Surgical management of advanced pancreatic neuroendocrine tumors: short-term and long-term results from an international multi-institutional study

Proactive multi-modality treatment of Pancreatic Neuroendocrine Tumours (PNETs): Potential survival benefits

BACKGROUND/OBJECTIVES

Primary and metastatic pancreatic neuroendocrine tumours (PNET) can be treated with combination of surgery, locoregional and systemic therapy. Survival benefits from individual treatments have been well reported, however, the combined outcome from multimodal treatments are not well described in the literature. We report outcomes in a cohort of PNET patients treated with proactive, multimodality therapy.

METHODS

106 patients were identified from a single tertiary referral centre prospective database. Outcomes of treatment were studied, with the primary end point being death from any cause.

RESULTS

Median follow-up was 71 months and overall 5-year survival of 62%. In patients with stage I-III disease (51 patients) estimated 5-year survival was 90%. Median survival in patients with stage IV disease was 51 months with an estimated 5-year survival of 40% in this group. A total of 80 patients (75%) had surgery of which 16% suffered complications requiring intervention. There was no perioperative mortality.

CONCLUSIONS

This study demonstrates that proactive multimodal treatment is safe and may confer a survival benefit to patients in this cohort compared to historical data.

Predictive Effect of the Total Number of Examined Lymph Nodes on N Staging and Survival in Pancreatic Neuroendocrine Neoplasms

OBJECTIVES

We aim to examine the predictive effect of the total number of examined lymph nodes on N stage and survival in pancreatic neuroendocrine neoplasms (pNENs) and to determine the optimal threshold.

METHODS

A pNENs data set from 2004 to 2013 was extracted from the Surveillance, Epidemiology, and End Result database. Multivariate logistic regression and Cox proportional hazards model were used to identify predictive factors associated with N stage and survival, respectively.

RESULTS

Totally, 1280 pNENs were analyzed. The 11 to 15 lymph nodes examined showed a strong association with the N1 stage (6-10 vs 11-15: odds ratio, 0.672; P = 0.042; 11-15 vs 16-20: odds ratio, 1.049; P = 0.840). However, it failed to show any survival benefit in pNENs with or without lymph node metastasis.

CONCLUSIONS

Examining at least 11 lymph nodes may be useful to accurately classify the N stage for pNENs.

Major postoperative complications after pancreatic resection for P-NETS are not associated to earlier recurrence

BACKGROUND

The oncological impact of surgical complications has been studied in visceral and pancreatic cancer.

AIM

To investigate the impact of complications on tumour recurrence after resections for pancreatic neuroendocrine tumours.

METHODS

We have retrospectively analysed 105 consecutive resections performed at the Royal Free London Hospital from 1998 to 2014, and studied the long-term outcome of nil-minor (<3) versus major (≥3) Clavien-Dindo complications (CD) on disease-free (DFS) and overall survival (OS).

RESULTS

The series accounted for 41 (39%) pancreaticoduodenectomies, two (1.9%) central, 48 (45.7%) distal pancreatectomies, eight (7.6%) enucleations, four (3.8%) total pancreatectomies. Sixteen (15.2%) were extended to adjacent organs, 13 (12.3%) to minor liver resections. Postoperative complications presented in 43 (40.1%) patients; CD grade 1 or 2 in 23 (21.9%), grades ≥3 in 20 (19%). Among 25 (23.8%) pancreatic fistulas, 14 (13.3%) were grades B or C. Thirty-four (32.4%) patients developed exocrine, and 31 (29.5%) endocrine insufficiency. Seven patients died during a median 27 (0-175) months follow up. Thirty-day mortality was 0.9%. OS was 94.1% at 5 years. Thirty tumours recurred within 11.7 (0.8-141.5) months. DFS was 44% at 5 years. At univariate analysis, high-grade complications were not associated with shorter DFS (p = 0.744). At multivariate analysis, no parameter was independent predictor for DFS or OS. The comparison of nil-minor versus major complications showed no DFS difference (p = 0.253).

CONCLUSION

From our series, major complications after P-NETs resection are not associated to different disease recurrence; hence do not require different follow up or adjuvant regimens.

