Comprehensive genomic and transcriptomic characterization of high-grade gastro-entero-pancreatic neoplasms.

BACKGROUND: High-grade gastro-entero-pancreatic neoplasms (HG GEP-NENs) can be stratified according to their morphology and Ki-67 values into three prognostic classes: neuroendocrine tumors grade 3 (NETs G3), neuroendocrine carcinomas with Ki-67 < 55% (NECs <55) and NECs with Ki-67 ≥ 55% (NECs ≥55). METHODS: We analyzed a cohort of 49 HG GEP-NENs by targeted Next-Generation Sequencing (TrueSight Oncology 500), RNA-seq, and immunohistochemistry for p53, Rb1, SSTR-2A, and PD-L1. RESULTS: Frequent genomic alterations affected TP53 (26%), APC (20%), KRAS and MEN1 (both 11%) genes. NET G3 were enriched in MEN1 (p = 0.02) mutations, while both NECs groups were enriched in TP53 (p = 0.001), APC (p = 0.002) and KRAS (p = 0.02) mutations and tumors with TMB ≥ 10 muts/Mb (p = 0.01). No differentially expressed (DE) gene was found between NECs <55% and NECs ≥55%, while 1129 DE genes were identified between NET G3 and NECs. A slight enrichment of CD4+ and CD8+ T cells in NECs and of cancer-associated fibroblasts and macrophages (M2-like) in NET G3. Multivariate analysis identified histologic type and Rb1 loss as independent prognostic factors for overall survival. CONCLUSIONS: This study showed that GEP-NET G3 and GEP-NECs exhibit clear genomic and transcriptomic differences, differently from GEP-NECs <55% and GEP-NECs ≥55%, and provided molecular findings with prognostic and potentially predictive value.

NALIRIFOX, FOLFIRINOX, and Gemcitabine With Nab-Paclitaxel as First-Line Chemotherapy for Metastatic Pancreatic Cancer: A Systematic Review and Meta-Analysis.

Importance: The NAPOLI 3 trial showed the superiority of fluorouracil, leucovorin, liposomal irinotecan, and oxaliplatin (NALIRIFOX) over the combination of gemcitabine and nab-paclitaxel (GEM-NABP) as first-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC). Analyses comparing NALIRIFOX and GEM-NABP with fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) have not yet been reported. Objective: To derive survival, response, and toxic effects data from phase 3 clinical trials and compare NALIRIFOX, FOLFIRINOX, and GEM-NABP. Data Sources: After a systematic search of PubMed, Scopus, Embase, and American Society of Clinical Oncology and European Society for Medical Oncology meetings' libraries, Kaplan-Meier curves were extracted from phase 3 clinical trials conducted from January 1, 2011, until September 12, 2023. Study Selection: Phase 3 clinical trials that tested NALIRIFOX, FOLFIRINOX, or GEM-NABP as first-line treatment of metastatic PDAC and reported overall survival (OS) and progression-free survival (PFS) curves were selected. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses of Individual Participant Data reporting guidelines. Data Extraction And Synthesis: Individual patient OS and PFS data were extracted from Kaplan-Meier plots of original trials via a graphic reconstructive algorithm. Overall response rates (ORRs) and grade 3 or higher toxic effects rates were also collected. A pooled analysis was conducted, and results were validated via a network meta-analysis. Main Outcomes and Measures: The primary end point was OS. Secondary outcomes included PFS, ORR, and toxic effects rates. Results: A total of 7 trials with data on 2581 patients were analyzed, including 383 patients treated with NALIRIFOX, 433 patients treated with FOLFIRINOX, and 1756 patients treated with GEM-NABP. Median PFS was longer in patients treated with NALIRIFOX (7.4 [95% CI, 6.1-7.7] months) or FOLFIRINOX (7.3 [95% CI, 6.5-7.9] months; [HR], 1.21 [95% CI, 0.86-1.70]; P = .28) compared with patients treated with GEM-NABP (5.7 [95% CI, 5.6-6.1] months; HR vs NALIRIFOX, 1.45 [95% CI, 1.22-1.73]; P < .001). Similarly, GEM-NABP was associated with poorer OS (10.4 [95% CI, 9.8-10.8]; months) compared with NALIRIFOX (HR, 1.18 [95% CI, 1.00-1.39]; P = .05], while no difference was observed between FOLFIRINOX (11.7 [95% CI, 10.4-13.0] months) and NALIRIFOX (11.1 [95% CI, 10.1-12.3] months; HR, 1.06 [95% CI, 0.81-1.39]; P = .65). There were no statistically significant differences in ORR among NALIRIFOX (41.8%), FOLFIRINOX (31.6%), and GEM-NABP (35.0%). NALIRIFOX was associated with lower incidence of grade 3 or higher hematological toxic effects (eg, platelet count decreased 1.6% vs 11.8% with FOLFIRINOX and 10.8% with GEM-NABP), but higher rates of severe diarrhea compared with GEM-NABP (20.3% vs 15.7%). Conclusions and Relevance: In this systematic review and meta-analysis, NALIRIFOX and FOLFIRINOX were associated with similar PFS and OS as first-line treatment of advanced PDAC, although NALIRIFOX was associated with a different toxicity profile. Careful patient selection, financial toxic effects consideration, and direct comparison between FOLFIRINOX and NALIRIFOX are warranted.

