Management of Functional Pancreatic Neuroendocrine Neoplasms.

OPINION STATEMENT: Functional pancreatic neuroendocrine neoplasms (pNENs) are rare and heterogeneous diseases in terms of both clinical and pathological aspects. These tumors secrete hormones or peptides, which may cause a wide variety of symptoms related to a clinical syndrome. The management of functional pNENs is still challenging for clinicians due to the need to control both tumor growth and specific symptoms. Surgery remains the cornerstone in the management of local disease because it can definitively cure the patient. However, when the disease is not resectable, a broad spectrum of therapeutic options, including locoregional therapy, somatostatin analogs (SSAs), targeted therapies, peptide-receptor radionuclide therapy (PRRT), and chemotherapy, are available. The present review summarizes the main key issues regarding the clinical management of these tumors, providing a specific highlight on their therapeutic approach.

Survival after active surveillance versus upfront surgery for incidental small pancreatic neuroendocrine tumours.

BACKGROUND: The safety of observing small non-functioning pancreatic neuroendocrine tumours (NF-Pan-NETs) remains under debate. METHODS: This was a multicentre retrospective study of patients with small incidental NF-Pan-NETs. Survival of patients who underwent upfront surgery versus active surveillance was compared. The risk of death was matched with that in the healthy population. The excess hazard rate and probability of a normal lifespan (NLP) were calculated. Propensity score matching (PSM) with a 1 : 1 ratio was used to minimize the risk of selection bias. RESULTS: Some 222 patients (43.7 per cent) underwent upfront surgery and 285 (56.3 per cent) were observed. The excess hazard rate for the entire cohort was quantifiable as 0.04 (95 per cent c.i. 0 to 0.08) deaths per 1000 persons per year, and the NLP was 99.7 per cent. Patients in the active surveillance group were older (median age 65 versus 58 years; P < 0.001), and more often had co-morbidity (45.3 versus 24.8 per cent; P = 0.001), and smaller tumours (median 12 versus 13 mm; P < 0.001), less frequently located in the pancreatic body-tail (59.5 versus 69.6 per cent; P = 0.008, 59.3 versus 73.9 per cent; P = 0.001). Median follow-up was longer for patients who underwent upfront surgery (5.6 versus 2.7 years; P < 0.001). After PSM, 118 patients per group were included. The excess hazard rates were 0.2 and 0.9 deaths per 1000 persons per year (P = 0.020) for patients in the active surveillance and upfront surgery groups respectively. Corresponding NLPs were 99.9 and 99.5 per cent respectively (P = 0.011). CONCLUSION: Active surveillance of small incidental NF-Pan-NETs is a reasonable alternative to resection.

CT-based radiomics for prediction of therapeutic response to Everolimus in metastatic neuroendocrine tumors.

AIM: To test radiomic approach in patients with metastatic neuroendocrine tumors (NETs) treated with Everolimus, with the aim to predict progression-free survival (PFS) and death. MATERIALS AND METHODS: Twenty-five patients with metastatic neuroendocrine tumors, 15/25 pancreatic (60%), 9/25 ileal (36%), 1/25 lung (4%), were retrospectively enrolled between August 2013 and December 2020. All patients underwent contrast-enhanced CT before starting Everolimus, histological diagnosis, tumor grading, PFS, overall survival (OS), death, and clinical data collected. Population was divided into two groups: responders (PFS ≤ 11 months) and non-responders (PFS > 11 months). 3D segmentation was performed on whole liver of naïve CT scans in arterial and venous phases, using a dedicated software (3DSlicer v4.10.2). A total of 107 radiomic features were extracted and compared between two groups (T test or Mann-Whitney), radiomics performance assessed with receiver operating characteristic curve, Kaplan-Meyer curves used for survival analysis, univariate and multivariate logistic regression performed to predict death, and interobserver variability assessed. All significant radiomic comparisons were validated by using a synthetic external cohort. P < 0.05 is considered significant. RESULTS: 15/25 patients were classified as responders (median PFS 25 months and OS 29 months) and 10/25 as non-responders (median PFS 4.5 months and OS 23 months). Among radiomic parameters, Correlation and Imc1 showed significant differences between two groups (P < 0.05) with the best performance (internal cohort AUC 0.86-0.84, P < 0.0001; external cohort AUC 0.84-0.90; P < 0.0001). Correlation < 0.21 resulted correlated with death at Kaplan-Meyer analysis (P = 0.02). Univariate analysis showed three radiomic features independently correlated with death, and in multivariate analysis radiomic model showed good performance with AUC 0.87, sensitivity 100%, and specificity 66.7%. Three features achieved 0.77 ≤ ICC < 0.83 and one ICC = 0.92. CONCLUSIONS: In patients affected by metastatic NETs eligible for Everolimus treatment, radiomics could be used as imaging biomarker able to predict PFS and death.