Impact of Snail and E-cadherin expression in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare type of malignancy with a prognosis that is relatively good, compared with that of pancreatic adenocarcinoma. However, a number of patients with PNETs have distant metastasis and a less favorable prognosis. Epithelial-mesenchymal transition (EMT) is essential for tumor progression and metastasis. Snail and E-cadherin serve key roles in the process of EMT in numerous tumor types, including gastric and pancreatic adenocarcinoma. However, the role of EMT in PNETs remains unclear. The aim of the present study was to investigate the significance of Snail and E-cadherin expression in PNETs. Tissue samples were obtained from 40 resected PNETs. The expression of Snail and E-cadherin was evaluated in the primary tumors using immunohistochemical staining. The association between protein expression and patient clinicopathological features was then analyzed. High and low Snail expression levels were observed in 11 (27.5%) and 29 (72.5%) patients, respectively. Preserved and reduced E-cadherin expression was observed in 19 (47.5%) and 21 (52.5%) patients, respectively. Patients with low Snail expression and preserved E-cadherin expression had a significantly lower risk of vascular invasion, lymphatic invasion, lymph node metastasis and liver metastasis and a lower WHO classification, as compared with the group that included patients with high Snail and reduced E-cadherin, high Snail and preserved E-cadherin, and low Snail and reduced E-cadherin expression. In addition, the patients with low Snail expression levels and preserved E-cadherin expression had more a favorable prognosis compared with the other group. The present study indicates that EMT serves an important role in tumor progression in PNETs. Immunohistochemical evaluation of Snail and E-cadherin is useful for predicting the risk of vessel invasion and metastasis in PNETs.

A Modular Dual-Labeling Scaffold That Retains Agonistic Properties for Somatostatin Receptor Targeting

Fluorescence-guided surgery is an emerging imaging technique that can enhance the ability of surgeons to detect tumors when compared with visual observation. To facilitate characterization, fluorescently labeled probes have been dual-labeled with a radionuclide to enable cross-validation with nuclear imaging. In this study, we selected the somatostatin receptor imaging agent DOTATOC as the foundation for developing a dual-labeled analog. We hypothesized that a customized dual-labeling approach with a multimodality chelation (MMC) scaffold would minimize steric effects of dye conjugation and retain agonist properties. Methods: An MMC conjugate (MMC-TOC) was synthesized on solid-phase and compared with an analog prepared using conventional methods (DA-TOC). Both analogs were conjugated to IRDye 800 using copper-free click chemistry. The resulting compounds, MMC(IR800)-TOC and DA(IR800)-TOC, were labeled with Cu and ⁶⁴Cu and tested in vitro in somatostatin receptor subtype 2-overexpressing HEK-293 cells to assess agonist properties, and in AR42J rat pancreatic cancer cells to determine receptor binding characteristics. Multimodality imaging was performed in AR42J xenografts. Results: Cu-MMC(IR800)-TOC demonstrated higher potency for cyclic adenosine monophosphate inhibition (half maximal effective concentration [EC₅₀]: 0.21 ± 0.18 vs. 1.38 ± 0.54 nM) and receptor internalization (EC₅₀: 41.9 ± 29.8 vs. 455 ± 299 nM) than Cu-DA(IR800)-TOC. Radioactive uptake studies showed that blocking with octreotide caused a dose-dependent reduction in ⁶⁴Cu-MMC(IR800)-TOC uptake whereas ⁶⁴Cu-DA(IR800)-TOC was not affected. In vivo studies revealed higher tumor uptake for ⁶⁴Cu-MMC(IR800)-TOC than ⁶⁴Cu-DA(IR800)-TOC (5.2 ± 0.2 vs. 3.6 ± 0.4 percentage injected dose per gram). In vivo blocking studies with octreotide reduced tumor uptake of ⁶⁴Cu-MMC(IR800)-TOC by 66%. Excretion of ⁶⁴Cu-MMC(IR800)-TOC was primarily through the liver and spleen whereas ⁶⁴Cu-DA(IR800)-TOC was cleared through the kidneys. Ex vivo analysis at 24 h confirmed PET/CT data by showing near-infrared fluorescence signal in tumors and a tumor-to-muscle ratio of 5.3 ± 0.8 as determined by γ-counting. Conclusion: The findings demonstrate that drug design affected receptor pharmacology and suggest that the MMC scaffold is a useful tool for the development of dual-labeled imaging agents.

