Enteroendocrine tumors other than carcinoid: a review of clinically significant advances

Carcinoid Syndrome and Hyperinsulinemic Hypoglycemia Associated with Neuroendocrine Neoplasms: A Critical Review on Clinical and Pharmacological Management

The carcinoid syndrome (CS) and hyperinsulinemic hypoglycemia (HH) represent two of the most common clinical syndromes associated with neuroendocrine neoplasms (NENs). The former is mainly related to the serotonin secretion by a small bowel NEN, whereas the latter depends on an insulin hypersecretion by a pancreatic insulinoma. Both syndromes/conditions can affect prognosis and quality of life of patients with NENs. They are often diagnosed late when patients become strongly symptomatic. Therefore, their early detection and management are a critical step in the clinical management of NEN patients. A dedicated and experienced multidisciplinary team with appropriate therapeutic strategies is needed and should be encouraged to optimize clinical outcomes. This review aims to critically analyze clinical features, evidence and treatment options of CS and HH and therefore to improve their management.

Postrecurrence Survival After Liver Transplantation for Liver Metastases From Neuroendocrine Tumors

BACKGROUND

Liver metastases from neuroendocrine tumors (NETs) is an accepted indication for liver transplantation (LT). Despite strict patient selection, post-LT recurrence is observed in 30-50% of cases. Postrecurrence survival is poorly investigated as well as factors influencing postrecurrence outcomes.

METHODS

Consecutive patients treated at a single Institution for post-LT recurrence of NET between Jan 1st, 2004 and Dec 31th, 2018 were included. Baseline patients' characteristics, data on the primary tumor, pretransplant therapies, posttransplant recurrence and treatments and long-term outcomes were prospectively collected and retrospectively analyzed.

RESULTS

Thirty-two patients presented with post-LT NET recurrence occurring 82.9 months (IQR 29.4-119.1) from LT, and the most common sites were abdominal lymph nodes (59.4%), peritoneum (6.3%) and lungs (6.3%). Fourteen patients (43.8%) underwent surgery with radical intent. Five- and 10-years survival after recurrence were 76.3% and 45.5%, respectively. Only time from LT to recurrence had a significant impact on post recurrence survival, being 5-years OS 89.5% versus 0% for patients recurring > 24 months after LT versus ≤ 24 months, respectively (p=.001). Moreover, for patients with Mib-1 > 2% at recurrence, 5-years OS was 87.5% versus 0% for those undergoing surgery versus loco-regional or systemic treatments (p=0.011).

CONCLUSIONS

The presented results, although based on a retrospective and relatively small series, show that excellent long-term survival is observed after post-LT NET recurrence, particularly in those patients recurring long after LT (> 24 months). An aggressive surgical treatment might result in a new chance of cure for a selected subgroup of patients.

Cardiotoxicity and cardiac monitoring following the use of radiotheranostics agents including 177Lu-PSMA for prostate cancer and 177Lu-DOTATATE for neuroendocrine tumors

BACKGROUND

 The aim of this study was to determine the probable cardiotoxicity following radionuclide therapy (RNT), specifically peptide receptor radionuclide therapy (PRRT) with ¹⁷⁷Lu-DOTATATE and radioligand therapy (RLT) with ¹⁷⁷Lu-PSMA by evaluation of serum troponin I and cardiac profile change during a follow-up time.

MATERIALS AND METHODS

 Patients with prostate cancer and neuroendocrine tumours (NETs) referred for PRRT and RLT, respectively, were enrolled in this study. The cardiac profiles of the patients were evaluated by a cardiologist and a cardiac history was obtained from all patients. Also, troponin I was measured before and 48 hours after treatment.

RESULTS

 In this retrospective study for assessment of RLT associated cardiotoxicity, 24 patients were evaluated with a median age of 64 years (27-99 years) including 13 NET patients and 11 prostate cancer patients. Patients were followed up for 4 to 31 months which no cardiovascular problem was observed. In evaluation of troponin I, 39 RNT cycles were evaluated. In all patients, the value of troponin I was in normal range. In all patients, the median values of serum troponin I before and after treatment were 0.2 ± 0.02 (range: 0.00-0.42) and 0.28 ± 0.02 (range: 0.00-0.46) ng/ml, respectively (p > 0.05). In the prostate cancer patients, the median values of serum troponin I before and after treatment were 0.26 ± 0.04 (0.04-0.42) and 0.30 ± 0.04 (0.00-0.41) ng/ml, respectively (p > 0.05). In the NET patients, the median values of serum troponin I before and after treatment were 0.18 ± 0.03 (0.00-0.42) and 0.17 ± 0.03 (0.00-0.46) ng/ml, respectively (p > 0.05).

CONCLUSION

 PRRT with ¹⁷⁷Lu-DOTATATE and RLT with ¹⁷⁷Lu-PSMA as emerging therapeutic modalities have no significant cardiotoxicity. However, further well-designed studies are recommended.

mTOR Pathway in Gastroenteropancreatic Neuroendocrine Tumor (GEP-NETs)

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) originate from neuroendocrine cells in the gastrointestinal tract. They are heterogeneous, and though initially considered rare tumors, the incidence of GEP-NENs has increased in the last few decades. Therapeutic approaches for the metastatic disease include surgery, radiological intervention by chemoembolisation, radiofrequency ablation, biological therapy in addition to somatostatin analogs, and PRRT therapy (177Lu-DOTATATE). The PI3K-AKT-mTOR pathway is essential in the regulation of protein translation, cell growth, and metabolism. Evidence suggests that the mTOR pathway is involved in malignant progression and resistance to treatment through over-activation of several mechanisms. PI3K, one of the main downstream of the Akt-mTOR axis, is mainly involved in the neoplastic process. This pathway is frequently deregulated in human tumors, making it a central target in the development of new anti-cancer treatments. Recent molecular studies identify potential targets within the PI3K/Akt/mTOR pathway in GEP-NENs. However, the use of target therapy has been known to lead to resistance due to several mechanisms such as feedback activation of alternative pathways, inactivation of protein kinases, and deregulation of the downstream mTOR components. Therefore, the specific role of targeted drugs for the management of GEP-NENs is yet to be well-defined. The variable clinical presentation of advanced neuroendocrine tumors is a significant challenge for designing studies. This review aims to highlight the role of the PI3K/Akt/mTOR pathway in the development of neuroendocrine tumors and further specify its potential as a therapeutic target in advanced stages.

