NANETS treatment guidelines: well-differentiated neuroendocrine tumors of the stomach and pancreas

Neuroendocrine Tumors and Lanreotide Depot: Clinical Considerations and Nurse and Patient Preferences

BACKGROUND

Somatostatin analogs (SSAs) are a mainstay therapy for the treatment of carcinoid syndrome associated with neuroendocrine tumors (NETs). They are effective for a range of gastroenteropancreatic NETs (GEP-NETs). Lanreotide depot (Somatuline®) is an SSA that is approved for the treatment of GEP-NETs to improve progression-free survival (PFS).

OBJECTIVES

The article reviews the efficacy, safety, and administration of lanreotide depot and relates those attributes to considerations and preferences of oncology nurses and their patients.

METHODS

A review of the literature on the use of lanreotide for the treatment of NETs and carcinoid syndrome was conducted. In addition, the literature on drug delivery and routes of administration was surveyed to provide context for comparative studies related to clinical and patient preferences.

FINDINGS

Lanreotide depot prolongs PFS and is well tolerated by patients who expressed satisfaction in the ability to control symptoms related to carcinoid syndrome. Nurses cited several benefits to using lanreotide depot in the clinical setting, including more time saved to address other patient care issues. Attributes of lanreotide depot-including its efficacy, safety and tolerability, dosing and administration, and cost-may contribute to healthcare decisions regarding the treatment and management of NETs.

Netazepide, a gastrin/cholecystokinin-2 receptor antagonist, can eradicate gastric neuroendocrine tumours in patients with autoimmune chronic atrophic gastritis

AIMS

Netazepide, a gastrin/cholecystokinin 2 receptor antagonist, once daily for 12 weeks reduced the number of tumours and size of the largest one in 16 patients with autoimmune chronic atrophic gastritis (CAG), achlorhydria, hypergastrinaemia and multiple gastric neuroendocrine tumours (type 1 gastric NETs), and normalized circulating chromogranin A (CgA) produced by enterochromaffin-like cells, the source of the tumours. The aim was to assess whether longer-term netazepide treatment can eradicate type 1 gastric NETs.

METHODS

After a mean 14 months off netazepide, 13 of the 16 patients took it for another 52 weeks. Assessments were: gastroscopy; gene-transcript expression in corpus biopsies using quantitative polymerase chain reaction; blood CgA and gastrin concentrations; and safety assessments.

RESULTS

While off-treatment, the number of tumours, the size of the largest one, and CgA all increased again. Netazepide for 52 weeks: cleared all tumours in 5 patients; cleared all but one tumour in one patient; reduced the number of tumours and size of the largest one in the other patients; normalized CgA in all patients; and reduced mRNA abundances of CgA and histidine decarboxylase in biopsies. Gastrin did not increase further, confirming that the patients had achlorhydria. Netazepide was safe and well tolerated.

CONCLUSIONS

A gastrin/cholecystokinin 2 receptor antagonist is a potential medical and targeted treatment for type 1 gastric NETs, and an alternative to regular gastroscopy or surgery. Treatment should be continuous because the tumours will regrow if it is stopped. Progress can be monitored by CgA in blood or biomarkers in mucosal biopsies.

Surgical treatment of non-functioning pancreatic neuroendocrine tumours based on three clinical scenarios

INTRODUCTION

The treatment of patients with non-functioning pancreatic neuroendocrine tumours (NFPNET) is resection in locally pancreatic disease, or with resectable liver metastases. There is controversy about unresectable liver disease.

METHODS

We analysed the perioperative data and survival outcome of 63 patients who underwent resection of NFPNET between 1993 and 2012. They were divided into 3 scenarios: A, pancreatic resection (44patients); B, pancreatic and liver resection in synchronous resectable liver metastases (12patients); and C, pancreatic resection in synchronous unresectable liver metastases (6patients). The prognostic factors for survival and recurrence were studied.

RESULTS

Distal pancreatectomy (51%) and pancreaticoduodenectomy (38%) were more frequently performed. Associated surgery was required in 44% of patients, including synchronous liver resections in 9patients. Two patients received a liver transplant during follow-up. According to the WHO classification they were distributed into G1: 10 (16%), G2: 45 (71%), and G3: 8 (13%). The median hospital stay was 11days. Postoperative morbidity and mortality were 49% and 1.6%, respectively. At the closure of the study, 43 (68%) patients were still alive, with a mean actuarial survival of 9.6years. The WHO classification and tumour recurrence were risk factors of mortality in the multivariate analysis. The median actuarial survival by scenarios was 131months (A), 102months (B), and 75months (C) without statistically significant differences.

CONCLUSIONS

Surgical resection is the treatment for NFPNET without distant disease. Resectable liver metastases in well-differentiated tumours must be resected. The resection of the pancreatic tumour with unresectable synchronous liver metastasis must be considered in well-differentiated NFPNET. The WHO classification grade and recurrence are risk factors of long-term mortality.

Embolotherapy for Neuroendocrine Tumor Liver Metastases: Prognostic Factors for Hepatic Progression-Free Survival and Overall Survival

PURPOSE

The purpose of the study was to evaluate prognostic factors for survival outcomes following embolotherapy for neuroendocrine tumor (NET) liver metastases.

MATERIALS AND METHODS

This was a multicenter retrospective study of 155 patients (60 years mean age, 57 % male) with NET liver metastases from pancreas (n = 71), gut (n = 68), lung (n = 8), or other/unknown (n = 8) primary sites treated with conventional transarterial chemoembolization (TACE, n = 50), transarterial radioembolization (TARE, n = 64), or transarterial embolization (TAE, n = 41) between 2004 and 2015. Patient-, tumor-, and treatment-related factors were evaluated for prognostic effect on hepatic progression-free survival (HPFS) and overall survival (OS) using unadjusted and propensity score-weighted univariate and multivariate Cox proportional hazards models.

