Is long-term follow-up solely by imaging tests safe in non-operated pancreatic neuroendocrine tumors?

INTRODUCTION

the diagnosis of asymptomatic sporadic nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) has increased significantly due to the widespread use of high-resolution imaging tests, which is why the most appropriate management at the time of diagnosis is the subject of debate, as is how to follow-up patients.

AIMS

the objective of this study was to analyze the frequency of imaging and endoscopic studies performed during long-term follow-up.

METHODS

a retrospective review was performed of a database collected between January 2008 and December 2020 of patients with an incidental diagnosis of small NF-PNETs; follow-up was closed in March 2023. The imaging tests performed at the time of diagnosis and long-term follow-up were recorded. Growing less than 1 mm per year has not been considered as a worrisome feature. Follow-up was performed through imaging tests, considering endoscopic cytology for lesions with a faster grow rate.

RESULTS

fifty-eight patients were included; the median age was 69 years. The initial mean size of the lesions studied was 12.79 mm (5-27). Follow-up was carried out only with computed tomography (CT) or magnetic resonance imaging (MRI). The initial size did not influence the behavior of the lesion in a statistically significant manner. Twenty-eight tumors (45 %) increased in size, with a growth equal to or less than 4 mm in 24 cases. The mean follow-up time was 82.41 months (12-164). No patient developed metastasis or died from PNET progression.

CONCLUSIONS

the follow-up of neuroendocrine tumors of small size can be performed safely with only imaging tests.

Prognostic significance of systemic immune-inflammation index in patients with nonfunction pancreatic neuroendocrine tumor undergoing surgical resection

PURPOSE

The purpose of our study was to investigate the clinical significance and prognostic role of the systemic immune-inflammation index (SII) in patients who underwent surgical resection for nonfunctioning pancreatic neuroendocrine tumors (pNETs).

METHODS

We conducted a retrospective analysis of 364 patients with nonfunctioning pNETs. The association between the SII level and clinical parameters was investigated. The receiver operating characteristic (ROC) curve was used to calculate the optimal SII value. Cox proportional hazard analysis was performed to evaluate the prognostic factors.

RESULTS

Our study included 364 patients with nonfunctioning pNETs who underwent surgery. The median age was 51.0 (43.0, 59.3), and 164 (45.1%) were male. The optimal threshold of SII determined by ROC analysis was 523.95. Higher SII levels were significantly associated with older age (p = 0.001), sex (p = 0.011), tumor size (p = 0.032), and tumor grade (p = 0.002). Recurrence was observed in 70 (19.2%) patients following a median follow-up of 98 months. Univariate analysis showed that higher SII (p < 0.0001), tumor size >4 cm (p = 0.015), and G2/G3 grade (p = 0.002) were significantly associated with disease-free survival (DFS). Multivariate analysis revealed that higher SII (HR: 7.35; 95% CI: 3.44, 15.70; p < 0.0001) and G2/G3 grade (HR: 3.11; 95% CI: 1.42, 6.82; p = 0.005) remained significantly associated with tumor recurrence. Furthermore, 46 (12.6%) patients died during the follow-up. Higher SII (HR: 8.43; 95% CI: 3.19, 22.72; p < 0.0001) and G2/G3 grade (HR: 3.16; 95% CI: 1.01, 9.86; p = 0.048) were independent predictors of overall survival (OS) by multivariate analysis.

CONCLUSION

In conclusion, our study revealed that a higher SII level was associated with tumor-related features (larger tumor size and advanced grade) and subsequent shorter DFS and OS in patients with nonfunctioning pNETs. These results indicated that the SII could serve as an efficient prognostic biomarker for nonfunctioning pNETs.

Patient Priorities Concerning Treatment Decisions for Advanced Neuroendocrine Tumors Identified by Discrete Choice Experiments

BACKGROUND

Patients with advanced neuroendocrine tumors (NETs) have multiple treatment options. Ideally, treatment decisions are shared between physician and patient; however, previous studies suggest that oncologists and patients place different value on treatment attributes such as adverse event (AE) rates. High-quality information on NET patient treatment preferences may facilitate patient-centered decision making by helping clinicians understand patient priorities.

METHODS

This study used 2 discrete choice experiments (DCE) to elicit preferences of NET patients regarding advanced midgut and pancreatic NET (pNET) treatments. The DCEs used the "potentially all pairwise rankings of all possible alternatives" (PAPRIKA) method. The primary objective was to determine relative utility rankings for treatment attributes, including progression-free survival (PFS), treatment modality, and AE rates. Ranking of attribute profiles matching specific treatments was also determined. Levels for treatment attributes were obtained from randomized clinical trial data of NET treatments.

RESULTS

One hundred and 10 participants completed the midgut NET DCE, and 132 completed the pNET DCE. Longer PFS was the highest ranked treatment attribute in 64.5% of participants in the midgut NET DCE, and in 59% in the pNET DCE. Approximately, 40% of participants in both scenarios prioritized lower AE rates or less invasive treatment modalities over PFS. Ranking of treatment profiles in the midgut NET scenario identified 60.9% of participants favoring peptide receptor radionuclide therapy (PRRT), and 30.0% somatostatin analogue dose escalation.

