One hundred thirty resections for pancreatic neuroendocrine tumor: evaluating the impact of minimally invasive and parenchyma-sparing techniques

Improving fine needle aspiration to predict the tumor biological aggressiveness in pancreatic neuroendocrine tumors using Ki-67 proliferation index, phosphorylated histone H3 (PHH3), and BCL-2

INTRODUCTION

Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells.

MATERIALS AND METHODS

A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed.

RESULTS

After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs.

CONCLUSION

Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.

Risk factors for lymph node metastasis in patients with pancreatic neuroendocrine neoplasms

BACKGROUND

Although PNENs generally have a better prognosis than pancreatic cancers, some PNENs display malignant behavior including lymph node (LN) metastasis. Complete tumor resection can be the only potentially curative treatment for patients with resectable PNENs. However, the indications for LN dissection are still controversial. Over the last decade, minimally invasive surgery such as laparoscopic pancreatic surgery (LPS) has been increasingly performed for pancreatic tumors including PNENs.

AIM

To investigate the risk factors for LN metastasis in PNENs and to select appropriate patients for limited surgery by LPS.

METHODS

From April 2001 to December 2019, 92 patients underwent pancreatic resection for PNENs at Kumamoto University Hospital. Finally, 82 patients were enrolled in this study. Using perioperative factors, we examined the predictive factors for LN metastasis in PNENs.

RESULTS

Among the 82 patients, the percentage of LN metastasis according to the pathological findings was 12% (10/82 cases). The median tumor size was 12 mm (range: 5-90 mm). The median tumor size in the LN-positive group (37 mm) was significantly larger than that in the LN-negative group (12 mm) (P = 0.0001). Multivariate analyses revealed that larger tumor size (≥ 20 mm) was an independent risk factor for LN metastasis (odds ratio 16.8, P = 0.0062). In patients with small tumors (≤ 10 mm), LN metastasis was not found.

CONCLUSION

Larger tumor size (≥ 20 mm) is an independent risk factor for LN metastasis in PNENs. In smaller PNENs (≤ 10 mm), we may be able to choose limited surgery without LN dissection.

What Are the Place and Modalities of Surgical Management for Pancreatic Neuroendocrine Neoplasms? A Narrative Review

Pancreatic neuroendocrine neoplasms (panNENs) are a heterogeneous group of tumors derived from cells with neuroendocrine differentiation. They are considered malignant by default. However, their outcomes are variable depending on their presentation in the onset of hereditary syndromes, hormonal secretion, grading, and extension. Therefore, although surgical treatment has long been suggested as the only treatment of pancreatic neuroendocrine neoplasms, its modalities are an evolving landscape. For selected patients (small, localized, non-functional panNENs), a "wait and see" strategy is suggested, as it is in the setting of multiple neuroendocrine neoplasia type 1, but the accurate size cut-off remains to be established. Parenchyma-sparring pancreatectomy, aiming to limit pancreatic insufficiency, are also emerging procedures, which place beyond the treatment of insulinomas and small non-functional panNENs (in association with lymph node picking) remains to be clarified. Furthermore, giving the fact that the liver is generally the only metastatic site, surgery keeps a place of choice alongside medical therapies in the treatment of metastatic disease, but its modalities and extensions are still a matter of debate. This narrative review aims to describe the current recommended surgical management for pancreatic NENs and controversies in light of the actual recommendations and recent literature.

Frequency of Neuroendocrine Tumor Studies: Using Latent Dirichlet Allocation and HJ-Biplot Statistical Methods

Background: Neuroendocrine tumors (NETs) are severe and relatively rare and may affect any organ of the human body. The prevalence of NETs has increased in recent years; however, there seem to be more data on particular types, even though, despite the efforts of different guidelines, there is no consensus on how to identify different types of NETs. In this review, we investigated the countries that published the most articles about NETs, the most frequent organs affected, and the most common related topics. Methods: This work used the Latent Dirichlet Allocation (LDA) method to identify and interpret scientific information in relation to the categories in a set of documents. The HJ-Biplot method was also used to determine the relationship between the analyzed topics, by taking into consideration the years under study. Results: In this study, a literature review was conducted, from which a total of 7658 abstracts of scientific articles published between 1981 and 2020 were extracted. The United States, Germany, United Kingdom, France, and Italy published the majority of studies on NETs, of which pancreatic tumors were the most studied. The five most frequent topics were t_21 (clinical benefit), t_11 (pancreatic neuroendocrine tumors), t_13 (patients one year after treatment), t_17 (prognosis of survival before and after resection), and t_3 (markers for carcinomas). Finally, the results were put through a two-way multivariate analysis (HJ-Biplot), which generated a new interpretation: we grouped topics by year and discovered which NETs were the most relevant for which years. Conclusions: The most frequent topics found in our review highlighted the severity of NETs: patients have a poor prognosis of survival and a high probability of tumor recurrence.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

Updated Meta-analysis of Minimally Invasive Versus Open Surgery for Pancreatic Neuroendocrine Neoplasms

OBJECTIVES

The aim of this study was to compare the short-term and long-term outcomes of minimally invasive surgery (MIS) with those of open pancreas surgery (OPS) for the treatment of pancreatic neuroendocrine neoplasms (pNENs).

METHODS

Studies reporting the effects of MIS and OPS for pNENs, published on PubMed, Embase, and Cochrane Library before May 2020 were reviewed.

RESULTS

Seventeen cohort studies with a total of 1853 patients were eligible for analysis, including 655 patients in the MIS group and 1198 patients in the OPS group. The estimated blood loss, postoperative hospitalization time, overall complications, severe complications, spleen preservation, mortality, and recurrence in the MIS group were lower than those in the OPS group. The R0 rate, 3-year overall survival (OS), and 5-year OS in the MIS group were higher than those in the OPS group. There were no significant differences in operative time, postoperative pancreatic fistula, clinical postoperative pancreatic fistula, postoperative bleeding, reoperation, readmission, and 1-year OS.

CONCLUSIONS

Minimally invasive surgery can reach lower recurrence rate, higher long-term survival rate, and better outcomes in terms of estimated blood loss, postoperative hospitalization time, R0 rate, mortality, overall complications, and severe complications for pNENs. More high quality studies need to be conducted for further verification.

Minimally invasive vs open pancreatectomy for nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

The mainstay of treating nonfunctioning-pancreatic neuroendocrine tumors(NF-PNETs) is surgical resection. However, minimally invasive approaches to pancreatic resection for treating NF-PNETs are not widely accepted, and the long-term oncological outcomes of such approaches remain unknown.

AIM

To determine the short- and long-term outcomes of minimally invasive pancreatic resection conducted in patients with NF-PNETs.

METHODS

Prospective databases from Severance Hospital were searched for 110 patients who underwent curative resection for NF-PNETs between January 2003 and August 2018.

RESULTS

The proportion of minimally invasive surgery (MIS) procedures performed for NF-PNET increased to more than 75% after 2013. There was no significant difference in post-operative complications (P = 0.654), including pancreatic fistula (P = 0.890) and delayed gastric emptying (P = 0.652), between MIS and open approaches. No statistically significant difference was found in disease-free survival between the open approach group and the MIS group (median follow-up period, 28.1 mo; P = 0.428). In addition, the surgical approach (MIS vs open) was not found to be an independent prognostic factor in treating NF-PNET patients [Exp(β) = 1.062; P = 0.929].