Outcomes of 101 Consecutive Surgical Resections of Gastroenteropancreatic Neuroendocrine Tumours (GEPNETs) at Tata Memorial Hospital: a Referral Bias for Nonfunctional Duodenopancreatic Tumours and the Need for Greater Awareness of GEPNETs as a Distinct Entity

Data from India regarding the disease spectrum and surgical results of neuroendocrine tumours (GEPNETs) are sparse. Tempered surgical radicality in a high-volume oncology centre, conforming to existing guidelines, may further our understanding of tumour characteristics and behavioural patterns of nonfunctional GEPNETs. Surgical outcomes of patients with histopathologically confirmed GEPNETs from January 2003 to December 2013 were analyzed from a prospectively maintained database. Tumour grade, organ of primary tumour, perioperative factors, quality/radicality of resection and presence of metastatic disease were correlated with perioperative outcomes, overall survival and disease-free survival. Ninety of the 101 operated patients had nonfunctional tumours. These comprised radical resections (n = 69), organ-preserving procedures (n = 16) and inoperable tumours (n = 5). The primary tumour sites were pancreatic in 48 patients and gastroenteric in 42 patients. The overall perioperative morbidity and mortality rates were 30 and 3 %, respectively. Fifteen patients harboured metastatic disease at presentation. At a median follow-up of 22 months, 18 patients had residual disease, 7 developed recurrences and 10 patients died. The estimated actuarial 5-year overall survival was 81.6 %, and disease-free survival was 67.2 %. Tumour grade and organ of origin (pancreatic vs. gastroenteric) did not influence long-term survival (p = 0.315 and p = 0.624, respectively), but presence of metastatic disease at presentation significantly affected long-term survival (p = 0.009). Nonfunctional pancreatic/duodenal neuroendocrine tumours (NETs) accounted for 76 % of surgical resections at our centre with the minority being other resections. In selected patients with nonfunctional NETs, organ-preserving surgery may provide equivalent long-term survival with decreased operative morbidity. Although tumour grade is considered to be an important prognostic factor, the presence of metastatic disease at presentation also determines long-term survival. The referral bias suggests the need for greater awareness given the favourable long-term outcomes of these tumours. There is a need to correct this referral bias by increasing the awareness of GEPNETs in India.

Management Options for Advanced Low or Intermediate Grade Gastroenteropancreatic Neuroendocrine Tumors: Review of Recent Literature

Our understanding of the biology, genetics, and natural history of neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas has improved considerably in the last several decades and the spectrum of available therapeutic options is rapidly expanding. The management of patients with metastatic low or intermediate grade NETs has been revolutionized by the development of new treatment strategies such as molecular targeting therapies with everolimus and sunitinib, somatostatin analogs, tryptophan hydroxylase inhibitors, and peptide receptor radionuclide therapy that can be used alone or as a multimodal approach with or without surgery. To further define and clarify the utility, appropriateness, and the sequence of the growing list of available therapies for this patient population will require more high level evidence; however, data from well-designed randomized phase III clinical trials is rapidly accumulating that will further stimulate development of new management strategies. It is therefore important to thoroughly review emerging evidence and report major findings in frequent updates, which will expand our knowledge and contribute to a better understanding, characterization, and management of advanced NETs.

Role of Fluorouracil, Doxorubicin, and Streptozocin Therapy in the Preoperative Treatment of Localized Pancreatic Neuroendocrine Tumors

INTRODUCTION

5-Fluorouracil, doxorubicin, and streptozocin (FAS) leads to a 39 % response rate in advanced pancreatic neuroendocrine tumors (pNETs). We sought to validate our hypothesis that preoperative FAS may facilitate resection of locoregionally advanced pNETs by reducing the anatomic extent of the primary tumor.

PATIENTS

All patients who received FAS between 2000 and 2012 as initial therapy for a localized pNET were reviewed. Tumor size and vascular relationships were compared on pretreatment and posttreatment imaging studies to quantify treatment response.

RESULTS

Twenty-nine patients received a median 4 cycles of FAS (range 2-15). Rates of RECIST progressive disease (PD), stable disease (SD), and partial response (PR) were 3, 90, and 7 %, respectively. An interface was observed between the tumor and a major mesenteric artery and/or vein in 19 (66 %) and 24 (83 %) patients, respectively; after therapy with FAS, 17 (59 %) and 22 (76 %) had persistent interface with artery and/or vein. Fourteen (48 %) patients underwent pancreatectomy, 7 (50 %) required vascular management, and 9 (64 %) operations were R0. The median overall survival of unresected and resected patients was 41 months (95 % CI, 16-66) and 112 months (95 % CI, 104-120) (P = 0.04).