Safety and antitumor activity of metformin plus lanreotide in patients with advanced gastro-intestinal or lung neuroendocrine tumors: the phase Ib trial MetNET2.

In retrospective studies, metformin use has been associated with better clinical outcomes in diabetic patients with advanced, well-differentiated neuroendocrine tumors (WDNETs). However, prospective evidence of metformin safety and activity is lacking. Here, we conducted the first-in-human phase Ib MetNET2 trial to investigate the safety and antitumor activity of metformin in combination with the somatostatin analog lanreotide autogel (ATG) in both diabetic and non-diabetic patients with advanced WDNETs of the gastrointestinal (GI) or thoracic tract. Enrolled patients received lanreotide ATG 120 mg plus oral metformin, up to a maximum dosage of 2550 mg/day. We enrolled 20 patients, of whom 18 (90%) and 2 (10%) had WDNETs of the GI and thoracic tract, respectively. Fourteen patients (70%) were non-diabetic. With a 5% incidence of SAEs, the study met its primary objective of demonstrating treatment safety. With a median follow-up of 39 months (95% CI 28-NE), median PFS was 24 months (95% CI 16-NE), with 12-month and 24-month PFS probability of 75% (95% CI 58-97) and 49% (95% CI 31-77), respectively. We found no statistically significant PFS differences between diabetic and non-diabetic patients. Among exploratory analyses, the presence of tumor genomic alterations in DNA damage pathways was associated with trend towards worse PFS, whereas a precocious reduction of HOMA-IR index and plasma cholesterol concentration showed a trend towards an association with better PFS. In conclusion, metformin plus lanreotide ATG is a safe and well tolerated combination treatment that is associated with promising antitumor activity in both non-diabetic and diabetic patients with WDNETs, and that warrants further investigation in larger clinical trials.

The Role of Liver Transplantation in the Treatment of Liver Metastases from Neuroendocrine Tumors.

OPINION STATEMENT: Transplant oncology is a new field of medicine referred to the use of solid organ transplantation, particularly the liver, to improve prognosis and quality of life in cancer patients. In unresectable, liver-only metastases from neuroendocrine tumors (NETs) of the digestive tract, liver transplantation represents a competitive chance of cure. Due to the limited resource of donated organs, accurate patients' selection is crucial in order to maximize transplant benefit. Several tumor- and patient-related factors should be considered. Among them, primary tumors with a low grade of differentiation (G1-G2 or Ki67 < 10%), located in a region drained by the portal system and removed before transplantation with at least 3-6 months period of disease stability observed before transplant listing, can be considered for transplantation. In case of NET located in the pancreas, extended lymphadenectomy should complement curative pancreatic resection. A number of other features are described in this review of liver transplantation for NET metastases. Comprehensive approach including various forms of non-surgical treatment and detailed planning and timing of total hepatectomy are discussed. Open issues remain on possible expansion of current criteria while maintaining the same long-term benefit demonstrated with the Milan NET criteria with respect to other non-transplant options, with particular reference to liver resection, peptide receptor radionuclide therapy, and locoregional and systemic treatments.

Multidisciplinary Approach to the Diagnosis of Occult Primary Neuroendocrine Neoplasm: A Clinical Challenge.

