Survival impact of malignant pancreatic neuroendocrine and islet cell neoplasm phenotypes

FOXA2-initiated transcriptional activation of INHBA induced by methylmalonic acid promotes pancreatic neuroendocrine neoplasm progression

Pancreatic neuroendocrine neoplasms (PanNENs) are a group of highly heterogeneous neoplasms originating from the endocrine islet cells of the pancreas with characteristic neuroendocrine differentiation, more than 60% of which represent metastases when diagnosis, causing major tumor-related death. Metabolic alterations have been recognized as one of the hallmarks of tumor metastasis, providing attractive therapeutic targets. However, little is known about the molecular mechanism of metabolic changes regulating PanNEN progression. In this study, we first identified methylmalonic acid (MMA) as an oncometabolite for PanNEN progression, based on serum metabolomics of metastatic PanNEN compared with non-metastatic PanNEN patients. One of the key findings was the potentially novel mechanism of epithelial-mesenchymal transition (EMT) triggered by MMA. Inhibin βA (INHBA) was characterized as a key regulator of MMA-induced PanNEN progression according to transcriptomic analysis, which has been validated in vitro and in vivo. Mechanistically, INHBA was activated by FOXA2, a neuroendocrine (NE) specific transcription factor, which was initiated during MMA-induced progression. In addition, MMA-induced INHBA upregulation activated downstream MITF to regulate EMT-related genes in PanNEN cells. Collectively, these data suggest that activation of INHBA via FOXA2 promotes MITF-mediated EMT during MMA inducing PanNEN progression, which puts forward a novel therapeutic target for PanNENs.

A systems biology approach to define mechanisms, phenotypes, and drivers in PanNETs with a personalized perspective

Pancreatic neuroendocrine tumors (PanNETs) are a rare tumor entity with largely unpredictable progression and increasing incidence in developed countries. Molecular pathways involved in PanNETs development are still not elucidated, and specific biomarkers are missing. Moreover, the heterogeneity of PanNETs makes their treatment challenging and most approved targeted therapeutic options for PanNETs lack objective responses. Here, we applied a systems biology approach integrating dynamic modeling strategies, foreign classifier tailored approaches, and patient expression profiles to predict PanNETs progression as well as resistance mechanisms to clinically approved treatments such as the mammalian target of rapamycin complex 1 (mTORC1) inhibitors. We set up a model able to represent frequently reported PanNETs drivers in patient cohorts, such as Menin-1 (MEN1), Death domain associated protein (DAXX), Tuberous Sclerosis (TSC), as well as wild-type tumors. Model-based simulations suggested drivers of cancer progression as both first and second hits after MEN1 loss. In addition, we could predict the benefit of mTORC1 inhibitors on differentially mutated cohorts and hypothesize resistance mechanisms. Our approach sheds light on a more personalized prediction and treatment of PanNET mutant phenotypes.

Prognostic factors after resection of locally advanced non-functional pancreatic neuroendocrine neoplasm: an analysis from the German Cancer Registry Group of the Society of German Tumor Centers

OBJECTIVE

The available literature regarding outcome after pancreatic resection in locally advanced non-functional pNEN (LA-pNEN) is sparse. Therefore, this study evaluates the current survival outcomes and prognostic factors in after resection of LA-pNEN.

MATERIALS AND METHODS

This population-based analysis was derived from 17 German cancer registries from 2000 to 2019. Patients with upfront resected non-functional non-metastatic LA-pNEN were included.

RESULTS

Out of 2776 patients with pNEN, 277 met the inclusion criteria. 137 (45%) of the patients were female. The median age was 63 ± 18 years. Lymph node metastasis was present in 45%. G1, G2 and G3 pNEN were found in 39%, 47% and 14% of the patients, respectively. Resection of LA-pNEN resulted in favorable 3-, 5- and 10-year overall survival of 79%, 74%, and 47%. Positive resection margin was the only potentially modifiable independent prognostic factor for overall survival (HR 1.93, 95% CI 1.71-3.69, p value = 0.046), whereas tumor grade G3 (HR 5.26, 95% CI 2.09-13.25, p value < 0.001) and lymphangiosis (HR 2.35, 95% CI 1.20-4.59, p value = 0.012) were the only independent prognostic factors for disease-free survival.

CONCLUSION

Resection of LA-pNEN is feasible and associated with favorable overall survival. G1 LA-pNEN with negative resection margins and absence of lymph node metastasis and lymphangiosis might be considered as cured, while those not fulfilling these criteria might be considered as a high-risk group for disease progression. Herein, negative resection margins represent the only potentially modifiable prognostic factor in LA-pNEN but seem to be influenced by tumor grade.