CONCLUSION

NET patients have heterogeneous priorities when choosing between treatment options based on the results of 2 independent DCEs. These results highlight the importance of shared decision making for NET patients.

Pseudo-medical image-guided technology based on 'CBCT-only' mode in esophageal cancer radiotherapy

Purpose To minimize the various errors introduced by image-guided radiotherapy (IGRT) in the application of esophageal cancer treatment, this study proposes a novel technique based on the 'CBCT-only' mode of pseudo-medical image guidance. Methods The framework of this technology consists of two pseudo-medical image synthesis models in the CBCT→CT and the CT→PET direction. The former utilizes a dual-domain parallel deep learning model called AWM-PNet, which incorporates attention waning mechanisms. This model effectively suppresses artifacts in CBCT images in both the sinogram and spatial domains while efficiently capturing important image features and contextual information. The latter leverages tumor location and shape information provided by clinical experts. It introduces a PRAM-GAN model based on a prior region aware mechanism to establish a non-linear mapping relationship between CT and PET image domains.  As a result, it enables the generation of pseudo-PET images that meet the clinical requirements for radiotherapy. Results The NRMSE and multi-scale SSIM (MS-SSIM) were utilized to evaluate the test set, and the results were presented as median values with lower quartile and upper quartile ranges. For the AWM-PNet model, the NRMSE and MS-SSIM values were 0.0218 (0.0143, 0.0255) and 0.9325 (0.9141, 0.9410), respectively. The PRAM-GAN model produced NRMSE and MS-SSIM values of 0.0404 (0.0356, 0.0476) and 0.9154 (0.8971, 0.9294), respectively. Statistical analysis revealed significant differences (p < 0.05) between these models and others. The numerical results of dose metrics, including D98 %, Dmean, and D2 %, validated the accuracy of HU values in the pseudo-CT images synthesized by the AWM-PNet. Furthermore, the Dice coefficient results confirmed statistically significant differences (p < 0.05) in GTV delineation between the pseudo-PET images synthesized using the PRAM-GAN model and other compared methods. Conclusion The AWM-PNet and PRAM-GAN models have the capability to generate accurate pseudo-CT and pseudo-PET images, respectively. The pseudo-image-guided technique based on the 'CBCT-only' mode shows promising prospects for application in esophageal cancer radiotherapy.

A radiomics-based interpretable model to predict the pathological grade of pancreatic neuroendocrine tumors

OBJECTIVES

To develop a computed tomography (CT) radiomics-based interpretable machine learning (ML) model to predict the pathological grade of pancreatic neuroendocrine tumors (pNETs) in a non-invasive manner.

METHODS

Patients with pNETs who underwent contrast-enhanced abdominal CT between 2010 and 2022 were included in this retrospective study. Radiomics features were extracted, and five radiomics-based ML models, namely logistic regression (LR), random forest (RF), support vector machine (SVM), XGBoost, and GaussianNB, were developed. The performance of these models was evaluated using a time-independent testing set, and metrics such as sensitivity, specificity, accuracy, and the area under the receiver operating characteristic curve (AUC) were calculated. The accuracy of the radiomics model was compared to that of needle biopsy. The Shapley Additive Explanation (SHAP) tool and the correlation between radiomics and biological features were employed to explore the interpretability of the model.

RESULTS

A total of 122 patients (mean age: 50 ± 14 years; 53 male) were included in the training set, whereas 100 patients (mean age: 48 ± 13 years; 50 male) were included in the testing set. The AUCs for LR, SVM, RF, XGBoost, and GaussianNB were 0.758, 0.742, 0.779, 0.744, and 0.745, respectively, with corresponding accuracies of 73.0%, 70.0%, 77.0%, 71.9%, and 72.9%. The SHAP tool identified two features of the venous phase as the most significant, which showed significant differences among the Ki-67 index or mitotic count subgroups (p < 0.001).

CONCLUSIONS

An interpretable radiomics-based RF model can effectively differentiate between G1 and G2/3 of pNETs, demonstrating favorable interpretability.

CLINICAL RELEVANCE STATEMENT

The radiomics-based interpretable model developed in this study has significant clinical relevance as it offers a non-invasive method for assessing the pathological grade of pancreatic neuroendocrine tumors and holds promise as an important complementary tool to traditional tissue biopsy.

KEY POINTS

• A radiomics-based interpretable model was developed to predict the pathological grade of pNETs and compared with preoperative needle biopsy in terms of accuracy. • The model, based on CT radiomics, demonstrated favorable interpretability. • The radiomics model holds potential as a valuable complementary technique to preoperative needle biopsy; however, it should not be considered a replacement for biopsy.