Treatment Patterns and Survival among Patients with Metastatic Gastroenteropancreatic Neuroendocrine Tumours in Sweden - a Population-based Register-linkage and Medical Chart Review Study

Background: Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are neoplasms derived from the endocrine system in the gastrointestinal tract and pancreas. Treatment options include surgery; pharmacological treatments like somatostatin analogues (SSA), interferon alpha, molecular targeted therapy and chemotherapy; and peptide receptor radionuclide therapy.

The objective of this study was to describe treatment patterns and survival among patients with metastatic GEP-NET grade 1 or 2 in Sweden.

Methods: Data was obtained via linkage of nationwide registers. Patients diagnosed with metastatic GEP-NET grade 1 or 2 in Sweden between 2005 and 2013 were included (n=811; National population). In addition, medical chart review was performed for the subpopulation diagnosed at Sahlgrenska University Hospital, Gothenburg (n=127; Regional population). Treatment patterns, including treatment sequences, and overall survival were assessed.

Results: Most patients had small intestinal NET (76%). In the regional population, 72% had grade 1 tumours; 50% had functioning tumours. The two most common first-line treatments were surgery (57%) and SSA (25%). After first-line surgery, 46% received SSA, while 40% had no further treatment. After first-line SSA, 52% received surgery, while 27% had no further treatment. Overall median survival time from date of diagnosis was 7.0 years (95% CI 6.2-not reached). Among patients with distant metastases, pancreatic NET (vs. small intestinal NET) was associated with poorer survival (HR 1.9; 95% CI 1.1-3.3), as were liver metastases (HR 3.2; 95% CI 1.5-7.0).

Conclusions: First-line surgery was typically followed by SSA or no further treatment. Among patients with distant metastases, pancreatic NET or liver metastases were associated with a poorer survival.

A well differentiated neuroendocrine tumor of the jejunum with peritoneal carcinomatosis: A case report

Neuroendocrine tumors (NETs), belong to a group of neoplasms that arise from neuroendocrine cells and express markers such as synaptophysin and chromogranin A. The digestive system (DS) is the most common site of NET development. The World Health Organization classification divides NETs into low grade (G1-G2) tumors (NETs) and high grade carcinomas [neuroendocrine carcinomas (NECs)], based on mitotic index and histological criteria. NET prognosis depends on tumor stage and grade. Low grade G1 NETs are characterized by a low proliferative rate and an indolent clinical course with a 5-year survival rate ranging between 38% (pancreas) and 88% (rectum). The present study reports a case of a low grade (G1) multifocal jejunal tumor with histologically confirmed features of aggressiveness, namely peritoneal carcinomatosis, lymph node metastasis and vascular carcinomatous emboli. Prediction of clinical behavior and survival in such a case is challenging. Although multiplicity and nodal metastases is not unusual for low grade NETs in this part of the gastrointestinal tract, peritoneal carcinomatosis is an extremely rare finding. Surgeons and histopathologists should be familiar with such eventualities and tumor boards are required in order to conclude whether aggressive therapeutic interventions may have any impact on patients' long term survival.

Real-world treatment patterns, resource use and costs of treating uncontrolled carcinoid syndrome and carcinoid heart disease: a retrospective Swedish study

OBJECTIVES

To quantify healthcare resource use (HRU) and costs in relation to carcinoid syndrome (CS) and carcinoid heart disease (CHD) in a real-world setting, and to provide perspective on treatment patterns.

MATERIALS AND METHODS

Patient data and HRU were collected retrospectively from three Swedish healthcare registers. Adult patients diagnosed with metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs) grade 1 or 2 and CS who purchased somatostatin analogs (SSAs), and experienced controlled (defined by SSAs use) and uncontrolled (defined by SSAs dose escalation) CS for ≥8 months during the study period were included. Patients diagnosed with CHD from the date of the GEP-NET diagnosis were included in the CHD study group.

RESULTS

Overall, total HRU cost increased with uncontrolled CS and CHD. Total resource cost was 15,500€/patient during controlled CS (8 months), rising to 21,700€/patient during uncontrolled CS (8 months), representing an increase of ∼40% (6200€/patient). Costs/patient were driven mainly by SSA use, tumor-related medical interventions and examinations. The total mean cost/year of disease was 1100€/patient without CHD, compared to 4600€/patient with CHD, a difference of 3500€/patient. Excluding SSA cost burden, the main drivers of increased cost in CHD patients were surgical interventions and echocardiography.

CONCLUSIONS

This study provides a comprehensive overview of the treatment patterns and burden of uncontrolled CS symptoms and CHD using Swedish national register data. Increases in medical interventions and examinations HRU and increased SSA use suggest that SSA dose escalation alone may not effectively control the symptoms associated with uncontrolled CS, highlighting an unmet treatment need in this patient group.

Hindgut gastropancreatic neuroendocrine carcinoma mimicking hydatid disease

Primary neuroendocrine tumors of the colon are usually very rare and difficult to spot on a nonfunctional imaging. Metastatic lesions are mostly hypervascular, with only a small percentage appearing as cystic or hypovascular lesions. We present a case of a 34-year-old Hispanic female with a history of dull aching upper abdominal pain lasting for a few months. Initial abdominal ultrasound revealed multiple cystic lesions replacing the hepatic parenchyma concerning for a hydatid disease. Liver biopsy was obtained due to negative serology for hydatid disease, which surprisingly revealed a metastatic neuroendocrine tumor of unknown etiology. The primary disease was depicted within the sigmoid colon on a whole-body Octreotide single-photon emission computed tomography-computed tomography done following the biopsy.

Metastatic neuroendocrine tumor of the esophagus with features of medullary thyroid carcinoma

A 41-year-old female presented with a pedunculated mass in the upper esophagus and bilateral lymphadenopathy. Biopsies suggested a neuroendocrine tumor, possibly carcinoid, and ensuing imaging revealed cervical lymph node metastases. The esophageal mass was removed endoscopically and discovered by pathologists to closely resemble medullary thyroid carcinoma (MTC) on immunohistochemistry staining. Following surgery, further work up demonstrated very high serum calcitonin levels, suggestive of medullary thyroid carcinoma, however the thyroid gland was normal on ultrasound. The patient underwent a neck dissection to remove the lymph node metastases and subsequently her calcitonin levels dropped to 0 ng/mL, indicating remission. It appears that the primary tumor was not in the thyroid, but in the cervical esophagus. The thyroid has appeared normal on multiple ultrasounds without any detectable nodules or masses. This is quite a unique case because this patient presented with a tumor resembling medullary carcinoma of the thyroid that presented as a pedunculated mass in the cervical esophagus. The actual final diagnosis of this mass in the cervical esophagus was neuroendocrine tumor (NET), consistent with a carcinoid tumor, not ectopic MTC. This case report highlights that calcitonin-secreting tumors outside the thyroid should not lead to erroneous recommendations for thyroidectomy.