An Insight on Functioning Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are rare neoplasms arising from islets of the Langerhans in the pancreas. They can be divided into two groups, based on peptide hormone secretion, functioning and nonfunctioning PanNENs. The first group is characterized by different secreted peptides causing specific syndromes and is further classified into subgroups: insulinoma, gastrinoma, glucagonoma, somatostatinoma, VIPoma and tumors producing serotonin and adrenocorticotrophic hormone. Conversely, the second group does not release peptides and is usually associated with a worse prognosis. Today, although the efforts to improve the therapeutic approaches, surgery remains the only curative treatment for patients with PanNENs. The development of high-throughput techniques has increased the molecular knowledge of PanNENs, thereby allowing us to understand better the molecular biology and potential therapeutic vulnerabilities of PanNENs. Although enormous advancements in therapeutic and molecular aspects of PanNENs have been achieved, there is poor knowledge about each subgroup of functioning PanNENs.Therefore, we believe that combining high-throughput platforms with new diagnostic tools will allow for the efficient characterization of the main differences among the subgroups of functioning PanNENs. In this narrative review, we summarize the current landscape regarding diagnosis, molecular profiling and treatment, and we discuss the future perspectives of functioning PanNENs.

The role of oncologic resection and enucleation for small pancreatic neuroendocrine tumors

BACKGROUND

Surgical management of small pancreatic neuroendocrine tumors (PNETs) is variable. Patients may undergo formal oncologic resection, encompassing regional lymphadenectomy, or enucleation. This study's aim was to understand if enucleation is adequate treatment for PNETs <2 cm METHODS: The US National Cancer Database (NCDB) from 2004 to 2016 was used to identify patients who underwent oncologic resection or enucleation for PNETs <2 cm. Fisher's exact test, log-rank, and logistic regression were used.

RESULTS

Of 4083 patients, 75.6% underwent oncologic resection with a median (range) number of 8 (0-99) lymph nodes examined, and 24.1% underwent enucleation. Five-year overall survival rate was 89.7% in node-negative patients versus 82.1% in node-positive patients (p < 0.001). No survival difference existed between patients who underwent enucleation versus oncologic resection (5-yr OS of 88.5% vs 88.2%, p = 0.064). According to AJCC classification, 3776 patients were clinically-staged with evidence of node-negative disease. Of these, 75.1% underwent oncologic resection, of which 9.9% had node-positive disease after resection. Tumor grade and size independently predicted nodal upstaging after oncologic resection.

CONCLUSION

One-tenth of patients with clinically node-negative disease were node-positive after surgery. Although this was not reflected in overall survival, patients who receive enucleation with higher grade and larger size may benefit from enhanced surveillance for locoregional 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.

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.

Pancreatic islet cell tumors in adolescents and young adults

BACKGROUND

Pancreatic islet cell tumors are rare in adolescents, and most studies published to date focus on older patients. We utilized a national database to describe the histology and clinical pattern of pancreatic islet cell tumors in adolescent and young adult (AYA) patients, and to compare AYAs to older adults. We hypothesized that AYAs with pancreatic islet cell tumors would have better overall survival.

METHODS

The National Cancer Data Base (NCDB, 1998-2012) was queried for AYA patients (15-39 years) with a pancreatic islet cell tumor diagnosis. Demographics, tumor characteristics, treatment modalities, and outcomes were abstracted and compared to adults (≥40 years).

RESULTS

383 patients (56.4% female, 65% non-Hispanic Whites) were identified, with a median age of 27 (IQR 16-34) years. Islet cell carcinoma was the most common histology. Of patients with known stage of disease, 49% presented with early stage (I or II). Seventy percent of patients underwent surgical resection, including local excision 44%, Whipple procedure 37.5%, or total pancreatectomy 19%. Chemotherapy was utilized in 27% and radiotherapy in 7%. All-cause mortality was 36%. AYA patients underwent more extensive resections (p = 0.001) and had lower mortality rates (p < 0.001), with no differences in tumor stage or use of adjuvant therapies, when compared to adults.

CONCLUSIONS

AYA patients with pancreatic islet cell tumors had comparable utilization of adjuvant therapies but underwent more extensive resections and demonstrated a higher overall survival rate than adult counterparts. Further investigation into approaches to earlier diagnosis and tailoring of multimodality therapy of these neoplasms in the AYA population is needed.

LEVELS OF EVIDENCE

Prognostic Study, Level II - retrospective study.