CONCLUSIONS

Although patients receiving FAS for locoregionally advanced pNETs are unlikely to progress during systemic therapy, significant "downstaging" appears uncommon.

Shape and Enhancement Characteristics of Pancreatic Neuroendocrine Tumor on Preoperative Contrast-enhanced Computed Tomography May be Prognostic Indicators

BACKGROUND

Prognostic indicators of the malignant potential of pancreatic neuroendocrine tumors (PNET) are limited. We assessed tumor shape and enhancement pattern on contrast-enhanced computed tomography as predictors of malignant potential.

METHODS

Sixty cases of PNET patients undergoing curative surgery from 2001 to 2014 were enrolled onto our retrospective study. Preoperative enhanced CTs were assessed, and criteria defined for regularly shaped and enhancing tumors (group 1), and irregularly shaped and/or enhancing tumors (group 2). The relation of tumor shape and enhancement pattern to outcome was assessed.

RESULTS

Interobserver agreement was substantial (kappa = 0.74). Group 2 (n = 24) was significantly correlated with synchronous liver metastasis (23 vs. 0 %), lymph node metastasis (36 vs. 3 %), pathologic capsular invasion (68 vs. 8 %), larger tumor size (30 vs. 12 mm), tumor, node, metastasis classification system (TNM) stage III/IV disease (46 vs. 3 %), and histologic grade 2/3 (41 vs. 0 %). Multivariate analysis revealed that tumor grade 2/3 and group 2 criteria correlated with tumor relapse (hazard ratio 6.5 and 13.6, P = 0.0071 and 0.039, respectively), and that only group 2 criteria were independently correlated with poor overall survival (hazard ratio 5.56e + 9, P = 0.0041).

CONCLUSIONS

Irregular tumor shape/enhancement on preoperative computed tomography is a negative prognostic factor after curative surgery for PNET.

The efficacy and safety of everolimus for the treatment of progressive gastroenteropancreatic neuroendocrine tumors: A multi-institution observational study in Taiwan

AIM

Everolimus is an inhibitor of mTOR, approved for treatment of advanced pancreatic neuroendocrine tumors (NETs). The purpose of this observational study was to evaluate the efficacy and safety of everolimus in treatment of progressive, advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) in Taiwan.

METHODS

Fifty-three patients with progressive, advanced GEP-NETs who received everolimus treatment between January 2008 and August 2014 were selected. Patient characteristics, tumor features, safety profiles and treatment efficacy were retrospectively analyzed.

RESULTS

Mean follow-up duration was 23.7 (1.2-70) months and 37 of 53 patients (69.8%) remained alive at the end of study. The one- and two-year overall survival rates were 90.5% and 75.4%, respectively. The median progression-free survival (PFS) was 18.9 (95% confidence interval; 10.9-26.8) months. Partial response was observed in 15 (28.3%) patients, 29 (54.7%) patients had stable disease and nine (17%) patients had progressive disease. Patients with World Health Organization (WHO) grade I NETs, nonfunctional tumors and liver metastasis burden <10% had significantly better PFS with everolimus treatment. Adverse events observed were stomatitis (35.8%), hyperglycemia (22.6%) and rash (18.8%). Seven (15.4%) patients experienced severe adverse events (grade 3 or more), including hyperglycemia (4.4%), anemia (4.4%), fatigue (2.2%) and elevated liver function (2.2%). One (2.2%) patient died from grade 5 interstitial pneumonitis.

CONCLUSION

Everolimus was an effective treatment for Taiwanese patients with progressive advanced GEP-NETs. Patients with nonfunctional NETs had a trend toward longer PFS, whereas patients with liver metastases burden <10% had a trend toward longer overall survival time receiving everolimus treatment.

A retrospective cohort study of pancreatic neuroendocrine tumors at single institution over 15 years: New proposal for low- and high-grade groups, validation of a nomogram for prognosis, and novel follow-up strategy for liver metastases

PURPOSE

Pancreatic neuroendocrine tumors (PNETs) exhibit various tumor behaviors and symptoms that are difficult for physicians to stage and predict prognosis. We assess prognostic factors combined with staging classifications to optimal the models and try to improve follow-up strategy to monitor liver metastases after surgery.