Approximately 11% to 14% of subjects with neuroendocrine neoplasms (NENs) have metastatic lesions with unknown primary origin (UPO), with the majority of UPO-NENs found in the small bowel. Herein, we assessed the available literature on UPO-NENs, focusing on clinical presentation and diagnostic techniques to identify the primary site. The identification of the primary tumor is important as it affects the prognosis; however, the clinical presentation can be non-specific in non-functioning forms. In the presence of metastatic disease, the histological sample is fundamental to obtain immunohistochemical markers that might orientate the clinician in the search for the primary tumor through radiology, functional imaging and endoscopic techniques. In summary, multidisciplinary management plays a key role in UPO-NENs, even more than in other NENs. Molecular biology and gene-expression profiling represent areas of great interest which might be developed in the near future for both the diagnosis and the treatment of these neoplasms.

Assessing the safety and activity of cabozantinib combined with lanreotide in gastroenteropancreatic and thoracic neuroendocrine tumors: rationale and protocol of the phase II LOLA trial.

BACKGROUND: Well-differentiated (WD) neuroendocrine tumors (NETs) are a group of rare neoplasms with limited therapeutic options. Cabozantinib is an inhibitor of multiple tyrosine kinases with a pivotal role in NET pathogenesis, including c-MET and Vascular Endothelial Growth Factor Receptor 2 (VEGFR2). LOLA is the first prospective phase II trial aiming to assess the safety and activity of cabozantinib combined with lanreotide in WD NETs of gastroenteropancreatic (GEP), thoracic and of unknown origin. METHODS: This is a multicenter, open-label, double-cohort, non comparative, non-randomized, three-stage phase II trial. Eligible patients have to meet the following inclusion criteria: diagnosis of advanced or metastatic, progressive, non-functioning WD thoracic NETs, GEP-NETs or NETs of unknown origin with Ki67 ≥ 10%; positive 68 Ga-PET uptake or somatostatin receptor 2 immunohistochemical (IHC) stain; maximum 1 prior systemic regimen for metastatic disease. Two cohorts will be considered: pNETs and carcinoids (typical or atypical lung and thymus NETs, gastro-intestinal NETs or NETs of unknown origin). In stage I, the primary objective is to find the optimal dose of cabozantinib in combination with lanreotide and to evaluate the safety of the combination (percentage of patients experiencing grade 3-5 toxicities according to NCI-CTCAE version 5.0). Starting dose of cabozantinib is 60 mg/day continuously, plus lanreotide 120 mg every 28 days. In stage II and III, co-primary endpoints are safety and overall response rate (ORR) according to RECIST version 1.1. The uninteresting antitumor activity is fixed in ORR ≤ 5%. Secondary endpoints are progression-free survival and overall survival. Exploratory objectives include the assessment of c-MET, AXL and VEGFR2 IHC expression, to identify predictive or prognostic tissue biomarkers. Enrolment started in July 2020, with an expected trial duration of 42 months comprehensive of accrual, treatment and follow-up. Considering a drop-out rate of 5%, the maximum number of enrolled patients will be 69. DISCUSSION: Supported by a solid rationale, the trial has the potential to generate milestone data about the synergistic effects of cabozantinib plus lanreotide in a group of NET patients with relatively aggressive disease and limited therapeutic options. TRIAL REGISTRATION: LOLA is registered at ClinicalTrials.gov (NCT04427787) and EudraCT (2019-004506-10).

Long-term outcomes of resection versus transplantation for neuroendocrine liver metastases meeting the Milan criteria.

Liver resection (LR) is considered the treatment of choice for resectable neuroendocrine liver metastases (NELM), while liver transplantation (LT) is currently reserved for highly selected unresectable patients. We retrospectively analyzed data from consecutive patients undergoing either curative resection or transplantation for liver-only NELM meeting Milan criteria at a single center between 1984 and 2019. Patients who fit Milan criteria were 48 in the transplantation group and 56 in the resection group. After a median follow-up of 158 months for the transplantation group and 126 for the resection group, the 10-year survival rate was 93% for transplantation and 75% for resection (p = .007). The 10-year disease-free survival rate was 52% for transplantation and 18% for resection (p < .001). Transplantation was associated with improved survival at univariate analysis. The median disease-free interval between surgery and recurrence was 78 months for transplantation vs. 24 months for resection (p < .001). The transplantation group had more multisite recurrences (12/25, 48% vs. 5/42, 12% in the resection group, p = .001), while most recurrences in the resection group were intra-hepatic (37/42, 88%, versus 2/25, 8% in the transplantation group). In conclusion, LT was associated with improved survival outcomes in NELM meeting the Milan criteria compared with LR.