Management of asymptomatic, well-differentiated PNETs: results of the Delphi consensus process of the Americas Hepato-Pancreato-Biliary Association

BACKGROUND

Variation in the management of PNETs exist due to the limited high-level evidence to guide clinical practice. The aim of this work is to generate consensus guidelines with a Delphi process for managing PNETs.

METHODS

A panel of experts reviewed the surgical literature and scored a set of clinical case statements using a web-based survey to identify areas of agreement and disagreement. Results of the survey were discussed after each round of review. This cycle was repeated until no further likelihood of reaching consensus existed.

RESULTS

Twenty-two case statements related to surgical indications, preoperative biopsy, extent of resection, type of surgery, and tumor location were scored. Using a pre-defined definition of consensus, the panel achieved consensus on the following: i) resection is not recommended for <1 cm lesions; ii) resection is recommended for lesions greater than 2 cm; iii) lymph node dissection is recommended for radiographically-suspicious nodes with splenectomy for distal lesions; iv) tumor enucleation and central pancreatectomy are acceptable when technically feasible. No consensus was reached regarding issues of preoperative biopsy or 1-2 cm tumors.

CONCLUSIONS

Using a structured, validated system for identifying consensus, an expert panel identified areas of agreement regarding critical management decisions for patients with PNET. Issues without consensus warrant additional clinical investigation.

Natural History and Treatment Trends in Pancreatic Cancer Subtypes

BACKGROUND

While pancreatic ductal adenocarcinoma is the most common form of pancreatic cancer, many other histologic forms of pancreatic cancer are also recognized. These histologic variants portray unique characteristics in terms of patient demographics, tumor behavior, survival, and responsiveness to treatments.

MATERIALS AND METHODS

Patients who underwent surgical resection of the pancreas for non-metastatic, invasive pancreatic cancer between 2004 and 2014 were selected from the National Cancer Data Base and categorized by histologic variant according to WHO classification guidelines. Patient demographics, tumor variables, treatment characteristics, and survival were compared between histologic groups and subgroups.

RESULTS

A total of 57,804 patients met inclusion and exclusion criteria and were grouped into eight major histologic categories. Survival analysis by the histologic group showed median overall survival of 20.2 months for ductal adenocarcinoma, 20.5 months for squamous cell carcinoma, 26.8 months for mixed acinar-neuroendocrine carcinomas, 52.6 months for cystic mucinous neoplasms with an associated invasive carcinoma, 67.5 months for acinar cell carcinoma, and 69.3 months for mesenchymal tumors. Median survival was not reached for neuroendocrine tumors and solid-pseudopapillary neoplasms, with 5-year overall survival rates of 84% and 97% respectively.

CONCLUSIONS

Rare subtypes of pancreatic cancer present unique clinicopathologic characteristics and display distinct tumor biologies. This study presents data on demographic, prognostic, treatment, and survival outcomes between rare forms of pancreatic neoplasms in order to aid understanding of the natural history and behavior of these neoplasms, with the hope of serving as a reference in clinical decision-making and ability to provide accurate prognostic information to patients.

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.

Translational Diagnostics and Therapeutics in Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNET) are rare tumors, but have been increasing in incidence. Although typically thought of as indolent, more than half of patients present with metastatic disease. For many years, the only mutations commonly known in these tumors were those in the MEN1 gene. Recently, the genetics underlying PNETs have been further defined through exome sequencing. The most frequent alterations found in sporadic PNETs are in MEN1, DAXX/ATRX, and a variety of genes in the mTOR pathway. Confirmation of these mutations has prompted trials with a number of drugs active in these pathways, and two drugs were eventually approved in 2011-sunitinib and everolimus. New data additionally identify the MET and CD47 receptors as potential novel drug targets. Yet despite improvements in progression-free survival with sunitinib and everolimus, further studies defining when to use these agents and factors associated with limitations in their utility are needed. As more discoveries are made in the laboratory that elucidate additional molecular mechanisms important in the initiation and metastasis of PNETs, continued efforts to translate these discoveries into distinct new therapies will be needed to improve patient survival. Clin Cancer Res; 22(20); 5022-9. ©2016 AACR SEE ALL ARTICLES IN THIS CCR FOCUS SECTION, "ENDOCRINE CANCERS REVISING PARADIGMS".