Liver transplantation for metastatic liver tumors

Liver transplantation for metastatic neuroendocrine tumor in the liver used to be the main reason for liver transplantation for metastatic liver tumor. It is reported that liver transplantation in selected patients with non-resectable metastatic neuroendocrine tumor in the liver had favorable outcomes equivalent to liver transplantation for hepatocellular carcinoma. Recently, liver transplantation for colorectal liver metastasis has attracted attention. According to the SECA study in Oslo, liver transplantation for non-resectable colorectal liver metastasis had a high rate of recurrence but a favorable prognosis. Further discussion on patient selection, attempts at immunosuppressive therapy, and combination with chemotherapy and treatment at the time of relapse are required in order to improve the outcomes of liver transplantation for metastatic liver tumor.

Pancreatic Neuroendocrine Tumors and EMT Behavior Are Driven by the CSC Marker DCLK1

Doublecortin-like kinase 1 (DCLK1), a marker for intestinal and pancreatic cancer stem cells, is highly expressed in neuroblastomas. This study was conducted to assess DCLK1 expression levels in pancreatic neuroendocrine tumor (PNET) tissues and to explore the roles of this molecule in clinical tissue from multiple PNET patients, cells (BON1, QGP1, and CM) and tumor xenografts. Immunohistochemically, all PNET tissues highly and diffusely expressed DCLK1 as a full-length isoform, identical to that detected in primary liver NETs. A DCLK1-overexpressing PNET cell line (QGP1-DCLK1) exhibited epithelial-mesenchymal transition (EMT)-related gene signatures, and robust upregulation of Slug (SNAI2), N-Cadherin (CDH2), and Vimentin (VIM) was validated by real-time PCR and immunoblotting. QGP1-DCLK1 cells had increased cell migration in a wound-healing assay and formed significantly larger xenograft tumors in nude mice. The factors involved in the formation of the fast-growing tumors included p-FAK (on Tyr925), p-ERK1/2, p-AKT, Paxillin, and Cyclin D1, which upon knockdown or pharmacologic inhibition of DCLK1 abolished the expression of these molecules. In conclusion, robust and ubiquitous expression of DCLK1 was first demonstrated here in human PNET tissue specimens and cells. DCLK1 characterized the PNET cell behavior, inducing p-FAK/SLUG-mediated EMT. These findings suggest the possibility of developing novel therapeutic strategies against PNETs by targeting DCLK1.Implications: Evidence here reveals that human PNETs diffusely and robustly express the cancer stem cell marker DCLK1, which drives SLUG-mediated EMT, and suggests that NETs share biological features for druggable targets with other tumors, including neuroblastoma that also highly expresses DCLK1. Mol Cancer Res; 15(6); 744-52. ©2017 AACR.

Clinicopathologic study of neuroendocrine tumors of gastroenteropancreatic tract: a single institutional experience

BACKGROUND

The gastroenteropancreatic neuroendocrine tumors (GEPNET) have a characteristic histologic appearance unrelated of the exact site of origin. However the behavior of these tumors are different in each of these sites. In this article we study the clinicopathological features of GEPNET. These tumors were classified and graded according to WHO 2010 criteria. The immunohistochemical (IHC) features were evaluated and the grade of the tumor was correlated with Ki67.

METHODS

A total of 40 cases of GEPNET diagnosed on biopsies as well as resected specimens were analyzed from January 2012 to June 2015.

RESULTS

There were 28 resected specimens and 12 biopsies. Majority of the gastric neuroendocrine tumors (NET) showed classic morphology of cells arranged in islands. There were 3 cases each of grade 1 and grade 2 and one was diagnosed as mixed adenoneuroendocrine carcinoma (MANEC). All the duodenal NET were well differentiated (grade 1). There were 8 cases in colon and rectum, of which 4 cases were grade 3 and 3 cases were grade 2. Majority of the pancreatic tumors were grade 1. The mean mitotic count along with ki67 had good correlation in NET of stomach, duodenum colon and rectum.

CONCLUSIONS

The most common site was small intestine followed by pancreas. Majority of the tumors were NET G1. Tumors from colorectal region were mostly NEC G3. There was a strong correlation by spearman correlation analysis between Ki67 and mitotic count and moderate correlation between ki67 and tumor grade as well as mitotic rate and tumor grade. Ki67 was helpful in grading these tumors.

Pancreatic neuroendocrine tumors: contemporary diagnosis and management

Pancreatic neuroendocrine tumors (PNETs) are neoplasms that arise from the hormone producing cells of the islets of Langerhans, also known as pancreatic islet cells. PNETs are considered a subgroup of neuroendocrine tumors, and have unique biology, natural history and clinical management. These tumors are classified as 'functional' or 'non-functional' depending on whether they release peptide hormones that produce specific hormone- related symptoms, usually in established patterns based on tumor subtype. This manuscript will review pancreatic neuroendocrine tumor subtypes, syndromes, diagnosis, and clinical management.

Chromogranin A as a predictor of radiological disease progression in neuroendocrine tumours

BACKGROUND

Chromogranin A (CgA) is the best established neuroendocrine biomarker. This study was aimed at investigating the prognostic value of CgA as a predictor of radiological disease progression in neuroendocrine tumour (NET) patients.

METHODS

Patients with metastatic NETs and evidence of radiological progression (RP) according to RECIST 1.1 were identified from a NET database. Plasma CgA levels were measured 6 and 12 months before RP and at the event of RP. CgA was measured with the Supra-regional-Assay-Service radioimmunoassay (Hammersmith Hospital).

