Evolving diagnostic and treatment strategies for pancreatic neuroendocrine tumors

Comparison among different preclinical models derived from the same patient with a non-functional pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumors are the second most common tumors of the pancreas, and approximately half of patients are diagnosed with liver metastases. Currently, the improvement in the efficacy of relevant treatment methods is still limited. Therefore, there is an urgent need for in-depth research on the molecular biological mechanism of pancreatic neuroendocrine tumors. However, due to their relatively inert biology, preclinical models are extremely scarce. Here, the patient-derived organoid, and patient-derived xenograft were successfully constructed. These two models and the previously constructed cell line named SPNE1 all derived from the same patient with a grade 3 non-functional pancreatic neuroendocrine tumor, providing new tumor modeling platforms, and characterized using immunohistochemistry, whole-exome sequencing, and single-cell transcriptome sequencing. Combined with a tumor formation experiment in immunodeficient mice, we selected the model that most closely recapitulated the parental tumor. Overall, the patient-derived xenograft model most closely resembled human tumor tissue.

Ultrasound stimulation improves inflammatory resolution, neuroprotection, and functional recovery after spinal cord injury

Spinal cord injury (SCI) is associated with limited functional recovery. Despite advances in neuroscience, realistic therapeutic treatments for SCI remain unavailable. In this study, the effects of non-invasive ultrasound (US) treatment on behavior and inflammatory responses were evaluated in a rat model of SCI. Adult female Sprague–Dawley rats were subjected to spinal cord contusion injury. Two different US parameters (SCIU5: 5% and SCIU40: 40% duty cycle) were applied, and their effects on behavioral recovery after SCI were quantified. Tissue and neuronal responses were detected. Immunofluorescence was used to detect inflammatory markers. In the rat model of SCI, motor function was more effectively restored, and the lesion cavity area was smaller in the SCIU5 group. Furthermore, the SCIU5 protocol elicited an anti-inflammatory response at the injury site by reducing degenerative FJC-labeled neurons, macrophage/microglia activation, and infiltration. Thus, the lesion area decreased, and tissue density increased. Meanwhile, the SCIU40 protocol did not improve motor function or induce an anti-inflammatory response at the injury site. The SCIU5 protocol effectively accelerated the rate of improved exercise performance in the rat model while reducing inflammation. Accordingly, appropriate US stimulation may represent a promising treatment modality for SCI with beneficial anti-inflammatory effects.

90Y/177Lu-DOTATOC: From Preclinical Studies to Application in Humans

The PRRT (Peptide Receptor Radionuclide Therapy) is a promising modality treatment for patients with inoperable or metastatic neuroendocrine tumors (NETs). Progression-free survival (PFS) and overall survival (OS) of these patients are favorably comparable with standard therapies. The protagonist in this type of therapy is a somatostatin-modified peptide fragment ([Tyr3] octreotide), equipped with a specific chelating system (DOTA) capable of creating a stable bond with β-emitting radionuclides, such as yttrium-90 and lutetium-177. In this review, covering twenty five years of literature, we describe the characteristics and performances of the two most used therapeutic radiopharmaceuticals for the NETs radio-treatment: [90Y]Y-DOTATOC and [177Lu]Lu-DOTATOC taking this opportunity to retrace the most significant results that have determined their success, promoting them from preclinical studies to application in humans.

Prognostic Nomograms to Predict Overall Survival and Cancer-Specific Survival of Patients With Pancreatic Neuroendocrine Tumors: A Population-Based Study

OBJECTIVE

The objective of this research was to construct and validate prognostic nomograms predicting overall survival (OS) and cancer-specific survival (CSS) in patients with pancreatic neuroendocrine tumors (pNETs).

METHODS

We extracted 3787 patients with pNETs from the Surveillance, Epidemiology and End Results database. Nomograms for estimating 3- and 5-year OS and CSS were first established. Then, we used Harrell's Concordance Index, calibration plots, and the area under receiver operating characteristic curve to evaluate the nomograms. The Kaplan-Meier curve was plotted to evaluate the different survival outcomes.

RESULTS

In the multivariate analysis, age, grade, functional status, American Joint Committee on Cancer stage, and surgery were associated with OS and CSS. The established nomograms had good discriminative ability, with a Harrell's Concordance Index of 0.830 for OS and 0.855 for CSS. The calibration plots also revealed good agreement. The area under receiver operating characteristic curve values of the nomograms predicting 3- and 5-year OS and CSS rates were 0.836, 0.816 and 0.859, 0.841, respectively. In addition, Kaplan-Meier curve indicated that patients with higher risk had worse survival outcomes.

CONCLUSIONS

We have proposed and validated the nomograms predicting OS and CSS of pNETs. They can be convenient individualized tools to facilitate clinical decision making.

Ultrasound May Suppress Tumor Growth, Inhibit Inflammation, and Establish Tolerogenesis by Remodeling Innatome via Pathways of ROS, Immune Checkpoints, Cytokines, and Trained Immunity/Tolerance

BACKGROUND

The immune mechanisms underlying low-intensity ultrasound- (LIUS-) mediated suppression of inflammation and tumorigenesis remain poorly determined.

METHODS

We used microarray datasets from the NCBI GEO DataSet repository and conducted comprehensive data-mining analyses, where we examined the gene expression of 1376 innate immune regulators (innatome genes (IGs) in cells treated with LIUS.

RESULTS

We made the following findings: (1) LIUS upregulates proinflammatory IGs and downregulates metastasis genes in cancer cells, and LIUS upregulates adaptive immunity pathways but inhibits danger-sensing and inflammation pathways and promote tolerogenic differentiation in bone marrow (BM) cells. (2) LIUS upregulates IGs encoded for proteins localized in the cytoplasm, extracellular space, and others, but downregulates IG proteins localized in nuclear and plasma membranes, and LIUS downregulates phosphatases. (3) LIUS-modulated IGs act partially via several important pathways of reactive oxygen species (ROS), reverse signaling of immune checkpoint receptors B7-H4 and BTNL2, inflammatory cytokines, and static or oscillatory shear stress and heat generation, among which ROS is a dominant mechanism. (4) LIUS upregulates trained immunity enzymes in lymphoma cells and downregulates trained immunity enzymes and presumably establishes trained tolerance in BM cells. (5) LIUS modulates chromatin long-range interactions to differentially regulate IGs expression in cancer cells and noncancer cells.

CONCLUSIONS

Our analysis suggests novel molecular mechanisms that are utilized by LIUS to induce tumor suppression and inflammation inhibition. Our findings may lead to development of new treatment protocols for cancers and chronic inflammation.

Effectiveness of Liver-Directed Therapy for the Management of Intractable Hypoglycemia in Metastatic Insulinoma

OBJECTIVE

The aim of the study was to evaluate efficacy of chemoembolization and radioembolization in treating patients with recurrent hypoglycemia secondary to metastatic insulinoma.