Metastatic pheochromocytomas and paragangliomas: where are we?

Pheochromocytomas and paragangliomas (PPGLs) can metastasize in approximately 15-20% of cases. This review discusses the available evidence on the biology and treatment of metastatic PPGLs. Chemotherapy is the first-line treatment option for this evolving and symptomatic disease. In patients with high MIBG uptake and positive PETGa-68, radiometabolic treatment may be considered. The efficacy of sunitinib has been shown in observational studies, and pembrolizumab has been evaluated in phase II clinical studies, while other agents investigated in this setting are anti-angiogenic drugs cabozantinib, dovitinib, axitinib and lenvatinib. As these agents' efficacy and safety data, alone or in combination, are scant and based on few treated patients, enrollment in clinical trials is mandatory. Future therapeutic options may be represented by DNA repair system inhibitors (such as olaparib), HIF2 inhibitors and immunotherapy.

Gastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies.

Zollinger-Ellison syndrome (ZES) associated with pancreatic or duodenal gastrinoma is characterized by gastric acid hypersecretion, which typically leads to gastroesophageal reflux disease, recurrent peptic ulcers, and chronic diarrhea. As symptoms of ZES are nonspecific and overlap with other gastrointestinal disorders, the diagnosis is often delayed with an average time between the onset of symptoms and final diagnosis longer than 5 years. The critical step for the diagnosis of ZES is represented by the initial clinical suspicion. Hypergastrinemia is the hallmark of ZES; however, hypergastrinemia might recognize several causes, which should be ruled out in order to make a final diagnosis. Gastrin levels > 1000 pg/mL and a gastric pH below 2 are considered to be diagnostic for gastrinoma; some specific tests, including esophageal pH-recording and secretin test, might be useful in selected cases, although they are not widely available. Endoscopic ultrasound is very useful for the diagnosis and the local staging of the primary tumor in patients with ZES, particularly in the setting of multiple endocrine neoplasia type 1. Some controversies about the management of these tumors also exist. For the localized stage, the combination of proton pump inhibitory therapy, which usually resolves symptoms, and surgery, whenever feasible, with curative intent represents the hallmark of gastrinoma treatment. The high expression of somatostatin receptors in gastrinomas makes them highly responsive to somatostatin analogs, supporting their use as anti-proliferative agents in patients not amenable to surgical cure. Other medical options for advanced disease are super-imposable to other neuroendocrine neoplasms, and studies specifically focused on gastrinomas only are scant and often limited to case reports or small retrospective series. The multidisciplinary approach remains the cornerstone for the proper management of this composite disease. Herein, we reviewed available literature about gastrinoma-associated ZES with a specific focus on differential diagnosis, providing potential diagnostic and therapeutic algorithms.

Case Report: Exceptional Response to Avelumab After Failure of Electrochemotherapy in a Patient With Rapidly Progressive, PD-L1-Negative Merkel Cell Carcinoma.

This case report shows, for the first time, a patient experiencing a complete response after one dose of avelumab following extensive disease progression with prior electrochemotherapy (ECT) treatment. We suggest that ECT may help to establish a tumor microenvironment favorable to immunotherapy. Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with seldom durable chemotherapy responses. ECT has recently emerged as a potential treatment option for several malignancies, including MCC. Avelumab, an anti-programmed cell death-ligand 1 (PD-L1) monoclonal antibody, became the first approved treatment for patients with metastatic MCC. ECT has been shown to activate the immune response, but it is still unknown how ECT may affect patient's response to subsequent immunotherapy. We report a case of a patient with MCC who presented with a rapidly growing skin nodule of the right cheek and experienced extensive disease progression following surgical debulking and ECT treatment. The patient received a flat dose of 800 mg avelumab intravenously every 2 weeks showing complete tumor regression after only one dose. Immunohistochemical analysis of surgical and post-ECT biopsies collected from the primary lesion revealed tumor expression of programmed cell death protein-1 (PD-1), but not PD-L1. Analysis of the tumor samples also revealed no expression of Merkel cell polyomavirus (MCPyV). Comparison of the biopsies showed a decrease in myeloid and T-cell markers after ECT but an increase in major histocompatibility complex (MHC) class I expression on tumor cells. Additionally, the patient experienced an increase in neutrophil-to-lymphocyte ratio and lactate dehydrogenase values post-ECT, which subsequently decreased with avelumab treatment. As of 30 October 2019, the patient was still receiving avelumab treatment and had an ongoing complete response. In this case report, a patient with PD-L1-negative and MCPyV-negative MCC who had disease progression following ECT experienced complete tumor regression with avelumab treatment, suggesting, for the first time to our knowledge, that ECT may help to establish a tumor microenvironment favorable to immunotherapy via a potential abscopal effect. Tumor-intrinsic PD-1 expression and modulation of MHC class I antigens after ECT may contribute to the clinical efficacy of avelumab in this context.

