Lymph nodes and survival in pancreatic neuroendocrine tumors

Long-Term Proton Pump Inhibitor-Acid Suppressive Treatment Can Cause Vitamin B12 Deficiency in Zollinger-Ellison Syndrome (ZES) Patients

Whether the long-term treatment of patients with proton pump inhibitors (PPIs) with different diseases [GERD, Zollinger-Ellison syndrome (ZES), etc.] can result in vitamin B12 (VB12) deficiency is controversial. In this study, in 175 patients undergoing long-term ZES treatment with anti-acid therapies, drug-induced control acid secretory rates were correlated with the presence/absence of VB12 deficiency, determined by assessing serum VB12 levels, measurements of VB12 body stores (blood methylmalonic acid (MMA) and total homocysteine[tHYC]), and other features of ZES. After a mean of 10.2 yrs. of any acid treatment (5.6 yrs. with PPIs), 21% had VB12 deficiency with significantly lower serum and body VB12 levels (p < 0.0001). The presence of VB12 deficiency did not correlate with any feature of ZES but was associated with a 12-fold lower acid control rate, a 2-fold higher acid control pH (6.4 vs. 3.7), and acid control secretory rates below those required for the activation of pepsin (pH > 3.5). Over a 5-yr period, the patients with VB12 deficiency had a higher rate of achlorhydria (73% vs. 24%) and a lower rate of normal acid secretion (0% vs. 49%). In conclusion, in ZES patients, chronic long-term PPI treatment results in marked acid hyposecretion, resulting in decreased serum VB12 levels and decreased VB12-body stores, which can result in VB12 deficiency.

Development and validation of CT-based radiomics deep learning signatures to predict lymph node metastasis in non-functional pancreatic neuroendocrine tumors: a multicohort study

Background

Lymph node status is an important factor for the patients with non-functional pancreatic neuroendocrine tumors (NF-PanNETs) with respect to the surgical methods, prognosis, recurrence. Our aim is to develop and validate a combination model based on contrast-enhanced CT images to predict the lymph node metastasis (LNM) in NF-PanNETs.

Methods

Retrospective data were gathered for 320 patients with NF-PanNETs who underwent curative pancreatic resection and CT imaging at two institutions (Center 1, n = 236 and Center 2, n = 84) between January 2010 and March 2022. RDPs (Radiomics deep learning signature) were developed based on ten machine-learning techniques. These signatures were integrated with the clinicopathological factors into a nomogram for clinical applications. The evaluation of the model's performance was conducted through the metrics of the area under the curve (AUC).

Findings

The RDPs showed excellent performance in both centers with a high AUC for predicting LNM and disease-free survival (DFS) in Center 1 (AUC, 0.88; 95% CI: 0.84-0.92; DFS, p < 0.05) and Center 2 (AUC, 0.91; 95% CI: 0.85-0.97; DFS, p < 0.05). The clinical factors of vascular invasion, perineural invasion, and tumor grade were associated with LNM (p < 0.05). The combination nomogram showed better prediction capability for LNM (AUC, 0.93; 95% CI: 0.89-0.96). Notably, our model maintained a satisfactory predictive ability for tumors at the 2-cm threshold, demonstrating its effectiveness across different tumor sizes in Center 1 (≤2 cm: AUC, 0.90 and >2 cm: AUC, 0.86) and Center 2 (≤2 cm: AUC, 0.93 and >2 cm: AUC, 0.91).

Interpretation

Our RDPs may have the potential to preoperatively predict LNM in NF-PanNETs, address the insufficiency of clinical guidelines concerning the 2-cm threshold for tumor lymph node dissection, and provide precise therapeutic strategies.

Funding

This work was supported by JSPS KAKENHI Grant Number JP22K20814; the Rare Tumor Research Special Project of the National Natural Science Foundation of China (82141104) and Clinical Research Special Project of Shanghai Municipal Health Commission (202340123).

What Is the Role of Lymph Node Resections in Small Islet Tumors?

Well-differentiated nonfunctional pancreatic neuroendocrine tumors are often indolent neoplasms without lymph node (LN) metastasis at diagnosis. Patients with PNETs that are functional or >2 cm should have surgical resection as per the standard of care. However, in appropriately selected patients with NF PNETs <2 cm who are at low risk of LN metastasis, the extent of surgery and lymphadenectomy could be limited.

European Neuroendocrine Tumor Society 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromes

This ENETS guidance paper aims to provide practical advice to clinicians for the diagnosis, treatment and follow-up of functioning syndromes in pancreatic neuroendocrine tumours (NET). A NET-associated functioning syndrome is defined by the presence of a clinical syndrome combined with biochemical evidence of inappropriately elevated hormonal levels. Different hormonal syndromes can be encountered in pancreatic NET patients, including insulinoma, gastrinoma as well as the rare glucagonoma, VIPoma, ACTHoma, PTHrPoma, carcinoid syndrome, calcitoninoma, GHRHoma and somatostatinoma. The recommendations provided in this paper focus on the biochemical, genetic and imaging work-up as well as therapeutic management of the individual hormonal syndromes in well-differentiated, grade 1-3, functioning NET with the primary tumour originating in the pancreas, and for specific subtypes also in the duodenum.

Neuroendocrine tumors in a patient with multiple endocrine neoplasia type 1 syndrome: A case report and review of the literature

RATIONALE

Hyperparathyroidism is caused by parathyroid tumors combined with gastroenteropancreatic tumors and pituitary tumors, which is common in patients with multiple endocrine neoplasia 1 syndrome (MEN-1). As its main pathogenic factor involves genetic mutations, it can cause a variety of different clinical symptoms. However, cases with negative genetic testing results and multiple nonfunctional malignant neuroendocrine tumors (NETs) with metastasis are relatively rare.

PATIENT CONCERNS

A 33-year-old man was admitted to the hospital for hyperparathyroidism. Imaging examination revealed multiple nodules in the parathyroid gland, pancreas, thymus, and adrenal gland, and multiple metastases to the lung, liver, thoracolumbar, as well as mediastinal lymph nodes.

DIAGNOSES

After multidisciplinary consultation, this patient was diagnosed with MEN-1 syndrome with various original tumors and multiple systemic metastases.

INTERVENTIONS

The patient underwent parathyroid tumor resection and metastasis biopsy.

OUTCOMES

The patient received denosumab and sorafenib treatment.

LESSONS

As an autosomal dominant hereditary disease, MEN-1 patients present with parathyroid hyperplasia, pancreatic and intestinal tumors, pituitary tumors, and so on, which are caused by genetic mutations. These patients would have hyperparathyroidism, hypoglycemia, gastric ulcer, and gastrointestinal diseases. However, some patients with MEN-1 syndrome cannot be diagnosed by genetic testing and simultaneously present with multiple nonfunctional NETs with systemic metastasis. This increases the difficulty of diagnosis and the subsequent treatment.

Prognostic role and predictors of lymph node involvement in pancreatic neuroendocrine tumors

PURPOSE

To define the prognostic role of lymph node involvement (LNI) in patients with pancreatic neuroendocrine tumors (PNETs) and identify predictors of LNI using a comprehensive multifactor analysis focusing on preoperative radiological features.

METHODS

This study included 236 patients with preoperative computed tomography who underwent radical surgical resection of PNETs at our hospital between 2009 and 2019. Univariate and multivariable logistic regression analyses were performed to investigate the risk factors associated with LNI and tumor recurrence. The disease-free survival (DFS) rates with and without LNI were compared.