METHODS

A retrospective review was performed of all patients with metastatic insulinoma treated with liver-directed therapy (LDT) at a large academic medical center from January 1998 to August 2017. Primary outcomes included blood glucose levels, occurrence of symptomatic hypoglycemic episodes, and tumor imaging response rates.

RESULTS

Seven patients were identified (4 male patients). The mean age at the first LDT was 60.9 (standard deviation [SD], 9.2) years. The median follow-up was 1.8 years. Thirty-three sessions of LDT were performed including 30 sessions of chemoembolization and 3 sessions of radioembolization. Technical success rate was 97% (32/33 procedures) with an initial clinical success rate of 100%, defined as absence of recurrent symptomatic hypoglycemia within 1 month after first cycle of LDT and overall clinical success rate of 85%. Random daytime glucose levels increased from 75.0 (SD, 26) mg/dL to 152.8 (SD, 52.4) mg/dL after LDT. The mean time to recurrence of intractable hypoglycemia was 21 (SD, 9) months. No severe complications were reported.

CONCLUSIONS

Liver-directed therapy with chemoembolization or radioembolization is effective for treatment of symptomatic hypoglycemia secondary to malignant insulinoma metastatic to liver.

The Evolution of Surgical Strategies for Pancreatic Neuroendocrine Tumors (Pan-NENs): Time-trend and Outcome Analysis From 587 Consecutive Resections at a High-volume Institution

OBJECTIVE

The objective of the present analysis is 2-fold: first, to define the evolution of time trends on the surgical approach to pancreatic neuroendocrine neoplasms (Pan-NENs); second, to perform a complete analysis of the predictors of oncologic outcome.

BACKGROUND

Reflecting their rarity and heterogeneity, Pan-NENs represent a clinical dilemma. In particular, there is a scarcity of data regarding their long-term follow-up after surgical resection.

METHODS

From the Institutional Pan-NEN database, 587 resected cases from 1990 to 2015 were extracted. The time span was arbitrarily divided into 3 discrete clusters enabling a balanced comparison between patient groups. Analyses for predictors of recurrence and survival were performed, together with conditional survival analyses.

RESULTS

Among the 587 resected Pan-NENs, 75% were nonfunctioning tumors, and 5% were syndrome-associated tumors. The mean age was 54 years (±14 years), and 51% of the patients were female. The median tumor size was 20 mm (range 4 to 140), 62% were G1, 32% were G2, and 4% were G3 tumors. Time trends analysis revealed that the number of resected Pan-NENs constantly increased, while the size (from 25 to 20 mm) and G1 proportion (from 65% to 49%) decreased during the study period. After a mean follow-up of 75 months, recurrence analysis revealed that nonfunctioning tumors, tumor grade, N1 status, and vascular invasion were all independent predictors of recurrence. Regardless of size, G1 nonfunctioning tumors with no nodal involvement and vascular invasion had a negligible risk of recurrence at 5 years.

CONCLUSIONS

Pan-NENs have been increasingly diagnosed and resected during the last 3 decades, revealing reliable predictors of outcome. Functioning and nodal status, tumor grade, and vascular invasion accurately predict survival and recurrence with resulting implications for patient follow-up.

Establishment and validation of an AJCC stage- and histologic grade-based nomogram for pancreatic neuroendocrine tumors after surgical resection

Background

Development of an accurate model to predict prognosis for patients with pancreatic neuroendocrine tumors (P-NETs) after surgical resection is urgently needed.

Methods

In the present study, we conducted Cox proportional hazards regression to identify critical prognostic factors for P-NETs by analyzing data from 2174 patients in the Surveillance, Epidemiology, and End Results (SEER) database. Based on the results of multivariate analysis, a novel nomogram was established. Finally, the novel nomogram for P-NETs was validated in a cohort of 81 patients from a Chinese institute.

Results

In the multivariate analysis, age, tumor location, American Joint Committee on Cancer (AJCC) stage, histologic grade, lymph node ratio (LNR) and tumor size were independent risk factors for overall survival (OS) in P-NET patients who underwent radical resection. A nomogram consisting of age, sex, AJCC stage and histologic grade was found to have a concordance index (C-index) of 0.79 for OS in the SEER database, which was significantly higher than the C-index based on the AJCC stage, European Neuroendocrine Tumor Society (ENETS) stage or histologic grade alone. In the validation cohort, the C-index based on the nomogram reached 0.78 for OS. We also defined high-risk (total points >13.5 based on the nomogram) and low-risk populations (total points <13.5 based on the nomogram) in the validation cohort. We found that the actual 5-year recurrence rate in the high-risk group was significantly higher than that in the low-risk group (80.8% vs 23.4%, P<0.001). Kaplan-Meier analysis showed that the 5-year recurrence-free survival (RFS) in the low-risk group was significantly higher than that in the high-risk group (P<0.001).

Conclusion

An AJCC stage- and histologic grade-based model was found to be extremely efficient in predicting survival for patients with P-NETs after surgical resection and deserves further evaluation for future clinical applications.

Experimental Data-Mining Analyses Reveal New Roles of Low-Intensity Ultrasound in Differentiating Cell Death Regulatome in Cancer and Non-cancer Cells via Potential Modulation of Chromatin Long-Range Interactions

Background: The mechanisms underlying low intensity ultrasound (LIUS) mediated suppression of inflammation and tumorigenesis remain poorly determined. Methods: We used microarray datasets from NCBI GEO Dataset databases and conducted a comprehensive data mining analyses, where we studied the gene expression of 299 cell death regulators that regulate 13 different cell death types (cell death regulatome) in cells treated with LIUS. Results: We made the following findings: (1) LIUS exerts a profound effect on the expression of cell death regulatome in cancer cells and non-cancer cells. Of note, LIUS has the tendency to downregulate the gene expression of cell death regulators in non-cancer cells. Most of the cell death regulator genes downregulated by LIUS in non-cancer cells are responsible for mediating inflammatory signaling pathways; (2) LIUS activates different cell death transcription factors in cancer and non-cancer cells. Transcription factors TP-53 and SRF- were induced by LIUS exposure in cancer cells and non-cancer cells, respectively; (3) As two well-accepted mechanisms of LIUS, mild hyperthermia and oscillatory shear stress induce changes in the expression of cell death regulators, therefore, may be responsible for inducing LIUS mediated changes in gene expression patterns of cell death regulators in cells; (4) LIUS exposure may change the redox status of the cells. LIUS may induce more of antioxidant effects in non-cancer cells compared to cancer cells; and (5) The genes modulated by LIUS in cancer cells have distinct chromatin long range interaction (CLRI) patterns to that of non-cancer cells. Conclusions: Our analysis suggests novel molecular mechanisms that may be utilized by LIUS to induce tumor suppression and inflammation inhibition. Our findings may lead to development of new treatment protocols for cancers and chronic inflammation.