Target therapies plus somatostatin analogs in NETs: a network meta-analysis.

Although combination therapy is not recommended in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs), this strategy is widely used in clinical practice. This network meta-analysis of randomized trials evaluates targeted therapies and somatostatin analogues in GEP-advanced NETs, either alone or in combination, comparing the efficacy of different, single or combined treatment strategies in terms of progression-free survival (PFS). Interventions were grouped as analogs, everolimus, everolimus plus SSAs, sunitinib and placebo. In a secondary analysis, we also assessed the efficacy of individual-specific pharmacological treatments vs placebo or each other. From 83 studies identified, 8 randomized controlled trials were selected, with a total of 1849 patients with either functioning or non-functioning NETs. The analysis confirmed the superiority of all treatments over placebo (HR ranging from 0.34, 95% CI: 0.24-0.37 with the combination of everolimus plus SSAs to 0.42, 0.31-0.57 with the analogs; moderate quality of evidence). On ranking analysis, the combination of everolimus plus SSA (P score = 0.86) and then everolimus alone (P score = 0.65) ranked highest in increasing PFS. On comparative evaluation of different interventions, pasireotide (P score = 0.96) and everolimus + octreotide (P score = 0.82) ranked as the best pharmacological treatment options. Our findings support the use of combination therapy in the treatment of functioning and non-functioning GEP NETs. The role of pasireotide should be explored in selected subgroups of patients. Lastly, the combination of everolimus and octreotide appears promising and should be more widely considered in clinical practice.

Postrecurrence Survival After Liver Transplantation for Liver Metastases From Neuroendocrine Tumors.

BACKGROUND: Liver metastases from neuroendocrine tumors (NETs) are 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 January 1, 2004, and December 31, 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 mo (interquartile range, 29.4-119.1 mo) 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-y survival after recurrence were 76.3% and 45.5%, respectively. Only time from LT to recurrence had a significant impact on postrecurrence survival, being 5-y overall survival 89.5% versus 0% for patients recurring >24 mo after LT versus ≤24 mo, respectively (P = 0.001). Moreover, for patients with Ki-67 monoclonal antibody staining >2% at recurrence, 5 y overall survival was 87.5% versus 0% for those undergoing surgery versus locoregional 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 mo). An aggressive surgical treatment might result in a new chance of cure for a selected subgroup of patients.

Recent Advances in the Management of Typical and Atypical Lung Carcinoids.

Neuroendocrine neoplasms of the lung represent about 20% to 30% of all neuroendocrine tumors. On the basis of clinical and pathologic characteristics, 2 different categories of tumors may be defined: poorly differentiated neuroendocrine neoplasms, characterized by a high rate of recurrences and poor prognosis, and well-differentiated neuroendocrine neoplasms (typical carcinoids and atypical carcinoids), which generally display an indolent course. Lung carcinoids represent only 1% to 5% of all lung malignancies, but their incidence has significantly increased over the past 30 years. Surgery is the reference standard of treatment for lung carcinoids with locoregional disease. For advanced or unresectable lung carcinoids, several therapeutic options are available, but the choice should be shared within a multidisciplinary team to ensure optimal therapeutic outcomes. We describe the current management of these rare neoplasms.

Resection of Retro-Hepatic Vena Cava (RHVC) En-bloc with Caudate Lobe without Vascular Exclusion for a Low Grade Leiomyosarcoma of Inferior Vena Cava.