METHODS

Patients with PNETs treated at Sun Yat-sen Memorial Hospital between 2000 and 2015 were recruited. Patients were regrouped on the basis of functional status and mitotic rates. Nomograms to predict the prognostic values of classifications (AJCC, ENETS, and WHO) were constructed; the accuracy of the nomograms were quantified by the C-index and calibration plots.

RESULTS

We identified 78 PNETs patients with pathological reports. Correlations with OS in univariate analysis included nonfunctional status (P = 0.002), CgA>200 ng/ml (P < 0.001), Ki-67 (3-20%, P = 0.014; >20%, P < 0.001), and mitotic rate (3-20/10HPF, P = 0.011; >20/10HPF, P < 0.001). By multivariate analysis, nonfunctional status and mitotic rate maintained significance (P = 0.039; 3-20/10HPF, P = 0.015; >20/10HPF, P = 0.007). Evaluating the new proposed system, the difference in OS between low- and high-groups was statistically significant (P = 0.001). The C-index of the regrouped nomograms were higher than that of premise ones (AJCC cohort, 0.605 v 0.576, P < 0.01; ENETS cohort, 0.73 v 0.691, P < 0.01; WHO cohort, 0.678 v 0.603, P < 0.01).

CONCLUSION

An prognostic model based on mitotic rates and functional status correlates strongly with survival. PNETs should return visits every 2 months for the first half years, and every 3 months as followed until 2 years after surgery.

Islet Cell Tumors of the Pancreas

Islet cell tumors of the pancreas, also known as pancreatic neuroendocrine tumors, constitute less than 5% of pancreatic tumors, and 7% of all neuroendocrine tumors. Most are non-functional, and patients often present with metastatic disease. Functional tumors present with distinct clinical syndromes. Accurate staging is critical as surgery is both the cornerstone of treatment, and the only hope for cure. Medical management involves treating the manifestations of hormonal excess, and using somatastatin analogues when appropriate. Systemic chemotherapy, targeted molecular therapy, and peptide receptor radiotherapy may be used for refractory disease in lieu of or as an adjunct to surgery.

Pancreatic Aetiology for Massive Upper Gastrointestinal Haemorrhage in Pregnancy

We present herein what we believe is the first reported case of massive upper gastrointestinal bleeding in pregnancy due to a pancreatic neuroendocrine tumour causing left sided portal hypertension. A 37-year-old 27-week pregnant female presented with massive haematemesis and melaena requiring transfusion of 10 units of red cell concentrate. Gastric varices were evident at endoscopy. An MRI revealed a large mass infiltrating the pancreatic tail and spleen with massive upper abdominal varix formation secondary to splenic vein invasion. A caesarean section was performed, followed by a radical en bloc partial pancreatectomy and splenectomy with resection of the fundus of the stomach and ligation of gastric and splenic varices. Her postoperative course was uncomplicated. Histology revealed a well differentiated grade 2 neuroendocrine tumour with final staging of T4N0. This case highlights an infrequently encountered cause of massive gastrointestinal bleeding. Diagnosis and management of pancreatic neuroendocrine tumours, due to their rarity and variable clinical presentation, can be challenging particularly in the setting of pregnancy where the wellbeing of a second patient must also be considered. A multidisciplinary approach with input from obstetricians and general surgeons is required when deciding optimum management, while also taking into account the patient's preferences.

Adjusted Age-Adjusted Charlson Comorbidity Index Score as a Risk Measure of Perioperative Mortality before Cancer Surgery

Background

Identification of patients at risk of death from cancer surgery should aid in preoperative preparation. The purpose of this study is to assess and adjust the age-adjusted Charlson comorbidity index (ACCI) to identify cancer patients with increased risk of perioperative mortality.

Methods

We identified 156,151 patients undergoing surgery for one of the ten common cancers between 2007 and 2011 in the Taiwan National Health Insurance Research Database. Half of the patients were randomly selected, and a multivariate logistic regression analysis was used to develop an adjusted-ACCI score for estimating the risk of 90-day mortality by variables from the original ACCI. The score was validated. The association between the score and perioperative mortality was analyzed.