RESULTS

A total of 152 patients were evaluated including 91 midgut NETs and 61 pancreatic NETs (PNETs). Of these, 56 were G1 NETs, 65 G2, 10 G3, 21 of unknown histology. For all NETs, there was a positive trend in terms of increase of CgA values 6 months prior to RP compared to 12 months before RP. Subgroup analysis at first episode of RP showed that for PNETs there was evidence of a difference in the median CgA levels. CgA 6 months before RP was 100 pmol/L [interquartile 1 (Q1) =53 and Q3 =286.25 pmol/L) and 12 months before was 52 pmol/L (Q1 =36.25 and Q3 =128 pmol/L), W=52, P=0.48. This observation was not confirmed in midgut NETs, where median CgA 6 months before RP was 389.5 pmol/L (Q1 =131.5 and Q3 =791.5 pmol/L) and 12 months before was 319 pmol/L (Q1 =158 and Q3 =753 pmol/L), W=191, P=0.39]. Low grade tumours (G1) had a median CgA value at 6 months significantly higher than at 12 months [181 (Q1 =56.25, Q3 =624) vs. 149.5 (Q1 =44, Q3 =247.25) pmol/L, W=70, P=0.48].

CONCLUSIONS

CgA seems to have predictive value 6 months prior to RP for PNETs and G1 tumours. Further prospective analyses are needed to enable more definitive conclusions.

A Single Centre Analysis of Clinical Characteristics and Treatment of Endocrine Pancreatic Tumours

Background. Endocrine Pancreatic Tumours (PENs) are rare and can be nonfunctioning or functioning. They carry a good prognosis overall though high grade lesions show a relatively shorter survival. The aim of the current study is to describe a single centre analysis of the clinical characteristics and surgical treatment of PENs. Patients and Methods. This is a cohort analysis of 40 patients of PENs who underwent surgery at Sir Ganga Ram Hospital, New Delhi, India, from 1995 to 2013. Patient particulars, clinical features, surgical interventions, postoperative outcome, and followup were done and reviewed. The study group was divided based on grade (G1, G2, and G3) and functionality (nonfunctioning versus functioning) for comparison. Results. PENs comprised 6.3% of all pancreatic neoplasms (40 of 634). Twenty-eight patients (70%) had nonfunctioning tumours. Eighteen PENs (45%) were carcinomas (G3), all of which were nonfunctioning. 14 (78%) of these were located in the pancreatic head and uncinate process (P = 0.09). The high grade (G3) lesions were significantly larger in size than the lower grade (G1 + G2) tumours (7.0 ± 3.5 cms versus 3.1 ± 1.6 cms, P = 0.007). Pancreatoduodenectomy was performed in 18 (45%), distal pancreatectomy in 10 (25%), and local resection in 8 (20%) and nonresective procedures were performed in 4 patients (10%). Fourteen patients (35%) had postoperative complications. All G3 grade tumours which were resected had positive lymph nodes (100%) and 10 had angioinvasion (71%). Eight neoplasms (20%) were cystic, all being grade G3 carcinomas, while the rest were solid. The overall disease related mortality attributable to PEN was 14.3% (4 of 28) and for malignant PENs was 33.3% (4 of 12) after a mean follow-up period of 49.6 months (range: 2–137 months). Conclusion. Majority of PENs are nonfunctioning. They are more likely malignant if they are nonfunctioning and large in size, show cystic appearance, and are situated in the pancreatic head. Early surgery leads to good long term survival with acceptable postoperative morbidity.

The Role of Plasma Chromogranin A as Assessment of Treatment Response in Non-functioning Gastroenteropancreatic Neuroendocrine Tumors

PURPOSE

Chromogranin A (CgA) has been considered to be valuable not only in the diagnosis but also in monitoring the disease response to treatment. However, only a few studies have been published on this issue. We purposed to evaluate whether biochemical response using plasma CgA level is reliable in concordance with the clinical response of grade 1-3 nonfunctiong gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

MATERIALS AND METHODS

Between March 2011 and September 2013, a total of 27 cases in 18 patients were analysed, clinically and radiologically while serial CgA tests were also conducted during treatment. Tumor responses were defined by both Response Evaluation Criteria in Solid Tumors (RECIST) criteria ver. 1.1 and biochemical criteria based on the CgA level.

RESULTS

Among the 27 cases analysed, no difference in the basal CgA level was observed with regard to gender, primary tumor site, tumor grade (World Health Organization classification), liver metastasis, number of metastatic site, and line of chemotherapy. The overall response rate (RR) by RECIST criteria ver. 1.1 was six out of the 27 cases (22.2%) and eight out of the 27 cases (29.6%) for biochemical RR. The overall concordance rates of the response based on RECIST and biochemical criteria were 74%. In grades 1 and 2 GEP-NETs (n=17), the concordance rate of the disease control was 94.1%. There was a significant difference for progression-free survival (PFS) between responders and non-responder in accordance to biochemical criteria (35.73 months vs. 5.93 months, p=0.05).

CONCLUSION

This study revealed that changes of the plasma CgA levels were associated with tumour response. Additionally, biochemical response based on serial CgA may be a predictive marker for PFS in GEP-NETs.

A Novel Missense Mutation of the MEN1 Gene in a Patient with Multiple Endocrine Neoplasia Type 1 with Glucagonoma and Obesity

A 35-year-old obese diabetic man presented with recurrent primary hyperparathyroidism during a three-year outpatient follow-up. He was clinically diagnosed with multiple endocrine neoplasia type 1 (MEN1) due to the presence of a pituitary adenoma and multiple glucagonomas. The glucagonomas may have affected his glycemic control. However, he did not demonstrate weight loss, suggesting that the patient's obesity could have obscured the early diagnosis of a glucagonoma. Genetic testing revealed a novel missense mutation at codon 561 in exon 10, resulting in an amino acid substitution from methionine to arginine (M561R) in the MEN1 gene. This mutation appeared to be responsible for the MEN1 pathogenicity.

Pancreatic neuroendocrine tumors: current opinions on a rare, but potentially curable neoplasm

Pancreatic neuroendocrine tumors (PNETs) share a unique genetic identity, functional behavior, and clinical course. Compared with tumors of the exocrine pancreas, they are rare and show a different biologic behavior and prognosis. On the basis of data from recent studies, all PNETs, outside of small insulinomas, should be considered potentially malignant and treated accordingly. Untreated tumors have a high possibility to grow locally into adjacent structures or spread to distant organs. Although surgical excision irrespective of tumor functioning or nonfunctioning state remains the cornerstone of therapy, providing the best disease-free and survival rates to date, the understanding of the genetic nature of the disease yields new 'targets' to consider in drug development. The aim of this review is to summarize all recent advances of genetic research and new drug development in terms of PNETs, especially their genetic identity and subsequent alterations leading to the development of near or total malignant activity, and the new medical treatment strategies of this potentially curable disease on the basis of therapeutical agents acting, where possible, at the genetic level.