BACKGROUND: Leiomyosarcomas (LMS) of the inferior vena cava (IVC) originate in the retrohepatic (RHVC) portion in 15% of cases.1 Due to complex anatomy and need to preserve venous outflow from the infra-diaphragmatic viscera, the operation may require total vascular exclusion, veno-venous bypass and hypothermic liver resections.2,3 In this video, virtual planning of the operation allowed a parenchyma-sparing radical resection in a patient with limited liver reserve. METHODS: A 12-cm LMS of RHVC invading the entire segment 1 (i.e., Spiegel's lobe, paracaval portion, and caudate process) was diagnosed in a man with metabolic steato-hepatitis (BMI: 34). He had no response to previous chemotherapy. Major hepatectomy was excluded considering the high risk of postoperative liver failure. 3D-reconstruction of regional anatomy allowed planning of a parenchymal-sparing, en bloc resection of tumor, RHVC, and caudate lobe while avoiding hilar and suprahepatic venous clamping. RESULTS: The operation strategy relied on the en bloc separation of caudate lobe, RHVC, and tumor from the hepatic veins confluence and the posterior segments after complete mobilization of the liver. Vessel loop-assisted hanging maneuver, encircling tumor, and RHVC with superimposed 3D-reconstructions guided the parenchymal transection, while preserving the middle hepatic vein outflow. RHVC was replaced with prosthetic material. CONCLUSIONS: Complex resection of primary tumor of the IVC en bloc with caudate lobe and RHVC can be attempted in chronic liver diseases at-risk of postoperative failure. Preservations of transhepatic flow and liver function depends on tumor size and preservation of noninvaded hepatic-veins confluence. Preoperative virtual 3D reconstruction is crucial in surgical planning.

Impact of Diabetes and Metformin Use on Enteropancreatic Neuroendocrine Tumors: Post Hoc Analysis of the CLARINET Study.

The prognostic role of diabetes mellitus (DM) in advanced enteropancreatic neuroendocrine tumors (NETs) is unclear. Progression free survival (PFS) was assessed in post-hoc analyses of the 96-week, phase III, double-blind, placebo-controlled CLARINET study of lanreotide 120 mg in patients with advanced non-functional enteropancreatic NETs with DM (with/without metformin) and without DM. Of 204 patients, there were 79 with DM (lanreotide, n = 42 {metformin, n = 14}; placebo, n = 37 {metformin, n = 10}) and 125 without DM (lanreotide, n = 59; placebo, n = 66). Median PFS was 96.0 and 98.0 weeks with and without DM, respectively (hazard ratio 1.20 {95% confidence interval 0.79 to 1.82}; p = 0.380). No difference in PFS was observed in lanreotide-treated patients with/without DM (p = 0.8476). In the placebo group, median PFS was numerically shorter with versus without DM (p = 0.052) and was significantly longer in patients with DM and metformin (85.7 weeks) versus without metformin (38.7 weeks; p = 0.009). Multivariable Cox analyses showed that DM at baseline was not associated with PFS (p = 0.079); lanreotide was significantly associated with lower disease progression risk (p = 0.017). Lanreotide efficacy was confirmed in patients with advanced enteropancreatic NETs, regardless of diabetic status; DM was not a negative prognostic factor. A potential antitumor effect of metformin was observed in patients receiving placebo.

One size does not fit all for pancreatic cancers: A review on rare histologies and therapeutic approaches.

Exocrine pancreatic neoplasms represent up to 95% of pancreatic cancers (PCs) and are widely recognized among the most lethal solid cancers, with a very poor 5-year survival rate of 5%-10%. The remaining < 5% of PCs are neuroendocrine tumors that are usually characterized by a better prognosis, with a median overall survival of 3.6 years. The most common type of PC is pancreatic ductal adenocarcinoma (PDAC), which accounts for roughly 85% of all exocrine PCs. However up to 10% of exocrine PCs have rare histotypes, which are still poorly understood. These subtypes can be distinguished from PDAC in terms of pathology, imaging, clinical presentation and prognosis. Additionally, due to their rarity, any knowledge regarding these specific histotypes is mostly based on case reports and a small series of retrospective analyses. Therefore, treatment strategies are generally deduced from those used for PDAC, even if these patients are often excluded or not clearly represented in clinical trials for PDAC. For these reasons, it is essential to collect as much information as possible on the management of PC, as assimilating it with PDAC may lead to the potential mistreatment of these patients. Here, we report the most significant literature regarding the epidemiology, typical presentation, possible treatment strategies, and prognosis of the most relevant histotypes among rare PCs.