RESULTS

Median HPFS and OS were 18.5 and 125.1 months for G1 (n = 75), 12.2 and 33.9 months for G2 (n = 60), and 4.9 and 9.3 months for G3 tumors (n = 20), respectively (p < 0.05). Tumor burden >50 % hepatic volume demonstrated 5.5- and 26.8-month shorter median HPFS and OS, respectively, versus burden ≤50 % (p < 0.05). There were no significant differences in HPFS or OS between gut or pancreas primaries. In multivariate HPFS analysis, there were no significant differences among embolotherapy modalities. In multivariate OS analysis, TARE had a higher hazard ratio than TACE (unadjusted Cox model: HR 2.1, p = 0.02; propensity score adjusted model: HR 1.8, p = 0.11), while TAE did not differ significantly from TACE.

CONCLUSION

Higher tumor grade and tumor burden prognosticated shorter HPFS and OS. TARE had a higher hazard ratio for OS than TACE. There were no significant differences in HPFS among embolotherapy modalities.

The Long-Term Benefit of Liver Transplantation for Hepatic Metastases From Neuroendocrine Tumors

Selection criteria and benefit of liver transplantation for hepatic metastases from neuroendocrine tumors (NETs) remain uncertain. Eighty-eight consecutive patients with metastatic NETs eligible for liver transplantation according to Milan-NET criteria were offered transplant (n = 42) versus nontransplant options (n = 46) depending on list dynamics, patient disposition, and age. Tumor burden between groups did not differ. Transplant patients were younger (40.5 vs. 55.5 years; p < 0.001). Long-term outcomes were compared after matching between groups made on multiple Cox models adjusted for propensity score built on logistic models. Survival benefit was the difference in mean survival between transplant versus nontransplant options. No patients were lost or died without recurrence. Median follow-up was 122 months. The transplant group showed a significant advantage over nontransplant strategies at 5 and 10 years in survival (97.2% and 88.8% vs. 50.9% and 22.4%, respectively; p < 0.001) and time-to-progression (13.1% and 13.1% vs. 83.5% and 89%; p < 0.001). After adjustment for propensity score, survival advantage of the transplant group was significant (hazard ratio = 7.4; 95% confidence interval (CI): 2.4-23.0; p = 0.001). Adjusted transplant-related survival benefit was 6.82 months (95% CI: 1.10-12.54; p = 0.019) and 38.43 months (95% CI: 21.41-55.45; p < 0.001) at 5 and 10 years, respectively. Liver transplantation for metastatic NETs under restrictive criteria provides excellent long-term outcome. Transplant-related survival benefit increases over time and maximizes after 10 years.

Surgical management for non-functional pancreatic neuroendocrine neoplasms with synchronous liver metastasis: A consensus from the Chinese Study Group for Neuroendocrine Tumors (CSNET)

Pancreatic neuroendocrine neoplasms (p-NENs) are slowly growing tumors with frequent liver metastasis. There is a variety of approaches to treat non-functional p-NENs with synchronous liver metastasis (LM) which complicates the determination of optimal treatment. Based on updated literature review, we discussed the treatment strategy determinants for p-NEN with LM. According to the resectability of primary tumor, the WHO 2010 grade classification and the radiological type of liver metastasis, the CSNET group reached agreements on a number of issues, including the following. Prior to treatment, biopsy is required to confirm pathology. Liver biopsy is important for more accurate grading of tumor and percutaneous core needle biopsy is more available than EUS-FNA. In patients with unresectable primary, surgical resection for liver-metastatic lesions should be avoided. Curative surgery is recommended for G1/G2 p-NET with type I LM and R1 resection also seems to improve overall survival rate. Cytoreductive surgery is recommended for G1/G2 p-NET with type II LM in select patients, and should meet stated requirements. Surgical resection for G1/G2 p-NET with type III LM and p-NEC with LM should be avoided, and insufficient evidence exists to guide the surgical treatment of G3 p-NET with LM. Liver transplantation may be an option in highly select patients. In addition, the optimal time for surgical approach is still required for more evidence.

18F-FDG PET/CT Volumetric Parameters are Associated with Tumor Grade and Metastasis in Pancreatic Neuroendocrine Tumors in von Hippel-Lindau Disease

BACKGROUND

Approximately 8-17 % of patients with von Hippel-Lindau (VHL) syndrome develop pancreatic neuroendocrine tumors (PNETs), with 11-20 % developing metastases. Tumor grade is predictive of prognosis.

OBJECTIVE

The aim of this study was to determine if preoperative metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were associated with metastatic disease and tumor grade.

METHODS

Sixty-two patients with VHL-associated PNETs prospectively underwent ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT). MTV, TLG, and maximum standardized uptake value (SUV_max) were measured using a semi-automatic method. Surgically resected PNETs were classified according to 2010 World Health Organization tumor grade classification. MTV, TLG, and SUV_max were analyzed by metastatic disease and tumor grade using the Mann-Whitney test.

RESULTS

A total of 88 PNETs were identified by CT and ¹⁸F-FDG PET/CT, 10 of which were non-FDG-avid. Histologic grading was available for 20 surgical patients. Patients with metastatic PNETs had a higher TLG (median 25.9 vs. 7.7 mean SUV [SUV_mean]*mL; p = 0.0092) compared with patients without metastasis, while patients with grade 2 PNETs had a higher MTV (median 6.9 vs. 2.6 mL; p = 0.034) and TLG (median 41.2 vs. 13.1 SUV_mean*mL; p = 0.0035) compared with patients with grade 1 PNETs. No difference in tumor size or SUV_max was observed between the groups.

CONCLUSIONS

Patients with metastatic PNETs have a higher TLG compared with patients without metastasis. Grade 2 PNETs have a higher MTV and TLG compared with grade 1 PNETs. Tumor size and SUV_max were not associated with grade. Volumetric parameters on ¹⁸F-FDG PET/CT may be useful in detecting higher grade PNETs with a higher malignant potential that may need surgical intervention.