Bone Metastases in Neuroendocrine Tumors: Molecular Pathogenesis and Implications in Clinical Practice.

Skeletal colonization is often regarded as a rare event in patients with neuroendocrine tumors (NETs) although both national registries and retrospective series report an incidence of bone metastases as high as 20% in subjects with advanced disease. While the biological mechanisms leading to bone metastatic colonization in NETs have been poorly investigated so far, key steps of osteotropic mechanisms, including the epithelial-to-mesenchymal transition, preparation of the premetastatic niche, migration of circulating tumor cells towards the bone marrow as well as the resulting alterations of the skeletal metabolism, are likely to operate also during the development of NET bone metastases. The skeleton involvement by NETs has a detrimental impact on both quality of life and patients' prognosis, leading to pain in the majority of symptomatic subjects. While it is currently unclear whether or not the earlier recognition of bone involvement by PET/CT imaging techniques employing 68Ga-DOTA-conjugated peptides might improve outcomes through the exploitation of timely treatments, the management of bone-colonizing NETs is today based only on clinical experience from other osteotropic tumors. Here, we summarize the fundamental molecular mechanisms driving bone colonization and revisit both established and novel treatments for patients with bone metastatic NETs.

MYC Upregulation Confers Resistance to Everolimus and Establishes Vulnerability to Cyclin-Dependent Kinase Inhibitors in Pancreatic Neuroendocrine Neoplasm Cells.

INTRODUCTION: Dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1)-dependent pathways in pancreatic neuroendocrine neoplasms (PanNENs) underlies the introduction of the mTORC1 inhibitor everolimus as treatment of advanced progressive PanNENs. Although everolimus significantly increases progression-free survival, most patients acquire secondary resistance to the drug. This study aimed at identifying mechanisms involved in acquisition of resistance to everolimus. METHODS: BON-1 and everolimus-resistant (ER) BON-1 cells were used as in vitro system of sensitivity and acquired resistance. Transcriptome changes occurring in BON-1 and ER-BON-1 were investigated by RNA sequencing and validated by quantitative PCR analysis. RNA extracted from patients' biopsies was used to validate MYC upregulation. Drug screening and functional assays were performed using ER-BON-1 cells. Cell cycle progression was evaluated by FACS analysis. RESULTS: Our results show that MYC overexpression is a key event in the development of secondary resistance to everolimus in PanNEN cell lines and in metastatic lesions from neuroendocrine neoplasm patients. MYC knockdown restored ER-BON-1 sensitivity to everolimus. Pharmacological inhibition of MYC mediated by the cyclin-dependent kinase inhibitor dinaciclib strongly reduced viability of ER-BON-1. Dinaciclib synergized with everolimus and inhibited ER-BON-1 cell cycle progression. DISCUSSION: Our findings suggest that MYC upregulation drives the development of secondary resistance to everolimus in PanNENs and that its inhibition is an exploitable vulnerability. Indeed, our results indicate that combined treatments with cyclin-dependent kinase and mTOR inhibitors may counteract secondary resistance to everolimus in PanNENs and may pave the ground for new therapeutic regimens for these tumors.

Morphological Factors Related to Nodal Metastases in Neuroendocrine Tumors of the Appendix: A Multicentric Retrospective Study.