Angiogenesis in Pancreatic Cancer: Pre-Clinical and Clinical Studies

Angiogenesis is a crucial event in tumor development and progression, occurring by different mechanisms and it is driven by pro- and anti-angiogenic molecules. Pancreatic cancer vascularization is characterized by a high microvascular density, impaired microvessel integrity and poor perfused vessels with heterogeneous distribution. In this review article, after a brief introduction on pancreatic cancer classification and on angiogenesis mechanisms involved in its progression, the pre-clinical and clinical trials conducted in pancreatic cancer treatment using anti-angiogenic inhibitors will be described. Finally, we will discuss the anti-angiogenic therapy paradox between the advantage to abolish vessel supply to block tumor growth and the disadvantage due to reduction of drug delivery at the same time. The purpose is to identify new anti-angiogenic molecules that may enhance treatment regimen.

Neoplasms of the Neuroendocrine Pancreas: An Update in the Classification, Definition, and Molecular Genetic Advances

This review focuses on discussing the main modifications of the recently published 2017 WHO Classification of Neoplasms of the Neuroendocrine Pancreas (panNEN). Recent updates separate pancreatic neuroendocrine tumors into 2 broad categories: well-differentiated pancreatic neuroendocrine tumors (panNET) and poorly differentiated pancreatic neuroendocrine carcinoma (panNEC), and incorporates a new subcategory of "well-differentiated high-grade NET (G3)" to the well-differentiated NET category. This new classification algorithm aims to improve the prediction of clinical outcomes and survival and help clinicians select better therapeutic strategies for patient care and management. In addition, these neuroendocrine neoplasms are capable of producing large quantity of hormones leading to clinical hormone hypersecretion syndromes. These functioning tumors include, insulinomas, glucagonomas, somatostatinomas, gastrinomas, VIPomas, serotonin-producing tumors, and ACTH-producing tumors. Although most panNENs arise as sporadic diseases, a subset of these heterogeneous tumors present as parts on inherited genetic syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1, tuberous sclerosis, and glucagon cell hyperplasia and neoplasia syndromes. Characteristic clinical and morphologic findings for certain functioning and syndromic panNENs should alert both pathologists and clinicians as appropriate patient management and possible genetic counseling may be necessary.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advances and Current Concepts in the Medical Management of Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare and heterogeneous group of tumors presenting as localised or metastatic disease and in a subset with distinct clinical syndromes. Treatment is aimed at controlling the functional syndrome, eradicating the tumor, and/or preventing further tumor growth. Surgery is the treatment of choice in removing the primary tumor and/or reducing tumor burden but cannot be applied to all patients. Somatostatin analogs (SS-analogs) obtain control of functional syndromes in the majority of GEP-neuroendocrine tumors (NETs); phase III trials have shown that SS-analogs can be used as first-line antiproliferative treatment in patients with slow-growing GEP-NETs. The role of the recently approved serotonin inhibitor, telotristat ethyl, and gastrin receptor antagonist, netazepide, is evolving. Streptozotocin-based chemotherapy has been used for inoperable or progressing pancreatic NENs but the orally administered combination of capecitabine/temozolomide is becoming more popular due to its better tolerability and potential effect in other GEP-NENs. Phase III trials have shown efficacy of molecular targeted therapies in GEP-NETs and of radionuclide treatment in patients with midgut carcinoid tumors expressing somatostatin receptors. Most patients will develop disease progression necessitating further therapeutic options. A combination of currently available treatments along with the molecular signature of each tumor will guide future treatment.

Patient-Reported Outcomes and Quality of Life with Sunitinib Versus Placebo for Pancreatic Neuroendocrine Tumors: Results From an International Phase III Trial

OBJECTIVE

The objective of this analysis was to compare patient-reported outcomes and health-related quality of life (HRQoL) in a pivotal phase III trial of sunitinib versus placebo in patients with progressive, well-differentiated pancreatic neuroendocrine tumors (NCT00428597).

PATIENTS AND METHODS

Patients received sunitinib 37.5 mg (n = 86) or placebo (n = 85) on a continuous daily-dosing schedule until disease progression, unacceptable adverse events (AEs), or death. Patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 at baseline, Day 1 of every 4-week cycle, and end of treatment or withdrawal. Changes ≥10 points on each scale or item were deemed clinically meaningful.

RESULTS

Sunitinib had anti-tumor effects and improved progression-free survival (PFS) compared with placebo. The study was terminated early for this reason and because of more serious AEs and deaths with placebo. Baseline HRQoL scores were well balanced between study arms, and were generally maintained over time in both groups. In the first 10 cycles, there were no significant differences between groups in global HRQoL, cognitive, emotional, physical, role, and social functioning domains, or symptom scales, except for worsening diarrhea with sunitinib (p < 0.0001 vs. placebo). Insomnia also worsened with sunitinib (p = 0.0372 vs. placebo), but the difference was not clinically meaningful.

CONCLUSION

With the exception of diarrhea (a recognized side effect), sunitinib had no impact on global HRQoL, functional domains, or symptom scales during the progression-free period. Hence, in patients with pancreatic neuroendocrine tumors, sunitinib provided a benefit in PFS without adversely affecting HRQoL.

Low-Intensity Ultrasound-Induced Anti-inflammatory Effects Are Mediated by Several New Mechanisms Including Gene Induction, Immunosuppressor Cell Promotion, and Enhancement of Exosome Biogenesis and Docking

Background: Low-intensity ultrasound (LIUS) was shown to be beneficial in mitigating inflammation and facilitating tissue repair in various pathologies. Determination of the molecular mechanisms underlying the anti-inflammatory effects of LIUS allows to optimize this technique as a therapy for the treatment of malignancies and aseptic inflammatory disorders. Methods: We conducted cutting-edge database mining approaches to determine the anti-inflammatory mechanisms exerted by LIUS. Results: Our data revealed following interesting findings: (1) LIUS anti-inflammatory effects are mediated by upregulating anti-inflammatory gene expression; (2) LIUS induces the upregulation of the markers and master regulators of immunosuppressor cells including MDSCs (myeloid-derived suppressor cells), MSCs (mesenchymal stem cells), B1-B cells and Treg (regulatory T cells); (3) LIUS not only can be used as a therapeutic approach to deliver drugs packed in various structures such as nanobeads, nanospheres, polymer microspheres, and lipidosomes, but also can make use of natural membrane vesicles as small as exosomes derived from immunosuppressor cells as a novel mechanism to fulfill its anti-inflammatory effects; (4) LIUS upregulates the expression of extracellular vesicle/exosome biogenesis mediators and docking mediators; (5) Exosome-carried anti-inflammatory cytokines and anti-inflammatory microRNAs inhibit inflammation of target cells via multiple shared and specific pathways, suggesting exosome-mediated anti-inflammatory effect of LIUS feasible; and (6) LIUS-mediated physical effects on tissues may activate specific cellular sensors that activate downstream transcription factors and signaling pathways. Conclusions: Our results have provided novel insights into the mechanisms underlying anti-inflammatory effects of LIUS, and have provided guidance for the development of future novel therapeutic LIUS for cancers, inflammatory disorders, tissue regeneration and tissue repair.