RESULTS

Forty-four of the 236 patients (18.6%) had LNI. Biliopancreatic duct dilatation (odds ratio [OR], 2.295; 95% confidence interval [CI], 1.046-5.035; p = 0.038), tumor margin (OR, 2.189; 95% CI, 1.034-4.632; p = 0.041), and WHO grade (G2: OR, 2.923; 95% CI, 1.005-8.507; p = 0.049; G3: OR, 12.067; 95% CI, 3.057-47.629; p < 0.001) were independent risk factors of LNI in PNETs. Multivariable analysis showed that LNI (OR, 2.728; 95% CI, 1.070-6.954; p = 0.036), G3 (OR, 4.894; 95% CI, 1.047-22.866; p = 0.044), and biliopancreatic duct dilatation (OR, 2.895; 95% CI, 1.124-7.458; p = 0.028) were associated with PNET recurrence in patients after surgery. Patients with LNI had a significantly worse DFS than those without LNI (3-year DFS: 85.9 vs. 96.7%; p < 0.001; 5-year DFS: 65.1 vs. 93.9%; p < 0.001).

CONCLUSION

LNI was associated with decreased DFS. Biliopancreatic duct dilatation, irregular tumor margins, and grades G2 and G3 were independent risk factors for LNI.

Recurrence after surgical resection of nonmetastatic sporadic gastrinoma: Which prognostic factors and surgical procedure?

BACKGROUND

The only curative treatment of gastrinoma is complete resection, but its surgical management remains controversial and prognostic factors of sporadic nonmetastatic gastrinoma are poorly known.

METHODS

This was a retrospective study including all patients who underwent elective surgery for nonmetastatic sporadic gastrinoma between 2000 and 2020 in 15 hospitals. The primary and secondary outcomes were overall survival and disease-free survival predictive factors.

RESULTS

In total, 108 patients were included, of which 68 (63%) were duodenal, 19 (18%) pancreatic, and 21 (19%) primary lymph node gastrinomas, with no major difference in clinical presentation. Among the 68 duodenal gastrinomas, 26% (n = 18) underwent pancreaticoduodenectomy (PD) and 74% (n = 50) underwent duodenotomy with the excision of duodenal wall tumors and lymphadenectomy (DUODX + LN). Overall, the median overall survival was 173 months, and the 5-year overall survival was 94%, with no predictive factors identified. The median disease-free survival was 93 months, and the 5-year disease-free survival was 63%. Tumor size >2 cm (P = .00001), grade (P = .00001), and pancreatic tumor location (P = .0001) were predictive factors of recurrence; however, in multivariate analysis, only tumor size >2 cm (P = .005) and grade (P = .013) were independent predictors of recurrence. Age, sex, preoperative gastrin level, lymphadenectomy <10 resected lymph nodes, and metastatic lymph nodes on surgical specimens were not predictors of recurrence. For duodenal gastrinomas, surgical procedures (PD versus DUODX + LN) did not have a significant effect on overall survival and disease-free survival.

CONCLUSION

Sporadic nonmetastatic gastrinomas had an excellent overall survival. Recurrence is frequent and influenced by tumor size and grade. Regarding sporadic duodenal gastrinoma, duodenotomy with excision of duodenal wall tumors with lymphadenectomy could be considered a valid surgical option, in the absence of clear oncologic superiority of PD.

Lymph node metastases and recurrence in pancreatic neuroendocrine neoplasms

BACKGROUND

The impact of lymph node metastasis on survival in pancreatic neuroendocrine neoplasms as well as their best surgical treatment is controversial. We aimed to determine the frequency and prognostic impact of lymph node involvement in pancreatic neuroendocrine neoplasms.

METHODS

Patients undergoing pancreatic resections for pancreatic neuroendocrine neoplasms between 2001 and 2019 were retrospectively analyzed based on a prospective database. Clinicopathological parameters and perioperative outcome were assessed. Overall and disease-free survival was analyzed. Subgroup analysis was performed for sporadic, nonfunctional pancreatic neuroendocrine neoplasms without distant metastases and ≥4 analyzed lymph nodes.

RESULTS

Of 605 surgically resected pancreatic neuroendocrine neoplasms, 55% were G1, 36% were G2, and 9% were G3 differentiated. At the time of resection, 34% of patients had lymph node metastasis, and 16% had distant metastases. For subgroup analysis, 314 patients were analyzed. Lymph node metastases occurred in 36% of patients and were most frequent in G3 patients (67%). An increase in tumor size and advancement was associated with higher rates of lymph node metastasis, and disease-free survival was significantly impaired. Significant differences in disease-free survival were observed between 1 and 3 (5-year disease-free survival 52%) and ≥4 positive lymph nodes (5-year disease-free survival 28%), as well as when G3 tumors were excluded. In multivariable analysis, grading, tumor stage, and especially lymph node metastases as well as the proposed pN1 and pN2 categories were confirmed as independent predictors of recurrence.

CONCLUSION

The presence and extent of lymph node involvement has considerable prognostic impact in pancreatic neuroendocrine neoplasms. This study, for the first time, validated the proposed pN2 stage for well-differentiated pancreatic neuroendocrine neoplasms.

Hyperglycemia is associated with adverse prognosis in patients with pancreatic neuroendocrine neoplasms

BACKGROUND

Although glucose has a well-recognized protumoral role and the pancreas is a critical organ in adjusting glucose metabolism, the clinical value of hyperglycemia in pancreatic neuroendocrine neoplasms (pNENs) remains largely unidentified.

METHODS

A retrospective study including 335 patients with pathologically confirmed pNENs was conducted. A baseline fasting blood glucose concentration ≥5.6 mmol/L was defined as hyperglycemia (otherwise, normal). Survival and regression analyses were performed.

RESULTS

Compared with patients with normal glucose, patients with hyperglycemia (47.8%) had a higher proportion of preexisting diabetes mellitus (DM) (36.9% vs. 4.6%, p < 0.001), lymph node involvement (31.0% vs. 14.6%, p = 0.002), distant metastasis (34.4% vs. 22.9%, p = 0.019), and carbohydrate antigen 19-9 (CA19-9) ≥ 37 U/mL (16.6% vs. 7.2%, p = 0.009). Hyperglycemia was associated with CA19-9 ≥ 37 U/mL (Odds Ratio (OR) = 3.19, 95% CI: 1.11-9.17, p = 0.031), lymph node involvement (OR = 2.32, 95% CI: 1.02-5.28, p = 0.045), nonfunctional tumors (OR = 9.90, 95% CI: 2.11-46.34, p = 0.004), and preexisting diabetes (OR = 18.24, 95% CI: 4.06-81.95, p < 0.001). Hyperglycemia was an independent determinant for overall survival in the multivariate analysis (hazard ratio (HR) = 2.65, 95% CI: 1.31-5.34, p = 0.006).

CONCLUSION

Hyperglycemia is an independent predictor of overall survival and is associated with preexisting DM or lymphatic metastasis in patients with pNENs. Patients with hyperglycemia and resectable pNENs may benefit from radical resection with dissection of regional lymph nodes.

Complications in Distal Pancreatectomy versus Radical Antegrade Modular Pancreatosplenectomy: A Disease Risk Score Analysis Utilizing National Surgical Quality Improvement Project Data

INTRODUCTION

Radical antegrade modular pancreatosplenectomy (RAMPS) was developed to improve R0 resections and lymph node harvests versus distal pancreatectomy (DP) in pancreatic adenocarcinoma (PDAC); relative complication rates are understudied.

METHODS

Patients undergoing distal pancreas resections from 2006 to 2020 were identified from our institutional NSQIP database, grouped by resection method, and evaluated for the following outcomes: postoperative pancreatic fistula (POPF), clinically relevant POPF (crPOPF), incisional surgical site infection (iSSI), organ space SSI (osSSI), and Clavien-Dindo grade ≥ 3 (CD ≥ 3) complications using logistic regression. Patients were matched 1:1 based on disease risk score.