OBJECTIVE: The aim of this study was to evaluate clinical and morphological features related to nodal involvement in appendiceal neuroendocrine tumors (NETs), to identify patients who should be referred for oncological radicalization with hemicolectomy. BACKGROUND: Appendiceal NETs are usually diagnosed accidentally after appendectomy; the indications for right hemicolectomy are currently based on several parameters (ie, tumor size, grading, proliferative index, localization, mesoappendiceal invasion, lymphovascular infiltration). Available guidelines are based on scarce evidence inferred by small, retrospective, single-institution studies, resulting in discordant recommendations. METHODS: A retrospective analysis of a prospectively collected database was performed. Patients who underwent surgical resection of appendiceal NETs at 11 tertiary Italian centers, from January 1990 to December 2015, were included. Clinical and morphological data were analyzed to identify factors related to nodal involvement. RESULTS: Four-hundred fifty-seven patients were evaluated, and 435 were finally included and analyzed. Of them, 21 had nodal involvement. Grading G2 [odds ratio (OR) 6.04], lymphovascular infiltration (OR 10.17), size (OR 18.50), and mesoappendiceal invasion (OR 3.63) were related to nodal disease. Receiver operating characteristic curve identified >15.5 mm as the best size cutoff value (area under the curve 0.747). On multivariate analysis, grading G2 (OR 6.98), lymphovascular infiltration (OR 8.63), and size >15.5 mm (OR 35.28) were independently related to nodal involvement. CONCLUSIONS: Tumor size >15.5 mm, grading G2, and presence of lymphovascular infiltration are factors independently related to nodal metastases in appendiceal NETs. Presence of ≥1 of these features should be considered an indication for oncological radicalization. Although these results represent the largest study currently available, prospective validation is needed.

Biliary Stone Disease in Patients with Neuroendocrine Tumors Treated with Somatostatin Analogs: A Multicenter Study.

BACKGROUND: Somatostatin analogs (SSAs) are the mainstay of neuroendocrine tumor (NET) treatment. Biliary stone disease is reported as a common side effect of SSAs, with a frequency ranging from 10% to 63%. Studies on SSA-treated patients for acromegaly report an increased incidence of biliary stone disease compared with the general population, whereas data on patients with NETs are few. Guidelines are based on weak evidence, thus resulting in conflicting recommendations. The aim of the study is to evaluate biliary stone disease incidence, complications, and risk factors in a large population of SSA-treated patients with NETs. MATERIALS AND METHODS: A retrospective analysis of a prospectively collected database was performed. Patients with a diagnosis of NET in seven dedicated centers from 1995 to 2017 were included at the time of SSA start. RESULTS: A total of 754 SSA-treated patients were evaluated. Patients with history of cholecystectomy or with known biliary stone disease were excluded; 478 patients were included. Among them, 118 patients (24.7%) received prophylactic ursodeoxycholic acid (UDCA). During the study period, 129 patients (27.0%) developed biliary stone disease; of them, 36 (27.9%) developed biliary complications. On multivariate analysis, primary gastrointestinal (GI)-NET (hazard ratio [HR] 1.76) and related surgery (HR 1.58) were independent risk factors for biliary stone disease. CONCLUSION: We report a high incidence of biliary stone disease particularly in GI-NET or GI surgery. UDCA prophylaxis does not seem to have a protective role. Our data suggest that all patients with primary GI-NET or undergoing abdominal surgery should be considered for prophylactic cholecystectomy; no conclusion could be drawn on the indication of prophylactic cholecystectomy in patients with primary pancreatic or thoracic NET for whom abdominal surgery is not planned. IMPLICATIONS FOR PRACTICE: The results of this study confirm an increased rate of gallstones development and related complications in patients with neuroendocrine tumors (NETs) treated with somatostatin analogs (SSAs). NETs of the gastrointestinal (GI) tract and related surgery are independent risk factors for biliary stone disease development. Therefore, all patients with primary GI-NET or undergoing abdominal surgery should be considered for prophylactic cholecystectomy. Data on other subgroups are not exhaustive, and management also evaluating additional clinical features (life expectancy, surgical and anesthesiological risks) should be considered. Prophylactic treatment with ursodeoxycholic acid does not seem to be a protective factor for SSA-related biliary stone disease.

Occurrence of exocrine pancreatic insufficiency in patients with advanced neuroendocrine tumors treated with somatostatin analogs.

BACKGROUND: Although exocrine pancreatic insufficiency (EPI) has been described in patients with neuroendocrine neoplasia (NEN) treated with somatostatin analogs (SSAs), its role in the therapeutic management of these patients is not well established. AIM: To determine the frequency of EPI in patients with NEN long-term treated with SSAs. METHODS: This is a prospective single-center study evaluating 35 patients treated with SSAs for >12 months due to unresectable/advanced nonpancreatic well-differentiated NEN. Clinical evaluation, biochemical parameters, and fecal elastases 1 (FE-1) were assessed to diagnose EPI. RESULTS: A total of 7 patients (20%) had EPI, given the presence of abdominal symptoms and a median FE-1 value of 180 mcg/g stool (150-198). No patient had severe EPI, defined as FE-1 < 100 mcg/g stool. Elevated glycated Hb levels were a significant predictor for developing EPI (OR 4.81, p = 0.01). No significant difference in terms of duration of SSA treatment was observed between patients with or without EPI diagnosed (84 months and 72 months, respectively; p = 0.950). CONCLUSIONS: Mild-moderate EPI is a relatively common condition in patients receiving long-term treatment with SSAs. Specific clinical and biochemical evaluations, including FE-1, should be planned in these patients to diagnose this relevant condition early, which may deteriorate quality of life and cause malnutrition.