Is there still a role for the hepatic locoregional treatment of metastatic neuroendocrine tumors in the era of systemic targeted therapies?

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) frequently present with distant metastases at the time of diagnosis and the liver is the most frequent site of spreading. The early identification of metastatic disease represents a major prognostic factor for GEP-NENs patients. Radical surgical resection, which is feasible for a minority of patients, is considered the only curative option, while the best management for patients with unresectable liver metastases is still being debated. In the last few years, a number of locoregional and systemic treatments has become available for GEP-NEN patients metastatic to the liver. However, to date only a few prospective studies have compared those therapies and the optimal management option is based on clinical judgement. Additionally, locoregional treatments appear feasible and safe for disease control for patients with limited liver involvement and effective in symptoms control for patients with diffuse liver metastases. Considering the lack of randomized controlled trials comparing the locoregional treatments of liver metastatic NEN patients, clinical judgment remains key to set the most appropriate therapeutic pathway. Prospective data may ultimately lead to more personalized and optimized treatments. The present review analyzes all the locoregional therapy modalities (i.e., surgery, ablative treatments and transarterial approach) and aims to provide clinicians with a useful algorithm to best treat GEP-NEN patients metastatic to the liver.

Clinical outcomes and prognostic factors of resected pancreatic neuroendocrine neoplasms: A single-center experience in China

The aim of the present study was to investigate the clinical, pathological and prognostic characteristics of Chinese patients with resected pancreatic neuroendocrine neoplasms (p-NENs). Data from patients who were surgically treated and pathologically diagnosed with p-NENs at the Department of Pancreatic Oncology of the Fudan University Shanghai Cancer Center (Shanghai, China), between January 2003 and July 2015, were evaluated using univariate and multivariate analyses. A total of 162 patients with p-NENs met the criteria of the present study and were included in the analysis. Patients with poorly differentiated pancreatic neuroendocrine carcinoma (p-NEC) exhibited a significantly increased rate of lymph node metastasis, as compared with patients with grade (G)1/G2 pancreatic neuroendocrine tumors (p-NETs) (62.5 vs. 20.5%, P=0.003). Univariate analysis identified that the following factors led to decreased overall survival (OS): Lymph node metastasis (P=0.001, vs. the absence of lymph node metastasis); distant metastasis (P=0.043, vs. the absence of distant metastasis); resection margin R1/R2 (P=0.030, vs. R0 resection); NEC G3 (P<0.001, vs. NET G1). Following the multivariate analysis, NEC G3 remained a statistically significant risk factor (HR=12.593; 95% CI, 3.476-45.622; P<0.001, vs. NET G1/G2). Furthermore, according to the proliferation marker protein Ki-67 staining index, assigning a grade using the proliferative index (G1, ≤5%; G2, >5-20%; G3, >20%) was more efficient for prognostic stratification compared with the European Neuroendocrine Tumor Society (Berlin, Germany)/World Health Organization (Geneva, Switzerland) 2010 grading classification. The present study indicated that p-NEC was an important predictor of decreased OS in Chinese patients. Furthermore, a Ki-67 staining index of 5% represented a more efficient value for the distinction between G1 and G2.

Synthesis and Antitumor Activity of 5-Bromo-7-azaindolin-2-one Derivatives Containing a 2,4-Dimethyl-1H-pyrrole-3-carboxamide Moiety

We report herein the design and synthesis of a series of novel 5-bromo-7-azaindolin-2-one derivatives containing a 2,4-dimethyl-1H-pyrrole-3-carboxamide moiety. These newly synthesized derivatives were evaluated for in vitro activity against selected cancer cell lines by MTT assay. Results revealed that some compounds exhibit broad-spectrum antitumor potency, and the most active compound 23p (IC₅₀: 2.357-3.012 μM) was found more potent than Sunitinib (IC₅₀: 31.594-49.036 μM) against HepG2, A549 and Skov-3, respectively.

Neuroendocrine Tumors

Neuroendocrine tumors are increasingly diagnosed, either incidentally as part of screening processes, or for symptoms, which have commonly been mistaken for other disorders initially. The diagnostic workup to characterize tumor behaviour and prognosis focuses on histologic, anatomic, and functional imaging assessments. Several therapeutic options exist for patients ranging from curative and debulking surgery through to liver-directed therapies and systemic treatments. Multimodal therapies are often required over the patient's disease history. The management paradigm can be complex but should be focused on curative resections and then on controlling symptoms and limiting disease progression. There are several new systemic therapies that have completed phase 3 studies with new compounds being studied in phase 2. Genetic and epigenetic markers may lead to a new era of personalised therapy in the future.

Role of targeted agents in neuroendocrine tumors: Results from a meta-analysis

BACKGROUND

Several randomized phase III trials in neuroendocrine tumors (NETs) showed the clinical role of new targeted agents and their impact on tumor response and outcome of whose patients affected by advanced NET. In this study, we summarize the available clinical data related to clinical efficacy of targeted therapies in the treatment of advanced NETs.

METHODS

A meta-analysis of randomized studies in accordance with the PRISMA guidelines was performed after searching the databases of PubMed, the Cochrane Library, and the ASCO University Meeting for relevant publications.

RESULTS

One thousand 9 hundred and 8 cases were included in the meta-analysis; among these, 1012 were in the experimental arm and 896 were in the control arm. The pooled analysis of the use of target agents in NETs revealed significantly increased of progression free survival compared to control group (hazard ratio = 0.59, 95% CI:0.42-0.84; P = 0.003). Subgroup analysis of patients according to tumor site showed a difference in favor of pancreatic neuroendocrine tumors. Moreover, targeted therapies improved the overall survival (hazard ratio = 0.79, 95%CI: 0.63-0.98; P = 0.03), and response rate (hazard ratio = 3.33, 95% CI 2.02-5.49; P < 0.00001) in all types of NETs.

CONCLUSION

Our analysis supports the routine use of targeted agents for treatment of neuroendocrine tumors with particular regards to the pancreatic neuroendocrine tumors.

Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (Pan-NENs) are rare but clinically important lesions. Pan-NENs are known for and often categorized by their capacity to produce clinical syndromes mediated by the production of hormones. Despite sometimes presenting dramatically from excessive hormone production, not all Pan-NENs produce functional hormone, and they can pose diagnostic challenges to practicing pathologists. Distinguishing Pan-NENs from mimics can be crucial, because Pan-NENs carry different prognoses and have unique treatments available due to their specific biological properties. This article reviews the current categorization and features of Pan-NENs.