RESULTS

Two-hundred-thirty-six and 117 patients underwent DP and RAMPS, respectively. POPF, crPOPF, CD ≥ 3 complications, iSSI, and osSSIs occurred in 105 (30%), 43 (12%), 74 (21%), 34 (10%) and 52 (15%) patients, respectively. Disease risk score matching yielded 89 similar patients per group. On multivariable analysis, patients undergoing RAMPS were not significantly more likely to experience POPF (OR 0.69, P = 0.26), crPOPF (OR 0.41, P = 0.72), CD ≥ 3 complication (OR 0.78, P = 0.44), iSSI (OR 0.58, P = 0.27), or osSSI (OR 0.93, P = 0.86). Of patients with PDAC (n = 108) mean nodal harvest were 14.8 (SD 11.30) and 19.4 (SD 7.19) nodes for patients undergoing DP and RAMPS, respectively (P = 0.01). Six patients (20%) undergoing DP had positive margins versus 12 (15%) undergoing RAMPS (P = 0.56). At a median follow-up of 17 months, there was no difference in locoregional recurrence-free survival (P = 0.32) or overall survival (P = 0.92) on Kaplan-Meier analysis.

CONCLUSION

RAMPS does not result in increased complications compared to DP and routine use is encouraged in pancreatic malignancies.

Development and Validation of a Modified Eighth AJCC Staging System for Primary Pancreatic Neuroendocrine Tumors

OBJECTIVE

To improve the prognostic accuracy of the eighth edition of AJCC staging system for pNETs with establishment and validation of a new staging system.

BACKGROUND

Validation of the updated eighth AJCC staging system for pNETs has been limited and controversial.

METHODS

Data from the SEER registry (1975-2016) (n = 3303) and a multi-institutional database (2000-2016) (n = 825) was used as development and validation cohorts, respectively. A mTNM was proposed by maintaining the eighth AJCC T and M definitions, and the recently proposed N status as N0 (no LNM), N1 (1-3 LNM), and N2 (≥4 LNM), but adopting a new stage classification.

RESULTS

The eighth TNM staging system failed to stratify patients with stage I versus IIA, stage IIB versus IIIA, and overall stage I versus II relative to long-term OS in both database. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the SEER (5-year OS, stage I 87.0% vs stage II 80.3% vs stage III 72.9% vs stage IV 57.2%, all P < 0.001), and multi-institutional (5-year OS, stage I 97.6% vs stage II 82.7% vs stage III 78.4% vs stage IV 50.0%, all P < 0.05) datasets. On multivariable analysis, mTNM staging remained strongly associated with prognosis, as the hazard of death incrementally increased with each stage among patients in the 2 cohorts.

CONCLUSION

A mTNM pNETs clinical staging system using N0, N1, N2 nodal categories was better at stratifying patients relative to long-term OS than the eighth AJCC staging.

Enucleation Is a Feasible Procedure for Well-Differentiated pNEN-A Matched Pair Analysis

The extent of surgical resection in the treatment of pancreatic neuroendocrine neoplasms (pNEN) is still controversial. This study aimed to evaluate the outcomes of enucleation for well-differentiated non-functional (nf) pNEN. Patients undergoing enucleation (2001−2020) were analyzed. Clinicopathological parameters, perioperative outcomes and survival were assessed. The analysis was performed as a nested case-control study and matched-pair analysis with formal resection. Sixty-one patients undergoing enucleation were identified. Compared to patients undergoing formal resection, enucleation was associated with a significantly shorter median length of operative time (128 (IQR 95−170) versus 263 (172−337) minutes, p < 0.0001) and a significantly lower rate of postoperative diabetes (2% versus 21%, p = 0.0020). There was no significant difference in postoperative pancreatic fistula rate (18% versus 16% type B/C, p = 1.0), Clavien−Dindo ≥ III complications (20% versus 26%, p = 0.5189), readmission rate (12% versus 15%, p = 0.6022) or length of hospital stay (8 (7−11) versus 10 (8−17) days, p = 0.0652). There was no 30-day mortality after enucleation compared to 1.6% (n = 1) after formal resection. 10-year overall survival (OS) and disease-free survival (DFS) was similar between the two groups (OS: 89% versus 77%, p = 0.2756; DFS: 98% versus 91%, p = 0.0873). Enucleation presents a safe surgical approach for well-differentiated nf-pNEN with good long-term outcomes for selected patients.

[Surgery of pancreatic neuroendocrine neoplasms: state of the art]

Pancreatic neuroendocrine neoplasms (pNEN) have a rising incidence and are increasingly diagnosed at early and thus potentially resectable stages. Due to the rarity of these neoplasms the recommendations of currently available guidelines are mainly based on retrospective data. Surgical and oncological treatment of these rare diseases should only be performed at specialized centers. In cases of resectability without indications of diffuse metastases, complete resection with curative intent should be the treatment of choice. For small nonfunctional pNENs < 2 cm watch and wait strategies are recommended as an alternative to surgical treatment. Recent data, however, also showed an increased survival even of small (1-2 cm) pNENs after resection. For benign insulinomas and small nonfunctional well-differentiated pNENs parenchyma-sparing procedures, such as enucleation and segmental resection are available. The question of the influence of lymph node metastases on long-term disease-free survival and overall survival and consequently the role of systematic lymphadenectomy is still a matter of debate. In pNENs > 2 cm formal resection with lymphadenectomy is considered the gold standard. Minimally invasive and robotic-assisted procedures are of increasing importance also for formal pancreatic resection.

Patterns of Lymph Node Metastasis and Optimal Surgical Strategy in Small (≤20 mm) Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

Regional lymph node metastasis (LNM) is crucial for planning additional lymphadenectomy, and is directly correlated with poor prognosis in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). However, the patterns of LNM for small (≤20 mm) GEP-NETs remain unclear. This population-based study aimed at evaluating LNM patterns and identifying optimal surgical strategies from the standpoint of lymph node dissemination.

METHODS

This retrospective cohort study retrieved data from the Surveillance, Epidemiology, and End Results (SEER) 18 registries database for 17,308 patients diagnosed as having localized well-differentiated GEP-NETs ≤ 20 mm between January 1, 2004, and December 31, 2017. The patterns of LNM were characterized in 6,622 patients who underwent extended resection for adequate lymph node harvest.

RESULTS

Of 6,622 patients with localized small GEP-NETs in the current study, 2,380 (36%) presented with LNM after regional lymphadenectomy. Nodal involvement was observed in approximately 7.4%, 49.1%, 13.6%, 53.7%, 13.8%, 7.8%, and 15.4% of gastric (g-), small intestinal (si-), appendiceal (a-), colonic (c-), rectal (r-), non-functional pancreatic (nfp-), and functional pancreatic (fp-) NETs ≤ 20 mm. Patients with younger age, larger tumor size, and muscularis invasion were more likely to present with LNM. Additional lymphadenectomy conferred a significant survival advantage in NETs (≤10 mm: HR, 0.47; 95% CI, 0.33-0.66; p < 0.001; 11-20 mm: HR, 0.54; 95% CI, 0.34-0.85; p = 0.008) and fp-NETs ≤ 20 mm (HR, 0.08; 95% CI, 0.02-0.36; p = 0.001), as well as g-NETs (HR, 0.39; 95% CI, 0.16-0.96; p = 0.041) and c-NETs of 11-20 mm (HR, 0.07; 95% CI, 0.01-0.48; p = 0.007). Survival benefits of additional lymphadenectomy were not found in a-NETs, r-NETs, and nfp-NETs with a small size.

CONCLUSIONS

Given the increased risk for nodal metastasis, primary tumor resection with regional lymphadenectomy is a potential optimal surgical strategy for si-NETs and fp-NETs ≤ 20 mm, as well as g-NETs and c-NETs of 11-20 mm. Local resection is an appropriate and reliable surgical approach for a-NETs, r-NETs, and nfp-NETs ≤ 20 mm.