Subtype classification and management of gastric neuroendocrine neoplasms

Gastric neuroendocrine neoplasms (g-NENs) are a group of heterogeneous tumors arising from endocrine cells in the stomach. Because of the low incidence, clinical misdiagnosis and mismanagement of g-NENs may occasionally occur. In this review, I summarize the epidemiology, pathology, tumor staging, clinical classification, diagnostic algorithm, treatment and prognosis of g-NENs, to explain the standard diagnosis and management, as well as the latest advances in g-NEN research. The author advocates the four-type classification of g-NENs, and emphasizes that type 1 g-NENs are a recurrent disease which needs long-term follow-up. Molecular mechanism of recurrence of and medical therapy for type 1 g-NENs are the future research direction for neuroendocrine neoplasms.

Prognostic Validity of the American Joint Committee on Cancer and the European Neuroendocrine Tumors Staging Classifications for Pancreatic Neuroendocrine Tumors: A Retrospective Nationwide Multicenter Study in South Korea

OBJECTIVES

Pancreatic neuroendocrine tumors (pNETs) are diverse diseases with different prognosis. The American Joint Committee on Cancer (AJCC) and the European Neuroendocrine Tumor Society (ENETS) introduced 2 different tumor node metastasis (TNM) stages, and the World Health Organization (WHO) proposed WHO 2010 grading system for pNETs. Therefore, we aimed to validate the prognostic relevance of these 3 systems for pNETs in South Korea.

METHODS

The Korean Society of Gastrointestinal Cancer created a retrospective registry of pNETs in 153 patients from 15 hospitals between 2002 and 2012.

RESULTS

On the basis of the WHO 2010 grade, 2-year progression-free-survival (PFS) rates for G1, G2, and G3 were 92%, 62%, and 25% (P < 0.01). According to ENETS and AJCC staging, 2-year PFS rates for stages I through IV were 94%, 87%, 49%, 20%, and 92%, 61%, 60%, 20%, respectively (P < 0.01). A Cox multivariate regression analysis revealed that the only statistically significant prognostic factor was the TNM classification of either the AJCC or the ENETS stage (P < 0.01). In addition, the κ value between the AJCC and the ENETS stages was 0.46 indicating a "moderate" agreement (P < 0.01).

CONCLUSIONS

The AJCC and ENETS TNM classifications for pNETs are prognostic for PFS and can be adopted in clinical practice in South Korea.

Management of pancreatic neuroendocrine tumors

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

The First Case Report of Robotic Multivisceral Resection for Synchronous Liver Metastasis from Pancreatic Neuroendocrine Tumor: A Case Report and Literature Review

INTRODUCTION

Surgery for liver metastases in pancreatic neuroendocrine tumor (PNET) improves overall survival rate. We present the first case report for robotic multivisceral resection of distal pancreas, spleen, and left liver for metastatic PNET.

MATERIALS AND METHODS

We present a case of 52-year-old female diagnosed with PNET in the pancreatic neck metastatic to the liver, responding to somatostatin and bland embolization, who underwent surgical debulking using da Vinci robotic platform. Intraoperative Doppler ultrasound was used to define the vascular distribution and tumor extension. The parenchymal liver transection was performed with vessel sealer. The distal pancreas and the spleen were approached medial to lateral and resected in an en-bloc fashion. The left liver inflow, outflow, and splenic artery and vein were transected with vascular stapler device.

RESULTS

Da Vinci robot-assisted multivisceral resection has been performed with good postoperative outcome. Operative time was 369 minutes and the estimated blood loss was 100 mL. The patient had a short hospital stay with quick recovery and good outcome at 5 months follow-up after the surgery.

DISCUSSION

Liver metastases in PNETs are considered an adverse factor. Aggressive surgical management is a mainstay. The laparoscopic approach to pancreatic or hepatic surgery is difficult in inexperienced hands with steep learning curve. The recent robotic system seems to overcome many limitations. This is the first case of robotic multivisceral resection for synchronous liver metastasis from PNET. Concurrent primary tumor resection with hepatectomy offers potential curative intention.

Gastroenteropancreatic Well-Differentiated Grade 3 Neuroendocrine Tumors: Review and Position Statement

: In 2010, the World Health Organization (WHO) classification of neuroendocrine neoplasms was reviewed and validated the crucial role of the proliferative rate. According to the WHO classification 2010, gastroenteropancreatic neuroendocrine neoplasms are classified as well-differentiated neuroendocrine tumors (NETs) of grade 1 or 2 in up to 84%, or poorly differentiated neuroendocrine carcinomas in 6%-8%. Neuroendocrine carcinomas are of grade G. Recently, a proportion of neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified, calling for a new category, well-differentiated grade 3 NET (NET G-3). Studies that have reported the characteristics of neuroendocrine neoplasms have identified more well-differentiated NET G-3 than neuroendocrine carcinomas. The main localizations of NET G-3 are the pancreas, stomach, and colon. Treatment for NET G-3 is not standardized and is balanced between G-1/2 neuroendocrine tumor and neuroendocrine carcinoma treatments. In nonmetastatic neuroendocrine tumors, the European and American guidelines recommended a surgical resection for localized neuroendocrine neoplasm, irrespective of the tumor grading. In NET G-3, chemotherapy is the benchmark if the main treatment goal is reduction of the tumor mass, particularly if it would allow a secondary surgery. In the present work, we review the epidemiology and make recommendations for the management of NET G-3.

IMPLICATIONS FOR PRACTICE

Neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified and named well-differentiated grade 3 neuroendocrine tumors (NET G-3). The main localizations of NET G-3 are the pancreas, stomach, and colon. The prognosis is worse than that for NET G-2. In nonmetastatic NET G-3, surgery appeared to be the first option. The chemotherapy regimen in pancreatic NET G-3 should be in line with that implemented in NET G-1/2 when the Ki-67 index is below 55% and should be in line with that implemented for neuroendocrine carcinoma when Ki-67 is above 55%.