Epidemiology and economic burden of Von Hippel-Lindau Disease-associated central nervous system hemangioblastomas and pancreatic neuroendocrine tumors in the United States

BACKGROUND

To date, real-world evidence around the clinical and economic burden related to von Hippel-Lindau (VHL) disease is limited. Therefore, this study characterized the prevalence, healthcare resource utilization (HRU), and economic burden of von Hippel-Lindau-associated central nervous system hemangioblastoma (VHL-CNS-Hb) and pancreatic neuroendocrine tumors (VHL-pNET) in the United States (US).

METHODS

Patients with VHL-CNS-Hb or VHL-pNET were identified from Optum's de-identified Clinformatics® Data Mart Database (2007-2020) and matched 1:5 to control patients without VHL disease or CNS-Hb/pNET. Prevalence rates of VHL-CNS-Hb and VHL-pNET (standardized by age and sex) in 2019 were estimated. HRU and healthcare costs (2020 US dollars) were compared between the VHL-CNS-Hb/VHL-pNET and control cohorts.

RESULTS

In 2019, US prevalence rates of VHL-CNS-Hb and VHL-pNET were estimated to be 1.12 cases per 100,000 (3,678 patients) and 0.12 cases per 100,000 (389 patients), respectively. Patients with VHL-CNS-Hb (N = 220) had more inpatient, outpatient, and emergency department visits and $49,645 higher annual healthcare costs than controls (N = 1,100). Patients with VHL-pNET (N = 20) had more inpatient and outpatient visits and $56,580 higher annual healthcare costs than controls (N = 100). Costs associated with surgical removal of CNS-Hb and pNET were particularly high.

CONCLUSIONS

In this retrospective, claims-based study, both VHL-CNS-Hb and VHL-pNET were associated with substantial HRU and healthcare costs, particularly tumor reduction surgery-related costs. These findings provide important insight for healthcare payers regarding the expected real-world costs that enrollees with VHL-CNS-Hb and VHL-pNET may incur over the course of their disease.

Efficacy and safety of temozolomide-based regimens in advanced pancreatic neuroendocrine tumors: a systematic review and meta-analysis

BACKGROUND

Recent advances in the management of pancreatic neuroendocrine tumors (pNETs) highlight the potential benefits of temozolomide, an alkylating agent, for these patients. In this meta-analysis, we aimed to assess the outcome of temozolomide, alone or in combination with other anticancer medications in patients with advanced pNET.

METHODS

Online databases of PubMed, Web of Science, Embase, the Cochrane Library, and ClinicalTrials.gov were searched systematically for clinical trials that reported the efficacy and safety of temozolomide in patients with advanced pNET. Random-effect model was utilized to estimate pooled rates of outcomes based on Response Evaluation Criteria in Solid Tumors criteria, biochemical response, and adverse events (AEs).

RESULTS

A total of 14 studies, providing details of 441 individuals with advanced pNET, were included. The quantitative analyses showed a pooled objective response rate (ORR) of 41.2% (95% confidence interval, CI, of 32.4%-50.6%), disease control rate (DCR) of 85.3% (95% CI of 74.9%-91.9%), and a more than 50% decrease from baseline chromogranin A levels of 44.9% (95% CI of 31.6%-49.0%). Regarding safety, the results showed that the pooled rates of nonserious AEs and serious AEs were 93.8% (95% CI of 88.3%-96.8%) and 23.7% (95% CI of 12.0%-41.5%), respectively. The main severe AEs encompassed hematological toxicities.

CONCLUSIONS

In conclusion, our meta-analysis suggests that treatment with temozolomide, either as a monotherapy or in combination with other anticancer treatments might be an effective and relatively safe option for patients with advanced locally unresectable and metastatic pNET. However, additional clinical trials are required to further strengthen these findings. This study has been registered in PROSPERO (CRD42023409280).

A nomogram to preoperatively predict the aggressiveness of non-functional pancreatic neuroendocrine tumors based on CT features

OBJECTIVES

To develop a nomogram to predict the aggressiveness of non-functional pancreatic neuroendocrine tumors (NF-pNETs) based on preoperative computed tomography (CT) features.

METHODS

This study included 176 patients undergoing radical resection for NF-pNETs. These patients were randomly divided into the training (n = 123) and validation sets (n = 53). A nomogram was developed based on preoperative predictors of aggressiveness of the NF-pNETs which were identified by univariable and multivariable logistic regression analysis. The aggressiveness of NF-pNETs was defined as a composite measure including G3 grading, N+, distant metastases, and/ or disease recurrence.

RESULTS

Altogether, the number of patients with highly aggressive NF-pNETs was 37 (30.08 %) and 15 (28.30 %) in the training and validation sets, respectively. Multivariable logistic regression analysis identified that tumor size, biliopancreatic duct dilatation, lymphadenopathy, and enhancement pattern were preoperative predictors of aggressiveness. Those variables were used to develop a nomogram with good concordance statistics of 0.89 and 0.86 for predicting aggressiveness in the training and validation sets, respectively. With a nomogram score of 59, patients with NF-pNETs were divided into low-aggressive and high-aggressive groups. The high-aggressive group had decreased overall survival (OS) and disease-free survival (DFS). Moreover, the nomogram showed good performance in predicting OS and DFS at 3, 5, and 10 years.