The value of endoscopic ultrasound in a 47-year-old man with cystic lesions of the liver and pancreas

Most neuroendocrine tumors (NETs), like other tumors, are clinically silent, producing symptoms only as a consequence of tumor growth. Pancreatic NETs account for only 1% of pancreatic cancers by incidence, while representing 10% of all pancreatic cancers by 28-year limited duration prevalence. Here, we present a 47-year-old man with abdominal pain, icterus, itching and 8 kg weight loss during 5 months. Elevated liver enzymes, direct bilirubin and alkaline phosphatase were observed. Magnetic resonance cholangiopancreatography showed a prominence at the head of the pancreas and also liver cysts. Endoscopic ultrasound of the pancreas was performed and a specimen was obtained via fine needle aspiration. Immunohistochemical staining was performed and the result was compatible with NET. The patient referred to receive chemotherapy.

Liver transplantation for unresectable neuroendocrine tumor liver metastases

BACKGROUND

Liver transplantation (LT) is performed in selected patients with neuroendocrine hepatic metastases. Survival benefit and the risk of tumor recurrence after LT, also exacerbated by immunosuppressive therapy, remain important clinical issues. Whether patients with particular types of neuroendocrine tumors (NET) benefit more than others is unclear.

METHODS

Bibliographical searches were performed in PubMed for the terms "liver transplantation and neuroendocrine tumors," "liver transplant and neuroendocrine tumors," "liver transplantation and immunosuppressive therapy," "tumor recurrence."

RESULTS

Promising results have been reported for LT for NET metastases with 5-year survival of up to 90 % in patients with well-differentiated gastroenteropancreatic NETs, but only few patients are free of tumor 5 years after LT. Better outcomes have been reported for gastrointestinal tumors than for pancreatic NETs for both survival and risk or recurrence after LT. Selection criteria for LT are limited and include the 2007 Milan Criteria and the 2012 European Neuroendocrine Tumor Society guidelines, including: well-differentiated NET (Ki-67 <10 %), age <55 years, absence of extrahepatic disease, primary tumor removed before transplantation, stable disease for at least 6 months before LT, and <50 % liver involvement.

CONCLUSIONS

LT might be considered in carefully selected patients. The risk of tumor recurrence remains a significant clinical problem after LT, but data focused on immunosuppression issue are lacking, and there are no currently approved strategies for prevention of recurrence or follow-up protocols. Further studies are needed to define universally accepted inclusion criteria, reliable predictors of better outcome, and optimal timing for LT.

PET and PET/CT with 68gallium-labeled somatostatin analogues in Non GEP-NETs Tumors

Somatostatin (SST) is a 28-amino-acid cyclic neuropeptide mainly secreted by neurons and endocrine cells. A major interest for SST receptors (SSTR) as target for in vivo diagnostic and therapeutic purposes was born since a series of stable synthetic SST-analouges PET became available, being the native somatostatin non feasible for clinical use due to the very low metabolic stability. The rationale for the employment of SST-analogues to image cancer is both based on the expression of SSTR by tumor and on the high affinity of these compounds for SSTR. The primary indication of SST-analogues imaging is for neuroendocrine tumors (NETs), which usually express a high density of SSTR, so they can be effectively targeted and visualized with radiolabeled SST-analogues in vivo. Particularly, SST-analogues imaging has been widely employed in gastroenteropancreatic (GEP) NETs. Nevertheless, a variety of tumors other than NETs expresses SSTR thus SST-analogues imaging can also be used in these tumors, particularly if treatment with radiolabeled therapeutic SST-analouges PET is being considered. The aim of this paper is to provide a concise overview of the role of positron emission tomography/computed tomography (PET/CT) with (68)Ga-radiolabeled SST-analouges PET in tumors other than GEP-NETs.

Neuroendocrine tumors show altered expression of chondroitin sulfate, glypican 1, glypican 5, and syndecan 2 depending on their differentiation grade

Neuroendocrine tumors (NETs) are found throughout the body and are important as they give rise to distinct clinical syndromes. Glycosaminoglycans, in proteoglycan (PG) form or as free chains, play vital roles in every step of tumor progression. Analyzing tumor samples with different degrees of histological differentiation we determined the existence of important alterations in chondroitin sulfate (CS) chains. Analysis of the transcription of the genes responsible for the production of CS showed a decline in the expression of some genes in poorly differentiated compared to well-differentiated tumors. Using anti-CS antibodies, normal stroma was always negative whereas tumoral stroma always showed a positive staining, more intense in the highest grade carcinomas, while tumor cells were negative. Moreover, certain specific cell surface PGs experienced a drastic decrease in expression depending on tumor differentiation. Syndecan 2 levels were very low or undetectable in healthy tissues, increasing significantly in well-differentiated tumors, and decreasing in poorly differentiated NETs, and its expression levels showed a positive correlation with patient survival. Glypican 5 appeared overexpressed in high-grade tumors with epithelial differentiation, and not in those that displayed a neuroendocrine phenotype. In contrast, normal neuroendocrine cells were positive for glypican 1, displaying intense staining in cytoplasm and membrane. Low-grade NETs had increased expression of this PG, but this reduced as tumor grade increased, its expression correlating positively with patient survival. Whilst elevated glypican 1 expression has been documented in different tumors, the downregulation in high-grade tumors observed in this work suggests that this proteoglycan could be involved in cancer development in a more complex and context-dependent manner than previously thought.

Diarrhea caused by circulating agents

Circulating agents cause intestinal secretion or changes in motility with decreased intestinal transit time, resulting in secretory-type diarrhea. Secretory diarrhea as opposed to osmotic diarrhea is characterized by large-volume, watery stools, often more than 1 L per day; by persistence of diarrhea when patients fast; and by the fact that on analysis of stool-water, measured osmolarity is identical to that calculated from the electrolytes present. Although sodium plays the main role in water and electrolyte absorption, chloride is the major ion involved in secretion.

Neuroendocrine carcinoma of the ethmoid sinuses treated with radiotherapy alone

OBJECTIVE

We present the first report of a case of neuroendocrine carcinoma of the paranasal sinuses treated successfully with radiotherapy alone.

METHOD

A case report and literature review are presented.

RESULTS

Fewer than 50 cases of paranasal sinus neuroendocrine carcinoma have been reported. We present an 82-year-old man referred with recurrent epistaxis. He was investigated by biopsy, computed tomography and magnetic resonance imaging, and was found to have a rare neuroendocrine carcinoma. He declined any surgery or chemotherapy but consented to radiotherapy. Thirty months later, he remained clinically free from cancer.