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 1: a broad overview

This review article discusses the diagnoses and treatment of patients with multiple endocrine neoplasia type 1 (MEN 1). The most common tumors associated with MEN 1 are located in the pancreas, pituitary, and parathyroid glands. Less common tumors include neuroendocrine tumors of the lung and thymus, adrenal tumors, and cutaneous lesions. This article describes the diagnosis, clinical manifestations, treatment, and surveillance of tumors associated with patients who are diagnosed with MEN 1.

New Nodal Staging for Primary Pancreatic Neuroendocrine Tumors: A Multi-institutional and National Data Analysis

OBJECTIVE

To determine the prognostic role of metastatic lymph node (LN) number and the minimal number of LNs for optimal staging of patients with pancreatic neuroendocrine tumors (pNETs).

BACKGROUND

Prognosis relative to number of LN metastasis (LNM), and minimal number of LNs needed to evaluate for accurate staging, have been poorly defined for pNETs.

METHODS

Number of LNM and total number of LN evaluated (TNLE) were assessed relative to recurrence-free survival (RFS) and overall survival (OS) in a multi-institutional database. External validation was performed using Surveillance, Epidemiology and End Results (SEER) registry.

RESULTS

Among 854 patients who underwent resection, 233 (27.3%) had at least 1 LNM. Patients with 1, 2, or 3 LNM had a comparable worse RFS versus patients with no nodal metastasis (5-year RFS, 1 LNM 65.6%, 2 LNM 68.2%, 3 LNM 63.2% vs 0 LNM 82.6%; all P < 0.001). In contrast, patients with ≥4 LNM (proposed N2) had a worse RFS versus patients who either had 1 to 3 LNM (proposed N1) or node-negative disease (5-year RFS, ≥4 LNM 43.5% vs 1-3 LNM 66.3%, 0 LNM 82.6%; all P < 0.05) [C-statistics area under the curve (AUC) 0.650]. TNLE ≥8 had the highest discriminatory power relative to RFS (AUC 0.713) and OS (AUC 0.726) among patients who had 1 to 3 LNM, and patients who had ≥4 LNM in the multi-institutional and SEER database (n = 2764).

CONCLUSIONS

Regional lymphadenectomy of at least 8 lymph nodes was necessary to stage patients accurately. The proposed nodal staging of N0, N1, and N2 optimally staged patients.

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.

Predicting the Survival Probability of Neuroendocrine Tumor Populations: Developing and Evaluating a New Predictive Nomogram

Purpose

The purpose of this study was to develop and initially validate a nomogram model in order to predict the 3-year and 5-year survival rates of neuroendocrine tumor patients.

Methods

Accordingly, 348 neuroendocrine tumor patients were enrolled as study objects, of which 244 (70%) patients were included in the training set to establish the nomogram model, while 104 (30%) patients were included in the validation set to verify the robustness of the model. First, the variables related to the survival rate were determined by univariable analysis. In addition, variables that were sufficiently significant were selected for constructing the nomogram model. Furthermore, the concordance index (C-index), receiver operating characteristic (ROC), and calibration curve analysis were used to evaluate the performance of the proposed nomogram model. The survival analysis was then used to evaluate the return to survival probability as well as the indicators of constructing the nomogram model.

Results

According to the multivariable analysis, lymphatic metastasis, international normalized ratio (INR), prothrombin time (PT), tumor differentiation, and the number of tumor metastases were found to be independent predictors of survival rate. Moreover, the C-index results demonstrated that the model was robust in both the training set (0.891) and validation set (0.804). In addition, the ROC results further verified the robustness of the model either in the training set (AUC = 0.823) or training set (AUC = 0.768). Furthermore, the calibration curve results showed that the model can be used to predict the 3-year and 5-year survival probability of neuroendocrine tumor patients. Meaningfully, five variables were found: lymphatic metastasis (p = 0.0095), international standardized ratio (p = 0.024), prothrombin time (p = 0.0036), tumor differentiation (p = 0.0026), and the number of tumor metastases (p = 0.00096), which were all significantly related to the 3-year and 5-year survival probability of neuroendocrine tumor patients.

Conclusion

In summary, a nomogram model was constructed in this study based on five variables (lymphatic metastasis, international normalized ratio (INR), prothrombin time (PT), tumor differentiation, and number of tumor metastases), which was shown to predict the survival probability of patients with neuroendocrine tumors. Additionally, the proposed nomogram exhibited good ability in predicting survival probability, which may be easily adopted for clinical use.

Malignant Insulinoma: A Rare Form of Neuroendocrine Tumor

INTRODUCTION

Due to the rarity of malignant insulinoma, a lack of the literature describing factors affecting outcomes exists. Our aim was to review malignant insulinoma incidence, characteristics and survival trends.

METHODS

We identified all patients with malignant insulinoma in the SEER registries from 1973 to 2015. Incidence, neoplasm characteristics and factors affecting cancer-specific survival (CSS) were described.

RESULTS

A total of 121 patients were identified. The crude annual overall incidence was low (range 0.0-0.27 cases per million person years). The largest proportion had localized disease (40%), while 16% had regional disease, 39% distant metastatic disease, and stage was unreported in 5%. Most neoplasms were in the body/tail of the pancreas, followed by the head of the pancreas. Grade was reported in 40% of patients; only a single patient reported as having grade IV with the remainder all grades I/II. Surgical resection was performed in 64% of patients. Within surgical patients, the median primary neoplasm size was 1.8 cm. Regional lymph nodes were examined in 57.1% of surgical patients, while 34% of examined nodes were positive. The median CSS was 183 months. On multivariable analysis, surgical resection, male sex and absence of metastatic disease were associated with superior survival.

CONCLUSION

While the greatest proportion of patients with malignant insulinoma present with localized disease, regional lymph node involvement was found in 34% of whose nodes were tested. Further studies are needed to assess the role of lymph node dissection in improving survival and preventing recurrence given the observed frequency of lymph node involvement.

c-Myc promotes lymphatic metastasis of pancreatic neuroendocrine tumor through VEGFC upregulation

Pancreatic neuroendocrine tumor (pNET) is a pancreatic neoplasm with neuroendocrine differentiation. pNET in early stage can be treated with surgical resection with long‐term survival, whereas the prognosis of pNET with locoregional or distant metastasis is relatively poor. Lymphangiogenesis is essential for tumor metastasis via the lymphatic system and may overhead distant metastasis. c‐Myc overexpression is involved in tumorigenesis. The role of c‐Myc in lymphangiogenesis is unclear. In this study, we evaluated the mechanism and effect of c‐Myc on lymphangiogenesis of pNET via interaction of lymphatic endothelial cells (LECs) and pNET cells. Lymph node metastasis was evaluated in pNET xenograft mice. Potential target agents to inhibit lymph node metastasis were evaluated in an animal model. We found that vascular endothelial growth factor C (VEGFC) expression and secretion was increased in pNET cell lines with c‐Myc overexpression. c‐Myc transcriptionally upregulates VEGFC expression and the secretion of pNET cells by directly binding to the E‐box of the VEGFC promoter and enhances VEGF receptor 3 phosphorylation and the tube formation of LECs. c‐Myc overexpression is associated with lymph node metastasis in pNET xenograft mice. Combinational treatment with an mTOR inhibitor and c‐Myc inhibitor or VEGFC‐neutralizing chimera protein reduced lymph node metastasis in the mice with c‐Myc overexpression. The mTOR inhibitor acts on lymphangiogenesis by reducing VEGFC expression in pNET cells and inhibiting the tube formation of LECs. In conclusion, mTOR and c‐Myc are important for lymphangiogenesis of pNET and are potential therapeutic targets for prevention and treatment of lymph node metastasis in pNET.

Risk Factors of Lymph Node Metastasis in Patients with Pancreatic Neuroendocrine Tumors (PNETs)

BACKGROUND

The prognostic value of lymph node metastasis in patients with PNETs is controversial. Understanding the effect of lymph node metastasis on prognosis in pancreatic neuroendocrine tumors is helpful for surgery and follow-up. The purposes of this study are to identify predictors of lymph node metastasis among patients with PNETs and determine its prognostic associations.

