases out of 1334 liver transplantations performed in the Department of General, Transplant and Liver Surgery (Medical University of Warsaw) in the period between December 1989 and October 2013. Overall survival (OS) and disease-free survival (DFS) were set as primary and secondary outcome measures, respectively.

RESULTS

Median follow-up was 7.9 years. For all patients, OS rate was 78.6% at 10 years and DFS rate was 15.5% at 9 years. Intraoperative transfusions of packed red blood cells (P = .021), Ki-67 proliferative index more than 2% (P = .048), and grade 2 tumors (P = .037) were identified as factors significantly associated with worse DFS. Notably, loss of E-cadherin expression (P = .444), mitotic rate (P = .771), extent of liver involvement (P = .548), primary tumor site (P = .983), and recipient age (P = .425) were not significantly associated with DFS.

CONCLUSIONS

Excellent long-term OS rates support liver transplantation for unresectable NET metastases despite almost universal post-transplantation tumor recurrence. Selection of patients with G1 tumors with Ki-67 index not exceeding 2% and reducing the requirement for intraoperative blood transfusions might improve DFS rates.

The efficacy of hepatic 90Y resin radioembolization for metastatic neuroendocrine tumors: a meta-analysis

(90)Y resin radioembolization is an emerging treatment in patients with liver-dominant metastatic neuroendocrine tumors (mNETs), despite the absence of level I data. The aim of this study was to evaluate the efficacy of this modality in a meta-analysis of the published literature.

METHODS

A comprehensive review protocol screened all reports in the literature. Strict selection criteria were applied to ensure consistency among the selected studies: human subjects, complete response data with time interval, resin microspheres, more than 5 patients, not a duplicate cohort, English language, and separate and complete data for resin-based (90)Y treatment of mNET if the study included multiple tumor and microsphere types. Selected studies were critically appraised on 50 study criteria, in accordance with the research reporting standards for radioembolization. Response data (Response Evaluation Criteria in Solid Tumors) were extracted and analyzed using both fixed and random-effects meta-analyses.

RESULTS

One hundred fifty-six studies were screened; 12 were selected, totaling 435 procedures for response assessment. Funnel plots showed no evidence of publication bias (P = 0.841). Critical appraisal revealed a median of 75% of desired criteria included in selected studies. Very high between-study heterogeneity ruled out a fixed-effects model. The random-effects weighted average objective response rate (complete and partial responses, CR and PR, respectively) was 50% (95% confidence interval, 38%-62%), and weighted average disease control rate (CR, PR, and stable disease) was 86% (95% confidence interval, 78%-92%). The percentage of patients with pancreatic mNET was marginally associated with poorer response (P = 0.030), accounting for approximately 23% of the heterogeneity among studies. The percentage of CR and PR correlated with median survival (R = 0.85; P = 0.008).

CONCLUSION

This meta-analysis confirms radioembolization to be an effective treatment option for patients with hepatic mNET. The pooled data demonstrated a high response rate and improved survival for patients responding to therapy.