CONCLUSION

There is no consensus for the management of paranasal sinus neuroendocrine carcinoma. Most cases are treated with surgery with or without chemoradiotherapy. This case shows that radiotherapy alone may be a viable treatment option for some cases.

Acute pancreatitis secondary to neuroendocrine pancreatic tumors: report of 3 cases and literature review

Pancreatic tumors (particularly neuroendocrine) are an uncommon cause of acute pancreatitis (AP). This is a report of 3 cases of acute pancreatitis secondary to advanced neuroendocrine tumors and a literature review. Including these cases, only 30 have been reported. Most cases are non-functioning, diagnosed in an advanced stage, associating mild pancreatitis and in patients older than forty. Pancreatic neuroendocrine tumors are an uncommon cause of AP but must be included in the differential diagnosis of this disease, especially if the patient is older than 40 and the etiology of the AP is not clear.

Everolimus resolving hypoglycemia, producing hyperglycemia, and necessitating insulin use in a patient with diabetes and nonresectable malignant insulinoma

OBJECTIVE

To present a case of management of refractory hypoglycemia due to malignant insulinoma with use of everolimus, resulting in recurrent insulin-requiring diabetes.

METHODS

This report describes a case of a nonresectable malignant insulinoma in a 78-year-old patient with long-standing type 2 diabetes mellitus. Endogenous hyperinsulinism was confirmed by a fasting test, which revealed a glucose level of 35 mg/dL and an insulin value of 23.7 μIU/mL. Endoscopic ultrasonography, magnetic resonance imaging, and computed tomography identified a pancreatic mass, infiltration of the superior mesenteric vein, and metastatic lesions in the liver.

RESULTS

After chemoembolization of the metastatic lesions, hypoglycemia recurred, despite combined treatment with somatostatin analogues, dexamethasone, and diazoxide. Everolimus, an orally administered mammalian target of rapamycin, was used at a daily dose of 5 mg. After 6 months, the hypoglycemia was controlled, and the patient presented with a C-peptide level of 0.2 ng/mL and secondary hyperglycemia that necessitated insulin treatment.

CONCLUSION

The orally administered drug everolimus controlled hypoglycemia due to a malignant insulinoma in a patient with prior insulin-requiring diabetes. Secondary hyperglycemia was an acceptable drug effect (to the patient and managing physicians), in light of the complex and often poorly tolerated treatments available for this rare condition.

Pancreatic endocrine tumors: a report on a patient treated with sorafenib

A 31-yr-old man with abdominal pain was diagnosed with a pancreatic endocrine tumor and multiple hepatic metastases. Despite optimal treatment with interferon alpha, a somatostatin analog, local therapy with high-intensity focused ultrasound ablation for multiple hepatic metastases, and multiple lines of chemotherapy with etoposide/cisplatin combination chemotherapy and gemcitabine monotherapy, the tumor progressed. As few chemotherapeutic options were available for him, sorafenib (800 mg/day, daily) was administered as a salvage regimen. Sorafenib was continued despite two episodes of grade 3 skin toxicity; it delayed tumor progression compared to the previous immunotherapy and chemotherapy. Serial computed tomography scans showed that the primary and metastatic tumors were stable. Thirteen months after beginning targeted therapy, and up to the time of this report, the patient is well without disease progression. We suggest that sorafenib is effective against pancreatic endocrine tumors.

Pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms representing <5% of all pancreatic malignancies with an estimated incidence of 1-1.5 cases/100,000. PNETs are broadly classified as either functional or nonfunctional. Functional PNETs include insulinomas, gastrinomas, vasoactive intestinal peptideomas, glucagonomas, and somatostatinomas. The clinical manifestations associated with these tumors are the result of excessive hormonal secretion and action. The functional nature of these tumors makes pancreatic hormone testing critical not only for initial diagnosis but also for follow-up, because they are important tumor markers. Nonfunctional PNETs typically remain clinically silent until a substantial mass effect occurs. Although the majority of PNETs occur sporadically, it is important to recognize that these tumors may be associated with a variety of familial syndromes and in many cases genetic testing of PNET patients is warranted. This article familiarizes the reader with the clinical presentation and the biochemical, radiologic, and genetic testing indicated for diagnosis and follow-up of patients with PNET.

[Primary pancreatic lymphoma diagnosed by endoscopic ultrasound-guided fine needle aspiration biopsy]

Although primary pancreatic lymphoma (PPL) is a rare malignant tumor, the correct diagnosis is essential since their therapeutic management differs from other pancreatic tumors. The fine needle aspiration cytology guided by endoscopic ultrasonography (EUS-FNA) is currently the preferred technique for the diagnosis of neoplasms of the pancreas, being of particular interest in those pancreatic lesions with atypical characteristics or presentation. However, the usefulness of EUS-FNA in the PPL has been poorly studied because of the rarity of this entity. We report a case of a patient with HIV infection and PPL diagnosed by EUS-FNA.

Plasma chromogranin A response to octreotide test: prognostic value for clinical outcome in endocrine digestive tumors

OBJECTIVES

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) expressing somatostatin receptors may be treated with somatostatin analogs (SSAs). Selection criteria are a positive Octreoscan or a >50% hormone level decrease after octreotide subcutaneous (s.c.) injection (octreotide test) (OT). Plasma chromogranin A (CgA) is the best general GEP-NET marker, but data on CgA response to OT are scanty. Thus, we evaluated whether plasma CgA response to OT could predict the clinical response to SSAs.

METHODS

At diagnosis, 38 GEP-NET patients received octreotide 200 microg s.c., with plasma CgA determination at 0, 3, and 6 h. Long-term SSA treatment was then given by monitoring symptomatic, biochemical, and objective responses, and survival.

RESULTS

Basal plasma CgA levels were significantly higher in patients with functioning than non-functioning tumors (median (range): 220 (18-2,230) vs. 46 (25-8,610) U/l, P=0.03) and in those with than without metastases (171 (18-8,610) vs. 43 (28-220) U/l, P=0.04). CgA levels significantly correlated with WHO classification, clinical TNM staging, and Ki-67 proliferative index. After OT, CgA levels decreased from 146 (18-8,610) to 61 (10-8,535) U/l (basal and nadir values), P<0.001. In patients responsive to OT, a successful objective response occurred in 21/31 patients (68%). Successful symptomatic response occurred in 13/18 patients (72%), biochemical response in 25/31 (81%), and objective response in 21/31 (68%). In the remaining seven unresponsive cases, with CgA decrement <30%, disease progressed to death in six (86%). Median survival from enrollment was 48 months (6-138) in responsive and 6 (6-30) in unresponsive patients (P=0.0005).