Results

The adjusted-ACCI score yield a better discrimination on mortality after cancer surgery than the original ACCI score, with c-statics of 0.75 versus 0.71. Over 80 years of age, 70–80 years, and renal disease had the strongest impact on mortality, hazard ratios 8.40, 3.63, and 3.09 (P < 0.001), respectively. The overall 90-day mortality rates in the entire cohort varied from 0.9%, 2.9%, 7.0%, and 13.2% in four risk groups stratifying by the adjusted-ACCI score; the adjusted hazard ratio for score 4–7, 8–11, and ≥ 12 was 2.84, 6.07, and 11.17 (P < 0.001), respectively, in 90-day mortality compared to score 0–3.

Conclusions

The adjusted-ACCI score helps to identify patients with a higher risk of 90-day mortality after cancer surgery. It might be particularly helpful for preoperative evaluation of patients over 80 years of age.

Surgical management of neuroendocrine tumors

During the last decades an increase in the incidence of neuroendocrine tumors (NETs) was observed. Gastroenteropancreatic NETs represent the majority of NETs. Compared with their epithelial counterpart they usually have a more indolent behaviour and surgical resection improves survival. Tumor diameter is one of the main parameter in the decision making process for nonfunctioning forms. Generally, small lesions can be treated conservatively whereas larger tumors should be treated with standard surgical resection and lymphadenectomy. Functioning tumors should be resected regardless the dimension of the lesion. Locally advanced and metastatic disease should be also treated with extended resections, keeping in consideration the grading, size, Ki67, and presence of extra-abdominal disease. In the case of metastases the panel of operative treatment includes resection, ablation, up to liver transplantation.

Resection versus expectant management of small incidentally discovered nonfunctional pancreatic neuroendocrine tumors

BACKGROUND

Sporadic, nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) are diagnosed with increasing frequency. We compared the risk of tumor growth, metastasis, and mortality between patients treated versus those treated expectantly.

METHOD

A retrospective study of patients seen at our institution with sporadic NF-PNETs, with ≥ 12 months of follow-up. Kaplan-Meier analysis was performed.

RESULTS

Between 1999 and 2014, 35 patients with an incidentally discovered nonfunctional PNET were identified. Twenty underwent resection and 15 were followed with imaging. In the operative group, 8 had NF-PNETs < 2 cm, while 12 had NF-PNETs ≥ 2 cm. In the nonoperative expectant management by serial imaging group, 10 had NF-PNETs < 2 cm while 5 had NF-PNETs ≥ 2 cm. Small NF-PNETs (<2 cm) in either the operative or nonoperative groups demonstrated no evidence of progression or metastasis (median follow-up of 27.8 months). Morbidity in the operative group was 35% with pancreatic pseudocyst the most common.

CONCLUSION

Incidentally discovered NF-PNETs < 2 cm in size can be observed safely with serial imaging.

Long-term outcomes and prognostic factors in 78 Japanese patients with advanced pancreatic neuroendocrine neoplasms: a single-center retrospective study

OBJECTIVE

Despite an increase in the number of Japanese patients with pancreatic neuroendocrine neoplasms, long-term outcomes and prognostic factors, especially for those with advanced disease, remain unclear.

METHODS

We retrospectively reviewed the medical records of 78 patients with unresectable pancreatic neuroendocrine neoplasms treated at our hospital from January 1987 to March 2015. Survival analyses were performed using Kaplan-Meier methods. Prognostic significance of several clinicopathological factors were analyzed by univariate and multivariate analyses using a Cox regression model.

RESULTS

Median overall survivals of pancreatic neuroendocrine tumor (n = 64) and pancreatic neuroendocrine carcinoma (n = 14) were 83.7 and 9.1 months, respectively (hazard ratio: 0.02, 95% confidence interval: 0.01-0.08, P < 0.001). Although no significant differences were observed using a Ki-67 cut-off value of 2% (hazard ratio: 0.46, 95% confidence interval: 0.16-1.13, P = 0.0989), a Ki-67 cut-off of 10% was a significant predictor in patients with pancreatic neuroendocrine tumor (hazard ratio: 9.95, 95% confidence interval, 3.01-32.97, P < 0.001). Treatment after the advent of targeted therapy (hazard ratio: 0.07, 95% confidence interval: 0.03-0.19, P < 0.001) and the presence of bone metastases (hazard ratio: 4.38, 95% confidence interval: 1.42-11.29, P = 0.013) were significant prognostic factors in patients with pancreatic neuroendocrine tumor evaluated by univariate analysis. Multivariate analysis also revealed that a Ki-67 index ≥10% (hazard ratio: 38.8, 95% confidence interval: 8.42-226.62, P < 0.001), approval of targeted therapy (hazard ratio: 0.02, 95% confidence interval: 0.00-0.11, P < 0.001) and bone metastases (hazard ratio: 5.56, 95% confidence interval: 1.10-24.00, P = 0.039) were independent prognostic factors.