CONCLUSION

Regardless of the type of surgery, a minimally invasive approach can be safe and feasible for select NF-PNET patients.

Prognostic Value and Clinical Predictors of Lymph Node Metastases in Pancreatic Neuroendocrine Tumors

OBJECTIVES

To investigate the correlation between lymph node metastasis (LNM) and various clinicopathological features of pancreatic neuroendocrine tumors (pNETs) and its impact on prognosis.

METHODS

We searched the Surveillance Epidemiology and End Results database (2004-2015) for patients with surgically treated pNETs. Factors correlated with LNMs were analyzed by logistic regression and by Cox analysis.

RESULTS

For tumors of 1 to 4 cm, age (P < 0.001, P = 0.014), grade (P < 0.001, P < 0.001), LNMs (P = 0.008, P < 0.001), and size (P = 0.038, P = 0.002) predicted overall survival (OS) and disease-specific survival (DSS). For tumor greater than 4 cm, age (P < 0.001, P = 0.001) and grade (P = 0.011, P = 0.048) were independent prognostic factors of OS and DSS. Lymph node metastasis modestly predicted DSS (P = 0.028) but not OS (P = 0.218).

CONCLUSIONS

In pNETs greater than 4 cm, LNM is not a predictor of OS and modestly predicts DSS, and lymphadenectomy may be unhelpful in these patients. For pNETs 1 to 4 cm, LNM predicts poor OS and DSS, which supports lymphadenectomy in these patients. Pancreas-sparing resection with only limited peripancreatic node sampling needs to be questioned.

The North American Neuroendocrine Tumor Society Consensus Paper on the Surgical Management of Pancreatic Neuroendocrine Tumors

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the surgical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The group reviewed a series of questions of specific interest to surgeons taking care of patients with pancreatic neuroendocrine tumors, and for each, the available literature was reviewed. What follows are these reviews for each question followed by recommendations of the panel.

Surgical management of pancreatic neuroendocrine tumors: an introduction

Introduction: Neuroendocrine tumors of the pancreas (pNETs) represent only 1% to 2% of all pancreatic neoplasms. These tumors can be classified as functional or nonfunctional tumors; as sporadic or from a genetic origin; as neuroendocrine neoplasms or carcinoma. Over the last decade, diagnosis of pNETs has increased significantly mainly due to the widespread use of cross-sectional imaging. Those tumors are usually associated with a good prognosis. Surgery, the only curative option for those patients, should always be discussed, ideally in a multidisciplinary team setting.Areas covered: We discuss i), the preoperative management of pNETs and the importance of accurate diagnosis, localization, grading and staging with computed tomography, magnetic resonance imaging, endoscopic ultrasound, and nuclear medicine imaging; ii), surgical indications and iii), the surgical approach (standard pancreatectomy vs pancreatic-sparing surgery).Expert opinion: The treatment option of all patients presenting with pNETs should be discussed in a multidisciplinary team setting with surgeon's experienced in both pancreatic surgery and neuroendocrine tumor management. A complete preoperative imaging assessment - morphological and functional - must be performed. Surgery is usually recommended for functional pNETs, nonfunctional pNETs >2 cm (nf-pNETs) or for symptomatic nf-pNETs.

Pre- and intraoperative diagnostic requirements, benefits and risks of minimally invasive and robotic surgery for neuroendocrine tumors of the pancreas

Pancreatic neuroendocrine tumours (PanNET) are rare tumours, accounting for 1%-2% of all pancreatic neoplasms. These tumors are classified as functioning neuroendocrine tumours (F-PanNETs) or non-functioning (NF-PanNETs) depends on whether the tumour is associated with clinical hormonal hypersecretion syndrome or not. In the last decades, diagnosis of PanNETs has increased significantly due to the widespread of cross-sectional imaging. Whenever possible, surgery is the cornerstone of PanNETs management and the only curative option for these patients. Indeed, after R0 resection, the 5-year overall survival rate is around 90-100% for low grade lesions but significantly drops after incomplete resections. Compared to standard resections, pancreatic sparing surgery, i.e. enucleation and central pancreatectomy, significantly decreased the risk of pancreatic insufficiency. It should be performed in patients with good general condition and normal pancreatic function to limit the operative risk and enhance the benefit of surgery. Nowadays, due to many known advantages of minimally invasive surgery, there is an ongoing trend towards laparoscopic and robotic pancreatic surgery. The aim of this study is to describe the pre- and intraoperative diagnostic requirements for the management of PanNETs and the benefits and risks of minimally invasive surgery including laparoscopic and robotic approach in view of the recent literature.

Minimally invasive versus open distal pancreatectomy for pancreatic neuroendocrine tumors: An analysis from the U.S. neuroendocrine tumor study group

BACKGROUND

To determine short- and long-term oncologic outcomes after minimally invasive distal pancreatectomy (MIDP) with open distal pancreatectomy (ODP) for the treatment of pancreatic neuroendocrine tumor (pNET).

METHODS

The data of the patients who underwent curative MIDP or ODP for pNET between 2000 and 2016 were collected from a multi-institutional database. Propensity score matching (PSM) was used to generate 1:1 matched patients with MIDP and ODP.

RESULTS

A total of 576 patients undergoing curative DP for pNET were included. Two hundred and fourteen (37.2%) patients underwent MIDP, whereas 362 (62.8%) underwent ODP. MIDP was increasingly performed over time (2000-2004: 9.3% vs 2013-2016: 54.8%; P < 0.01). In the matched cohort (n = 141 in each group), patients who underwent MIDP had less blood loss (median, 100 vs 200 mL, P < 0.001), lower incidence of Clavien-Dindo ≥ III complications (12.1% vs 24.8%, P = 0.026), and a shorter hospital stay versus ODP (median, 4 versus 7 days, P = 0.026). Patients who underwent MIDP had a lower incidence of recurrence (5-year cumulative recurrence, 10.1% vs 31.1%, P < 0.001), yet equivalent overall survival (OS) rate (5-year OS, 92.1% vs 90.9%, P = 0.550) compared with patients who underwent OPD.

CONCLUSION

Patients undergoing MIDP over ODP in the treatment of pNET had comparable oncologic surgical metrics, as well as similar long-term OS.

Risk of Infectious Complications After Simultaneous Gastrointestinal and Liver Resections for Neuroendocrine Tumor Metastases

BACKGROUND

Neuroendocrine tumors (NETs) are a relatively rare category of cancers that arise in the gastrointestinal (GI) tract and other organs. Extended hepatectomies including resection of multiple organs are often necessary to achieve negative margins.

METHODS

We performed a review of patients undergoing liver resection for NET liver metastases from 2005 to 2015 using National Surgical Quality Improvement Program. We compared patients undergoing hepatectomy alone (HA) versus hepatectomy and a concomitant GI surgery procedure (colorectal, small bowel, and pancreatic) to evaluate postoperative infectious complications.