CONCLUSIONS

In GEP-NETs, plasma CgA is a reliable marker, and a >30% decrease after OT has a relevant prognostic meaning allowing the identification of the subgroup of patients most likely to be responsive to chronic SSAs.

Neuroendocrine tumors: a critical appraisal of management strategies

OBJECTIVES

This supplement represents the proceedings of a panel of investigators whose goal was to assess the quality of evidence pertaining to current therapeutic approaches in the management of neuroendocrine tumors (NETs). It will examine the differences in opinions between expert faculty and community physicians.

METHODS

The Neuroendocrine Tumors Summit convened in December 2009 to address 6 statements prepared by panel members that reflect important questions in the management of NETs.

RESULTS

Panel members were polled on their acceptance of each statement, and those results were compared with community-based oncologists, gastroenterologists, and endocrinologists.

CONCLUSIONS

More education regarding the treatment of NETs, including pertinent studies, is needed for physicians. Additional multicenter, prospective, placebo-controlled trials are necessary to demonstrate the benefits of somatostatin analogs, including their ability to control symptoms and affect tumor growth, and their synergistic effect with other therapies. New trials should be reported consistently and include time to tumor progression and progression-free survival as primary or secondary end points.

Immunostaining of gastric cancer with neuroendocrine differentiation: Reg IV-positive neuroendocrine cells are associated with gastrin, serotonin, pancreatic polypeptide and somatostatin

We previously reported that Reg IV is associated with neuroendocrine (NE) differentiation in gastric cancers. The aim was to examine which NE hormone products are related to Reg IV-positive NE cells and their roles in gastric cancers. In the present study, we performed immunohistochemical analysis in a tissue microarray (TMA) of a consecutive series of 630 cases with ten different antibodies, including chromogranin A, synaptophysin and neural cell adhesion molecule (NCAM) as NE differentiation markers, and gastrin, serotonin, calcitonin, gastrin-releasing peptide (GRP), pancreatic polypeptide (PP), somatostatin and glucagon as NE hormones. In 630 cases, we identified 205 (33%) with NE differentiation and 147 (23%) positive for Reg IV. Reg IV-positive cases showed NE differentiation more frequently than Reg IV-negative cases (P < 0.0001). In 205 cases with NE differentiation, Reg IV-positive cases expressed serotonin (P= 0.0032) and somatostatin (P= 0.036) more frequently than Reg IV-negative cases. Double immunofluorescence staining revealed co-expression of Reg IV with gastrin, serotonin and PP. These results indicate that Reg IV might be a mediating factor of several NE hormones.

Long-term suppressive effect of octreotide on progression of metastatic gastrinoma with multiple endocrine neoplasia type 1: seven-year follow up

A 30-year-old woman had a history of prolactinoma and primary hyperparathyroidism. She was diagnosed as having multiple endocrine neoplasia type 1 with gastrinoma and liver metastases. Octreotide therapy was started and the serum gastrin level decreased immediately. Octreotide continued to suppress gastrin secretion over the next 7 years. The Ki67/MIB1 proliferation index of this tumor was only 0.5 % and somatostatin receptor (SSTR) 2 expression was very strong in both 2002 and 2009. This case suggests the importance of investigating the Ki67/MIB1 index and SSTR expression in patients with metastatic gastrinoma.

Intraoperative localization of insulinoma and normal pancreas using invisible near-infrared fluorescent light

BACKGROUND

Neuroendocrine tumors of the pancreas, such as insulinoma, are difficult to localize, and complete resection is essential for cure. Our hypothesis is that a near-infrared (NIR) fluorophore exhibiting uptake in insulinoma could provide high-sensitivity detection intraoperatively.

MATERIALS AND METHODS

The optical properties of methylene blue (MB) were measured in vitro in 100% serum at 37 degrees C and in vivo after tissue uptake. MB was injected as a rapid intravenous bolus at doses ranging from 0.25 to 2 mg/kg into wildtype rats and pigs, and into insulinoma-bearing transgenic mice. The FLARE imaging system was used to acquire color video and NIR fluorescence images simultaneously and in real-time. The signal-to-background ratios (SBR) of tissues and tumors were quantified using FLARE software.

RESULTS

When appropriately diluted, MB exhibits moderate NIR fluorescence emission peaking at 688 nm. At doses > or =1 mg/kg, certain normal tissues, such as pancreas, accumulate MB and remain NIR fluorescent for up to 1 h with an SBR > or = 1.6. MB spectral properties are maintained after uptake into tissue. Interestingly, insulinoma exhibits even higher MB signal than normal pancreas, resulting in insulinoma-to-pancreas ratios of 3.7 and insulinoma-to-muscle ratios of 16.2. MB permitted high-sensitivity, real-time localization of primary, multicentric, and metastatic insulinoma and permitted differentiation among tumor, normal pancreas, and other abdominal structures.

CONCLUSION

A single intravenous injection of a clinically available, commonly used NIR fluorophore provides prolonged intraoperative localization of normal pancreas and insulinoma using invisible NIR fluorescent light.

Diarrhea and malabsorption in the elderly

Acute and chronic diarrheal disorders are common problems at all ages. It has been estimated that 5% to 7% of the population has an episode of acute diarrhea each year and that 3% to 5% have chronic diarrhea that lasts more than 4 weeks. It is likely that the prevalence of diarrhea is similar in older individuals. This article reviews the impact of diarrhea in the elderly, many of whom are less fit physiologically to withstand the effect of diarrhea on fluid balance and nutritional balance.

A fuller understanding of pancreatic neuroendocrine tumours combined with aggressive management improves outcome

BACKGROUND

Neuroendocrine tumours of the pancreas (PNETs) represent 1-2% of all pancreatic tumours. The terms 'islet cell tumours' and 'carcinoids' of the pancreas should be avoided. The aim of this review is to offer an overview of the history and diagnosis of PNETs followed by a discussion of the available treatment options.

METHODS

A search on PubMed using the keywords 'neuroendocrine', 'pancreas' and 'carcinoid' was performed to identify relevant literature over the last 30 years.