CONCLUSIONS

We elucidated the long-term outcomes and prognostic factors in Japanese patients with advanced pancreatic neuroendocrine neoplasms.

Non-functional neuroendocrine tumors of the pancreas: Advances in diagnosis and management

Nonfunctional neuroendocrine tumors of the pancreas (NF-PNETs) are a heterogeneous group of neoplasms. Although rare, the incidence of NF-PNETs is increasing significantly. The classification of PNETs has evolved over the past decades and is now based on a proliferation grading system. While most NF-PNETs are slow growing, tumors with more aggressive biology may become incurable once they progress to unresectable metastatic disease. Tumors of higher grade can be suspected preoperatively based on the presence of calcifications, hypoenhancement on arterial phase computed tomography, positron emission technology avidity and lack of octreotide scan uptake. Surgery is the only curative treatment and is recommended for most patients for whom complete resection is possible. Liver-directed therapies (thermal ablation, transarterial embolization) can be useful in controlling unresectable hepatic metastatic disease. In the presence of unresectable progressive disease, somatostatin analogues, everolimus and sunitinib can prolong progression-free survival. This article provides a comprehensive review of NF-PNETs with special emphasis on recent advances in diagnosis and management.

Systematic Review and Meta-Analysis of Enucleation Versus Standardized Resection for Small Pancreatic Lesions

BACKGROUND

The appropriate surgical strategy in patients with small pancreatic lesions of low malignant potential, such as pancreatic neuroendocrine tumors, remains unknown. Increasing reports suggest limited pancreatic surgery may be a safe option for parenchymal preservation.

METHODS

PubMed and MEDLINE were searched in the English literature for studies from January 2000 to February 2015 examining enucleation for pancreatic lesions that were single-arm and comparative studies (versus resection). Single-arm enucleation studies were systematically reviewed. Comparative studies were included for meta-analysis. Endpoints include safety, complications, mortality, survival, and parenchymal-related outcomes.

RESULTS

Thirteen studies comprising of 1101 patients undergoing enucleation were included. Seven studies were comparative studies of enucleation and standardized pancreatic resection. Enucleation was a shorter procedure (pooled mean differences (MD) = 109, 95 % confidence interval (CI) 105-114; Z = 46.37; P < 0.001) associated with less blood loss (pooled MD = 314, 95 % CI 297-330; Z = 37.47; P < 0.001). Both enucleation and resection had similar mortality and complication rates, but the rate of pancreatic fistula (all grades) (pooled odds ratio (OR) = 1.99; 95 % CI 1.2-3.4; Z = 2.57; P = 0.01] and rate of pancreatic fistula (grade B/C) (pooled OR = 1.58; 95 % CI 1.0-2.5; Z = 2.06; P = 0.04) was higher in the enucleation group. Enucleation resulted in lower rates of endocrine (pooled OR = 0.22; 95 % CI 0.1-0.5; Z = 3.21; P = 0.001) and exocrine (pooled OR = 0.07; 95 % CI 0.02-0.2; Z = 5.08; P < 0.001) insufficiency. The median 5-year survival was 95 % (range 93-98) and 84 % (range 79-90).

CONCLUSIONS

Enucleation appears to be a safe procedure and achieves parenchymal preservation for small pancreatic lesions of low malignant potential. Its oncologic efficacy compared with standardized pancreatic resection with respect to long-term survival and recurrences have not been reported adequately and hence may not be concluded as being comparable.