Metformin Use Is Associated With Longer Progression-Free Survival of Patients With Diabetes and Pancreatic Neuroendocrine Tumors Receiving Everolimus and/or Somatostatin Analogues.

BACKGROUND & AIMS: Metformin seems to have anticancer effects. However, it is not clear whether use of glycemia and metformin affect outcomes of patients with advanced pancreatic neuroendocrine tumors (pNETs). We investigated the association between glycemia and progression-free survival (PFS) of patients with pNETs treated with everolimus and/or somatostatin analogues, as well as the association between metformin use and PFS time. METHODS: We performed a retrospective analysis of 445 patients with advanced pNET treated at 24 medical centers in Italy from 1999 through 2015. Data on levels of glycemia were collected at time of diagnosis of pNET, before treatment initiation, and during treatment with everolimus (with or without somatostatin analogues), octreotide, or lanreotide. Diabetes was defined as prior or current use of glycemia control medication and/or fasting plasma glucose level ≥ 126 mg/dL, hemoglobin A1c ≥ 6.5% (48 mmol/L), or a random sample of plasma glucose ≥ 200 mg/dL (11.1 mmol/L), with reported classic symptoms of hyperglycemia or hyperglycemic crisis. Patients were assigned to groups based on diagnosis of diabetes before or during antitumor therapy. PFS was compared between patients with vs without diabetes. Among patients with diabetes, the association between metformin use and PFS was assessed. We performed sensitivity and landmark analyses to exclude patients who developed diabetes while receiving cancer treatment and to exclude a potential immortal time bias related to metformin intake. RESULTS: PFS was significantly longer in patients with diabetes (median, 32.0 months) than without diabetes (median, 15.1 months) (hazard ratio for patients with vs without diabetes, 0.63; 95% confidence interval, 0.50-0.80; P = .0002). PFS of patients treated with metformin was significantly longer (median PFS, 44.2 months) than for patients without diabetes (hazard ratio for survival of patients with diabetes receiving metformin vs without diabetes, 0.45; 95% confidence interval, 0.32-0.62; P < .00001) and longer than for patients with diabetes receiving other treatments (median PFS, 20.8 months; hazard ratio, 0.49; 95% confidence interval, 0.34-0.69; P < .0001). In multivariable analysis, adjusted for other factors associated with outcomes, metformin was associated with longer PFS but level of glycemia was not. Metformin was associated with increased PFS of patients receiving somatostatin analogues and in those receiving everolimus, with or without somatostatin analogues. Sensitivity and landmark analyses produced similar results. CONCLUSIONS: In a retrospective study of patients with pNETs, we found a significant association between metformin use and longer PFS.

Prognostic impact of tumour burden in stage IV neuroendocrine neoplasia: A comparison between pancreatic and gastrointestinal localizations.

BACKGROUND: Although prognosis of NENs is affected by several features including tumour burden, the specific role of this factor in pancreatic NENs (PanNENs) and gastrointestinal NENs (GI NENs) is not well established. AIM: To compare the prognostic role of tumour burden in PanNENs and GI NENs. PATIENTS AND METHODS: This study was a retrospective analysis of stage IV PanNENs and GI NENs. Tumours were classified based on liver tumour volume (<25% or >25%). Overall survival as assessed by Kaplan-Meier curves, and Cox proportional hazards method was used to perform risk factor analysis. RESULTS: The analysis included 300 patients, including 166 panNENs (55.3%) and 134 GI NENs (44.7%). A total of 158 patients (52.7%) had G2 tumours, 107 had G1 tumours (35.7%), and 35 had G3 tumours (11.6%). Tumour liver involvement >25% was observed in 187 patients (62.3%): 106 PanNENs (56.7%), and 81 GI NENs (43.3%) (p = 0.551). Bone metastases were present in 45 patients (15%): 22 PanNENs (13.2%) and 23 GI NENs (17.1%) (p = 0.416). Characteristics of the PanNENs, including: grading (G2 vs G1, HR = 3.7; G3 vs G1, HR = 16.40), liver involvement > 25% (HR = 3.09), and bone metastases (HR = 2.27) were independent predictors for poor survival, whereas the only significant risk factor in GI NENs was grading (G2 vs G1, HR = 4.36; G3 vs G1, HR = 8.60). CONCLUSIONS: PanNENs and GI NENs have different risk profiles. Liver tumour volume and the presence of bone metastases significantly affect survival in patients with PanNENs but has no impact on the clinical outcomes of GI NENs.