Differential Diagnosis and Management of Diarrhea in Patients with Neuroendocrine Tumors.

Diarrhea is a recurrent symptom in patients with neuroendocrine tumors (NETs) and can represent different etiologies; thus, differential diagnosis is challenging. This paper distinguishes the different causes of chronic diarrhea in patients with gastroenteropancreatic NETs, with the aim to identify the most appropriate therapeutic approach. Underlying causes of diarrhea can be multifactorial, including not only diarrhea that is related to specific hormonal hypersecretory syndromes, but also diarrhea that is secondary to the following: extensive surgery which can cause pancreatic exocrine insufficiency or short bowel syndrome, treatment with somatostatin analogs or other antineoplastic agents, and bile acid malabsorption. After initial management of diarrhea with general treatments (dietary modification, use of antidiarrheals), a proper differential diagnosis is necessary to treat patients with specific etiology-driven therapeutic approaches, such as somatostatin analogs, pancreatic enzyme replacement therapy, and tryptophan hydroxylase inhibitors. In conclusion, NETs should be considered in the differential diagnosis of patients suffering from chronic diarrhea, after the exclusion of more common etiologies. Furthermore, physicians should keep in mind that several different etiologies might be responsible for diarrhea occurrence in NET patients. A prompt diagnosis of the actual cause of diarrhea is necessary to guide the treatment and a multidisciplinary approach is mandatory.

The potential role of metformin in the treatment of patients with pancreatic neuroendocrine tumors: a review of preclinical to clinical evidence.

The incidence of pancreatic neuroendocrine tumors (panNETs) has increased worldwide in the last two decades. Given the indolent nature of these tumors, several patients are diagnosed with metastatic disease, which partially impairs the long-term efficacy of currently available treatments and reduces survival rates. The search for new therapeutic strategies for cancer patients has pushed towards the retrospective analysis of studies involving patients who concomitantly received other drugs together with standard anticancer agents. In this light, several retrospective analyses have shown that metformin use is associated with improved prognosis in patients with different tumor types treated with standard antitumor agents. Metformin, the cornerstone oral agent for the treatment of type 2 diabetes, plays a role in modulating glucose cell metabolism. Its potential ability to interfere with tumors may derive from the tight relationship between metabolic reprogramming in cancer cells and tumor progression. Indications for metformin use as an anticancer drug result from pre-clinical and clinical observations. In particular, metformin use in diabetic patients with advanced panNETs has been associated with better progression-free survival in patients treated with somatostatin analogues with or without metformin.

Management of Asymptomatic Sporadic Nonfunctioning Pancreatic Neuroendocrine Neoplasms (ASPEN) ≤2 cm: Study Protocol for a Prospective Observational Study.

Introduction: The optimal treatment for small, asymptomatic, nonfunctioning pancreatic neuroendocrine neoplasms (NF-PanNEN) is still controversial. European Neuroendocrine Tumor Society (ENETS) guidelines recommend a watchful strategy for asymptomatic NF-PanNEN <2 cm of diameter. Several retrospective series demonstrated that a non-operative management is safe and feasible, but no prospective studies are available. Aim of the ASPEN study is to evaluate the optimal management of asymptomatic NF-PanNEN ≤2 cm comparing active surveillance and surgery. Methods: ASPEN is a prospective international observational multicentric cohort study supported by ENETS. The study is registered in ClinicalTrials.gov with the identification code NCT03084770. Based on the incidence of NF-PanNEN the number of expected patients to be enrolled in the ASPEN study is 1,000 during the study period (2017-2022). Primary endpoint is disease/progression-free survival, defined as the time from study enrolment to the first evidence of progression (active surveillance group) or recurrence of disease (surgery group) or death from disease. Inclusion criteria are: age >18 years, the presence of asymptomatic sporadic NF-PanNEN ≤2 cm proven by a positive fine-needle aspiration (FNA) or by the presence of a measurable nodule on high-quality imaging techniques that is positive at 68Gallium DOTATOC-PET scan. Conclusion: The ASPEN study is designed to investigate if an active surveillance of asymptomatic NF-PanNEN ≤2 cm is safe as compared to surgical approach.