RESULTS

During the study period, 354 patients underwent liver resection for metastatic NET. Hepatectomy alone was performed in 98 patients, and concomitant GI surgery was performed in 256 patients, including 83 colorectal resections (HCCR), 68 small bowel resections, 75 distal pancreatectomies, and 35 pancreaticoduodenectomies (HCPD). Infectious complications were more likely to occur in those undergoing HCPD (60%, P < 0.001), and HCCR (32.5%, P < 0.05) than in those undergoing HA (16.3%). Patients undergoing HCPD and HCCR had a 7.69-fold and 2.52-fold increased risk of infectious complication, respectively, compared with HA after adjustment for other infection risk factors.

CONCLUSIONS

Neuroendocrine liver metastases requiring liver resection with concomitant colorectal resection or pancreaticoduodenectomy are at significantly increased risk of developing infectious complications.

Minimally invasive distal pancreatectomy for PNETs: laparoscopic or robotic approach?

Background

The most effective and radical treatment for pancreatic neuroendocrine tumors (PNETs) is surgical resection. Minimally invasive surgery has been increasingly used in pancreatectomy. Initial results in robotic distal pancreatectomy (RDP) have been encouraging. Nonetheless, data comparing outcomes of RDP with those of laparoscopic distal pancreatectomy (LDP) in treating PNETs are rare. The aim of this study was to compare the safety and efficacy of RDP and LDP for PNETs.

Methods

From September 2010 to January 2017, operative parameters and perioperative outcomes in an initial experience with 43 consecutive patients undergoing RDP were collected and compared with those in 31 patients undergoing LDP.

Results

Patients undergoing RDP and LDP demonstrated equivalent age, sex, ASA score, tumor location and tumor size. Operating time, length of resected pancreas, postoperative length of hospital stay and rates of conversion to open, pancreatic fistula, transfusion and reoperation were not statistically different. Patients in the RDP group were associated with significantly higher overall (79.1 vs. 48.4 %, P = 0.006) and Kimura spleen preservation rates (72.1 vs. 16.1%, P < 0.001) and had reduced risk of excessive blood loss (50 vs. 200mL, P < 0.001). Oncological outcomes in this series were superior for the RDP group with more lymph node harvest for G2 and G3 PNETs (3.5 vs. 2, P = 0.034).

Conclusions

Both RDP and LDP are efficacious and safe methods in treating PNETs located in the body or tail of pancreas. Robotic approach offers advantages with less intraoperative blood loss, higher spleen preservation rate and more lymph node harvest. It may be sensible to choose RDP for patients who fit indications for scheduled spleen preservation.

Surgical resection of neuroendocrine tumors of the pancreas (pNETs) by minimally invasive surgery: the laparoscopic approach

Neuroendocrine tumors of the pancreas (pNETs) are a rare group of neoplasms that originate from the endocrine portion of the pancreas. Tumors that either secrete or do not secrete compounds, resulting in symptoms, can be classified as functioning and non-functioning pNETs, respectively. The prevalence of such tumors has recently increased due to the use of more sensitive imaging techniques, such as multidetector computed tomography, magnetic resonance imaging and endoscopic ultrasound. The biological behavior of pNETs varies widely from indolent, well-differentiated tumors to those that are far more aggressive. The most effective and radical treatment for pNETs is surgical resection. Over the last decade, minimally invasive surgery has been increasingly used in pancreatectomy, with laparoscopic pancreatic surgery (LPS) emerging as an alternative to open pancreatic surgery (OPS) in patients with pNETs. Non-comparative studies have shown that LPS is safe and effective. In well-selected groups of patients with pancreatic lesions, LPS was found to results in good perioperative outcomes, including reduced intraoperative blood loss, postoperative pain, time to recovery, and length of hospital stay. Despite the encouraging results of studies from highly specialized centers with extensive experience, no randomized trials to date have conclusively validated these findings. Indications for minimally invasive LPS for patients with pNETs remain unclear. This review presents the current state of LPS for pNETs.

Role of surgery in pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumours (PNETs) are rare. They are generally accepted to be slow-growing and have an indolent course. These tumours can be non-functioning or functioning, consisting of a biochemically heterogeneous group of tumours including insulinomas, gastrinomas, carcinoids and glucagonomas. Although surgery remains the mainstay of treatment, controversy still exists especially for non-functioning tumours <2 cm in size. Whether these should be resected or undergo intensive surveillance remains unclear. The surgical approach depends on local expertise. Many studies have shown comparable short-term surgical outcome with laparoscopic pancreatic resection compared to open techniques, however data on long-term oncological outcome are still lacking. On the other hand, liver metastasis occurs in as high as 80% of PNET patients. Five-year survival rate is only 30% if left untreated compared to 60-80% if complete resection is achieved. Current evidence supports liver resection with an aim for symptomatic control and to improve survival in those with respectable disease and no extra-hepatic metastasis. Palliative debunking can be considered in those with intractable symptoms. This article reviews the current evidence on pancreatic resection for PNETs, in particular the role of laparoscopic resection and the management of liver metastasis.

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.

Computed Tomography Features Predictive of Lymph Node Involvement in Patients With a Nonfunctioning Pancreatic Neuroendocrine Tumor

OBJECTIVES

This study aims to identify the computed tomography (CT) features that may differentiate nonfunctioning pancreatic neuroendocrine tumors (NF-PanNETs) with lymph node (LN) metastasis from NF-PanNETs without lymph node metastasis.

METHODS

We retrospectively analyzed 166 NF-PanNETs in 166 patients who had undergone surgical resection (median age, 53). Two radiologists evaluated the qualitative and quantitative CT findings. Through univariate and multivariate logistic regression analyses, we determined independent significant findings for differentiating NF-PanNETs with LN metastasis from NF-PanNETs without LN metastasis. Recurrence-free survival (RFS) and overall survival (OS) were compared between the 2 groups using Kaplan-Meier analysis and log-rank testing.

RESULTS

Of the 166 NF-PanNETs, 24 (14.5%) tumors demonstrated LN metastasis. Three CT findings, radiologic LN enlargement (adjusted odds ratio [OR], 11.76; P = 0.001), liver metastasis (OR, 10.31; P = 0.027), and portal enhancement ratio of <1.238 (OR, 3.58; P = 0.033), were independently significant for differentiating NF-PanNETs with LN metastasis from NF-PanNETs without LN metastasis. Tumor size greater than 2 cm also showed a statistically marginal significance (OR, 8.47; P = 0.050). The median RFS and OS in NF-PanNETs with LN metastasis were significantly shorter than NF-PanNETs without LN metastasis (23.7 months vs 33.2 months, P < 0.001; 33.7 months vs 54.8 months, P < 0.001).

CONCLUSIONS

Four CT findings can be useful to differentiate NF-PanNETs with LN metastasis and NF-PanNETs without LN metastasis.

[Laparoscopic pancreatic resection]

INTRODUCTION AND PURPOSE

Despite being technically challenging, laparoscopic surgical procedures are increasingly being used also in pancreatic surgery. This review attempts to evaluate these procedures based on the currently available literature against the background of the high mortality of pancreatic surgery observed nationwide and the as yet unclear oncological validation of these procedures.

MATERIAL AND METHODS

Recently published retrospective cohort and register trials have evaluated not only perioperative outcome but also long-term survival after laparoscopic pancreatic resection.