Learning experiences with sunitinib continuous daily dosing in patients with pancreatic neuroendocrine tumours

Molecular strategies to improve outcomes for patients with pancreatic neuroendocrine tumours (nets) have focused on targeting vascular endothelial growth factor, platelet-derived growth factor, and mtor (the mammalian target of rapamycin). This approach has led to the regulatory approval of two molecularly targeted agents for advanced pancreatic nets: sunitinib, a multi-targeted tyrosine kinase inhibitor, and everolimus, an mtor inhibitor. Initial experience with sunitinib in advanced pancreatic net was gained from the phase iii registration trial, which used a continuous daily dosing (cdd) schedule instead of daily drug administration for 4 consecutive weeks every 6 weeks (schedule 4/2), the approved schedule for advanced renal cell carcinoma (rcc) and gastrointestinal stromal tumour (gist). Clinical experience gained with schedule 4/2 in rcc and gist shows that, using a therapy management approach, patients can start and be maintained on the recommended dose and schedule, thus optimizing treatment outcomes. Here, we discuss challenges that can potentially be faced by physicians who use sunitinib on the cdd schedule, and we use clinical data and real-life clinical experience to present therapy management approaches that support cdd in advanced pancreatic net.

Localization of sunitinib in in vivo animal and in vitro experimental models by MALDI mass spectrometry imaging

The spatial distribution of an anticancer drug and its intended target within a tumor plays a major role on determining how effective the drug can be at tackling the tumor. This study provides data regarding the lateral distribution of sunitinib, an oral antiangiogenic receptor tyrosine kinase inhibitor using an in vitro animal model as well as an in vitro experimental model that involved deposition of a solution of sunitinib onto tissue sections. All tumor sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging and compared with subsequent histology staining. Six tumors at four different time points after commencement of in vivo sunitinib treatment were examined to observe the patterns of drug uptake. The levels of sunitinib present in in vivo treated tumor sections increased continuously until day 7, but a decrease was observed at day 10. Furthermore, the in vitro experimental model was adjustable to produce a drug level similar to that obtained in the in vivo model experiments. The distribution of sunitinib in tissue sections treated in vitro appeared to agree with the histological structure of tumors, suggesting that this approach may be useful for testing drug update.

Consensus Recommendations for the Diagnosis and Management of Pancreatic Neuroendocrine Tumors: Guidelines from a Canadian National Expert Group

Pancreatic neuroendocrine tumors (pNETs) are rare heterogeneous tumors that have been steadily increasing in both incidence and prevalence during the past few decades. Pancreatic NETs are categorized as functional (F) or nonfunctional (NF) based on their ability to secrete hormones that elicit clinically relevant symptoms. Specialized diagnostic tests are required for diagnosis. Treatment options are diverse and include surgical resection, intraarterial hepatic therapy, and peptide receptor radionuclide therapy (PRRT). Systemic therapy options include targeted agents as well as chemotherapy when indicated. Diagnosis and management should occur through a collaborative team of health care practitioners well-experienced in managing pNETs. Recent advances in pNET treatment options have led to the development of the Canadian consensus document described in this report. The discussion includes the epidemiology, classification, pathology, clinical presentation and prognosis, imaging and laboratory testing, medical and surgical management, and recommended treatment algorithms for pancreatic neuroendocrine cancers.

A tale of two tumors: treating pancreatic and extrapancreatic neuroendocrine tumors

Despite their perceived rarity, gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rising in incidence and prevalence. The biology, natural history, and therapeutic options for GEP-NETs are heterogeneous: NETs arising in the pancreas can be distinguished from those arising elsewhere in the gastrointestinal tract, and therapy is dichotomized between these two groups. Somatostatin analogues are the mainstay of oncologic management of bowel NETs; everolimus, streptozocin, and sunitinib are approved to treat pancreatic NETs. There are significant differences in molecular genetics between pancreatic and extrapancreatic NETs, and studies are evaluating whether additional NET patients may benefit from targeted agents. We discuss the distinguishing features of these two groups of tumors, as well as the therapeutic implications of the distinction. We also examine the evolving therapeutic landscape and discuss the likelihood that treatment will be developed independently for pancreatic and extrapancreatic gastrointestinal NETs, with novel therapeutics effective for newly identified pathologically or molecularly defined subgroups.

Practical management of sunitinib toxicities in the treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are infrequent malignancies which manifest in both functional (hormone-secreting) and more commonly non-functional (non-secreting) forms. The oral multitargeted tyrosine kinase inhibitor sunitinib and mammalian target of rapamycin (mTOR) inhibitor everolimus are approved as targeted therapies for patients with well-differentiated, non-resectable disease and evidence of disease progression. The recent approval of sunitinib for the management of advanced pNET is based on a continuous daily dosing (CDD) schedule that differs from the intermittent 4weeks on/2weeks off (4/2) schedule approved for sunitinib in advanced renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST). Therefore, although clinicians may be familiar with therapy management approaches for sunitinib in advanced RCC and GIST, there is less available experience for the management of patients with a CDD schedule. Here, we discuss the similarities and differences in the treatment of pNET with sunitinib compared with advanced RCC and GIST. In particular, we focus on the occurrence and management of sunitinib-related toxicity in patients with pNET by drawing on experience in these other malignancies. We aim to provide a relevant and useful guide for clinicians treating patients with pNET covering the management of events such as fatigue, mucositis, hand-foot syndrome, and hypertension.

Co-existence of insulinoma and diabetes: A case report

Neuroendocrine tumors constitute a group of heterogeneous neoplasms, both those that are clinically asymptomatic and those which present with an array of symptoms. This variable clinical manifestation and unsatisfactory detection rate on diagnostic imaging make preoperative diagnosis particularly challenging. Insulinoma is a rare tumor originating from insulin-synthetizing pancreatic beta cells which clinically manifests hypoglycemia. The current study presents the case of a patient with a one month history of diabetes, and a tumor of the pancreatic head diagnosed at the Regional Hospital of Lomza (Lomza, Poland). The patient subsequently underwent surgery. The histological examination indicated insulinoma; islet cell tumor of the pancreas. The patient’s postoperative period was uneventful and during two years of follow-up, the patient has remained in good health with completely controlled diabetes mellitus. The hereby-presented case of pancreatic insulinoma confirms this finding, as a correct diagnosis could only be established on the basis of pathomorphological examination. In addition, radical surgical resection is currently the only available treatment.