Well-differentiated neuroendocrine tumor of the stomach: A rare case at an uncommon site

INTRODUCTION

A 13-year-old African-American female presented to her primary care physician's office with fatigue, syncope, and hematemesis. After initial evaluation, the patient was referred to pediatric gastroenterology clinic for further evaluation.

MAIN CONCERNS, IMPORTANT FINDINGS

An upper gastrointestinal endoscopy was performed to evaluate the source of her bleeding. Endoscopy revealed a 3-cm mass in the lesser curvature of the stomach, and a biopsy of the mass revealed a concern for carcinoid (neuroendocrine) features.

DIAGNOSIS

She underwent an open gastrectomy. Post-surgical pathology reports confirmed a well-differentiated neuroendocrine tumor of the stomach.

CONCLUSION

Neuroendocrine tumors of the stomach in children are rare and we presently do not have pediatric-specific diagnostic and treatment guidelines. Although adult-based The North American Neuroendocrine Tumor Society (NANETS) guidelines are helpful, they are clearly not geared toward pediatric patients. To establish pediatric guidelines and to assess effectiveness of treatments, multicenter data collection is essential. In the long run, accumulation of clinically useful treatment information and long-term follow-up guidelines should enable clinicians to improve standard of care given to children with neuroendocrine tumors.

Systemic therapies for advanced gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors are a heterogeneous group of malignancies, characterised by production of hormones and vasoactive peptides. The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NET) is rising, and they have the highest prevalence amongst upper gastro-intestinal tumors. Diagnosis remains challenging due to wide variations in presentation and slow onset of symptoms. A multi-disciplinary approach is vital in appropriately managing the diverse spectrum of GEP-NET. Areas covered: Investigations in GEP-NET and biomarkers are described. Moreover, all available therapeutic options for GEP-NET including surgery, somatostatin analogues, targeted agents, Peptide Receptor Radionuclide Therapy and chemotherapy are also discussed. Expert commentary: The landscape of management has changed significantly in the last decade as a result of many practice-changing clinical trials. Long- acting somatostatin analogues are used not only for symptom control but also for their anti-proliferative effect. Targeted agents, such as everolimus and sunitinib, have improved PFS in GEP-NET. The recently presented NETTER-1 trial confirms the place of peptide receptor radionuclide treatment (PRRT) in treating NET. While chemotherapy remained an important option for high grade tumors. Despite promising results from recent trials, challenges include establishing the optimal sequencing of therapies to optimize outcome and preserve the quality of life.

Comparison of the prognostic values of the 2010 WHO classification, AJCC 7th edition, and ENETS classification of gastric neuroendocrine tumors

The ability of the European Neuroendocrine Tumor Society (ENETS) system, 2010 World Health Organization (WHO) grading system, and American Joint Committee on Cancer (AJCC) staging system to predict survival after gastric neuroendocrine tumor (NET) resection has not yet been validated.We retrospectively evaluated 175 gastric NETs from 1996 to 2014. WHO grade 3 (G3) patients (n = 66) had a lower survival rate than grade 1 (G1) (n = 39) or grade 2 (G2) (n = 13) patients, with similar high survival rates for G1 and G2 patients. G3 patients had a lower survival rate than mixed-type patients (n = 57). Using the AJCC classification, most of the G1/2 NETs (86.6%) were confined to T1/T2, N0 tumor, and stage I/IIa, but the survival rate was not well distributed. In contrast, G3/mixed tumors were well distributed in terms of T, N, stage, and survival. Using the ENETS classification, 64.6% of the tumors were T2 and only 8.6% were T3. In addition, 49.7% were stage IIIb and only 1.9% was IIa, with poor survival distribution.Our findings strongly suggested that the WHO and ENETS classification systems have shown a low prognostic value. The AJCC TNM system showed a low prognostic value for well-differentiated NETs (G1 or G2). In contrast, the AJCC TNM system had a high prognostic value for G3 or mixed tumors.

Systematic Review and Meta-Analysis on the Role of Chemotherapy in Advanced and Metastatic Neuroendocrine Tumor (NET)

BACKGROUND/OBJECTIVES

In the era of somatostatin analogues and targeted therapies, the role of chemotherapy in NET remains largely undefined. This systematic review aimed to assess the effect of chemotherapy on response rates (RR), progression-free survival (PFS), overall survival (OS) and toxicity compared to other chemotherapies/systemic therapies or best supportive care in patients with advanced or metastatic NET.

METHODS

Randomised controlled trials (RCTs) from 1946 to 2015 were identified from MEDLINE, EMBASE, other databases and conference proceedings. Review of abstracts, quality assessment and data abstraction were performed independently by two investigators. Meta-analyses were conducted using Mantel-Haenszel analysis with random-effects modelling.

RESULTS

Six RCTs comparing standard streptozotocin plus 5-fluorouacil (STZ/5FU) chemotherapy to other chemotherapy regimens, and 2 comparing this to interferon (IFN) were included. Only 1 study was considered at low risk of bias. STZ/5-FU was no different to other chemotherapies in response rate [RR 0.96; 95% confidence interval (CI) 0.72-1.27], PFS (RR 0.95; CI 0.81-1.13), or OS (RR 1.03; CI 0.77-1.39). IFN may produce higher response than STZ/5FU (RR 0.20; CI 0.04-1.13), but event rates were small and survival was no different. Interferon was associated with higher overall haematological (RR 0.47; CI 0.27-0.82) and lower overall renal toxicity (RR 3.61; CI 1.24-10.51).