RESULTS AND CONCLUSION

Laparoscopic interventions are increasingly being used for treatment of malignant tumors of the pancreas. The advantages of laparoscopy, such as less intraoperative blood loss, reduced postoperative pain and a shorter duration of hospital stay, have all been demonstrated in retrospective trials. Equivalent long-term survival after oncological laparoscopic pancreatic surgery compared to open procedures was also observed in these trials; however, mortality even after laparoscopic pancreatic surgery was found to be significantly increased in low-volume centers. Prospective trials are still needed to prove adequate oncological treatment. Laparoskopische Verfahren haben sich in den letzten Jahren in fast allen Bereichen der Chirurgie quasi zum Standard entwickelt und werden von Patienten zunehmend nachgefragt. Die kosmetischen Ergebnisse sind deutlich besser als bei konventionellem Vorgehen und sie reduzieren unter anderem den postoperativen Schmerz, Schmerzmittelbedarf sowie den Krankenhausaufenthalt [29]. Daher ist es wenig überraschend, dass minimal-invasive Verfahren auch bei technisch hochkomplexen Eingriffen, wie z. B. am Pankreas, zunehmend eingesetzt werden. Allerdings wird ihr Einsatz hier noch immer kontrovers diskutiert.

Systematic review and meta-analysis on laparoscopic pancreatic resections for neuroendocrine neoplasms (PNENs)

The safety of laparoscopic resections (LPS) of pancreatic neuroendocrine neoplasms (PNENs) has been well established in the literature. Areas covered: Studies conducted between January 2003 and December 2015 that reported on LPS and open surgery (OPS) were reviewed. The primary outcomes were the rate of post-operative complications and the length of hospital stay (LoS) after laparoscopic and open surgical resection. The rate of recurrence was the secondary outcome. Eleven studies were included with a total of 907 pancreatic resections for PNENs, of whom, 298 (32.8%) underwent LPS and 609 (67.2%) underwent open surgery. LPS resulted in a significantly shorter LoS (p < 0.0001) and lower blood loss (p < 0.0001). The meta-analysis did not show any significant difference in the pancreatic fistula rate, recurrence rate or post-operative mortality between the two groups. Expert commentary: LPS is a safe approach even for PNENs and it is associated with a shorter LoS.

Impact and Clinical Predictors of Lymph Node Metastases in Nonfunctional Pancreatic Neuroendocrine Tumors

Background:

The optimal surgical management of nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) is still controversial. Here, we evaluated the impact of lymph node status on postoperative recurrence in patients with NF-PNET and the potential of preoperative variables for predicting lymph node metastasis (LNM).

Methods:

In this mono-institutional retrospective cohort study conducted in 100 consecutive patients who underwent NF-PNET resection between January 2004 and December 2014, we evaluated risk factors for survival using the Kaplan–Meier method and the Cox regression model. Predictors of LNM were evaluated using the logistic regression model, and the power of predictive models was evaluated using receiver operating characteristic curve analysis.

Results:

Five-year disease-free survival of resected NF-PNET was 64.1%. LNM was independently associated with postoperative recurrence (hazard ratio = 3.995, P = 0.003). Multivariate analysis revealed tumor grade as an independent factor associated with LNM (G2 vs. G1: odds ratio [OR] =6.287, P = 0.008; G3 vs. G1: OR = 12.407, P = 0.001). When tumor grade was excluded, radiological tumor diameter >2.5 cm (OR = 5.430, P = 0.013) and presence of symptoms (OR = 3.366, P = 0.039) were significantly associated with LNM. Compared to neoplasms with radiological diameter >2.5 cm (32.1%), tumors ≤2.5 cm had an obviously lower risk of LNM (7.7%), indicating the reliability of this parameter in predicting LNM (area under the curve, 0.693). Incidentally discovered NF-PNETs ≤2.5 cm were associated with a low-risk of LNM and excellent survival.

Conclusions:

LNM is significantly associated with postoperative recurrence. Radiological tumor diameter is a reliable predictor of LNM in NF-PNETs. Our results indicate that lymphadenectomy in small (≤2.5 cm) NF-PNETs is not routinely necessary.

Propensity score-matched analysis of robotic versus open surgical enucleation for small pancreatic neuroendocrine tumours

BACKGROUND

Enucleation of pancreatic neuroendocrine tumours (pNETs) via robotic surgery has rarely been described. This study sought to assess the safety and efficiency of robotic surgery for the enucleation of small pNETs.

METHODS

A comparison was conducted of enucleation of pNETs smaller than 2 cm by robotic or open surgery between January 2000 and May 2015. Propensity score matching was used to balance sex, age, BMI, tumour location and tumour diameter. Pathological results, safety-related outcomes (postoperative pancreatic fistula (POPF) rate, estimated blood loss, and short-term mortality and morbidity) and efficiency-related outcomes (duration of surgery and postoperative length of hospital stay) were compared between the groups.

RESULTS

A cohort of 120 patients with pNET were enrolled in the study (1 : 1 matched for open or robotic surgery, 60 per group). Ninety-three patients (77·5 per cent) had a grade 1 tumour and 114 (95·0 per cent) had an insulinoma. Robotic surgery had a conversion rate of 5 per cent (3 of 60), and was not associated with an increased POPF rate (10 per cent versus 17 per cent after open surgery; P = 0·283) or grade III-V surgical complications according to the Dindo-Clavien classification (3 versus 10 per cent respectively; P = 0·272). Estimated blood loss was reduced with the robotic approach (32·5 versus 80·0 ml in the open group; P = 0·008), as was duration of surgery (117 versus 150 min; P < 0·001). Length of hospital stay after surgery was similar in the two groups (12·0 versus 13·5 days respectively; P = 0·071).

CONCLUSION

Robotic surgery for enucleation of pNETs smaller than 2 cm did not increase POPF or major complication rates, and reduced the duration of surgery and estimated blood loss, compared with open surgery.

REGISTRATION NUMBER

NCT02125929 ( https://www.clinicaltrials.gov/).

Management of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are rare tumors that have a better prognosis than their exocrine counterpart, but frequently present with advanced disease. Management of pNETs has evolved considerably over the past decade. Surgical resection remains the only potentially curative option for patients with pNETs. Patients who have locoregionally advanced and/or metastatic pNETs require additional treatments. These include liver-directed (transarterial (chemo)-embolization, selective intraarterial radio therapy) and systemic therapies (somatostatin analogs, targeted therapy such as tyrosine-kinase inhibitors and mammalian target of rapamycin inhibitor, peptide receptor radionuclide therapy and cytotoxic chemotherapy). The aim of this article is to review the current treatment options as well as potential future therapeutic perspectives for patients with pNETs.

Laparoscopic long sleeve pancreaticogastrostomy (LPG): a novel pancreatic anastomosis following central pancreatectomy

BACKGROUND

Central pancreatectomy (CP) is preferred to distal pancreatectomy (DP) for the excision of benign tumours at the neck or body of the pancreas, in order to preserve pancreatic function and the spleen. However, the pancreaticoenterostomy is technically difficult to perform laparoscopically and the postoperative pancreatic fistula (POPF) rate is high.

METHODS

A novel laparoscopic reconstruction of the pancreatic stump during CP is described, the laparoscopic long sleeve pancreaticogastrostomy (LPG).