Common genetic variants associated with pancreatic adenocarcinoma may also modify risk of pancreatic neuroendocrine neoplasms.

Pancreatic neuroendocrine neoplasms (pNEN) account for less than 5% of all pancreatic neoplasms and genetic association studies on susceptibility to the disease are limited. We sought to identify possible overlap of genetic susceptibility loci between pancreatic ductal adenocarcinoma (PDAC) and pNEN; therefore, PDAC susceptibility variants (n = 23) from Caucasian genome-wide association studies (GWAS) were genotyped in 369 pNEN cases and 3277 controls from the PANcreatic Disease ReseArch (PANDoRA) consortium to evaluate the odds associated with pNEN risk, disease onset and tumor characteristics. Main effect analyses showed four PDAC susceptibility variants-rs9854771, rs1561927, rs9543325 and rs10919791 to be associated with pNEN risk. Subsequently, only associations with rs9543325, rs10919791 and rs1561927 were noteworthy with false positive report probability (FPRP) tests. Stratified analyses considering age at onset (50-year threshold), showed rs2736098, rs16986825 and rs9854771 to be associated with risk of developing pNEN at a younger age. Stratified analyses also showed some single nucleotide polymorphisms to be associated with different degrees of tumor grade, metastatic potential and functionality. Our results identify known GWAS PDAC susceptibility loci, which may also be involved in sporadic pNEN etiology and suggest that some genetic mechanisms governing pathogenesis of these two entities may be similar, with few of these loci being more influential in younger cases or tumor subtypes.

Clinical Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography in the Diagnostic Algorithm of Advanced Entero-Pancreatic Neuroendocrine Neoplasms.

BACKGROUND: The role of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the diagnostic algorithm of entero-pancreatic neuroendocrine neoplasms (EP NENs) is unclear because most available data derive from heterogeneous populations in terms of tumor biology and disease status at time of examination. The aim of this study was to determine the ability of 18F-FDG PET to identify patients with more aggressive disease among those with advanced EP NENs. Subjects, Materials, and Methods . Patients with advanced EP NENs and known disease status (progressive disease [PD] or stable disease [SD]) according to imaging procedures, who received 18F-FDG PET and computed tomography scans during a time frame of 1 month, were included. RESULTS: A total of 93 patients, including 69 patients with pancreatic NENs and 24 patients with small-intestine NENs, were included. At the time of study entry, 64 patients (68.8%) had PD, and the remaining 29 patients (31.2%) had SD. A total of 62 patients (66.7%) had positive 18F-FDG PET, whereas 18F-FDG PET was negative in the remaining 31 patients (33.3%). Overall, 18F-FDG PET sensitivity and specificity to detect PD were 90.6% and 86.2%, respectively, resulting in a diagnostic accuracy of 89.2%. A positive 18F-FDG PET was significantly associated with PD at the time of study entry (p < .0001 at multivariate analysis). Although a higher proportion of 18F-FDG PET-positive examinations were observed in patients with higher tumor grade (p = .01), 53.8% of patients with grade 1 neuroendocrine tumors (NETs) had positive 18F-FDG PET, and 37.5% of patients with grade 2 NETs had negative 18F-FDG PET. Overall survival was significantly shorter in 18F-FDG PET-positive patients (median: 60 months) in comparison with 18F-FDG PET-negative patients (median not reached; p = .008). CONCLUSION: 18F-FDG PET has a high diagnostic accuracy to identify progression of disease with unfavorable clinical outcome in patients with advanced EP NENs. Knowledge of disease status and G grading are key factors for physicians to better select patients for whom 18F-FDG PET is clinically useful. IMPLICATIONS FOR PRACTICE: The findings of the present study may help physicians dealing with advanced neuroendocrine neoplasms to select patients for whom 18F-fluorodeoxyglucose positron emission tomography is useful to predict poor clinical outcome.

Heterogeneity of Duodenal Neuroendocrine Tumors: An Italian Multi-center Experience.