CONCLUSION

Strong evidence is lacking in the area of chemotherapy in neuroendocrine tumors. There is currently no evidence that one chemotherapeutic regimen is significantly better than the other, nor is interferon better than chemotherapy. There is an urgent need to design RCTs comparing modern chemotherapy to other agents in NET.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Neuroendocrine Cancer of Rectum Metastasizing to Ovary

Neuroendocrine carcinomas (NECs) are rare malignancies that originate from the hormone-producing cells of the body's neuroendocrine system. Rectal high grade NEC (HG-NEC) constituting less than 1% of colorectal cancers can cause large ovarian metastasis that may be the initial presenting complaint. Ovarian Krukenberg tumor from a primary rectal HG-NEC is a very unusual and exceedingly uncommon differential diagnosis for secondary ovarian malignancy. This case report describes one such extremely rare case of a woman who had presented to the gynecology department with features suggestive of ovarian malignancy and was ultimately diagnosed to have Krukenberg tumor originating from neuroendocrine cancer of rectum. We felt this is a good opportunity to spread more light on neuroendocrine neoplasms that are very rare in gynecological practice.

Laparoscopic pancreatic surgery for benign and malignant disease

Laparoscopic surgery for benign and malignant pancreatic lesions has slowly been gaining acceptance over the past decade and is being introduced in many centres. Some studies suggest that this approach is equivalent to or better than open surgery, but randomized data are needed to assess outcomes. In this Review, we aim to provide a comprehensive overview of the state of the art in laparoscopic pancreatic surgery by aggregating high-quality published evidence. Various aspects, including the benefits, limitations, oncological efficacy, learning curve and latest innovations, are discussed. The focus is on laparoscopic Whipple procedure and laparoscopic distal pancreatectomy for both benign and malignant disease, but robot-assisted surgery is also addressed. Surgical and oncological outcomes are discussed as well as quality of life parameters and the cost efficiency of laparoscopic pancreatic surgery. We have also included decision-aid algorithms based on the literature and our own expertise; these algorithms can assist in the decision to perform a laparoscopic or open procedure.

Multidisciplinary management of nonfunctional neuroendocrine tumor of the pancreas

Pancreatic neuroendocrine tumors (PNETs) are a rare and diverse group of tumors; nonfunctional (NF) PNETs account for the majority of cases. Most patients with NF-PNETs have metastatic disease at the time of presentation. A variety of treatment modalities exist, including medical, liver directed, and surgical treatments. Aggressive surgical management is associated with prolonged survival, however available data are limited by selection bias and the frequent combination of PNETs with carcinoid tumors. Although few patients with metastatic disease will be cured, application of currently available therapies in a multidisciplinary setting can lead to excellent outcomes with prolonged patient survival.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pancreatic neuroendocrine tumors: Challenges in an underestimated disease

Pancreatic neuroendocrine tumours (PanNETs) are considered a relatively unusual oncologic entity. Due to its relative good prognosis, surgery remains the goal standard therapy not only in localized disease but also in the setting of locally or metastatic disease. Most of the patients are diagnosed in metastatic scenario, where multidisciplinary approach based on surgery, chemotherapies, liver-directed and/or molecular targeted therapies are commonly used. Owing to a deeper molecular knowledge of this disease, these targeted therapies are nowadays widely implemented, being the likely discovery of predictive biomarkers that would allow its use in other settings. This review is focused on describing the different classifications, etiology, prognostic biomarkers and multidisciplinary approaches that are typically used in PanNET.

Postoperative Complications, In-Hospital Mortality and 5-Year Survival After Surgical Resection for Patients with a Pancreatic Neuroendocrine Tumor: A Systematic Review

Studies on postoperative complications and survival in patients with pancreatic neuroendocrine tumors (pNET) are sparse and randomized controlled trials are not available. We reviewed all studies on postoperative complications and survival after resection of pNET. A systematic search was performed in the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE from 2000-2013. Inclusion criteria were studies of resected pNET, which described postoperative complications separately for each surgical procedure and/or 5-year survival after resection. Prospective and retrospective studies were pooled separately and overall pooled if heterogeneity was below 75%. The random-effect model was used. Overall, 2643 studies were identified and after full-text analysis 62 studies were included. Pancreatic fistula (PF) rate of the prospective studies after tumor enucleation was 45%; PF-rates after distal pancreatectomy, pancreatoduodenectomy, or central pancreatectomy were, respectively, 14-14-58%. Delayed gastric emptying rates were, respectively, 5-5-18-16%. Postoperative hemorrhage rates were, respectively, 6-1-7-4%. In-hospital mortality rates were, respectively, 3-4-6-4%. The 5-year overall survival (OS) and disease-specific survival (DSS) of resected pNET without synchronous resected liver metastases were, respectively, 85-93%. Heterogeneity between included studies on 5-year OS in patients with synchronous resected liver metastases was too high to pool all studies. The 5-year DSS in patients with liver metastases was 80%. Morbidity after pancreatic resection for pNET was mainly caused by PF. Liver resection in patients with liver metastases seems to have a positive effect on DSS. To reduce heterogeneity, ISGPS criteria and uniform patient groups should be used in the analysis of postoperative outcome and survival.

AAVP displaying octreotide for ligand-directed therapeutic transgene delivery in neuroendocrine tumors of the pancreas

Patients with inoperable or unresectable pancreatic neuroendocrine tumors (NETs) have limited treatment options. These rare human tumors often express somatostatin receptors (SSTRs) and thus are clinically responsive to certain relatively stable somatostatin analogs, such as octreotide. Unfortunately, however, this tumor response is generally short-lived. Here we designed a hybrid adeno-associated virus and phage (AAVP) vector displaying biologically active octreotide on the viral surface for ligand-directed delivery, cell internalization, and transduction of an apoptosis-promoting tumor necrosis factor (TNF) transgene specifically to NETs. These functional attributes of AAVP-TNF particles displaying the octreotide peptide motif (termed Oct-AAVP-TNF) were confirmed in vitro, in SSTR type 2-expressing NET cells, and in vivo using cohorts of pancreatic NET-bearing Men1 tumor-suppressor gene KO mice, a transgenic model of functioning (i.e., insulin-secreting) tumors that genetically and clinically recapitulates the human disease. Finally, preclinical imaging and therapeutic experiments with pancreatic NET-bearing mice demonstrated that Oct-AAVP-TNF lowered tumor metabolism and insulin secretion, reduced tumor size, and improved mouse survival. Taken together, these proof-of-concept results establish Oct-AAVP-TNF as a strong therapeutic candidate for patients with NETs of the pancreas. More broadly, the demonstration that a known, short, biologically active motif can direct tumor targeting and receptor-mediated internalization of AAVP particles may streamline the potential utility of myriad other short peptide motifs and provide a blueprint for therapeutic applications in a variety of cancers and perhaps many nonmalignant diseases as well.