CONCLUSION

The nomogram integrating CT features helped preoperatively predict the aggressiveness of NF-pNETs and could potentially facilitate clinical decision-making.

Preoperative prediction of pancreatic neuroendocrine tumor grade based on 68Ga-DOTATATE PET/CT

OBJECTIVE

To establish a prediction model for preoperatively predicting grade 1 and grade 2/3 tumors in patients with pancreatic neuroendocrine tumors (PNETs) based on 68Ga-DOTATATE PET/CT.

METHODS

Clinical data of 41 patients with PNETs were included in this study. According to the pathological results, they were divided into grade 1 and grade 2/3. 68Ga-DOTATATE PET/CT images were collected within one month before surgery. The clinical risk factors and significant radiological features were filtered, and a clinical predictive model based on these clinical and radiological features was established. 3D slicer was used to extracted 107 radiomic features from the region of interest (ROI) of 68Ga-dotata PET/CT images. The Pearson correlation coefficient (PCC), recursive feature elimination (REF) based five-fold cross validation were adopted for the radiomic feature selection, and a radiomic score was computed subsequently. The comprehensive model combining the clinical risk factors and the rad-score was established as well as the nomogram. The performance of above clinical model and comprehensive model were evaluated and compared.

RESULTS

Adjacent organ invasion, N staging, and M staging were the risk factors for PNET grading (p < 0.05). 12 optimal radiomic features (3 PET radiomic features, 9 CT radiomic features) were screen out. The clinical predictive model achieved an area under the curve (AUC) of 0.785. The comprehensive model has better predictive performance (AUC = 0.953).

CONCLUSION

We proposed a comprehensive nomogram model based on 68Ga-DOTATATE PET/CT to predict grade 1 and grade 2/3 of PNETs and assist personalized clinical diagnosis and treatment plans for patients with PNETs.

Value of markers of systemic inflammation for the prediction of postoperative progression in patients with pancreatic neuroendocrine tumors

Background

Non-invasive prognostic predictors for rare pancreatic neuroendocrine tumors (PNETs) are lacking. We aimed to approach the prognostic value of preoperative systemic inflammatory markers in patients with PNETs.

Methods

The clinical data of 174 patients with PNETs undergoing surgical treatment were retrospectively analyzed to explore the correlation of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), and platelet to white blood cell ratio (PWR) with clinicopathological parameters and the progression of tumor after the operation. The optimal cutoff values for predictors and the area under the curve (AUC) of the receiver operating characteristic (ROC) were estimated. Univariate and multivariate Cox proportional hazards models were used to assess the relation between NLR, LMR, PLR, and progression-free survival (PFS), examined by the Kaplan-Meier and log-rank tests.

Results

The scores of the NLR (P = 0.039) and PLR (P = 0.011) in the progression group were significantly higher than those in the progression-free group, and the LMR was significantly lower than those in the progression-free group (P = 0.001). The best cutoff values of NLR, LMR, and PLR before operation were 2.28, 4.36, and 120.91. The proportions of tumor progression in the high NLR group (P = 0.007) and high PLR group (P = 0.013) obviously increased, and the proportion of tumor development in the low LMR group was higher than that in the high LMR group (P < 0.001). The K-M survival curve showed that the progression-free survival rate was lower in the high NLR group (P = 0.004), the low LMR group (P < 0.001), and the high PLR group (P = 0.018). The results of the multivariate Cox proportional hazards model suggested that preoperative LMR (HR = 3.128, 95% CI: 1.107~8.836, P = 0.031) was an independent predictor of PFS.

Conclusion

The markers of systemic inflammation, especially LMR, can predict the postoperative progression of PNETs.

Pancreatic Neuroendocrine Tumors: Signaling Pathways and Epigenetic Regulation

Pancreatic neuroendocrine tumors (PNETs) are characterized by dysregulated signaling pathways that are crucial for tumor formation and progression. The efficacy of traditional therapies is limited, particularly in the treatment of PNETs at an advanced stage. Epigenetic alterations profoundly impact the activity of signaling pathways in cancer development, offering potential opportunities for drug development. There is currently a lack of extensive research on epigenetic regulation in PNETs. To fill this gap, we first summarize major signaling events that are involved in PNET development. Then, we discuss the epigenetic regulation of these signaling pathways in the context of both PNETs and commonly occurring-and therefore more extensively studied-malignancies. Finally, we will offer a perspective on the future research direction of the PNET epigenome and its potential applications in patient care.

Accurate non-invasive grading of nonfunctional pancreatic neuroendocrine tumors with a CT derived radiomics signature

PURPOSE

The purpose of this study was to develop a radiomics-signature using computed tomography (CT) data for the preoperative prediction of grade of nonfunctional pancreatic neuroendocrine tumors (NF-PNETs).