BACKGROUND: The optimal management of duodenal neuroendocrine neoplasms (dNENs) is unclear, and endoscopic resection is increasingly performed instead of surgery. METHODS: This is a retrospective analysis of patients with histologically confirmed diagnosis of dNENs, managed at five Italian tertiary referral Centers in Italy. RESULTS: From 2000 to 2017, 108 patients (69 males, 39 females, median age 59.5 years) were included in this study. Seventy-one patients had G1, 21 G2, 4 G3 dNENs (12 Ki-67 not available). Fifty-four patients showed metastases at diagnosis, and 20 patients developed metachronous metastases. Thirty patients had a functioning dNEN (14 metastatic). Fifty-seven patients had the dNEN surgically resected, 16 endoscopically, 23 metastatic, received medical therapy + surgery or endoscopy. Seven patients underwent liver-directed therapies, and one patient had PRRT. Median OS was 187 months. During a median follow-up of 76 months, 20 patients died (19 of disease-related causes). At Cox's multivariate proportional hazard regression, grading and age were the only variables independently related to OS. Median PFS was 170 months. Grading and staging at the initial diagnosis were independently related to PFS. No differences in terms of OS and PFS were observed between patients treated surgically or endoscopically. CONCLUSIONS: dNENs prognosis may be highly variable. These tumors can be metastatic in up to 50% of cases at the time of first diagnosis and can develop metastases thereafter. Functioning neoplasms express high metastatic potential. Nuclear imaging should be performed to exclude distant metastases in all dNENs. Endoscopy and surgery play a primary role in the management of the disease. Further prospective studies are needed.

Sunitinib in patients with pre-treated pancreatic neuroendocrine tumors: A real-world study.

INTRODUCTION: Besides data reported in a Phase-III trial, data on sunitinib in pancreatic Neuroendocrine Tumors (panNETs) are scanty. AIM: To evaluate sunitinib efficacy and tolerability in panNETs patients treated in a real-world setting. PATIENTS AND METHODS: Retrospective analysis of progressive panNETs treated with sunitinib. Efficacy was assessed by evaluating progression-free survival, overall survival, and disease control (DC) rate (stable disease (SD) + partial response + complete response). Data are reported as median (25th-75th IQR). RESULTS: Eighty patients were included. Overall, 71.1% had NET G2, 26.3% had NET G1, and 2.6% had NET G3 neoplasms. A total of 53 patients (66.3%) had received three or more therapeutic regimens before sunitinib, with 24 patients (30%) having been treated with four previous treatments. Median PFS was 10 months. Similar risk of progression was observed between NET G1 and NET G2 tumors (median PFS 11 months and 8 months, respectively), and between patients who had received ≥ 3 vs ≤ 2 therapeutic approaches before sunitinib (median PFS 9 months and 10 months, respectively). DC rate was 71.3% and SD was the most frequent observed response, occurring in 43 pts (53.8%). Overall, 59 pts (73.8%) experienced AEs, which were grade 1-2 in 43 of them (72.9%), grade 3 in 15 pts (25.4%), and grade 4 in one patient (1.7%). Six pts (7.5%) stopped treatment due to toxicity. CONCLUSIONS: The present real-world experience shows that sunitinib is a safe and effective treatment for panNETs, even in the clinical setting of heavily pre-treated, progressive diseases.

Competitive Testing of the WHO 2010 versus the WHO 2017 Grading of Pancreatic Neuroendocrine Neoplasms: Data from a Large International Cohort Study.

BACKGROUND: The World Health Organization (WHO) and the American Joint Cancer Committee (AJCC) modified the grading of pancreatic neuroendocrine neoplasms from a three-tier (WHO-AJCC 2010) to a four-tier system by introducing the novel category of NET G3 (WHO-AJCC 2017). OBJECTIVES: This study aims at validating the WHO-AJCC 2017 and identifying the most effective grading system. METHOD: A total of 2,102 patients were enrolled; entry criteria were: (i) patient underwent surgery; (ii) at least 2 years of follow-up; (iii) observation time up to 2015. Data from 34 variables were collected; grading was assessed and compared for efficacy by statistical means including Kaplan-Meier method, Cox regression analysis, Harrell's C statistics, and Royston's explained variation in univariable and multivariable analyses. RESULTS: In descriptive analysis, the two grading systems demonstrated statistically significant differences for the major category sex but not for age groups. In Cox regression analysis, both grading systems showed statistically significant differences between grades for OS and EFS; however, no statistically significant difference was observed between the two G3 classes of WHO-AJCC 2017. In multivariable analysis for the two models fitted to compare efficacy, the two grading systems performed equally well with substantially similar optimal discrimination and well-explained variation for both OS and EFS. The WHO-AJCC 2017 grading system retained statistically significant difference between the two G3 classes for OS but not for EFS. CONCLUSIONS: The WHO-AJCC 2017 grading system is at least equally performing as the WHO-AJCC 2010 but allows the successful identification of the most aggressive PanNET subgroup. Grading is confirmed as probably the most powerful tool for predicting patient survival.