Validation of the 2010 WHO classification and a new prognostic proposal: A single centre retrospective study of well-differentiated pancreatic neuroendocrine tumours

BACKGOUND

In 2010, the World Health Organization (WHO) modified the classification for pancreatic neuroendocrine tumours (NETs). Recently, some modifications were proposed to improve its prognostic value. The aim of this study was to test the prognostic value of both the original and the modified 2010 WHO grading systems.

METHODS

One hundred and twenty consecutive patients surgically resected for well-differentiated NETs were evaluated in multivariate Cox regression models. Age, sex, hormonal status, size, lymph node ratio, stage, margin status and grading were evaluated in order to predict disease-free survival (DFS). Four models were evaluated: model 1: grading according to the 2010 WHO; model 2: modified grading with cut-off at 5% of the Ki-67 index; model 3: modified grading in which the G2 category was divided into two subgroups (2-5% and 5-20%) and model 4: the Ki-67 index as a continuous variable. Decision curve analysis (DCA) was carried out to evaluate the clinical utility of the various cut-offs.

RESULTS

All the grading systems remained independent factors in predicting DFS. Model 2 (c index = 0.814 and P = 0.012) and model 3 (c index = 0.865 and P = 0.015) showed higher predictive powers with respect to model 1 (c index = 0.799). Model 4 had a high predictive value (c index 0.848, P = 0.013). Decision curve analysis confirmed that biological behaviour represented the best prognostic parameter.

CONCLUSION

This study presented some limitations: single centre, retrospective design and a long period of enrolment. The result showed that, by increasing the cut-off of the G2 category to 5% or by creating two subgroups in the G2 category, it was possible to obtain a better stratification of patients.

Risk factors for aggressive nonfunctional pancreatic neuroendocrine tumors and the role of endoscopic ultrasound guided fine-needle aspiration

Background:

Nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) are increasingly being diagnosed but management, especially of small tumors, remains a clinical dilemma. Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) is now routinely used for diagnosis of pancreatic neuroendocrine tumors (pNETs) but has not been well studied as a tool for identifying aggressive disease.

Materials and Methods:

A systematic search of the cytology database identified all patients at our center who underwent EUS-FNA from 1999 through 2011 and were diagnosed with NF-pNET.

Results:

A total of 50 patients were identified. Though patients with metastatic disease had a mean tumor size of 40 mm compared to 25 mm in patients without metastatic disease (P = 0.04), we also identified several patients with tumors <20 mm who presented with metastatic disease. Furthermore, we found no statistically significant difference in metastatic disease between tumors <20 mm and >20 mm (P = 0.13). Using receiver operating characteristic (ROC) analysis, we found that using a cutoff point of 20 mm only led to a sensitivity of 85% in screening for metastases, while lowering the cutoff point to 18 mm allowed for a sensitivity of 95%.

Conclusion:

Currently, guidelines suggest that only patients with tumors greater than 20 mm undergo surgical resection, as tumors less than this size are thought to have low risk of metastases. Our analysis suggests that these recommendations could lead to undertreating patients with small tumors. Tumor size alone may be inadequate as a marker for aggressive NF-pNETs. Given this, other risk factors for aggressive pNETs should be studied to help identify the patients most likely to benefit from surgery.

Weight Gain in Zollinger-Ellison Syndrome After Acid Suppression

OBJECTIVES

Zollinger-Ellison syndrome (ZES) is characterized by hypergastrinemia and gastric acid hypersecretion resulting in peptic ulcer disease, diarrhea, and weight loss. Acid secretion can be controlled with medication, and biochemical cure is possible with surgery. Data on how these interventions affect patients' weight are lacking. We aimed to determine how medical and surgical acid control affects weight over time.

METHODS

We performed a retrospective cohort study on 60 ZES patients. Acid control was achieved with appropriate-dose proton pump inhibitor (PPI) therapy. Surgery was performed for curative intent when appropriate. Weight change was assessed versus pre-acid control or immediate preoperative weights and expressed as absolute and percent change from baseline at 6, 12, 18, and 24 months.

RESULTS

A total of 30 PPI-controlled patients and 20 surgery-controlled patients were analyzed. Weight gain was noted at all time points while on appropriate-dose PPI therapy (P < 0.005). Of patients who had surgery with curative intent, weight gain was noted at 12 months (7.9%, P = 0.013) and 18 months (7.1%, P = 0.007). There was a trend toward weight gain seen at all time points in the patients who were surgically cured.

CONCLUSIONS

These data represent a novel description of weight gain after acid suppression in ZES.

Case Report of Cirrhosis following Yttrium-90 Radioembolization for Pancreatic Neuroendocrine Liver Metastases

Background

Management options for pancreatic neuroendocrine tumors (pNETs) metastatic to the liver include surgical, ablative, cytotoxic, and radioisotope approaches. One potential local treatment option includes selective internal radiotherapy utilizing yttrium-90 (⁹⁰Y) microspheres. ⁹⁰Y has also been used in the treatment of hepatocellular carcinoma and tumors metastatic to the liver. It appears to be well tolerated; however, there is no randomized controlled trial reporting long-term toxicities. Previous retrospective reports have described biliary damage as a potential complication of therapy with ⁹⁰Y and chemoembolization; however, the long-term sequelae of ⁹⁰Y treatment are poorly understood.

Case Presentation

We present the case of a 65-year-old Caucasian woman who suffered biliary damage following ⁹⁰Y administration for metastatic pNETs and subsequently developed cirrhosis. Given the timeline of her various treatments and the lack of any other identifiable etiology for her cirrhosis, we believe this to be a potential long-term complication of ⁹⁰Y therapy.