MATERIALS AND METHODS

A retrospective study was performed on patients undergoing resection for NF-PNETs between 2010 and 2019. A total of 2436 radiomic features were extracted from arterial and venous phases of pancreas-protocol CT examinations. Radiomic features that were associated with final pathologic grade observed in the surgical specimens were subjected to joint mutual information maximization for hierarchical feature selection and the development of the radiomic-signature. Youden-index was used to identify optimal cutoff for determining tumor grade. A random forest prediction model was trained and validated internally. The performance of this tool in predicting tumor grade was compared to that of EUS-FNA sampling that was used as the standard of reference.

RESULTS

A total of 270 patients were included and a fusion radiomic-signature based on 10 selected features was developed using the development cohort (n = 201). There were 149 men and 121 women with a mean age of 59.4 ± 12.3 (standard deviation) years (range: 23.3-85.0 years). Upon internal validation in a new set of 69 patients, a strong discrimination was observed with an area under the curve (AUC) of 0.80 (95% confidence interval [CI]: 0.71-0.90) with corresponding sensitivity and specificity of 87.5% (95% CI: 79.7-95.3) and 73.3% (95% CI: 62.9-83.8) respectively. Of the study population, 143 patients (52.9%) underwent EUS-FNA. Biopsies were non-diagnostic in 26 patients (18.2%) and could not be graded due to insufficient sample in 42 patients (29.4%). In the cohort of 75 patients (52.4%) in whom biopsies were graded the radiomic-signature demonstrated not different AUC as compared to EUS-FNA (AUC: 0.69 vs. 0.67; P = 0.723), however greater sensitivity (i.e., ability to accurately identify G2/3 lesion was observed (80.8% vs. 42.3%; P < 0.001).

CONCLUSION

Non-invasive assessment of tumor grade in patients with PNETs using the proposed radiomic-signature demonstrated high accuracy. Prospective validation and optimization could overcome the commonly experienced diagnostic uncertainty in the assessment of tumor grade in patients with PNETs and could facilitate clinical decision-making.

Radiomics analysis from magnetic resonance imaging in predicting the grade of nonfunctioning pancreatic neuroendocrine tumors: a multicenter study

OBJECTIVES

To explore the potential of radiomics features to predict the histologic grade of nonfunctioning pancreatic neuroendocrine tumor (NF-PNET) patients using non-contrast sequence based on MRI.

METHODS

Two hundred twenty-eight patients with NF-PNETs undergoing MRI at 5 centers were retrospectively analyzed. Data from center 1 (n = 115) constituted the training cohort, and data from centers 2-5 (n = 113) constituted the testing cohort. Radiomics features were extracted from T2-weighted images and the apparent diffusion coefficient. The least absolute shrinkage and selection operator was applied to select the most important features and to develop radiomics signatures. The area under receiver operating characteristic curve (AUC) was performed to assess models.

RESULTS

Tumor boundary, enhancement homogeneity, and vascular invasion were used to construct the radiological model to stratify NF-PNET patients into grade 1 and 2/3 groups, which yielded AUC of 0.884 and 0.684 in the training and testing groups. A radiomics model including 4 features was constructed, with an AUC of 0.941 and 0.871 in the training and testing cohorts. The fusion model combining the radiomics signature and radiological characteristics showed good performance in the training set (AUC = 0.956) and in the testing set (AUC = 0.864), respectively.

CONCLUSION

The developed model that integrates radiomics features with radiological characteristics could be used as a non-invasive, dependable, and accurate tool for the preoperative prediction of grade in NF-PNETs.

CLINICAL RELEVANCE STATEMENT

Our study revealed that the fusion model based on a non-contrast MR sequence can be used to predict the histologic grade before operation. The radiomics model may be a new and effective biological marker in NF-PNETs.

KEY POINTS

The diagnostic performance of the radiomics model and fusion model was better than that of the model based on clinical information and radiological features in predicting grade 1 and 2/3 of nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs). Good performance of the model in the four external testing cohorts indicated that the radiomics model and fusion model for predicting the grades of NF-PNETs were robust and reliable, indicating the two models could be used in the clinical setting and facilitate the surgeons' decision on risk stratification. The radiomics features were selected from non-contrast T2-weighted images (T2WI) and diffusion-weighted imaging (DWI) sequence, which means that the administration of contrast agent was not needed in grading the NF-PNETs.