RESULTS

Two males and two females with a median age of 49 years had a laparoscopic CP with LPG. After a median follow-up of 27.5 months, there was no mortality. One patient had a grade A POPF, managed conservatively.

CONCLUSIONS

The LPG is a safe and technically less demanding method to reconstruct pancreatic drainage laparoscopically.

Thirty-day outcomes underestimate endocrine and exocrine insufficiency after pancreatic resection

BACKGROUND

Long-term incidence of endocrine and exocrine insufficiency after pancreatectomy is poorly described. We analyze the long-term risks of pancreatic insufficiency after pancreatectomy.

METHODS

Subjects who underwent pancreatectomy from 2002 to 2012 were identified from a prospective database (n = 227). Subjects who underwent total pancreatectomy or pancreatitis surgery were excluded. New post-operative endocrine and exocrine insufficiency was defined as the need for new pharmacologic intervention within 1000 days from resection.

RESULTS

28 (16%) of 178 subjects without pre-existing endocrine insufficiency developed post-operative endocrine insufficiency: 7 (25%) did so within 30 days, 8 (29%) between 30 and 90 days, and 13 (46%) after 90 days. 94 (43%) of 214 subjects without pre-operative exocrine insufficiency developed exocrine insufficiency: 20 (21%) did so within 30 days, 29 (31%) between 30 and 90 days, and 45 (48%) after 90 days. Adjuvant radiation was associated with new endocrine insufficiency. On multivariate regression, pancreaticoduodenectomy and chemotherapy were associated with a greater risk of exocrine insufficiency.

CONCLUSION

Reporting 30-day functional outcomes for pancreatic resection is insufficient, as nearly 45% of subjects who develop disease do so after 90 days. Reporting of at least 90-day outcomes may more reliably assess risk for post-operative endocrine and exocrine insufficiency.

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.

Minimally Invasive Techniques for Resection of Pancreatic Neuroendocrine Tumors

Surgical resection remains the treatment of choice for primary pancreatic neuroendocrine tumors (PNETs), because it is associated with increased survival. Minimally invasive procedures are a safe modality for the surgical treatment of PNETs. In malignant PNETs, laparoscopy is not associated with a compromise in terms of oncologic resection, and provides the benefits of decreased postoperative pain, better cosmetic results, shorter hospital stay, and a shorter postoperative recovery period. Further prospective, multicenter, randomized trials are required for the analysis of these minimally invasive surgical techniques for the treatment of PNETs and their comparison with traditional open pancreatic surgery.

Parenchyma-sparing pancreatectomies for pancreatic neuroendocrine tumors

Parenchyma-sparing pancreatectomy, including enucleation and central pancreatectomy, has been investigated as an alternative to standard resection (pancreaticoduodenectomy or left/distal pancreatectomy) for pancreatic neuroendocrine tumor (PNET). In selected patients, with small (<2 cm) and low-grade tumors, PSP are associated with excellent both overall and disease-free survivals. These procedures are associated with an increased postoperative morbidity but an excellent long-term postoperative pancreatic function. Therefore, they should be considered as a valid therapeutic option in selected well-differentiated PNET.

Distal pancreatic resection for neuroendocrine tumors: is laparoscopic really better than open?

BACKGROUND

The latest studies on surgical and cost-analysis outcomes after laparoscopic distal pancreatectomy (LDP) highlight mixed and insufficient results. Whereas several investigators have compared surgical outcomes of LDP vs. open distal pancreatectomy (ODP) for adenocarcinomas, few similar studies have focused on pancreatic neuroendocrine tumors (PNETs).

METHODS

We reviewed the medical records of PNET patients undergoing distal pancreatectomy between 2004 and 2014. Patients were divided into LDP vs. ODP groups. Demographics, relevant comorbidities, oncologic variables, and cost-analysis data were assessed. Survival and Cox proportional hazards analyses were used to evaluate outcomes.

RESULTS

Of the 171 distal pancreatectomies for PNETs, 73 were laparoscopic, whereas 98 were open. Patients undergoing LDP demonstrated significantly lower rates of postoperative complications (P=0.028) and had significantly shorter hospital stays (P=0.008). On multivariable analysis, positive resection margins (P=0.046), G3 grade (P=0.036), advanced WHO classification (P=0.016), TNM stage (P=0.018), and readmission (P=0.019) were significantly associated with poor survival; however, method of resection (LDP vs. ODP) was not (P=0.254). The median total direct costs of LDP vs. ODP did not differ significantly.

CONCLUSIONS

In response to the recent considerable controversy surrounding the costs and surgical outcomes of LDP vs. ODP, our results show that LDP for PNETs is cost-neutral and significantly reduces postoperative morbidity without compromising oncologic outcomes and survival.

Distal pancreatic resection for neuroendocrine tumors: is laparoscopic really better than open?

BACKGROUND

The latest studies on surgical and cost-analysis outcomes after laparoscopic distal pancreatectomy (LDP) highlight mixed and insufficient results. Whereas several investigators have compared surgical outcomes of LDP vs. open distal pancreatectomy (ODP) for adenocarcinomas, few similar studies have focused on pancreatic neuroendocrine tumors (PNETs).

METHODS

We reviewed the medical records of PNET patients undergoing distal pancreatectomy between 2004 and 2014. Patients were divided into LDP vs. ODP groups. Demographics, relevant comorbidities, oncologic variables, and cost-analysis data were assessed. Survival and Cox proportional hazards analyses were used to evaluate outcomes.

RESULTS

Of the 171 distal pancreatectomies for PNETs, 73 were laparoscopic, whereas 98 were open. Patients undergoing LDP demonstrated significantly lower rates of postoperative complications (P=0.028) and had significantly shorter hospital stays (P=0.008). On multivariable analysis, positive resection margins (P=0.046), G3 grade (P=0.036), advanced WHO classification (P=0.016), TNM stage (P=0.018), and readmission (P=0.019) were significantly associated with poor survival; however, method of resection (LDP vs. ODP) was not (P=0.254). The median total direct costs of LDP vs. ODP did not differ significantly.

CONCLUSIONS

In response to the recent considerable controversy surrounding the costs and surgical outcomes of LDP vs. ODP, our results show that LDP for PNETs is cost-neutral and significantly reduces postoperative morbidity without compromising oncologic outcomes and survival.

[Surgery for gastrinoma: Short and long-term results]

INTRODUCTION

Zollinger-Ellison syndrome (Z-E) is characterized by gastrin-secreting tumors, responsible for causing refractory and recurrent peptic ulcers in the gastrointestinal tract. The optimal approach and the extension of tumor resection remains the subject of debate.

METHODS

During the period February 2005 and February 2014, 6 patients with Z-E underwent surgery, 4 men and 2 women with a median age 46.8 years (22-61). Two patients were affected with multiple endocrine neoplasia type-1 (MEN-1). Fasting gastrin levels greater than 200pg/ml (NV: <100) was diagnostic. Radiologic imaging to localize the lesion included octreoscan 6/6, computer tomography (CT) 6/6, and endoscopic ultrasonography (EUS) 1/6.