METHODS

A retrospective analysis of the surveillance, epidemiology, and end results (SEER) database was performed. Patients with PNETs that underwent surgery and pathologic nodal staging were identified. Logistic regression and Cox regression were performed to identify independent predictors and prognostic factors, respectively.

RESULTS

Of 1956 patients (age: 56.8 ± 13.4 years, 53.3% males), 748 (38.2%) had lymph node metastasis. On multivariable analysis, tumor located in pancreas head, distant metastasis, and poorly differentiated, undifferentiated, and unknown differentiated histology grades were three independent risk factors of lymph node metastasis. In the entire cohort, lymph node metastasis indicated a worse overall survival (HR: 1.48, 95% CI: 1.17-1.88, p < 0.001) and disease-specific survival (HR: 1.87, 95% CI: 1.41-2.48, p < 0.001) on multivariable analysis. Lymph node metastasis was associated with worse overall (HR: 1.45, 95% CI: 1.08-1.93, p = 0.012) and disease-specific survival (HR: 2.13, 95% CI: 1.48-3.05, p < 0.001) in patients without distant metastasis on multivariate analysis. Lymph node metastasis was also independently associated with worse disease-specific survival among patients in well differentiation (HR: 2.16, 95% CI: 1.35-3.46, p = 0.001) and moderately differentiation (HR: 2.67, 95% CI: 1.28-5.56, p = 0.009) groups on multivariate analysis.

CONCLUSIONS

Tumor located in pancreas head, distant metastasis, and poorly differentiated, undifferentiated, and unknown differentiated histology grades were three independent risk factors for lymph node metastasis. Lymph node metastasis was an independent prognostic factor of worse OS and DSS in patients with tumor located in pancreas head. Lymph node metastasis was an independent prognostic factor of worse OS and DSS in patients without distant metastasis. Lymph node metastasis was an independent prognostic factor of worse DSS in well differentiation and moderately differentiation groups.

The Landmark Series: Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) comprise a heterogeneous group of neoplasms arising from pancreatic islet cells that remain relatively rare but are increasing in incidence worldwide. While significant advances have been made in recent years with regard to systemic therapies for patients with advanced disease, surgical resection remains the standard of care for most patients with localized tumors. Although formal pancreatectomy with regional lymphadenectomy is the standard approach for most PNETs, pancreas-preserving approaches without formal lymphadenectomy are acceptable for smaller tumors at low risk for lymph node metastases. Furthermore, observation of small, asymptomatic, low-grade PNETs is a safe, initial strategy and is generally recommended for tumors < 1 cm in size. In this Landmark Series review, we highlight the critical studies that have defined the surgical management of PNETs.

Role of Pre-operative Inflammatory Markers as Predictors of Lymph Node Positivity and Disease Recurrence in Well-Differentiated Pancreatic Neuroendocrine Tumours: Pancreas2000 Research and Educational Program (Course 9)

Pancreatic neuroendocrine tumours (PNET) is a rare disease and in the absence of metastases, surgical resection is recommended. Key factors affecting survival in PNETs are the stage and grade of the disease, but there is increasing evidence suggesting lymph node involvement is associated with shorter disease-free and overall survival. Ability to predict the likelihood of lymph node involvement at the time of diagnosis would affect surgical decision making in these patients. A systemic inflammatory index such as neutrophil to lymphocyte ratio or platelet to lymphocyte ratio has been associated with poor prognosis in several cancers.

Method: This study is a retrospective multi-centre study. The data including pre-operative inflammatory markers such as haemoglobin, neutrophil, lymphocyte counts and pathological data including number of positive lymph nodes, tumour grade and size, are collected to assess the association between inflammatory index and lymph node involvement.

Conclusion: This study aims to assess the value of routinely available pre-operative haematological markers in predicting lymph node involvement in non-functioning PNETs.

Elevated Serum Amino Acids Induce a Subpopulation of Alpha Cells to Initiate Pancreatic Neuroendocrine Tumor Formation

The cellular origin of sporadic pancreatic neuroendocrine tumors (PNETs) is obscure. Hormone expression suggests that these tumors arise from glucagon-producing alpha cells or insulin-producing β cells, but instability in hormone expression prevents linage determination. We utilize loss of hepatic glucagon receptor (GCGR) signaling to drive alpha cell hyperproliferation and tumor formation to identify a cell of origin and dissect mechanisms that drive progression. Using a combination of genetically engineered Gcgr knockout mice and GCGR-inhibiting antibodies, we show that elevated plasma amino acids drive the appearance of a proliferative population of SLC38A5⁺ embryonic progenitor-like alpha cells in mice. Further, we characterize tumors from patients with rare bi-allelic germline GCGR loss-of-function variants and find prominent tumor-cell-associated expression of the SLC38A5 paralog SLC7A8 as well as markers of active mTOR signaling. Thus, progenitor cells arise from adult alpha cells in response to metabolic signals and, when inductive signals are chronically present, drive tumor initiation.

GCGR inhibition induces an SLC38A5⁺ alpha cell population in aged mice

An SLC38A5⁺ alpha cell subpopulation initiates pancreatic tumors in aged Gcgr^−/− mice

Tumors exhibit low mutational burden and response to mTOR inhibition by rapamycin

Tumors in GCGR loss-of-function models lack immune cell infiltration

Intratumoral Fibrosis and Tumor Growth Pattern as Prognostic Factors in Optimally Resected Pancreatic Neuroendocrine Neoplasms: An Analysis of 168 Cases

OBJECTIVES

Pancreatic neuroendocrine neoplasms (PanNENs) can recur after curative resection. We sought to establish the significance of tumor fibrosis and tumor growth pattern as predictors of recurrence-free survival and overall survival.

METHODS

A retrospective query of an institutional surgical database was performed from 2000 to 2018 to identify optimally resected PanNENs. All eligible slides were reviewed by an experienced gastrointestinal pathologist for established histopathologic prognostic factors, as well as fibrosis and tumor growth pattern. We evaluated the effect of the interested variables through Cox proportional hazards models.

RESULTS

One hundred sixty-eight cases were considered. The majority of patients (90%) had grade 1 or 2 tumors, 46% showed significant fibrosis, and 22% demonstrated an infiltrative growth pattern. Twenty-one percent of patients had a recurrence. In multivariable analysis, lymphovascular invasion with a hazard ratio (HR) of 5.1 and infiltrative growth pattern (HR, 2.8) were significantly associated with increased risk of recurrence and increased risk of death (HR, 3.6 and 2.7, respectively). There was a significant decrease in recurrence-free survival and overall survival for fibrosis and infiltrative growth pattern.

CONCLUSIONS

In optimally resected PanNENs, the presence of fibrosis and infiltrative growth pattern are significant risk factors for recurrence and/or decreased survival.

Novel scoring system for recurrence risk classification of surgically resected G1/2 pancreatic neuroendocrine tumors - Retrospective cohort study

BACKGROUND

Existing staging systems for pancreatic neuroendocrine neoplasms only provide accuracy in stratifying disease severity without enough sensitivity in prognosis predicting. Previously presented models mainly set overall survival as endpoint but ignore the importance of recurrence.

METHODS

Univariate and multivariate analyses were retrospectively conducted on the potential prognostic factors of 245 patients who underwent curable surgery of G1/2 pancreatic neuroendocrine tumors from December 2002 to May 2018 in our institute. Proposed model based on statistically significant factors were tested for recurrence risk classification estimation validity as measured by discrimination (receiver operator characteristic [ROC] curve and Harrell's c-index [HCI]) and calibration.