Long-term Follow-up of Small Nonfunctioning Pancreatic Neuroendocrine Tumors Diagnosed Using Endoscopic Ultrasound-guided Fine-needle Aspiration

Objective Clinical practice guidelines in Japan recommend surgery for all nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs), regardless of their size or associated symptoms. Because pancreatic resection is highly invasive, follow-up for small NF-PNETs is often chosen in clinical practice. However, the natural history of NF-PNET remains poorly understood. We aimed to examine the natural history of pathologically confirmed NF-PNET. Methods This single-center retrospective case series investigated NF-PNETs that were pathologically diagnosed using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) at our hospital between 2014 and 2018. Patients who were followed up without treatment due to their general condition or their wish were included in the study. Patients' background characteristics, imaging findings, pathological findings, and long-term prognoses were investigated using medical records. Results Overall, 26 patients were diagnosed with NF-PNET by EUS-FNA during the observation period. Of these, 9 patients (3 men and 6 women; median age: 64 years old) were followed up without treatment. All of these patients were asymptomatic, and localization was noticed in 3 cases in the head, body, and tail (1 each), with a median size of 12 (range: 4-18) mm. Neuroendocrine tumor (Grade 1 [G1]) was pathologically diagnosed in all patients with EUS-FNA. The median observation period was 63 (range: 26-90) months. Tumor growth and distant metastasis were not observed in any of the nine patients who remained asymptomatic. Conclusion Follow-up is a feasible option for asymptomatic NF-PNET ≤20 mm in size with a pathological grade of G1.

Predicting resection margin status of pancreatic neuroendocrine tumors on CT: performance of NCCN resectability criteria

OBJECTIVE

To test the performance of the National Comprehensive Cancer Network (NCCN) CT resectability criteria for predicting the surgical margin status of pancreatic neuroendocrine tumor (PNET) and to identify factors associated with margin-positive resection.

METHODS

Eighty patients with pre-operative CT and upfront surgery were retrospectively enrolled. Two radiologists assessed the CT resectability (resectable [R], borderline resectable [BR], unresectable [UR]) of the PNET according to NCCN criteria. Logistic regression was used to identify factors associated with resection margin status. κ statistics were used to evaluate interreader agreements. Kaplan-Meier method with log-rank test was used to estimate and compare recurrence-free survival (RFS).

RESULTS

Forty-five patients (56.2%) received R0 resection and 35 (43.8%) received R1 or R2 resection. R0 resection rates were 63.6-64.2%, 20.0-33.3%, and 0% for R, BR, and UR diseases, respectively (all p ≤ 0.002), with a good interreader agreement (κ, 0.74). Tumor size (<2 cm, 2-4 cm, and >4 cm; odds ratio (OR), 9.042-18.110; all p ≤ 0.007) and NCCN BR/UR diseases (OR, 5.918; p = 0.032) were predictors for R1 or R2 resection. The R0 resection rate was 91.7% for R disease <2 cm and decreased for larger R disease. R0 resection and smaller tumor size in R disease improved RFS.

CONCLUSION

NCCN resectability criteria can stratify patients with PNET into distinct groups of R0 resectability. Adding tumor size to R disease substantially improves the prediction of R0 resection, especially for PNETs <2 cm.

ADVANCES IN KNOWLEDGE

Tumor size and radiologic resectability independently predicted margin status of PNETs.

Quantitative SSTR-PET/CT for predicting response and survival outcomes in patients with pancreatic neuroendocrine tumors receiving CAPTEM

BACKGROUND

This study aimed to evaluate the predictive and monitoring role of somatostatin receptor (SSTR) positron emission tomography-computed tomography (PET/CT) and clinical parameters in patients with neuroendocrine liver metastases (NELM) from pancreatic neuroendocrine tumors (pNET) receiving capecitabine and temozolomide (CAPTEM).

PATIENTS AND METHODS

This retrospective study included twenty-two patients with pNET and NELM receiving CAPTEM who underwent pre- and post-therapeutic 68Ga-DOTATATE/-TOC PET/CT. Imaging (including standardized uptake value [SUV] of target lesions [NELM and pNET], normal spleen and liver) and clinical (Chromogranin A [CgA], Ki-67) parameters were assessed. Treatment outcome was evaluated as response according to RECIST 1.1, progression free survival (PFS) and overall survival (OS).

RESULTS

The median PFS (mPFS) was 7 months. Responders had a significantly longer mPFS compared to non-responders (10 vs. 4 months p = 0.022). Median OS (mOS) was 33 months (mOS: responders = 80 months, non-responders = 24 months p = 0.182). Baseline imaging showed higher SUV in responders, including absolute SUV, tumor-to-spleen (T/S), and tumor-to-liver (T/L) ratios (p < 0.02). All SUV parameters changed only in the responders during follow-up. Univariable Cox regression analysis identified baseline Tmax/Smean ratio and percentage change in size of pNETs as significant factors associated with PFS. A baseline Tmax/Smean ratio < 1.5 was associated with a shorter mPFS (10 vs. 4 months, (p < 0.05)). Prognostic factors for OS included age, percentage change in CgA and in T/S ratios in univariable Cox regression.

CONCLUSIONS

SSTR-PET/CT can be useful for predicting response and survival outcomes in pNET patients receiving CAPTEM: Higher baseline SUV values, particularly Tmax/Smean ratios of liver metastases were associated with better response and prolonged PFS.