RESULTS

The octreoscan was positive in 5 patients. The CT localized the tumor in the pancreas in 2 patients, in the duodenum in 3 patients (1 confirmed by EUS) and between the common bile duct and vena cava in one patient. The laparoscopic approach was used in 4 patients, 2 patients converted to open surgery. The following surgical techniques were performed: 2 pylorus-preserving pancreatico-duodenectomy (PPPD), one spleen-preserving distal pancreatectomy, one duodenal nodular resection, 1 segmental duodenectomy and one extrapancreatic nodular resection. Pathological studies showed lymph nodes metástasis in 2 patients with pancreatic gastrinomas, and in one patient with duodenal gastrinoma. The median follow-up was 76,83 months (5-108) and all patients presented normal fasting gastrin levels.

CONCLUSIONS

Surgery may offer a cure in patients with Z-E. The laparoscopic approach remains limited to selected cases.

Incidence and severity of pancreatogenic diabetes after pancreatic resection

BACKGROUND

While many patients experience prolonged survival after pancreatic resection for benign or malignant disease, the long-term risk of pancreatogenic diabetes mellitus (DM) remains poorly characterized.

METHODS

One thousand one hundred seven patients underwent pancreatectomy at Thomas Jefferson University between 2006 and 2013. Attempts were made to contact all living patients by telephone and a DM-focused questionnaire was administered.

RESULTS

Two hundred fifty-nine of 691 (37 %) surviving patients completed the survey, including 179 pancreaticoduodenectomies (PD), 78 distal pancreatectomies (DP), and 2 total pancreatectomies. In the PD group, 44 (25 %) patients reported having DM prior to resection. Of these, 5 (12 %) had improved glucose control after resection and 21 (48 %) reported escalated DM medication requirements post-resection. Of 135 PD patients without preoperative DM, 24 (18 %) had new-onset DM postoperatively. In the DP group, 23 patients (29 %) had DM preoperatively. None had improved glucose control after resection, while six (26 %) had worse control after resection. Seventeen of 55 DP patients (31 %) without preoperative DM developed new-onset DM postoperatively (p = 0.04 vs. PD). Preoperative HgbA1C >6.0 %, glucose >124 mg/dL, and insulin use >2 units per day were associated with an increased risk of new-onset postoperative DM.

CONCLUSIONS

The development or worsening of DM after pancreatic resection is extremely common, with different types of resections conveying different risks for disease progression. DP places patients at a greater risk for the development of new-onset postoperative diabetes when compared to PD. In contrast, patients with preoperative diabetes are more likely to experience worsening of their disease after PD as compared to DP. Patients should be screened prospectively, particularly those at highest risk, and informed of and educated about the potential for post-resection DM.

[Minimally invasive pancreatic tumor surgery : oncological safety and surgical feasibility]

INTRODUCTION AND PURPOSE

Despite being technically challenging, minimally-invasive pancreatic surgery is increasingly being used to treat pancreatic diseases. Therefore, the evaluation of its oncological safety and its advantages arebecoming increasingly more important. This review focuses on these questions based on the currently available literature.

MATERIAL AND METHODS

The technically less demanding laparoscopic distal pancreatectomy has been evaluated in numerous meta-analyses. Minimally invasive pancreaticoduodenectomy has only been reported from a few centers worldwide.

RESULTS AND CONCLUSION

Minimally invasive pancreatic surgery, in particular laparoscopic distal pancreatectomy, is increasingly being used to treat pancreatic tumors. The advantages of laparoscopy, such as less intraoperative blood loss, reduced postoperative pain and a shorter length of stay have all been demonstrated in large trials. However, a sufficient oncological treatment was only assessed via indirect surrogate parameters, such as the number of lymph nodes obtained and R0 resection rates; therefore, larger prospective trials are needed to prove adequate oncological treatment. To date, minimally invasive techniques should only be employed in trials on treatment of pancreatic malignancies.

Role of fine-needle aspiration in the surgical management of pancreatic neuroendocrine tumors: utility and limitations in light of the new World Health Organization classification

CONTEXT

Pancreatic neuroendocrine tumors (Panc-NETs) are rare and tend to get overshadowed by their more prevalent and aggressive ductal adenocarcinoma counterparts. The biological behavior of PancNETs is unpredictable, and thus management is controversial. However, the new World Health Organization classification has significantly contributed to the prognostic stratification of these patients. Concurrently, there have been advances in surgical techniques for benign or low-grade pancreatic tumors. These procedures include minimally invasive and parenchyma-sparing operations such as laparoscopy and enucleation.

OBJECTIVE

To report on the utility and limitations of fine-needle aspiration in the preoperative evaluation and management of PancNETs.

DESIGN

This was a retrospective review of our institutional tumor database from 2002 to 2012. There were 25 cases of PancNETs that were localized and staged by medical imaging and diagnosed by fine-needle aspiration.

RESULTS

Fourteen patients underwent laparotomy, with some requiring only limited surgery; 4 had laparoscopic resections; 4 were serially observed without surgical intervention; and another 3 were inoperable. After a mean follow-up of 37 months, more than half of the patients had no evidence of disease, including most of those who underwent minimally invasive surgery.

CONCLUSIONS

Fine-needle aspiration is a useful diagnostic adjunct to medical imaging in the preoperative evaluation and management of PancNETs. However, there are limitations with regard to grading PancNETs using this technique.

Laparoscopic resection of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare heterogeneous group of endocrine neoplasms. Surgery remains the best curative option for this type of tumor. Over the past two decades, with the development of laparoscopic pancreatic surgery, an increasingly larger number of PNET resections are being performed by these minimally-invasive techniques. In this review article, the various laparoscopic surgical options for the excision of PNETs are discussed. In addition, a summary of the literature describing the outcome of these treatment modalities is presented.

Hepatic parenchymal preserving technique in the management of diffuse bilateral neuroendocrine tumour liver metastases: a feasible approach

BACKGROUND

Aggressive surgical resection of neuroendocrine tumour liver metastases (NET-LM) is associated with symptomatic relief. Debulking up to 90% of tumour burden, even with positive margins, may be beneficial. However, patients with diffuse hepatic metastases may not qualify for resection owing to associated insufficient remnant liver parenchyma. The purpose of this study is to describe an early experience with a hepatic parenchymal preserving (HPP) approach.

METHODS

We retrospectively reviewed our institutional neuroendocrine tumours database to identify patients with NET-LM, including symptomatic patients with extensive bilobar involvement, who underwent virtual volumetric assessment (VVA) combined with HPP resection between October 2008 and July 2011.

RESULTS

Our study involved 9 patients. The median number of liver metastases resected was 10 (range 4-50). Symptomatic improvement was observed in all patients. Immediate postoperative normalization of 5-HIAA 24-hour urine levels occurred in 89% of patients. Symptomatic and biochemical response remained stable or improved in 75% of patients at 12 months of follow-up. Four patients had postoperative complications. There was no 90-day mortality.

CONCLUSION

The described HPP approach is feasible and safe. Most patients experienced symptomatic and biochemical improvement. This reproducible approach could expand surgical resection options for patients with NET-LM and diffuse bilobar involvement.

Regional lymphadenectomy is indicated in the surgical treatment of pancreatic neuroendocrine tumors (PNETs)

OBJECTIVE

To explore the prognostic importance and preoperative predictors of lymph node metastasis in an effort to guide surgical decision making in patients with pancreatic neuroendocrine tumors (PNETs).