RESULTS

Multivariate analyses found lymph node metastasis, larger tumor size and grade 2 independent risk factors of disease-free survival (DFS). The novel scoring system for recurrence risk classification sorted patients into three groups: score<15.4 for low risk (79.0%, 3- and 5-year recurrence risk 0.8% and 4.3%, median DFS not reached), score>15.4, <24.5 for intermediate risk (20.8%, 3- and 5-year recurrence risk 11.6% and 21.4%, median DFS 70 months) and score >24.5 for high risk (10.2%, 3- and 5-year recurrence risk 37.3% and 68.7%, median DFS 49 months).The area under curve (AUC) and HCI of our system were 0.871 and 0.929, superior to those of European Neuroendocrine Tumor Society (AUC 0.833, HCI 0.806).

CONCLUSION

The presented system can be utilized to identify G1/2 pancreatic neuroendocrine tumors patients with high recurrence risk, which might be appropriate for peri-operative adjuvant therapy.

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.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

Immunohistochemically Detected Expression of ATRX, TSC2, and PTEN Predicts Clinical Outcomes in Patients With Grade 1 and 2 Pancreatic Neuroendocrine Tumors

OBJECTIVE

The goal of this retrospective study was to clarify the clinical implications of immunohistochemically detected protein expression for genes that are frequently mutated in pancreatic neuroendocrine tumors (PNETs).

BACKGROUND

The clinical management of PNETs is hindered by their heterogenous biological behavior. Whole-exome sequencing recently showed that 5 genes (DAXX/ATRX, MEN1, TSC2, and PTEN) are frequently mutated in PNETs. However, the clinical implications of the associated alterations in protein expression remain unclear.

METHODS

We collected Grade 1 and 2 (World Health Organization 2017 Classification) primary PNETs samples from 100 patients who underwent surgical resection. ATRX, DAXX, MEN1, TSC2, and PTEN expression were determined immunohistochemically to clarify their relationships with prognosis and clinicopathological findings.

RESULTS

Kaplan-Meier analysis indicated that loss of TSC2 (n = 58) or PTEN (n = 37) was associated with significantly shorter overall survival, and that loss of TSC2 or ATRX (n = 41) was associated with significantly shorter recurrence-free survival. Additionally, loss of ATRX or TSC2 was significantly associated with nodal metastasis. In a multivariate analysis, combined loss of TSC2 and ATRX (n = 31) was an independent prognostic factor for shorter recurrence-free survival (hazard ratio 10.1, 95% confidence interval 2.1-66.9, P = 0.003) in G2 PNETs.

CONCLUSIONS

Loss of ATRX, TSC2, and PTEN expression might be useful as a method of clarifying the behavior and clinical outcomes of Grade 1 and 2 PNETs in routine clinical practice. Combined loss of TSC2 and ATRX had an especially strong, independent association with shorter recurrence-free survival in patients with G2 PNETs. Loss of pairs in ATRX, TSC2, or PTEN would be useful for selecting the candidate for postoperative adjuvant therapy.

A Novel Validated Recurrence Risk Score to Guide a Pragmatic Surveillance Strategy After Resection of Pancreatic Neuroendocrine Tumors: An International Study of 1006 Patients

OBJECTIVE

Despite heterogeneous biology, similar surveillance schemas are utilized after resection of all pancreatic neuroendocrine tumors (PanNETs). Given concerns regarding excess radiation exposure and financial burden, our aim was to develop a prognostic score for disease recurrence to guide individually tailored surveillance strategies.

METHODS

All patients with primary nonfunctioning, nonmetastatic well/moderately differentiated PanNETs who underwent curative-intent resection at 9-institutions from 2000 to 2016 were included (n = 1006). A Recurrence Risk Score (RRS) was developed from a randomly selected derivation cohort comprised of 67% of patients and verified on the validation-cohort comprised of the remaining 33%.

RESULTS

On multivariable analysis, patients within the derivation cohort (n = 681) with symptomatic tumors (jaundice, pain, bleeding), tumors >2 cm, Ki67 >3%, and lymph node (LN) (+) disease had increased recurrence. Each factor was assigned a score based on their weighted odds ratio that formed a RRS of 0 to 10: symptomatic = 1, tumor >2 cm = 2, Ki67 3% to 20% = 1, Ki67 >20% = 6, LN (+) = 1. Patients were grouped into low- (RRS = 0-2; n = 247), intermediate-(RRS = 3-5; n = 204), or high (RRS = 6-10; n = 9)-risk groups. At 24 months, 33% of high RRS recurred, whereas only 2% of low and 14% of intermediate RRS recurred. This persisted in the validation cohort (n = 325).

CONCLUSIONS

This international, novel, internally validated RRS accurately stratifies recurrence-free survival for patients with resected PanNETs. Given their unique recurrence patterns, surveillance intervals of 12, 6, and 3 months are proposed for low, intermediate, and high RRS patients, respectively, to minimize radiation exposure and optimize cost/resource utilization.

Surgical management of Zollinger-Ellison syndrome: Classical considerations and current controversies

Zollinger-Ellison syndrome (ZES) is characterized by gastric acid hypersecretion causing severe recurrent acid-related peptic disease. Excessive secretion of gastrin can now be effectively controlled with powerful proton pump inhibitors, but surgical management to control gastrinoma itself remains controversial. Based on a thorough literature review, we design a surgical algorithm for ZES and list some significant consensus findings and recommendations: (1) For sporadic ZES, surgery should be routinely undertaken as early as possible not only for patients with a precisely localized diagnosis but also for those with negative imaging findings. The surgical approach for sporadic ZES depends on the lesion location (including the duodenum, pancreas, lymph nodes, hepatobiliary tract, stomach, and some extremely rare sites such as the ovaries, heart, omentum, and jejunum). Intraoperative liver exploration and lymphadenectomy should be routinely performed; (2) For multiple endocrine neoplasia type 1-related ZES (MEN1/ZES), surgery should not be performed routinely except for lesions > 2 cm. An attempt to perform radical resection (pancreaticoduodenectomy followed by lymphadenectomy) can be made. The ameliorating effect of parathyroid surgery should be considered, and parathyroidectomy should be performed first before any abdominal surgery for ZES; and (3) For hepatic metastatic disease, hepatic resection should be routinely performed. Currently, liver transplantation is still considered an investigational therapeutic approach for ZES. Well-designed prospective studies are desperately needed to further verify and modify the current considerations.

Outcomes of Lymph Node Dissection for Non-metastatic Pancreatic Neuroendocrine Tumors: A Propensity Score-Weighted Analysis of the National Cancer Database

BACKGROUND

Although the National Comprehensive Cancer Network (NCCN) guidelines recommend use of lymph node dissection (LND) in patients with pancreatic neuroendocrine tumors (pNETs) > 2 cm, there is limited evidence to support the association between use of LND and overall survival (OS).

METHODS

Patients with resected pNETs were identified in the National Cancer Database (2004-2014). The inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. IPTW-adjusted Kaplan-Meier curves and Cox proportional hazards models were used to compare OS of patients in different treatment groups.

RESULTS

A total of 2664 patients diagnosed met the study entry criteria. Of these, 2132 patients (80.6%) received LND, with a median of nine nodes removed. Positive nodes were identified in 28.0% of patients who underwent LND. IPTW-adjusted Kaplan-Meier analysis showed that median OS was similar between the LND and LND-omitted groups (152.8 vs. 147.3 months; p = 0.61). In IPTW-adjusted Cox proportional hazards regression analysis, LND was not associated with an OS benefit (hazard ratio [HR] 1.15, 95% confidence interval [CI] 0.94-1.42; p = 0.18). The results were consistent across subgroups stratified by clinical T and N stages. Among patients with lymph node metastasis, the number of removed nodes (NRN) above the median was not associated with an improved OS (HR 0.82, 95% CI 0.60-1.13; p = 0.22).

CONCLUSIONS

LND had no additional therapeutic benefit among patients undergoing resection for pNETs. The present findings should be considered when managing patients with resectable pNETs.