Comparative analysis of nascent RNA sequencing methods and their applications in studies of cotranscriptional splicing dynamics

High-throughput detection of nascent RNA is critical for studies of transcription and much more challenging than that of mRNA. Recently, several massively parallel nascent RNA sequencing methods were established in eukaryotic cells. Here, we systematically compared 3 classes of methods on the same pure or crude nuclei preparations: GRO-seq for sequence nuclear run-on RNAs, pNET-seq for sequence RNA polymerase II-associated RNAs, and CB RNA-seq for sequence chromatin-bound (CB) RNAs in Arabidopsis (Arabidopsis thaliana). To improve the resolution of CB RNAs, 3'CB RNA-seq was established to sequence the 3' ends of CB RNAs. In addition, we modified pNET-seq to establish the Chromatin Native Elongation Transcript sequencing (ChrNET) method using chromatin as the starting material for RNA immunoprecipitation. Reproducibility, sensitivity and accuracy in detecting nascent transcripts, experimental procedures, and costs were analyzed, which revealed the strengths and weaknesses of each method. We found that pNET and GRO methods best detected active RNA polymerase II. CB RNA-seq is a simple and cost-effective alternative for nascent RNA studies, due to its high correlation with pNET-seq and GRO-seq. Compared with pNET, ChrNET has higher specificity for nascent RNA capture and lower sequencing cost. 3'CB is sensitive to transcription-coupled splicing. Using these methods, we identified 1,404 unknown transcripts, 4,482 unannotated splicing events, and 60 potential recursive splicing events. This comprehensive comparison of different nascent/chromatin RNA sequencing methods highlights the strengths of each method and serves as a guide for researchers aiming to select a method that best meets their study goals.

Synchronous Insulinoma and Glucagonoma: A Review of the Literature

BACKGROUND/AIM

Pancreatic neuroendocrine tumors (PNETs) are pancreatic neoplasms with neuroendocrine features, divided into functioning and non-functioning. The non-functioning PNETs are the largest group, and their morbidity is the result of their potential to invade surrounding tissues and metastasize. The functioning PNETs produce hormonal symptoms due to over-secretion of specific hormones. They constitute 1% to 2% of all pancreatic tumors. The use of novel imaging methods has rendered their detection more frequent. Insulinoma, the most common functioning PNET, comprises 35-40% of all functioning PNETs. Its clinical presentation is due to hyperinsulinemia and the subsequent hypoglycemia. Glucagonoma accounts for 5% of all PNETs and is the fourth most frequent functioning PNET, following insulinoma, gastrinoma, and vipoma. Its symptoms are due to the massive secretion of glucagon and ensuing hyperglycemia. The co-existence of two PNETs is a very rare entity. This report aimed to describe cases of concomitant insulinomas and glucagonomas.

MATERIALS AND METHODS

A review of the literature was performed using the PubMed database and Cochrane library aiming to identify reported cases of concomitant pancreatic insulinoma and glucagonoma. Specifically, the research was conducted using the keywords, separately and in various combination, including insulinoma, glucagonoma, cystic, pancreatic neuroendocrine tumors and hypoglycemia. Only publications in English were included in the present study.

RESULTS

A total of 8 cases of concomitant pancreatic insulinoma and glucagonoma were identified, corresponding to the period 1992-2021.

CONCLUSION

Concomitant insulinoma and glucagonoma are rare and challenging. A multidisciplinary approach is necessary for diagnosis, prognosis, and therapy.

[Peripheral neuroblastic tumors in childhood]

Peripheral neuroblastic tumors represent the fourth-largest group of malignant tumors in childhood. The majority of these tumors are neuroblastomas, which can be classified into undifferentiated, poorly differentiated, and differentiating subtypes. In addition, peripheral neuroblastic tumors include ganglioneuroblastoma, a composite tumor composed of Schwannian cell stroma and neuroblasts as well as benign ganglioneuroma. In this overview, histopathological diagnostic criteria and grading systems, as well as common molecular alterations that are of prognostic and therapeutic significance, are discussed.

A preoperative computed tomography radiomics model to predict disease-free survival in patients with pancreatic neuroendocrine tumors

IMPORTANCE

Imaging has demonstrated capabilities in the diagnosis of pancreatic neuroendocrine tumors (pNETs), but its utility for prognostic prediction has not been elucidated yet.

OBJECTIVE

The aim of this study was to build a radiomics model using preoperative computed tomography (CT) data that may help predict recurrence-free survival (RFS) or OS in patients with pNET.

DESIGN

We performed a retrospective observational study in a cohort of French patients with pNETs.

PARTICIPANTS

Patients with surgically resected pNET and available CT examinations were included.

INTERVENTIONS

Radiomics features of preoperative CT data were extracted using 3D-Slicer® software with manual segmentation. Discriminant features were selected with penalized regression using least absolute shrinkage and selection operator method with training on the tumor Ki67 rate (≤2 or >2). Selected features were used to build a radiomics index ranging from 0 to 1.

OUTCOME AND MEASURE

A receiving operator curve was built to select an optimal cutoff value of the radiomics index to predict patient RFS and OS. Recurrence-free survival and OS were assessed using Kaplan-Meier analysis.