Conclusion

This case provides pathologic confirmation of cirrhosis as a potential long-term sequela of ⁹⁰Y treatment. This long-term risk needs to be considered when sequencing therapy for patients with neuroendocrine tumors who have a good prognosis. There are now several other systemic and ablative treatment options available to these patients, and long-term complications must be considered during treatment.

Imaging in multiple endocrine neoplasia type 1: recent studies show enhanced sensitivities but increased controversies

In multiple endocrine neoplasia type 1 (MEN1) patients, a number of recent studies compare the ability of different, new imaging modalities to existing modalities to localize the important neuroendocrine tumors (NETs) that contribute to their decreased life expectancy (pancreatic NETs [pNETs] and thymic carcinoids). These included the use of ⁶⁸Ga-DOTATOC-PET/CT, endoscopic ultrasound and MRI. The current paper analyzes these results in light of current guidelines and controversies involved in the treatment/management of MEN1 patients. Particular attention is paid to results in these studies with thymic carcinoids and nonfunctional pNETs/gastrinomas, which recent studies show are particularly important in determining long-term survival. These studies show a number of promising imaging results but also raise a number of controversies, which will need to be addressed both in their use initially and for serial studies in these patients.

Pancreatic neuroendocrine tumors: Nosography, management and treatment

Pancreatic neuroendocrine tumors (pNETs) represent about 7% of all NETs, 8.7% of gastroenteropancreatic NETs (GEP-NETs) and 1-2% of all pancreatic neoplasms. In the last two decades, the increased diagnosis of pNETs has generated great interest and the development of different classifications, grading and staging systems. Recently, several trials were performed in order to improve the knowledge of biomarkers and imaging and to provide an early diagnosis, but their role is still under debate. Nowadays, surgery represents the only curative approach for pNETs. Approximately 90% of pNETs are silent and non-functional; therefore, most patients are diagnosed in late stage and present metastatic (60%) or locally unresectable advanced disease (21%) with a poor prognosis. Not many therapeutic options are available for pNETs, with different treatments for G1-G2 and G3 tumors, because these diseases are still rare and trials are made up of few series of patients. At present, medical treatments is controversial. On these bases, we believe that a multidisciplinary team composed of surgeons, oncologists, endocrinologists, radiation oncologists, radiologists, pathologists and medicals nuclear is required. This paper presents a review of present state-of-the-art in the field of pNETs.

Pancreatic neuroendocrine tumors: a review

Neuroendocrine tumors (NETs) are a rare and heterogeneous group of tumors with widely varying morphologies and behaviors. Due to their rarity and heterogeneity, progress in improving their treatment has been slow. However, in recent years there have been advances both in their characterization and in the available treatment options. This review will attempt to address these, with particular reference to pancreatic NETs. Pancreatic NETs are a subset of NETs, previously known as islet cell tumors, which appear to be a distinct biological entity, responding differently to systemic treatments compared with NETs arising elsewhere in the GI tract.

Pancreatic insulinomas: Laparoscopic management

Insulinomas are rare pancreatic neuroendocrine tumors that are most commonly benign, solitary, and intrapancreatic. Uncontrolled insulin overproduction from the tumor produces neurological and adrenergic symptoms of hypoglycemia. Biochemical diagnosis is confirmed by the presence of Whipple’s triad, along with corroborating measurements of blood glucose, insulin, proinsulin, C-peptide, β-hydroxybutyrate, and negative tests for hypoglycemic agents during a supervised fasting period. This is accompanied by accurate preoperative localization using both invasive and non-invasive imaging modalities. Following this, careful preoperative planning is required, with the ensuing procedure being preferably carried out laparoscopically. An integral part of the laparoscopic approach is the application of laparoscopic intraoperative ultrasound, which is indispensable for accurate intraoperative localization of the lesion in the pancreatic region. The extent of laparoscopic resection is dependent on preoperative and intraoperative findings, but most commonly involves tumor enucleation or distal pancreatectomy. When performed in an experienced surgical unit, laparoscopic resection is associated with minimal mortality and excellent long-term cure rates. Furthermore, this approach confers equivalent safety and efficacy rates to open resection, while improving cosmesis and reducing hospital stay. As such, laparoscopic resection should be considered in all cases of benign insulinoma where adequate surgical expertise is available.

Differing Clinical Courses and Prognoses in Patients With Gastric Neuroendocrine Tumors Based on the 2010-WHO Classification Scheme

The aim of this study is to test the prognostic accuracy of the 2010-WHO classification for postsurgery survival in nonmetastatic gastric neuroendocrine tumor (NET) cases. Whether the 2010-WHO classification of NETs can predict relapse after surgical resection has not yet been established.We selected 175 nonmetastatic gastric NET patients at Asan Medical Center, Seoul, Korea between 1996 and 2013. All tumors were classified using the WHO-2010 scheme.Among 175 patients with gastric NETs, we diagnosed 39 cases as WHO grade 1, 13 cases as grade 2, 66 cases as grade 3 (neuroendocrine carcinomas; NECs), and 57 cases as mixed with adenocarcinoma. Patients with grade 3 had a lower relapse-free survival (RFS) and overall survival (OS) than those with WHO grade 1/2 and had a lower OS than patients with mixed type tumors. Patients with grade 1/2 had a better OS than patients with mixed type. There was no significant difference in RFS and OS between small and large cell type lesions. Among WHO grade 1/2 patients with ≤1 cm sized lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion, and we detected no lymph node metastases or recurrences.Our findings strongly suggest that WHO grade 3 behaves more aggressively than adenocarcinoma. Additionally, the survival of cases with large and small cell NEC was similar. Among WHO grade 1/2 patients who had ≤1 cm lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion and all could be treated by endoscopic resection or minimally invasive surgery without node dissection.