Aggressive Locoregional Treatment Improves the Outcome of Liver Metastases from Grade 3 Gastroenteropancreatic Neuroendocrine Tumors

Grade 3 (G3) gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are rare, and there is no report specifically dealing with patients of liver metastases from G3 GEP NETs.From January 2004 to January 2014, 36 conservative patients with G3 GEP NET liver metastases were retrospectively identified from 3 hepatobiliary centers in China. The clinical features and treatment outcomes were analyzed.Aggressive locoregional treatments (LT, including cytoreductive surgery, radiofrequency ablation, and liver-directed intra-arterial intervention) and systemic therapy (ST) were introduced separately or combined, with 26 (72%) patients receiving resection of primary tumor and/or hepatic metastases, 12 patients receiving non-surgical locoregional interventions (NSLRIs), and 22 patients receiving certain kind of STs. Median overall survival (OS) was 20.0 months (95% confidence interval [CI]: 8.9-31.1 months) and survival rates were 62.6%, 30.1%, and 19.8%, at 1, 3, and 5 years, respectively. The median OS was 9.0 months (95%CI: 3.3-14.7 months) for patients receiving only STs (n = 6), 19 months (95%CI: 1.3-36.8 months) for patients receiving LT followed by STs (n = 16), and 101 months (95%CI: 0.0-210.2 months) for patients receiving only LT (n = 12). Moreover, compared with those receiving only ST or best supportive care, patients given certain types of LTs had higher rates of symptom alleviation (3/8 versus 20/23). On univariate analysis, positive prognostic factors of survival were pancreatic primary tumor (P = 0.013), normal total bilirubin level (P = 0.035), receiving surgery (P = 0.034), receiving NSLRI (P = 0.014), and sum of diameters of remnant tumor < 5 cm (P = 0.008). On multivariate analyses, pancreatic primary tumor (P = 0.015), normal total bilirubin level (P = 0.002), and sum of diameters of remnant tumor < 5 cm (P = 0.001) remained to be independent prognostic factors.For patients with G3 GEP NET liver metastases, aggressive LTs may improve clinical outcomes. Larger studies with prospective design are warranted to consolidate these results, and to discover the most appropriate seletion criteria for patients to undergo different kinds of aggressive LTs and to find the most effective combinations, with or without ST.

Long-Term Survival with Long-Acting Somatostatin Analogues Plus Aggressive Cytoreductive Surgery in Patients with Metastatic Neuroendocrine Carcinoma

BACKGROUND

Long-acting somatostatin analogues (S-LAR) improve recurrence-free survival in patients with metastatic neuroendocrine tumor (NET) from gastrointestinal (GI) primary, but their impact on overall survival when combined with aggressive cytoreductive surgery is unclear.

STUDY DESIGN

We reviewed our institutional cancer database to identify patients who underwent cytoreductive surgery for metastatic NET from GI primary between December 1997 and June 2013. Additionally, a cohort selected from 3,384 metastatic neuroendocrine cases in the SEER-Medicare database (January 2003 to December 2009) was used to verify and expand on our results.

RESULTS

Most of the 49 patients from our institution had primary lesions in the small intestine (22 of 49 [44.9%]) or pancreas (14 of 49 [28.6%]); 37 patients (75.5%) had metastatic disease at initial diagnosis. These patients underwent 1 (32 of 49 [65.3%]), 2 (11 of 49 [22.4%]), or at least 3 (6 of 49 [12.3%]) surgical procedures; 33 patients (67.3%) underwent resection plus ablation, 19 (38.7%) underwent major hepatectomy, and 34 (69.4%) received S-LAR (29.4% administered preoperatively). Median follow-up was 112 months. Rates of 1-, 5-, 10-, and 15-year disease-specific survival (DSS) were 94%, 78%, 64%, and 31%, respectively, in the 34 patients undergoing aggressive cytoreductive surgery plus S-LAR. Of the SEER-Medicare population, 1,741 patients met inclusion criteria. The DSS for the 104 patients treated with combination therapy was 68.3% at 5 years and 60.6% at 10 years, as compared with 54.7% and 51.8%, respectively, for the 202 patients receiving surgery alone, and 50.0% and 36.0%, respectively, for the 342 patients receiving S-LAR alone (p < 0.0001). The group receiving neither treatment (n = 1,093) had 5-year and 10-year DSS of 34.3% and 26.3%, respectively.

CONCLUSIONS

Long-acting somatostatin analogues combined with aggressive cytoreductive surgery improves the long-term survival of select patients with metastatic NET from GI primary.