Does attending a Delphi consensus conference impact surgeon attitudes? Survey results from the Americas HepatoPancreatoBiliary Association consensus conference on small asymptomatic pancreatic neuroendocrine tumors

BACKGROUND

Management of asymptomatic small well-differentiated (panNET) <2 cm remains controversial. A consensus conference was held on this topic. The impact of attending the conference and participating in the audience response survey on surgeon's clinical approach to pancreatic neuroendocrine tumors was assessed.

METHODS

Audience members were surveyed using a smartphone real-time response system at the beginning and end of the conference.

RESULTS

The majority of 75 attendees underwent fellowship training, and 30% had >10 years experience as attending surgeons. Previously published consensus statements on the topic were considered insufficient to guide surgical practice by 82% of attendees, and over 96% desired additional data. After review of the data, consensus statements, and decision-making process, a significant number of participants changed their opinions regarding indications for tissue biopsy (p = 0.001), size thresholds for excision (p = 0.002), and regional lymph node dissection (p = 0.002) independent of whether a consensus was reached by the content-expert panel.

CONCLUSIONS

This represented the first Delphi process consensus on the topic, and the survey confirmed the topic as well-chosen and timely. Attendees changed opinions on management of panNET regardless of whether formal consensus was reached. Therefore, statements of consensus combined with presentation of literature and live discussion served to impact attendees' approach to this disease.

Validation of the 8th AJCC Cancer Staging System for Pancreas Neuroendocrine Tumors Using Korean Nationwide Surgery Database

Purpose

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic neuroendocrine tumor (PNET) included several significant changes. We aim to evaluate this staging system compared to the 7th edition AJCC staging system and European Neuroendocrine Tumors Society (ENETS) system.

Materials and Methods

We used Korean nationwide surgery database (2000-2014). Of 972 patients who had undergone surgery for PNET, excluding patients diagnosed with ENETS/World Health Organization 2010 grade 3 (G3), only 472 patients with accurate stage were included.

Results

Poor discrimination in overall survival rate (OSR) was noted between AJCC 8th stage III and IV (p=0.180). The disease-free survival (DFS) curves of 8th AJCC classification were well separated between all stages. Compared with stage I, the hazard ratio of II, III, and IV was 3.808, 13.928, and 30.618, respectively (p=0.007, p < 0.001, and p < 0.001). The curves of OSR and DFS of certain prognostic group in AJCC 7th and ENETS overlapped. In ENETS staging system, no significant difference in DFS between stage IIB versus IIIA (p=0.909) and IIIA versus IIIB (p=0.291). In multivariable analysis, lymphovascular invasion (p=0.002), perineural invasion (p=0.003), and grade (p < 0.001) were identified as independent prognostic factors for DFS.

Conclusion

This is the first large-scale validation of the AJCC 8th edition staging system for PNET. The revised 8th system provides better discrimination compared to that of the 7th edition and ENETS TNM system. This supports the clinical use of the system.

Lymphadenectomy in pancreatic neuroendocrine neoplasms: Why are we still debating?

Pancreatic Neuroendocrine Neoplasms (PNEN) are rare tumours exhibiting very heterogeneous behaviour. For these reasons, studies with high level of evidence are lacking. Whether lymphadenectomy should be performed for PNEN is a matter of debate. In this review, we perform a critical analysis of the available literature regarding the clinical significance of lymphnode metastases, the importance of lymphadenectomy, and the implications on disease-specific survival.

Gastrinomas: Medical or Surgical Treatment

This article reviews the role of surgical and medical management in patients with Zollinger-Ellison syndrome (ZES) due to a gastrin-secreting neuroendocrine tumor (gastrinoma). It concentrates on the status at present but also briefly reviews the changes over time in treatment approaches. Generally, surgical and medical therapy are complementary today; however, in some cases, such as patients with ZES and multiple endocrine neoplasia type 1, the treatment approach remains controversial.

Current Management of Pancreatic Neuroendocrine Tumors: From Demolitive Surgery to Observation

Incidental diagnosis of pancreatic neuroendocrine tumors (PanNETs) greatly increased in the last years. In particular, more frequent diagnosis of small PanNETs leads to many challenging clinical decisions. These tumors are mostly indolent, although a percentage (up to 39%) may reveal an aggressive behaviour despite the small size. Therefore, there is still no unanimity about the best management of tumor smaller than 2 cm. The risks of under/overtreatment should be carefully evaluated with the patient and balanced with the potential morbidities related to surgery. The importance of the Ki-67 index as a prognostic factor is still debated as well. Whenever technically feasible, parenchyma-sparing surgeries lead to the best chance of organ preservation. Lymphadenectomy seems to be another important prognostic issue and, according to recent findings, should be performed in noninsulinoma patients. In the case of enucleation of the lesion, a lymph nodal sampling should always be considered. The relatively recent introduction of minimally invasive techniques (robotic) is a valuable option to deal with these tumors. The current management of PanNETs is analysed throughout the many available published guidelines and evidences with the aim of helping clinicians in the difficult decision-making process.

Incidental Neuroendocrine Tumor Discovered After Total Pancreatectomy Intended for Islet Autotransplantation: Important Considerations for Surgical Decision-Making

Total pancreatectomy (TP) is a treatment option for patients experiencing chronic pancreatitis (CP) refractory to medical management. Patients who are candidates for TP benefit from islet autotransplantation (IAT), which preserves available β-cell mass and thereby reduces the risk of brittle diabetes. Malignancy is an absolute contraindication for IAT to prevent the transplantation of occult malignant cells. We present the case of a patient with CP who was approved to undergo TP with IAT (TPIAT) but was intraoperatively discovered to have a pancreatic neuroendocrine tumor. The case illustrates a number of important surgical decision-making considerations for patients undergoing TPIAT and should help guide surgeons should they be presented with this clinical scenario. We stress the importance of vigilance for possible malignancy and to consider an intraoperative biopsy to further investigate unexpected findings that might represent an occult pancreatic malignancy in patients with CP undergoing TPIAT.

Curative and palliative surgery in patients with neuroendocrine tumors of the gastro-entero-pancreatic (GEP) tract

The incidence of neuroendocrine tumors (NET) increases with age. Lately, the diagnosis of NET was mainly caused by early detection of small NET (<1 cm) in the rectum and stomach, which are depicted by chance during routine and prophylactic endoscopy. Also in patients with large and metastatic pancreatic and intestinal tumors thorough pathologic investigation with use of different immunohistologic markers discovers more neuroendocrine tumors with low differentiation grade (G2-G3) and more neuroendocrine carcinomas (NEC), nowadays, than in former times. While gastric and rectal NET are discovered as small (<1 cm in diameter) and mainly highly differentiated tumors, demonstrating lymph node metastases in less than 10% of the patients, the majority of pancreatic and small bowel NET have already metastasized at the time of diagnosis. This is of clinical importance, since tumor stage and differentiation grade not only influence prognosis but also surgical procedure and may define whether a combination of surgery with systemic biologic therapy, chemotherapy or local cytoreductive procedures may be used. The indication for surgery and the preferred surgical procedure will have to consider personal risk factors of each patient (i.e. general health, additional illnesses, etc.) and tumor specific factors (i.e. tumor stage, grade of differentiation, functional activity, mass and variety of loco regional as well as distant metastases etc.). Together they define, whether radical curative or only palliative surgery can be applied. Altogether surgery is the only cure for locally advanced NET and helps to increase quality of life and overall survival in many patients with metastatic neuroendocrine tumors. The question of cure versus palliative therapy sometimes only can be answered with time, however. Many different aspects and various questions concerning the indication and extent of surgery and the best therapeutic procedure are still unanswered. Therefore, a close multidisciplinary cooperation of colleagues involved in biochemical and localization diagnostics and those active in various treatment areas is warranted to search for the optimal strategy in each individual patient. How far genetic screening impacts survival remains to be seen. Since surgeons do have a central role in the treatment of NET patients, they have to understand the need for integration into such an interdisciplinary team.