Both sunitinib and sorafenib are effective treatments for pheochromocytoma in a xenograft model

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors which develop from chromaffin cells of the adrenal medulla and extra-adrenal sites, leading to excess catecholamine release and hypertension. Many of the tumors are characterized by a high vascularity, suggesting the possible implementation of anti-angiogenic therapies for patients. Here, the efficacy of the tyrosine kinase inhibitors sunitinib and sorafenib was investigated in vivo and in vitro. Oral treatment with either sunitinib or sorafenib (40mg/kg/day) for 14days induced a marked reduction in the volume and weight of PC12 pheochromocytoma cell tumor xenografts in mice. Assessment of tumoral neo-angiogenesis, assessed by morphometric analysis of the vascular network after CD31 immunolabeling, showed that both sunitinib and sorafenib reduced the microvessel area (-85% and -80%, respectively) and length (-80% and -78%, respectively) in treated compared to control tumors. In addition, the number of vessel nodes was significantly lower in treated tumors (-95% and -84%, respectively). Furthermore, cleaved caspase 3 immunolabeling revealed a marked increase in the number of apoptotic cells in tumors from treated animals. Sunitinib and sorafenib could exert a direct effect on PC12 cell viability in vitro. While sunitinib induced a rapid (4h) and pronounced (5-fold) increase in caspase-3/7-dependent apoptosis, sorafenib seems to exert its cytotoxic activity through a different mechanism. Altogether, our data demonstrate that sunitinib and sorafenib have the ability to impair pheochromocytoma development by inhibiting angiogenesis and reducing tumor cell viability. These results strongly suggest that both sunitinib and sorafenib could represent valuable therapeutic tools for pheochromocytoma.

A single institution's 26-year experience with nonfunctional pancreatic neuroendocrine tumors: a validation of current staging systems and a new prognostic nomogram

OBJECTIVE

To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature.

BACKGROUND

The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease.

METHODS

Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration.

RESULTS

Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74.

CONCLUSIONS

Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.

Everolimus and sunitinib for advanced pancreatic neuroendocrine tumors: a matching-adjusted indirect comparison

Background

Everolimus and sunitinib have been approved for the treatment advanced pancreatic neuroendocrine tumors, but have not been compared to each other in a randomized trial and have not demonstrated prolonged overall survival compared to placebo. This study aimed to indirectly compare overall and progression-free among everolimus, sunitinib and placebo across separate randomized trials.

Methods

A matching adjusted indirect comparison was conducted in which individual patient data from the pivotal trial of everolimus (n = 410) were adjusted to match the inclusion criteria and average baseline characteristics reported for the pivotal trial of sunitinib (n = 171). Prior to matching, trial populations differed in baseline performance status and prior treatments. After matching, these and all other available baseline characteristics were balanced between trials.

Results

Compared to the placebo arm in the sunitinib trial, everolimus was associated with significantly prolonged overall survival (HR = 0.61, 95% CI = 0.38-0.98, p = 0.042).

Compared to sunitinib, everolimus was associated with similar progression-free (hazard ratio for death (HR) = 0.84, 95% CI = 0.46–1.53, p = 0.578) and overall survival (HR = 0.81, 95% CI = 0.49–1.31, p = 0.383).

Conclusion

After adjusting for observed cross-trial differences, everolimus treatment was associated with longer overall survival than the placebo arm in the sunitinib trial for advanced pancreatic neuroendocrine tumors.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Zollinger-Ellison syndrome: recent advances and controversies

PURPOSE OF REVIEW

To review the recent advances and current controversies in patients with Zollinger-Ellison syndrome (ZES).

RECENT FINDINGS

Recent advances in the management of ZES include: improved understanding of the pathogenesis of gastrinoma and pancreatic neuroendocrine tumors, new prognostic classification systems, new diagnostic algorithms, more sensitive localization studies, new treatment strategies including improved control of gastric acid secretion and role for surgery, and new approaches to patients with advanced disease. Controversies include: the best approach to a patient with hypergastrinemia suspected of possibly having ZES, the appropriate gastrin assay to use, the role of surgery in patients with ZES, especially those with multiple endocrine neoplasia type 1, and the precise order of therapeutic modalities in the treatment of patients with advanced disease.

SUMMARY

This review updates clinicians regarding important advances and controversies required to optimally diagnose and manage patients with ZES.

Free somatostatin receptor fraction predicts the antiproliferative effect of octreotide in a neuroendocrine tumor model: implications for dose optimization

Somatostatin receptors (SSTR) are highly expressed in well-differentiated neuroendocrine tumors (NET). Octreotide, an SSTR agonist, has been used to suppress the production of vasoactive hormones and relieve symptoms of hormone hypersecretion with functional NETs. In a clinical trial, an empiric dose of octreotide treatment prolonged time to tumor progression in patients with small bowel neuroendocrine (carcinoid) tumors, irrespective of symptom status. However, there has yet to be a dose optimization study across the patient population, and methods are currently lacking to optimize dosing of octreotide therapy on an individual basis. Multiple factors such as total tumor burden, receptor expression levels, and nontarget organ metabolism/excretion may contribute to a variation in SSTR octreotide occupancy with a given dose among different patients. In this study, we report the development of an imaging method to measure surface SSTR expression and occupancy level using the PET radiotracer (68)Ga-DOTATOC. In an animal model, SSTR occupancy by octreotide was assessed quantitatively with (68)Ga-DOTATOC PET, with the finding that increased occupancy resulted in decreased tumor proliferation rate. The results suggested that quantitative SSTR imaging during octreotide therapy has the potential to determine the fractional receptor occupancy in NETs, thereby allowing octreotide dosing to be optimized readily in individual patients. Clinical trials validating this approach are warranted.

The use of targeted therapies in pancreatic neuroendocrine tumours: patient assessment, treatment administration, and management of adverse events

Together with the use of novel oral targeted therapies, a multidisciplinary approach can be used to effectively treat patients with advanced pancreatic neuroendocrine tumours (pNETs). Here we review the integration of the oncology nurse to the newly developed oral treatment setting for patients with pNETs. From the outset, the nurse must be involved in various processes, including performance of baseline assessments (e.g. blood pathology, cardiac and lung function testing, patient history) and general medical observations, treatment administration, dietary guidance, evaluation of comorbidities, and review of concomitant medications. Patient education and establishment of a strong partnership in care before the start of pNET therapy ultimately increase treatment adherence and reduce potential toxicities. Regular review of general patient status and disease progression and continuous monitoring of adverse events also help enhance treatment outcomes and subsequently improve quality of life. Nurses' knowledge of agent-specific toxicities and prompt, proactive management is a critical aspect of care. In essence, as the pNET treatment landscape evolves, the role of the healthcare professional in overall patient care must shift accordingly.

Prolonged clinical benefit of everolimus therapy in the management of high-grade pancreatic neuroendocrine carcinoma

Treatment options for patients with high-grade pancreatic neuroendocrine tumors (pNET) are limited, especially for those with progressive disease and for those who experience treatment failure. Everolimus, an oral inhibitor of mammalian target of rapamycin (mTOR), has been approved for the treatment of patients with low- or intermediate-grade advanced pNET. In the randomized phase III RADIANT-3 study in patients with low- or intermediate-grade advanced pNET, everolimus significantly increased progression-free survival (PFS) and decreased the relative risk for disease progression by 65% over placebo. This case report describes a heavily pretreated patient with high-grade pNET and liver and peritoneal metastases who achieved prolonged PFS, clinically relevant partial radiologic tumor response, and resolution of constitutional symptoms with improvement in Karnofsky performance status while receiving a combination of everolimus and octreotide long-acting repeatable (LAR). Radiologic and clinical responses were maintained for 19 months, with minimal toxicity over the course of treatment. This case supports the findings that the combination of everolimus plus octreotide LAR may be considered for use in patients with high-grade pNET and progressive disease. Although behavior and aggressiveness are different between low- or intermediate-grade and high-grade pNET, some high-grade pNET may express mTOR; hence, everolimus should be considered in a clinical trial.