RESULTS

The introduction of a revised classification of neuroendocrine tumours by the World Health Organisation (WHO) in 2000 significantly changed our understanding of and approach to the management of these tumours. Advances in laboratory and radiological techniques have also led to an increased detection of PNETs. Surgery remains the only treatment that offers a chance of cure with increasing number of non-surgical options serving as beneficial adjuncts. The better understanding of the behaviours of PNETs together with improvements in tumour localisation has resulted in a more aggressive management strategy with a concomitant improvement in symptom palliation and a prolongation of survival.

CONCLUSION

Due to their complex nature and the wide range of therapeutic options, the involvement of specialists from all necessary disciplines in a multidisciplinary team setting is vital to provide optimal treatment of this disease.

Pancreatic endocrine tumor EUS-guided FNA DNA microsatellite loss and mortality

BACKGROUND

The clinical course of pancreatic endocrine tumors (PET) depends on tumor size, the presence of invasion or metastasis, the Ki-67 index, mitoses per high power field, and mutational damage. Most of this information is not available before surgery for clinical decision making or prognostication.

OBJECTIVE

To evaluate PET EUS-guided FNA (EUS-FNA) microsatellite loss analysis in the context of PET-related mortality.

DESIGN

A single institution retrospective cohort.

PATIENTS

Patients with PET diagnosed by EUS-FNA who underwent DNA microsatellite loss analysis and at least 1 year of follow-up or subsequent death.

INTERVENTION

PET microsatellite loss analysis results and current clinical status were compared.

RESULTS

Twenty-nine patients were included in the final analysis; the mean age of the patients was 57 years, and 10 were women (35%). The mean follow-up was 33.7 months (median 30 months, range 2-66 months). Twelve patients had disease progression, and 8 died, all from disease-specific causes. Malignant PET contained multiple microsatellite losses, with a median fractional allelic loss (FAL) of 0.37 (range 0.12-0.69, interquartile range [IQR] 0.23-0.42), significantly different from benign PET, median FAL 0 (range 0-0.18, IQR 0-0.08, P < .0001). Survival analysis revealed a significant difference in disease recurrence or progression at 2 years (P < .0001) and in the 5-year survival between patients with FAL </=0.2 compared with >0.2 (P < .0001). Logistic regression could not be performed because of the perfect association between an FAL >0.2 and disease status or mortality.

LIMITATIONS

Retrospective design, referral bias, and DNA analysis availability.

CONCLUSIONS

PET EUS-FNA microsatellite loss analysis provides preoperative prognostic information. An FAL >0.2 is not only associated with disease progression but also with mortality.

C-type natriuretic peptide receptor expression in pancreatic alpha cells

Atrial natriuretic peptide (ANP), brain type natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) comprise a family of natriuretic peptides that mediate their biological effects through three natriuretic peptide receptor subtypes, NPR-A (ANP, BNP), NPR-B (CNP) and NPR-C (ANP, BNP, CNP). Several reports have provided evidence for the expression of ANP and specific binding sites for ANP in the pancreas. The purpose of this study was to identify the ANP receptor subtype and to localize its expression to a specific cell type in the human pancreas. NPR-C immunoreactivity, but neither ANP nor NPR-A, was detected in human islets by immunofluorescent staining. No immunostaining was observed in the exocrine pancreas or ductal structures. Double-staining revealed that NPR-C was expressed mainly in the glucagon-containing alpha cells. NPR-C mRNA and protein were detected in isolated human islets by RT-PCR and Western blot analysis, respectively. NPR-C expression was also detected by immunofluorescent staining in glucagonoma but not in insulinoma. ANP, as well as BNP and CNP, stimulated glucagon secretion from perifused human islets (1,111 +/- 55% vs. basal [7.3 fmol/min]; P < 0.001). This response was mimicked by cANP(4-23), a selective agonist of NPR-C. In conclusion, the NPR-C receptor is expressed in normal and neoplastic human alpha cells. These findings suggest a role for natriuretic peptides in the regulation of glucagon secretion from human alpha cells.

Neuroendocrine tumors of the gastro-entero-pancreatic system

Gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs) are rare neoplasms, although their prevalence has increased substantially over the past three decades. Moreover, there has been an increased clinical recognition and characterization of these neoplasms. They show extremely variable biological behavior and clinical course. Most NETs have endocrine function and secrete peptides and neuroamines that cause distinct clinical syndromes, including carcinoid syndrome; however, many are clinically silent until late presentation with mass effects. Investigation and management should be individualized for each patient, taking into account the likely natural history of the tumor and general health of the patient. Management strategies include surgery for cure or palliation, and a variety of other cytoreductive techniques, and medical treatment including chemotherapy, and biotherapy to control symptoms due to hormone release and tumor growth, with somatostatin analogues (SSAs) and alpha-interferon. New biological agents and somatostatin-tagged radionuclides are under investigation. Advances in the therapy and development of centers of excellence which coordinate multicenter studies, are needed to improve diagnosis, treatment and therefore survival of patients with GEP NETs.

A rapid rise in circulating pancreastatin in response to somatostatin analogue therapy is associated with poor survival in patients with neuroendocrine tumours

Aim

To assess the value of pancreastatin as a predictive factor for identifying patients with neuroendocrine tumours (NETs) who respond poorly to somatostatin analogues.

Methods

A retrospective study of patients with NETs. Patient records from the Northern Ireland Neuroendocrine Tumour Register were interrogated. Those who had pancreastatin concentrations measured on two or more occasions, before and during somatostatin analogue therapy (within the set time-limits) were selected. Data relating to diagnosis, surgery, somatostatin analogue therapy and survival outcome were noted. Data were subjected to univariate and multivariate analysis using Cox proportional hazard model.

Results

Fifty-nine patients with gastroenteropancreatic NETs fulfilled the inclusion criteria. Factors associated with a poor survival outcome on univariate analysis were primary tumour site ( P = 0.006) and rapid rise in pancreastatin during somatostatin analogue treatment ( P < 0.001). In multivariate analysis, highly significant clinical prognostic indicators were: tumour location ( P < 0.001), pre-treatment pancreastatin ( P < 0.001) and pancreastatin change ( P < 0.001).

Conclusions

This study endorses the finding that pancreastatin is a useful prognostic indicator of neuroendocrine disease. On commencement of treatment, one-third of the subjects showed an immediate negative pancreastatin response to somatostatin analogues, which was associated with poor survival. This is the first study to document such an association. These findings have significant therapeutic consequences. In the presence of a rapidly rising pancreastatin alternative, treatment modalities should be sought.