Catching the Zebra: Clinical Pearls and Pitfalls for the Successful Diagnosis of Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome (ZES) results from an ectopic gastrin-secreting tumor leading to peptic ulcer disease, reflux, and chronic diarrhea. While early recognition portends an excellent prognosis with >80% survival at 15 years, symptoms are often nonspecific making the diagnosis difficult to establish. Diagnosis involves a series of tests, including fasting gastrin, gastric pH, chromogranin A, and secretin stimulation. Performing these tests in the correct sequence and at the proper time is essential to avoid inaccurate results. Tumor localization is equally nuanced. Although providers have classically used ¹¹¹indium-radiolabeled octreotide with somatostatin receptor scintigraphy to evaluate tumor size and metastases, recent studies have shown superior results with newer imaging modalities. In particular, ⁶⁸gallium (⁶⁸Ga)-labeled somatostatin radiotracers (i.e., ⁶⁸Ga-DOTATOC, ⁶⁸Ga-DOTANOC and ⁶⁸Ga-DOTATATE) used with positron emission tomography/computed tomography can provide excellent results. Endoscopic ultrasound is another useful modality, particularly in patients with ZES in the setting of multiple endocrine neoplasia type 1. This review aims to provide clinicians with an overview of ZES with a focus on both clinical presentation and the proper utilization of the various biochemical and imaging tests available.

Malignant-functioning neuroendocrine tumors of the pancreas: A survival analysis

BACKGROUND

Malignant-functioning pancreatic neuroendocrine tumors (mFpNETs) are rare. Research analyzing the presentation, biological behavior, and patient outcomes of these tumors is limited.

METHODS

We used the Surveillance, Epidemiology, and End Results database to identify patients with malignant insulinomas, gastrinomas, glucagonomas, vasoactive intestinal peptide secreting tumors (VIPomas), somastatinomas, and mixed islet cell tumors (MICTs). The primary endpoint of this study was to identify factors affecting survival.

RESULTS

We identified 401 patients with mFpNETs. Between histologic subtypes, there were significant differences in sex and age, and in tumor size, grade, location, and stage. Median survival time for insulinomas was 12.7 years; gastrinomas, 10.2 years; glucagonomas, 7.7 years; VIPomas, 7.9 years; and MICTs, 3.4 years. Multivariable analysis showed that histology (insulinoma, gastrinoma, and VIPoma; P = .009), absence of distant metastases (P = .002), age < 50 years (P = .001), surgical intervention (P = .001), and stage I/II disease (P = .011) were independently associated with prolonged survival. Subgroup analysis demonstrated that removal of the primary tumor in stage IV mFpNETs was associated with significantly prolonged survival (P = .01).

CONCLUSION

mFpNETs are rare tumors that commonly present at an advanced stage despite hormonal secretion. Primary tumor resection is associated with longer survival in stages I-III as well as stage IV tumors.

Post-brushing and fine-needle aspiration biopsy follow-up and treatment options for patients with pancreatobiliary lesions: The Papanicolaou Society of Cytopathology Guidelines

The Papanicolaou Society of Cytopathology (PSC) has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) biopsy, techniques of EUS-FNA, terminology and nomenclature for pancreatobiliary cytology, ancillary testing and post-procedure management. All documents are based on the expertise of the authors, a review of the literature and discussions of the draft document at several national and international meetings over an 18 month period and synthesis of online comments of the draft document on the PSC web site (www.papsociety.org). This document selectively presents the results of these discussions and focuses on the follow-up and treatment options for patients after procedures performed for obtaining cytology samples for the evaluation of biliary strictures and solid and cystic masses in the pancreas. These recommendations follow the six-tiered terminology and nomenclature scheme proposed by committee III.

Population-level analysis of pancreatic neuroendocrine tumors 2 cm or less in size

BACKGROUND

There is a paucity of evidence regarding incidence and predictors of survival in pancreatic neuroendocrine tumors (PNETs)≤2 cm in size.

METHODS

Patients having undergone resection for nonfunctioning PNETs were selected from the SEER database (1988-2009) and an institutional pathology database (1996-2012). PNETs≤2 cm were compared with PNETs>2 cm. Data were analyzed with χ2 tests, ANOVA, the Kaplan-Meier method, log rank tests, and Cox proportional hazard, and binary logistic regression.

RESULTS

The incidence of PNETs≤2 cm in the United States has increased by 710.4% over the last 22 years. Rates of extrapancreatic extension, nodal metastasis, and distant metastasis in PNETs≤2 cm in the SEER database were 17.9, 27.3, and 9.1%, respectively. The rate of nodal metastasis in our institutional series was 5.7%. Disease-specific survival at 5, 10, and 15 years for PNETs≤2 cm was 91.5, 84.0, and 76.8%. Decreased disease-specific survival was not associated with nodal metastasis, but rather with high grade [moderately differentiated, hazard ratio (HR) 37.2, 95% confidence interval (CI) 2.7-518.8; poorly differentiated, HR 94.2, 95% CI 4.9-1,794.4; reference, well differentiated], and minority race (Asian, HR 30.2, 95% CI 3.1-291.7; Black, HR 60.1, 95% CI 2.1-1,027.9; reference, White).