Stage IV Gastro-Entero-Pancreatic Neuroendocrine Neoplasms: A Risk Score to Predict Clinical Outcome.

BACKGROUND: Several risk factors predict clinical outcome in gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs); however, the impact of their combination has not been investigated so far. PATIENTS AND METHODS: A retrospective analysis of stage IV GEP-NENs was performed. Multivariate analysis for progression of disease (PD) was performed by Cox proportional hazards method to obtain a risk score. Area under the curve obtained by receiver operating characteristic analysis was used to assess the score performance. Progression-free survival analysis was performed by Kaplan-Meier method. RESULTS: Two hundred eighty-three stage IV GEP-NENs were evaluated, including 93 grade 1 neuroendocrine tumors (32.9%), 153 grade 2 neuroendocrine tumors (54%), and 37 grade 3 neuroendocrine carcinomas (13.1%). Independent risk factors for PD were Ki67, proportion of metastatic liver involvement, and presence of extra-abdominal metastases. The risk score was calculated as follows: (0.025 × Ki67) + [(0 if no liver metastases or liver involvement <25%) OR (0.405 if liver involvement 25%-50%) OR (0.462 if liver involvement >50%)] + [(0 if no extra-abdominal metastases) OR (0.528 if extra-abdominal metastases present)]. The risk score accuracy to predict PD was superior compared with the G grading system (area under the curve: 0.705 and 0.622, respectively). Three subgroups of patients with low, intermediate, and high risk of PD according to risk score were identified, median progression-free survival being 26 months, 19 months, and 12 months, respectively. CONCLUSION: In stage IV GEP-NENs, a risk score able to predict PD was obtained by combining Ki67, proportion of metastatic liver involvement, and presence of extra-abdominal metastases. The score may help to discriminate patients with different progression risk level to plan tailored therapeutic approaches and follow-up programs. The Oncologist 2017;22:409-415Implications for Practice: Clinical outcome of patients with advanced gastro-entero-pancreatic neuroendocrine neoplasms is affected by several risk factors, including the proliferative index Ki67, extension of liver metastases, and the presence of distant extra-abdominal lesions. A risk score that combines these variables may help physicians dealing with these diseases to plan the optimal therapeutic approach and follow-up program.

Risk and Protective Factors for Small Intestine Neuroendocrine Tumors: A Prospective Case-Control Study.

BACKGROUND: The incidence of small intestine neuroendocrine tumors (SI-NETs) is increasing, but few studies have investigated risk factors for their occurrence, suggesting that family history (FH) of any cancer, smoking and previous cholecystectomy are associated with an increased risk. Such studies investigated small series or examined cancer registries without direct interviews. AIM: We therefore aimed at clarifying risk and protective factors for the occurrence of sporadic SI-NETs. SUBJECTS AND METHODS: We performed a multicenter case-control study. Patients with a histologic diagnosis of SI-NETs were prospectively evaluated, excluding familial syndromes. Controls with non-neoplastic/non-chronic disorders seen at gastrointestinal outpatients clinics were matched for sex and age (4:1). All subjects were directly interviewed by means of a specific questionnaire on potential risk and protective factors. Cases and controls were compared by Fisher's test or Student's t test for categorical or continuous variables. Explanatory variables were analyzed by simple logistic regression analysis. A multiple logistic regression analysis was performed with an Enter model; p < 0.05 was considered significant. RESULTS: 215 SI-NET patients and 860 controls were enrolled. FH of colorectal cancer (CRC) (8.8 vs. 5.0%) and breast cancer (10.2 vs. 4.8%), heavy smoking (24.7 vs. 14.8%) and drinking >21 alcohol units per week (7.4 vs. 3.8%) were all significantly more frequent in SI-NET patients than in controls. Multivariate analysis showed that FH of CRC (OR 2.23, 95% CI 1.29-3.84, p = 0.003), FH of breast cancer (OR 2.05, 95% CI 1.13-3.69, p = 0.01) and smoking (OR 1.47, 95% CI 1.07-2.03, p = 0.01) and in particular heavy smoking (OR 1.94, 95% CI 1.29-3.84, p = 0.0008) were associated with an increased risk for carcinoid occurrence, while use of aspirin can be considered a protective factor (OR 0.20, 95% CI 0.06-0.65, p = 0.008). CONCLUSION: FH of colorectal and breast cancer as well as smoking seem to be risk factors for the development of SI-NETs, while use of aspirin might be a protective factor. These factors partially overlap with those associated with CRC, but are different from those previously associated with pancreatic neuroendocrine tumors. These findings may suggest that the mechanisms of carcinogenesis for endocrine cells in different sites can be specific and similar to those of their exocrine counterparts.