Targeted therapies in neuroendocrine tumors (NET): clinical trial challenges and lessons learned

In the past 3 years, we have witnessed the completion of four randomized phase III studies in neuroendocrine tumors and the approval of two new drugs, everolimus and sunitinib, for the treatment of patients with well-differentiated pancreatic neuroendocrine tumors. These studies demonstrate a shift from case series and single-arm studies toward prospective, randomized controlled clinical trials and evidence-based therapy in the neuroendocrine tumor field. However, the clinical development of these agents also highlights the potential challenges awaiting other new drugs in this area. Herein, we discuss the strengths and weaknesses of the most recent phase II and phase III neuroendocrine tumor studies and discuss how limitations inherent in current trial design can lead to potential pitfalls. We also discuss how trial design can be improved, with the hope of increasing the number of drugs successfully developed to treat patients with neuroendocrine tumors.

United States-based practice patterns and resource utilization in advanced neuroendocrine tumor treatment

AIM

To assess advanced neuroendocrine tumor (NET) treatment patterns and resource utilization by tumor progression stage and tumor site in the United States.

METHODS

United States Physicians meeting eligibility criteria were provided with online data extraction forms to collect patient chart data on recent NET patients. Resource utilization and treatment pattern data were collected over a baseline period (after diagnosis and before tumor progression), as well as initial and secondary progression periods, with progression defined according to measureable radiographic evidence of tumor progression. Resource categories used in the analysis include: Treatments (e.g., surgery, chemotherapy, radiotherapy, targeted therapies), hospitalizations and physician visits, diagnostic tests (biomarkers, imaging, laboratory tests). Comparisons between categories of resource utilization and tumor progression status were examined using univariate (by tumor site) and multivariate analyses (across all tumor sites).

RESULTS

Fifty-five physicians were included in the study and completed online data extraction forms using the charts of 110 patients. The physician sample showed a relatively even distribution for those affiliated with academic versus community hospitals (46% vs 55%). Forty (36.3%) patients were reported to have pancreatic NET (pNET), while 70 (63.6%) patients had gastrointestinal tract (GI)/Lung as the primary NET site. Univariate analysis showed the proportion of patients hospitalized increased from 32.7% during baseline to 42.1% in the progression stages. While surgeries were performed at similar proportions overall at baseline and progression, pNET patients, were more likely than GI/Lung NET patients to have undergone surgery during the baseline (33.3% vs 25.0%) and any progression periods (26.7% vs 23.4%). While peptide-receptor radionuclide and targeted therapy utilization was low across NET types and tumor stages, GI/Lung types exhibited greater utilization of these technologies compared to pNET. Chemotherapy utilization was also greater among GI/Lung types. Multivariate analysis results demonstrated that patients in first progression period were over 3 times more likely to receive chemotherapy when compared to baseline (odds ratio: 3.31; 95%CI: 1.46-7.48, P = 0.0041). Further, progression was associated with a greater likelihood of having a study physician visit [relative risk (RR): 1.54; 95%CI: 1.10-2.17, P = 0.0117], and an increased frequency of other physician visits (RR: 1.84; 95%CI: 1.10-3.10, P = 0.0211).

CONCLUSION

Resource utilization in advanced NET in the United States is significant overall and data suggests progression has an impact on resource utilization regardless of NET tumor site.

PI3K/Akt/mTOR pathway inhibitors in the therapy of pancreatic neuroendocrine tumors

The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is implicated in the pathogenesis of pancreatic neuroendocrine tumors (pNETs). Activation of this pathway is driven by aberrant tyrosine kinase receptor activities. Mutations in the PI3K/Akt/mTOR pathway occur in 15% of pNETs, and expression of genes of the PI3K/Akt/mTOR pathway is altered in the majority of pNETs. The mTOR inhibitor everolimus has been approved by the FDA for the treatment of pNET, but its efficacy may be limited by its inability to prevent mTORC2-mediated activation of Akt. Specific inhibitors of PI3K, Akt, or other pathway nodes, and their concomitant use with mTOR inhibitors, or agents with dual activity, may be more effective. Preclinical studies demonstrate that inhibitors of the PI3K pathway have antitumor activity in pNET cells, either through direct inhibition of individual pathway nodes or indirect inhibition of molecular chaperones such as heat-shock protein 90. Clinical studies are underway evaluating individual node and dual node inhibitors.

PET/CT of cancer patients: part 1, pancreatic neoplasms

OBJECTIVE

Pancreatic cancer continues to have a poor prognosis despite impressive improvements in the outcomes of many other types of cancer, often because most pancreatic neoplasms are found to be unresectable at diagnosis. The purpose of this review is to provide an overview of pancreatic cancer and the role of modern imaging in its diagnosis and management with an emphasis on (18)F-FDG PET/CT fusion imaging.

CONCLUSION

Multimodality imaging is critical in the diagnosis and management of pancreatic cancer. PET/CT is increasingly viewed as a useful, accurate, and cost-effective modality in diagnosing and managing pancreatic cancer, but further studies are warranted. Early data suggest that contrast-enhanced PET/CT performed with modern PET/CT scanners yields high-resolution anatomic information for surgical and radiotherapeutic planning and functional information for whole-body staging in the care of patients with this disease.

Surgical treatment of sporadic pancreatic neuroendocrine tumors: a state of the art review

Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms. They are clinically diverse and divided into functioning and nonfunctioning disease, depending on their ability to produce symptoms due to hormone production. Surgical resection is the only curative treatment and remains the cornerstone therapy for this patient group, even in patients with advanced disease. Over the last decade there has been a noticeable trend towards more aggressive surgery as well as more minimally invasive surgery in patients with PNETs. This has resulted in improved long-term survival in patients with locally advanced and metastatic disease treated aggressively, as well as shorter hospital stays and comparable long-term outcomes in patients with limited disease treated minimally invasively. There are still controversies related to issues of surgical treatment of PNETs, such as to what extent enucleation, lymph node sampling, and vascular reconstruction are beneficial for the oncologic outcome. Histopathologic tumor classification is of high clinical importance for treatment planning and prognostic evaluation of patients with PNETs. A constant challenge, which relates to the treatment of PNETs, is the lack of an internationally accepted histopathological classification system. This paper reviews current issues on the surgical treatment of sporadic PNETs with specific focus on surgical approaches and tumor classification.