The latest exploration of staging and prognostic classification for pancreatic neuroendocrine tumors: a large population-based study

Background: A modified European Neuroendocrine Tumor Society (mENETS) staging system has been confirmed to be more suitable for pancreatic neuroendocrine tumors (pNETs) when compared to the American Joint Committee on Cancer (AJCC) or the European Neuroendocrine Tumor Society (ENETS) systems in the last few years. However, the importance of N stage has been recently published with several significant updates. Methods: SEER registry (n = 2,209) was used to evaluate the application of the AJCC 7th staging system, ENETS staging system, mENETS staging system and reformed ENETS (rENETS) staging system in this study. Results: For the ENETS staging system, patients with stage I disease had a similar prognosis to patients with stage II disease (P=0.154), and patients with stage IIIA and stage IIIB diseases showed adverse prognostic potential. The proportion of patients with stage III diseases using AJCC 7th staging system was extremely lower than those with mENETS staging system or rENETS staging system (3.6%, 23.0% and 23.7%, respectively). Furthermore, the hazard ratio of death for patients with stage II or III disease using rENETS staging system was slightly higher than that of mENETS staging system. Besides, survival curves were better separated by rENETS staging system. A prognostic nomogram for overall survival (OS) was formulated to obtain superior discriminatory abilities. Conclusions: The rENETS staging system has superior distribution in proportion than the AJCC 7th, ENETS or mENETS staging system, and one more accurate and advanced predictive model will be achieved via the incorporation to be adopted in clinical practice.

Prognostic factors and survival after surgical resection of pancreatic neuroendocrine tumor with validation of established and modified staging systems

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) display wide heterogeneity with highly variable prognosis. This study aimed to identify variables related to survival after surgical resection of PNET.

METHODS

A total of 143 patients were identified from a prospectively maintained database. Patient characteristics were analyzed and prognostic factors for overall survival and progression-free survival were evaluated. The WHO, ENETS and AJCC scoring systems were applied to the cohort, and their ability to predict patient outcomes were compared.

RESULTS

Multivariate analysis found that female gender, lymph node metastases and increasing WHO 2010 grade to be independently associated with reduced overall survival (P < 0.05). Patients requiring multi-visceral resection or debulking surgery found to be associated with shortest survival. ROC analysis found the ENETS and AJCC scoring systems to be similarly predictive of 5-year overall survival. Modified Ki67 significantly improved its accuracy in predicting 5-year overall survival (AUROC: 0.699 vs 0.605; P < 0.01).

CONCLUSIONS

Multi-visceral or debulking surgery is associated with poor outcomes. There seems to be no significant difference between enucleation and anatomical segmental resection. Available scoring systems have reasonable accuracy in stratifying disease severity, with no system identified as being superior. Prognostic stratification with modified grading systems needs further validation before applied in clinical practice.

Prognostic factors of non-functioning pancreatic neuroendocrine tumor revisited: The value of WHO 2010 classification

Backgrounds/Aims

Various factors have been reported as prognostic factors of non-functional pancreatic neuroendocrine tumors (NF-pNETs). There remains some controversy as to the factors which might actually serve to successfully prognosticate future manifestation and diagnosis of NF-pNETs. As well, consensus regarding management strategy has never been achieved. The aim of this study is to further investigate potential prognostic factors using a large single-center cohort to help determine the management strategy of NF-pNETs.

Methods

During the time period 1995 through 2013, 166 patients with NF-pNETs who underwent surgery in Samsung Medical Center were entered in a prospective database, and those factors thought to represent predictors of prognosis were tested in uni- and multivariate models.

Results

The median follow-up time was 46.5 months; there was a maximum follow-up period of 217 months. The five-year overall survival and disease-free survival rates were 88.5% and 77.0%, respectively. The 2010 WHO classification was found to be the only prognostic factor which affects overall survival and disease-free survival in multivariate analysis. Also, pathologic tumor size and preoperative image tumor size correlated strongly with the WHO grades (p<0.001, and p<0.001).

Conclusions

Our study demonstrates that 2010 WHO classification represents a valuable prognostic factor of NF-pNETs and tumor size on preoperative image correlated with WHO grade. In view of the foregoing, the preoperative image size is thought to represent a reasonable reference with regard to determination and development of treatment strategy of NF-pNETs.

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.

A Lymph Node Ratio-Based Staging Model Is Superior to the Current Staging System for Pancreatic Neuroendocrine Tumors

CONTEXT

The incidence of pancreatic neuroendocrine tumors (PNETs) is increasing. Current staging systems include nodal positivity, but the association of lymph node status and worse survival is controversial.

OBJECTIVE

The study aim was to determine the prognostic significance of lymph node ratio (LNR) and compare it with nodal positivity for PNET.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

A retrospective analysis of the Surveillance, Epidemiology, and End Results database between 2004 and 2011 was performed in patients who underwent a pancreatectomy with lymphadenectomy. The primary outcome was disease-specific survival (DSS).

RESULTS

Of the 896 patients analyzed, T stage, N stage, distant metastasis, grade, extent of resection, sex, and age ≥57 years were significantly associated with worse DSS on univariate analysis. On multivariate analysis, age ≥57 [hazard ratio (HR) 1.75, 95% confidence interval (CI), 1.12 to 2.74, P = 0.015], male sex (HR 1.58; 95% CI, 1.01 to 2.48; P = 0.046), grade (poorly differentiated/undifferentiated: HR 7.59; 95% CI, 4.71 to 12.23; P < 0.001), distant metastases (HR 2.45; 95% CI, 1.58 to 3.79; P < 0.001), and partial pancreatectomy (HR 2.55; 95% CI, 1.2 to 5.4; P = 0.015) were associated with worse DSS. Comparison between staging models constructed based on LNR cutoffs and the American Joint Committee on Cancer (AJCC) eighth edition staging system revealed that a model based on LNR ≥0.5 was superior.

CONCLUSIONS

LNR ≥0.5 is independently associated with worse DSS. A staging system with LNR ≥0.5 was superior to the current AJCC eighth edition staging system.

Intrinsic Contact Between T and N Classifications in Resected Well-Moderately Differentiated Locoregional Pancreatic Neuroendocrine Neoplasms

BACKGROUND

The role of N classification is controversial in several prognostication systems proposed for pancreatic neuroendocrine neoplasms (pNENs). The widely accepted modified European Neuroendocrine Tumor Society (mENETS) system suggests this contradiction may be related to T classification.

METHODS

Data were collected retrospectively from 981 patients in the Surveillance, Epidemiology, and End Results (SEER) database (1973-2012; cohort 1) and 140 patients from the Pancreatic Cancer Institute of Fudan University (2006-2016; cohort 2). All patients had resected well- to moderately differentiated locoregional pNENs, whereby the mENETS system was adopted. Factors related to N1 classification and the association between N and T classifications were analyzed, and N classification prognosis based on T classification was assessed.

RESULTS

In cohorts 1 and 2, tumor size (2-4 cm: p < 0.001 and p = 0.037, respectively; > 4 cm: p < 0.001 and p = 0.012, respectively) and tumors extending beyond the pancreas (p < 0.001 and p = 0.016, respectively), which are factors for T classification, affected N1 classification. For tumors limited to the pancreas, the N1 classification was associated with tumor size (p < 0.001 and p = 0.046, respectively) and predicted poor disease-specific survival (DSS), while for tumors extending beyond the pancreas, the N1 classification did not affect patient outcomes. Findings obtained with data from the SEER database were reproducible with our institutional data.

CONCLUSIONS

N classification is associated with T classification, limiting the value of N1 classification for the pNENs tumor-node-metastasis system. A new risk model is necessary to predict patient outcomes and guide clinical practice for the prognosis of pNENs.