Biochemical Diagnosis and Preoperative Imaging of Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors are a group of neoplasms that can arise in a variety of locations throughout the body and often metastasize early. A patient's only chance for cure is surgical removal of the primary tumor and all associated metastases, although even when surgical cure is unlikely, patients can benefit from surgical debulking. A thorough preoperative workup will often require multiple clinical tests and imaging studies to locate the primary tumor, delineate the extent of the disease, and assess tumor functionality. This review discusses the biomarkers important for the diagnosis of these tumors and the imaging modalities needed.

Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are uncommon tumors with a range of clinical behavior. Some PNETs are associated with symptoms of hormone secretion, with increased systemic levels of insulin, gastrin, glucagon, or other hormones. More commonly, PNETs are nonfunctional, without hormone secretion. Surgical resection is the mainstay of therapy, particularly for localized disease. Surgical therapy must be tailored to tumor and clinical characteristics. Resection may be particularly indicated in the setting of hormone hypersecretion. Small, incidental PNETs are increasingly managed nonoperatively. Surgery may also be indicated in some instances of metastatic disease, if all metastatic foci may be removed.

Pancreatic Neuroendocrine Tumors: an Update

Pancreatic neuroendocrine tumors (pNETs) are rare and comprise only 1-2 % of all pancreatic neoplastic disease. Although the majority of these tumors are sporadic (90 %), pNETs can arise in the setting of several different hereditary genetic syndromes, most commonly multiple endocrine neoplasia type 1 (MEN1). The presentation of pNETs varies widely, with over 60 % having malignant distant disease at the time of initial diagnosis involving the liver or other distant sites. Functioning pNETs represent approximately 10 % of all pNETs, secrete a variety of peptide hormones, and are responsible for several clinical syndromes caused by profound hormonal derangement. Surgery remains the cornerstone of therapy and the only curative approach. It should be pursued for localized disease and for metastatic lesions amenable to resection. Multimodality therapies, including liver-directed therapies and medical therapy, are gaining increasing favor in the treatment of advanced pNETs. Their utility is multifold and spans from ameliorating symptoms of hormonal excess (functional pNETs) to controlling the local and systemic disease burden (non-functional pNETs). The recent introduction of target molecular therapy has promising results especially for the treatment of progressive well-differentiated G1/G2 tumor. In this review, we summarize the current knowledge and give an update on recent advancements made in the therapeutic strategies for pNETs.

Problems with the diagnosis of metastatic neuroendocrine neoplasms. Which diagnostic criteria should we use to determine tumor origin and help guide therapy?

Neuroendocrine neoplasms (NENs) can often present with metastatic disease before the primary tumor is discovered. Metastatic lesions are generally classified as well differentiated and poorly differentiated for prognostic and therapeutic purposes. In addition, for well-differentiated neuroendocrine tumors (WDNETs), pathologists are expected to determine the site of origin, if not already known, and grade the tumors. However, it is often difficult for pathologists to provide this information with certainty without knowing the site of tumor origin, as different criteria have been proposed by WHO for classification of gastrointestinal and pulmonary NENs. In this review, we will discuss the current classification and grading schema of NENs and their impact on clinical care, the differential diagnosis of NENs, the use of immunohistochemical stains that help identify tumor site of origin, and a proposed approach for the diagnosis and classification of metastatic NENs.

Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

Nonfunctioning pancreatic neuroendocrine tumors (NFpNET) present with distant metastases in up to 50% of patients. It is unknown whether removal of the primary tumor in patients with NFpNET and metastases is beneficial.

METHODS

We used the Surveillance, Epidemiology, and End Results database to identify patients with NFpNET and distant metastases. The primary outcome measure in this study was overall survival.

RESULTS

We identified 882 patients with metastatic NFpNET who had survival data; 303 (34%) patients had operative removal of their primary tumor of which 243 (80%) were grade I or II. Median survival of patients undergoing resection of the primary site was 65 (95% confidence interval 60-86) versus 10 (8-12) months for those without resection (P < .0001). Patients diagnosed after 2003 (n = 625, 71%) were more likely to undergo an operation than those diagnosed earlier (P = .001). Multivariable analysis showed that a lesser tumor grade (P < .0001), younger age (P < .0001), diagnosis during or after 2003 (P = .0003), tumor site in the body/tail (P = .009), and operative resection of the primary tumor site (P < .0001) were associated with prolonged survival of patients with NFpNET and distant metastases.

CONCLUSION

This study suggests that resection of the site of the primary NFpNET is associated with greater survival in patients with distant metastases and could therefore be considered as a additional treatment option in this patient population.

Somatic alterations of CDKN1B are associated with small bowel neuroendocrine tumors

CDKN1B, a cyclin-dependent kinase inhibitor associated with G1 arrest, was recently proposed as an important tumor suppressor gene in small bowel neuroendocrine tumors (SBNETs). The rate of frameshift mutations in SBNET primaries are reportedly 7.4%, and hemizygous deletions are 6.7%. We set out to confirm the role of CDKN1B mutations and copy number variants (CNVs) in primary SBNETs, and whether these are also found in pancreatic neuroendocrine tumors (PNETs). Genomic DNA was isolated from 90 primary SBNETs and 67 PNETs. Coding exons of CDKN1B were amplified by PCR and sequenced. CNV analysis was performed by quantitative PCR, p27 expression was evaluated using immunohistochemistry. In SBNETS, three frameshifts, one missense mutation, and three CNVs were observed. The total rate of CDKN1B alterations was 7.0% (6 of 86; 95% confidence interval (CI) 3.2-4.4%). The frameshift rate was 3.5% (95% CI 1.1-9.8%). One SBNET patient had a hemizygous deletion of CDKN1B, and two patients had duplications (3.4%; 95% CI -0.41-7.2%). One PNET patient had a duplication, and two patients had hemizygous deletions (4.8%; 95% CI -0.44-10%). Alterations of cell-cycle control due to alterations in CDKN1B may be one mechanism by which SBNETs develop, which could have implications for new treatment modalities.