BACKGROUND

PNETs are uncommon, and the natural history of the disease is not well described. As a result, there remains controversy regarding the optimal management of regional lymph nodes during resection of the primary tumor.

METHODS

A retrospective review of a prospectively maintained database of patients who underwent surgery for locoregional PNET between 1994 and 2012 was performed. Logistic regression was used to identify predictors of nodal metastasis. Overall survival and disease-free survival were calculated using Kaplan-Meier method. Results were expressed as P values and odds ratio estimates, with 95% confidence intervals.

RESULTS

One hundred thirty-six patients were identified, of whom 50 (38%) patients had nodal metastasis. The frequency of lymph node metastasis was higher for larger tumors [> 1.5 cm (odds ratio [OR] = 4.7)], tumors of the head as compared with body-tail of the pancreas (OR = 2.8), tumors with Ki-67 greater than 20% (OR = 6.7), and tumors with lymph vascular invasion (OR = 3.6) (P < 0.05). Median disease-free survival was lower for patients with nodal metastases (4.5 vs 14.6 years, P < 0.0001).

CONCLUSIONS

Lymph node metastasis is predictive of poor outcomes in patients with PNETs. Preoperative variables are not able to reliably predict patients where the probability of lymph node involvement was less than 12%. These data support inclusion of regional lymphadenectomy in patients undergoing pancreatic resections for PNET.

The value of gadoxetic acid-enhanced and diffusion-weighted MRI for prediction of grading of pancreatic neuroendocrine tumors

BACKGROUND

Parenchyma-preserving resection for the treatment of benign pancreatic neuroendocrine tumors (NETs) has been tried, and preoperative prediction of benign pancreatic NET is important. Recently, diffusion-weighted imaging (DWI) of abdomen magnetic resonance imaging (MRI) has been used to characterize benign and malignant tumors and DWI might be helpful in prediction of benign pancreatic NETs.

PURPOSE

To evaluate the value of gadoxetic acid-enhanced MRI and DWI in predicting benign pancreatic NETs for determination of parenchyma-preserving resection.

MATERIAL AND METHODS

Our ethics committee approved this study with a waiver of informed consent given its retrospective design. We searched radiology and pathology databases from November 2010 to July 2012 to identify patients who underwent surgery for pancreatic NETs (<4 cm). Twenty patients in the benign group and 14 patients in the non-benign group were included in this study. Two radiologists analyzed the morphologic features, signal intensity on MR images including DWI (b = 800), and dynamic enhancement pattern of the tumors with consensus. The tumor-to-parenchyma ratio and tumor apparent diffusion coefficients (ADCs) were quantitatively assessed.

RESULTS

The benign pancreatic NETs were more often round (7/20, 35%) or ovoid (13/20, 65%) in shape and less hypovascular on the arterial phase (3/20, 15%) than were the non-benign pancreatic NETs (1/14, 7.1% and 5/14, 35.8%; 7/14, 50% respectively; P < 0.05). Main pancreatic duct dilatation by tumors was demonstrated only in non-benign pancreatic NETs (4/14, 28.4%; P = 0.021). ADC values and ratios were significantly different between benign pancreatic NETs (mean, 1.48 × 10(-3 )mm(2)/sec, 1.11 ± 0.25, each) and non-benign pancreatic NETs (mean, 1.04 × 10(-3 )mm(2)/sec, 0.74 ± 0.13, each) (P < 0.01). Other qualitative and quantitative analyses between benign and non-benign pancreatic NETs were not significantly different (P > 0.05).

CONCLUSION

Abdominal MRI with DWI may be useful for differentiating benign pancreatic NETs from non-benign pancreatic NETs, which might be helpful for determination of parenchyma-preserving resection.

Zollinger-Ellison syndrome: classical considerations and current controversies

Zollinger-Ellison syndrome (ZES) is an endocrinopathy characterized by gastrin-secreting tumors, responsible for causing the formation of multiple, refractory, and recurrent peptic ulcers in the distal duodenum and proximal jejunum. Two main variants have been described, sporadic and those found in association with parathyroid and pituitary tumors, a genetic disorder known as multiple endocrine neoplasia-1 (MEN-1). Biochemical serum evaluation for elevated gastrin, followed by radiological or nuclear localization of the primary lesion, is mandated for establishing diagnosis. The mainstays of treatment include management of hypersecretory state with medical suppression of gastric acid production and surgical resection of primary tumor for the prevention of malignant transformation and metastatic complications. Medical therapy with proton pump inhibitors has virtually eliminated the need for acid-reducing surgical procedures. Surgical approach to sporadic and MEN-1-associated ZES varies based on our understanding of the natural history of the condition and the probability of cure; however, resection to a negative microscopic margin is indicated in both cases. Postoperative surveillance involves measurement of gastrin level, followed by imaging if elevation is detected. Re-excision of recurrent or resection of metastatic disease is a subject of controversy; however, at the present time aggressive cytoreductive approach is favored.

Nonfunctional pancreatic neuroendocrine tumors <2 cm on preoperative imaging are associated with a low incidence of nodal metastasis and an excellent overall survival

BACKGROUND

The optimal surgical management of small nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) remains controversial. We sought to identify (1) clinicopathologic factors associated with survival in NF-PNETs and (2) preoperative tumor characteristics that can be used to determine which lesions require resection and lymph node (LN) harvest.

METHODS

The records of all 116 patients who underwent resection for NF-PNETs between 1989 and 2012 were reviewed retrospectively. Preoperative factors, operative data, pathology, surgical morbidity, and survival were analyzed.

RESULTS

The overall 5- and 10-year survival rates were 83.9 and 72.8 %, respectively. Negative LNs (p = 0.005), G1 or G2 histology (p = 0.033), and age <60 years (p = 0.002) correlated with better survival on multivariate analysis. The 10-year survival rate was 86.6 % for LN-negative patients (n = 73) and 34.1 % for LN-positive patients (n = 32). Tumor size ≥2 cm on preoperative imaging predicted nodal positivity with a sensitivity of 93.8 %. Positive LNs were found in 38.5 % of tumors ≥2 cm compared to only 7.4 % of tumors <2 cm.

CONCLUSIONS

LN status, a marker of systemic disease, was a highly significant predictor of survival in this series. Tumor size on preoperative imaging was predictive of nodal disease. Thus, it is reasonable to consider parenchyma-sparing resection or even close observation for NF-PNETs <2 cm.

Quality of life in patients after total pancreatectomy is comparable with quality of life in patients who undergo a partial pancreatic resection

BACKGROUND

Quality of life after total pancreatectomy (TP) is perceived to be poor secondary to insulin-dependent diabetes and pancreatic insufficiency. As a result, surgeons may be reluctant to offer TP for benign and premalignant pancreatic diseases.

METHODS

We retrospectively reviewed presenting features, operative characteristics, and postoperative outcomes of all patients who underwent TP at our institution. Quality of life was assessed using institutional questionnaires and validated general, pancreatic disease-related, and diabetes-related instruments (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30 and module EORTC-PAN26], Audit of Diabetes Dependent Quality of Life), and compared with frequency-matched controls, patients after a pancreaticoduodenectomy (PD). Continuous variables were compared using Student t-test or analysis of variance. Categorical variables were compared using χ(2) or Fisher exact test.