Selecting patients for cytotoxic therapies in gastroenteropancreatic neuroendocrine tumours

Gastroenteropancreatic neuroendocrine tumours (GEP-NET) have heterogenic clinical presentations. The majority of GEP-NET tumours have an indolent behaviour, but patients will eventually develop symptoms of tumour progression or hormone secretion that may require systemic medical interventions. Cytotoxic chemotherapy has been tested in GEP-NETs since the 80s, but treatment recommendations are controversial in many instances. Patient selection is mandatory for optimal use of chemotherapy. Important prognostic factors such as primary tumour site, tumour differentiation, tumour staging and proliferation index have been identified and validated in retrospective and prospective series. The combination of those factors and the natural history of GEP-NET provide valuable information with respect to treatment planning. In this report we provide treatment recommendations to improve systemic therapy in patients with advanced GEP-NETs based on a comprehensive review of the literature.

Nonfunctional neuroendocrine tumor of the pancreas: Case report and review of the literature

INTRODUCTION

Pancreatic neuroendocrine tumors (PNET) have an incidence of one per 100,000 individuals per year. They represent about 1-2% of all pancreatic tumors. PNETs are a heterogeneous group with various clinical presentations and lineage. Non functional PNET (NF-PNET) are incidentally discovered in most cases. This article presents a review of NF-PNET and the case of a patient with this disease, in addition to its diagnosis, clinical presentation, and treatment.

PRESENTATION OF CASE

The patient is a 37-year-old asymptomatic man who was sent from his reference unit because of a pancreatic tumor that was visualized incidentally during a laparotomy performed three months before due to an acute abdomen secondary to blunt abdominal trauma. A CT scan was requested that showed a retroperitoneal mass 7.5cm×6.6cm×7cm with infiltration of the duodenal wall. Endoscopy was performed, which reported a duodenal ulcer with nonconclusive histological findings. A percutaneous biopsy was obtained out and a diagnosis of a neuroendocrine tumor was made. Chemotherapy was started because infiltration of the portomesenteric axis was suspected. The patient presented signs of toxicity during his third cycle and therefore was scheduled for exploratory laparotomy. Pancreatoduodenectomy was performed with a histologic diagnosis of a pancreatic neuroendocrine tumor.

DISCUSSION

The presentation of a NF-PNET is nonspecific. They continue to be tumors with a low incidence and few studies directed toward early detection and management have been carried out. Currently, CT scans are the studies most used for detection.

CONCLUSION

Surgical treatment is preferred in patients without evidence of unresectability with longer survival. The characteristics of NF-PNETs make their detection difficult and new strategies are needed for early detection and management. New studies in early stages with new cytotoxics or analogs are promising.

Therapy of metastatic pancreatic neuroendocrine tumors (pNETs): recent insights and advances

Neuroendocrine tumors (NETs) [carcinoids, pancreatic neuroendocrine tumors (pNETs)] are becoming an increasing clinical problem because not only are they increasing in frequency, but they can frequently present with advanced disease that requires diagnostic and treatment approaches different from those used in the neoplasms that most physicians are used to seeing and treating. In the past few years there have been numerous advances in all aspects of NETs including: an understanding of their unique pathogenesis; specific classification systems developed which have prognostic value; novel methods of tumor localization developed; and novel treatment approaches described. In patients with advanced metastatic disease these include the use of newer chemotherapeutic approaches, an increased understanding of the role of surgery and cytoreductive methods, the development of methods for targeted delivery of cytotoxic agents, and the development of targeted medical therapies (everolimus, sunitinib) based on an increased understanding of the disease biology. Although pNETs and gastrointestinal NETs share many features, recent studies show they differ in pathogenesis and in many aspects of diagnosis and treatment, including their responsiveness to different therapies. Because of limited space, this review will be limited to the advances made in the management and treatment of patients with advanced metastatic pNETs over the past 5 years.

[Surgery for neuroendocrine tumors of the gastroenteropancreatic system (GEP-NET)]

Surgical treatment is still the only curative treatment proven for patients with neuroendocrine tumors (NET) of the gastroenteropancreatic system. In addition to the therapy of incidental findings, the treatment of NET with variable aggressiveness and often good long-term prognosis requires a thorough preoperative assessment and a surgical procedure that is based on each individual case. Treatment can be surgery alone (if the disease is locally confined) or can be combined with other therapies. Early NET of the stomach and rectum can be cured endoscopically without further diagnostics, while early findings of the appendix can be treated by an appendectomy. Functionally active pancreatic NET and NET of the small intestine are often preoperatively diagnosed based on symptoms. Thus, it is possible to refer the patient to a NET center, if necessary. Stratification of the necessary treatment combination can be made early. An alternative to radical surgical treatment is the operative reduction of the tumor size and hormone production in metastasized NET, which can lead to improved life expectancy and quality of life. Combination with other treatment forms is absolutely necessary in these patients. It has been proven useful to divide the large group of NET based on the different tumor locations, hormone activity, and the degree of differentiation of the tumor. Early forms, locoregionally limited tumor stages, and tumor stages with distant metastases are considered separately.

Rate of clinically significant postoperative pancreatic fistula in pancreatic neuroendocrine tumors

BACKGROUND

In 2005, the International Study Group of Pancreatic Fistula (ISGPF) developed a definition and grading system for postoperative pancreatic fistula (POPF). The authors sought to determine the rate of POPF after enucleation and/or resection of pancreatic neuroendocrine tumors (PNET) and to identify clinical, surgical, or pathologic factors associated with POPF.

METHODS

A retrospective analysis of pancreatic enucleations and resections performed from March 1998 to April 2010. We defined a clinically significant POPF as a grade B that required nonoperative intervention and grade C.

RESULTS

One hundred twenty-two patients were identified; 62 patients had enucleations and 60 patients had resections of PNET. The rate of clinically significant POPF was 23.7 % (29/122). For pancreatic enucleation, the POPF rate was 27.4 % (17/62, 14 grade B, 3 grade C). The pancreatic resection group had a POPF rate of 20 % (12/60, 10 grade B, 2 grade C). This difference was not significant (p = 0.4). In univariate analyses, patients in the enucleation group with hereditary syndromes (p = 0.02) and non-insulinoma tumors (p = 0.02) had a higher POPF rate. Patients in the resection group with body mass index (BMI) > 25 (p < 0.01), multiple endocrine neoplasia type 1 (MEN-1; p < 0.01) and those who underwent simultaneous multiple procedures (p = 0.02) had a higher POPF rate. Multivariate analyses revealed that hereditary syndromes were able to predict POPF in the enucleation group, while having BMI > 25 and increasing lesion size were also associated with POPF in the group undergoing resection.

CONCLUSIONS

We found a clinically significant POPF rate after surgery in PNET to be 23.7 % with no difference by the type of operation. Our POPF rate is comparable to that reported in the literature for pancreatic resection for other types of tumors. Certain inherited genetic diseases-von Hippel-Lindau disease (VHL) and MEN-1-were associated with higher POPF rates.