CONCLUSIONS

Pancreatic neuroendocrine tumors≤2 cm are increasingly common, and the most significant predictors of disease-specific survival are grade and race. The SEER database excludes PNETs considered to be benign, and rates of extrapancreatic extension, nodal metastasis, and distant metastasis are overestimated. Small size, however, does not preclude malignant behavior.

Outcomes of the patients who were postoperatively diagnosed as malignancy after laparoscopic distal pancreatectomy

PURPOSE

Laparoscopic distal pancreatectomy (LDP) is a reliable and safe operation for selected patients with benign and low-grade malignant lesions in the body and tail of the pancreas. However, its application for malignant disease has been rarely reported. The aim of this study is to analyze postoperative outcomes of the patients with a diagnosis of benign or borderline malignancy, who were postoperatively diagnosed as malignancy after LDP.

METHODS

From January 2005 to March 2011, LDP was performed on 88 patients, and 11 were subsequently diagnosed as malignancy in postoperative pathologic reports. A retrospective analysis of the clinical outcomes of these 11 patients was conducted.

RESULTS

The patients were 4 men and 7 women with a median age of 68 years (range, 29 to 83 y). The postoperative diagnoses were 5 with ductal adenocarcinoma, 3 with invasive intraductal papillary mucinous neoplasm, 1 with mucinous cystadenocarcinoma, 1 with neuroendocrine carcinoma, and 1 with pancreas metastasis from a renal cell carcinoma. The median operation time was 180 minutes (range, 80 to 325 min), and the median estimated blood loss was 200 mL (range, 150 to 500 mL). There were no open conversions. Four (36%) patients experienced complications: intra-abdominal fluid collection (2), spleen infarction (1), and enterocutaneous fistula (1). The median postoperative hospital stay was 11 days (range, 6 to 18 d). All the patients were considered to have curative resection (R0), postoperatively. During the median follow-up period of 30 months (range, 3 to 58 mo), 1 patient was found to have liver metastasis, which had been present and misdiagnosed as benign hemangioma on preoperative diagnostic workup. This patient died 1 year after LDP. Another patient was found to have liver metastasis 30 months after LDP. The patient was treated with radiofrequency ablation, and he was still alive 60 months postoperatively. The remaining patients were alive without any recurrent disease.

CONCLUSIONS

The postoperative outcomes of the patients, who were diagnosed postoperatively as having a malignant pancreatic disease, are acceptable.

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.

Lymph nodes and survival in pancreatic neuroendocrine tumors

HYPOTHESIS

Lymph node metastases decrease survival in patients with pancreatic neuroendocrine tumors (pNETs).

DESIGN

Prospective database searches.

SETTING

National Institutes of Health (NIH) and Stanford University Hospital (SUH).

PATIENTS

A total of 326 patients underwent surgical exploration for pNETs at the NIH (n = 216) and SUH (n = 110).

MAIN OUTCOME MEASURES

Overall survival, disease-related survival, and time to development of liver metastases.

RESULTS

Forty patients (12.3%) underwent enucleation and 305 (93.6%) underwent resection. Of the patients who underwent resection, 117 (35.9%) had partial pancreatectomy and 30 (9.2%) had a Whipple procedure. Forty-one patients also had liver resections, 21 had wedge resections, and 20 had lobectomies. Mean follow-up was 8.1 years (range, 0.3-28.6 years). The 10-year overall survival for patients with no metastases or lymph node metastases only was similar at 80%. As expected, patients with liver metastases had a significantly decreased 10-year survival of 30% (P < .001). The time to development of liver metastases was significantly reduced for patients with lymph node metastases alone compared with those with none (P < .001). For the NIH cohort with longer follow-up, disease-related survival was significantly different for those patients with no metastases, lymph node metastases alone, and liver metastases (P < .001). Extent of lymph node involvement in this subgroup showed that disease-related survival decreased as a function of the number of lymph nodes involved (P = .004).

CONCLUSIONS

As expected, liver metastases decrease survival of patients with pNETs. Patients with lymph node metastases alone have a shorter time to the development of liver metastases that is dependent on the number of lymph nodes involved. With sufficient long-term follow-up, lymph node metastases decrease disease-related survival. Careful evaluation of number and extent of lymph node involvement is warranted in all surgical procedures for pNETs.