RESULTS

Between 1994 and 2011, 77 TPs were performed. Overall morbidity was 49%, but only 15.8% patients experienced a major complication. Perioperative mortality was 2.6%. Comparing 17 TP and 14 PD patients who returned surveys, there were no statistically significant differences in quality of life in global health, functional status, or symptom domains of EORTC QLQ-C30 or in pancreatic disease-specific EORTC-PAN26. TP patients had slightly but not significantly higher incidence of hypoglycemic events as compared with PD patients with postoperative diabetes. A negative impact of diabetes assessed by Audit of Diabetes Dependent Quality of Life did not differ between TP and PD. Life domains most negatively impacted by diabetes involved travel and physical activity, whereas self-confidence, friendships and personal relationships, motivation, and feelings about the future remained unaffected.

CONCLUSIONS

Although TP-induced diabetes negatively impacts select activities and functions, overall quality of life is comparable with that of patients who undergo a partial pancreatic resection.

Laparoscopic pancreatic resections

PURPOSE

Pancreatic surgery is technically complex and requires considerable expertise. Laparoscopic pancreatic surgery adds the need for considerable experience with advanced laparoscopic techniques. Despite the technical difficulties, an increasing number of centers propagate the use of laparoscopy in pancreatic surgery over the last decade.

METHODS

In this review, we provide an overview of the literature regarding the advantages and disadvantages of laparoscopic pancreatic surgery. Larger prospective randomized studies have emerged in the subset of laparoscopic or retroperitoneoscopic surgery for acute pancreatitis, considerable single center experience has been reported for laparoscopic pancreatic tail resection, and laparoscopic pancreatic head resection, however, is still restricted to a few experienced centers worldwide.

RESULTS AND CONCLUSIONS

Laparoscopic pancreatic surgery is becoming more and more established, in particular for the treatment of benign and premalignant lesions of the pancreatic body and tail. It has been shown to decrease postoperative pain, narcotic use, and length of hospital stay in larger single center experience. However, prospective trials are needed in laparoscopic resective pancreatic surgery to evaluate its advantages, safety, and efficacy in the treatment of pancreatic neoplasms and in particular in malignant pancreatic tumors.

Long-term outcome of laparoscopic surgery for pancreatic neuroendocrine tumors

BACKGROUND

As most pancreatic neuroendocrine tumors (PNET) are relatively small and solitary, they may be considered well suited for removal by a minimally invasive approach. There are few large series that describe laparoscopic surgery for PNET. The primary aim of this study was to describe the feasibility, outcome, and histopathology associated with laparoscopic pancreatic surgery (LS) of PNET in a large series.

METHODS

All patients with PNET who underwent LS at a single hospital from March 1997 to April 2011 were included retrospectively in the study.

RESULTS

A total of 72 patients with PNET underwent 75 laparoscopic procedures, out of which 65 were laparoscopic resections or enucleations. The median operative time of all patients who underwent resections or enucleations was 175 (60-520) min, the median blood loss was 300 (5-2700) ml, and the median length of hospital stay was 7 (2-27) days. The overall morbidity rate was 42%, with a surgical morbidity rate of 21% and postoperative pancreatic fistula (POPF) formation in 21%. Laparoscopic enucleations were associated with a higher rate of POPF than were laparoscopic resections. Five-year disease-specific survival rate was 90%. The T stage, R stage, and a Ki-67 cutoff value of 5% significantly predicted 5-year survival.

CONCLUSION

LS of PNET is feasible with acceptable morbidity and a good overall disease-specific long-term prognosis.

Current management of the Zollinger-Ellison syndrome

In summary, ZES is a syndrome caused by gastrinoma, usually located within the gastrinoma triangle and associated with symptoms of peptic ulcer disease, GERD, and diarrhea. The diagnosis of ZES is made by measuring fasting levels of serum gastrin, BAO, and the secretin stimulation test. Because of the high association of ZES and MEN1, HPT must be excluded by obtaining a serum calcium and parathyroid hormone level. Treatment of ZES consists of medical control of symptoms with PPIs and evaluation for potentially curative surgical intervention. Noninvasive imaging studies including SRS, CT, and MRI should be performed initially to evaluate for metastases and identify resectable disease. Invasive imaging modalities such as EUS may be performed to further evaluate primary tumors. IOUS, palpation, and duodenotomy are used for intraoperative localization of gastrinomas. In patients with MEN1, surgical resection should be pursued only if there is an identifiable tumor larger than 2 cm and after surgery for the primary hyperparathyroidism (3 1/2-gland parathyroidectomy). All patients with resectable localized sporadic gastrinoma should undergo surgical exploration, even those with biochemical evidence but negative imaging studies. Tumor is most commonly found in the duodenum, and the cure rate is high. In patients with liver metastases, surgery should be considered if all identifiable tumor can be safely removed. A multidisciplinary approach including surgical and nonsurgical therapies should be taken in patients with advanced disease.

Minimalinvasive Chirurgie bei Malignomen des Gastrointestinaltrakts: Pankreas - Kontra-Position

<b><i>Hintergrund: </i></b>Für eine Vielzahl von Erkrankungen der Bauchspeicheldrüse gilt die chirurgische Resektion als die Therapie der Wahl. In den vergangenen Jahren wurden die offenen Operationsmethoden für Pankreaserkrankungen zunehmend standardisiert und können mittlerweile mit hoher Sicherheit durchgeführt werden. Unabhängig davon wird zunehmend über laparoskopische Pankreasresektionen berichtet. <b><i>Methode: </i></b>In diesem Artikel stellen wir die aktuelle Literatur zur minimalinvasiven Chirurgie der Bauchspeicheldrüse vor, um sie mit offenen Operationsverfahren zu vergleichen. Besondere Berücksichtigung finden laparoskopische und roboterassistierte Duodenopankreatektomien sowie laparoskopische Pankreasschwanzresektionen bei Patienten mit chronischer Pankreatitis sowie mit gutartigen und bösartigen Tumoren. <b><i>Ergebnisse: </i></b>Laparoskopische und roboterassistierte Pankreaskopfresektionen sollten nur in ausgewählten Fällen angewandt werden und gelten als technisch äußerst anspruchsvoll - mit einer erhöhten Inzidenz von Pankreasfisteln. Laparoskopische Pankreasschwanzresektionen sind sichere Verfahren mit einem Trend zu einer kürzeren Krankenhausaufenthaltsdauer, sollten jedoch nur für gutartige Tumoren in Betracht gezogen werden. Im Rahmen der onkologischen Chirurgie sollte die offene Pankreasresektion bevorzugt werden. Werden onkologische Eingriffe laparoskopisch durchgeführt, ist eine ausgezeichnete präoperative Diagnostik und gegebenenfalls der Einsatz eines intraoperativen laparoskopischen Ultraschalls notwendig. <b><i>Schlussfolgerungen: </i></b>Obwohl laparoskopische Pankreasresektionen in ausgewählten Fällen von Nutzen sein können, werden sie zukünftig wohl eher die Ausnahme darstellen. Eine allgemeine Umstellung auf laparoskopische Pankreasschwanzresektionen wird aufgrund des Mangels an eindeutigen Vorteilen gegenüber dem offenen Verfahren höchstwahrscheinlich nicht stattfinden.