Real-world study of everolimus in advanced progressive neuroendocrine tumors.

Everolimus is a valid therapeutic option for neuroendocrine tumors (NETs); however, data in a real-world setting outside regulatory trials are sparse. The aim of this study was to determine everolimus tolerability and efficacy, in relation to previous treatments, in a compassionate use program. A total of 169 patients with advanced progressive NETs treated with everolimus were enrolled, including 85 with pancreatic NETs (pNETs) and 84 with nonpancreatic NETs (non-pNETs). Previous treatments included somatostatin analogs (92.9%), peptide receptor radionuclide therapy (PRRT; 50.3%), chemotherapy (49.7%), and PRRT and chemotherapy (22.8%). Overall, 85.2% of patients experienced adverse events (AEs), which were severe (grade 3-4) in 46.1%. The most frequent severe AEs were pneumonitis (8.3%), thrombocytopenia (7.7%), anemia (5.3%), and renal failure (3.5%). In patients previously treated with PRRT and chemotherapy, a 12-fold increased risk for severe toxicity was observed, with grade 3-4 AEs reported in 86.8% (vs. 34.3% in other patients). In addition, 63.3% of patients required temporarily everolimus discontinuation due to toxicity. Overall, 27.8% of patients died during a median follow-up of 12 months. Median progression-free survival (PFS) and overall survival (OS) were 12 months and 32 months, respectively. Similar disease control rates, PFS, and OS were reported in pNETs and non-pNETs. In the real-world setting, everolimus is safe and effective for the treatment of NETs of different origins. Higher severe toxicity occurred in patients previously treated with systemic chemotherapy and PRRT. This finding prompts caution when using this drug in pretreated patients and raises the issue of planning for everolimus before PRRT and chemotherapy in the therapeutic algorithm for advanced NETs.

The role of combined Ga-DOTANOC and (18)FDG PET/CT in the management of patients with pancreatic neuroendocrine tumors.

PURPOSE: The aim of this study was to evaluate the effect of combined (68)Ga and (18)F-FDG PET/CT on treatment management for patients with pancreatic neuroendocrine tumor (PNET). METHODS: Between January 2012 and April 2014, 49 consecutive patients with a cytologically and/or histologically proven diagnosis of PNET underwent combined (68)Ga and (18)FDG PET/CT on the same day. RESULTS: The study group consisted of 21 males and 28 females with a median age of 59 years. Disease detection was achieved in 48 out of the 49 cases with (68)Ga imaging, and in 36 of the 49 cases with (18)FDG PET/CT. These results corresponded to sensitivities of 98% for (68)Ga versus 73% for (18)FDG PET/CT. Patients with NET-G1/NET-G2 had a positive (68)Ga and negative (18)FDG PET/CT in 13 cases, whereas both (68)Ga and (18)FDG PET/CT were positive in 27 cases. Patients with NEC-G3 were positive by both (68)Ga and (18)FDG PET/CT in 7 cases and positive only by (18)FDG in 1 case. Another NEC-G3 patient was only positive by (68)Ga PET/CT. The median Ki67 was 7% for (68)Ga PET/CT-positive tumors and 10% for tumors with both (68)Ga and (18)FDG PET/CT positivity (p = 0.130). Half of the patients with a prevalent uptake of (18)FDG (n = 7) had an NEC-G3 compared with 12% of patients with a prevalent uptake of (68)Ga (p = 0.012). There were no significant differences between patients with positive (68)Ga and those with positive (18)FDG with regards to treatment choice. CONCLUSIONS: The association of (18)FDG slightly increases sensitivity of (68)Ga PET/CT alone in the diagnosis of PNET. A combined dual tracer PET/CT does not influence the choice of treatment strategy.