RESULTS

Thirty-seven patients (median age, 61 years; 20 men) with 37 pNETs (grade 1, 21/37 [57%]; grade 2, 12/37 [32%]; grade 3, 4/37 [11%]) were included. Patients with a radiomics index >0.4 had a shorter median RFS (36 months; range: 1-133) than those with a radiomics index ≤0.4 (84 months; range: 9-148; P = .013). No associations were found between the radiomics index and OS (P = .86).

Upregulation of Somatostatin Receptor Type 2 Improves 177Lu-DOTATATE Therapy in Receptor-Deficient Pancreatic Neuroendocrine Tumor Model

Pancreatic neuroendocrine tumors (PNET) express high levels of somatostatin receptor type 2 (SSTR2), a unique target for both tumor imaging and therapy. This surface expression is lost in metastatic high-grade PNETs, making patients ineligible for SSTR2-targeted 177 Lutetium (Lu)-DOTATATE peptide receptor radionuclide therapy (PRRT), and represents an unmet clinical need. Here, we aimed to restore SSTR2 expression through the reversal of inhibitory epigenetic gene silencing to improve tumor responsiveness to PRRT. We first assessed human SSTR2 promoter methylation and expression levels in 96 patient samples. We then used three NET cell lines (QGP-1, BON-1, GOT-1) with variable SSTR2 expression profiles for functional in vitro studies using histone deacetylase inhibitors (HDACi). Finally, the QGP-1 xenograft mouse model, with low basal SSTR2 expression, was used to assess the therapeutic efficacy of combined HDACi and 177Lu-DOTATATE therapies. We confirm that SSTR expression is decreased and correlates with SSTR2 promoter methylation in patients with high-grade NETs. When exposed to HDACis, SSTR2 surface expression is increased in three NET cell lines in vitro. In an in vivo PNET xenograft model with low basal SSTR2 expression, our studies demonstrate significantly higher tumor uptake of SSTR2-targeted 177Lu-DOTATATE in animals pretreated with HDACis compared with controls. For the first time, we show that this higher tumor uptake results in significant antitumor response when compared with standard PRRT alone. These preclinical results provide a rationale for utilizing HDACi pretreatment to improve targeted radionuclide therapy in patients with SSTR2-negative, metastatic PNETs.

Glioblastoma with Primitive Neuroectodermal Tumor like Component: Rare and Enigmatic

Glioblastoma (GBM) with Primitive Neuroectodermal tumor (PNET) like features is an extremely rare tumor showing dual features of malignant glioma and primitive neuroectodermal tumour occurring mostly in adults. It poses diagnostics dilemma to the neuropathologist and treating oncologist team because of its rarity, tendency to spread to cerebrospinal fluid and dismal prognosis. We have described this tumor in a 11 years old male child in this case report. Keywords: glioma,glioblastoma,primitive neuroectodermal tumor, variant, pediatric.

Pancreatic neuroendocrine tumor: prediction of tumor grades by radiomics models based on ultrasound images

OBJECTIVE

We aimed to investigate whether the radiomics analysis based on B-mode ultrasound (BMUS) images could predict histopathological tumor grades in pancreatic neuroendocrine tumors (pNETs).

METHODS

A total of 64 patients with surgery and histopathologically confirmed pNETs were retrospectively included (34 male and 30 female, mean age 52.4 ± 12.2 years). Patients were divided into training cohort (n = 44) and validation cohort (n = 20). All pNETs were classified into Grade 1 (G1), Grade 2 (G2), and Grade 3 (G3) tumors based on the Ki-67 proliferation index and the mitotic activity according to WHO 2017 criteria. Maximum relevance minimum redundancy, least absolute shrinkage and selection operator were used for feature selection. Receiver operating characteristic curve analysis was used to evaluate the model performance.

RESULTS

Finally, 18 G1 pNETs, 35 G2 pNETs, and 11 G3 pNETs patients were included. The radiomic score derived from BMUS images to predict G2/G3 from G1 displayed a good performance with an area under the receiver operating characteristic curve of 0.844 in the training cohort, and 0.833 in the testing cohort. The radiomic score achieved an accuracy of 81.8% in the training cohort and 80.0% in the testing cohort, a sensitivity of 0.750 and 0.786, a specificity of 0.833 and 0.833 in the training/testing cohorts. Clinical benefit of the score also exhibited superior usefulness of the radiomic score, as shown by the decision curve analysis.

CONCLUSIONS

Radiomic data constructed from BMUS images have the potential for predicting histopathological tumor grades in patients with pNETs.

ADVANCES IN KNOWLEDGE

The radiomic model constructed from BMUS images has the potential for predicting histopathological tumor grades and Ki-67 proliferation indexes in patients with pNETs.

[Expression and significance of INSM1 and SOX11 in pancreatic neuroendocrine tumor and solid pseudopapillary neoplasm]

OBJECTIVE

To investigate the expression and significance of insulinoma associated protein 1 (INSM1) and SRY-related high-mobility group box 11 (SOX11) in pancreatic neuroendocrine tumor (PNET) and solid pseudopapillary neoplasm (SPN).

METHODS

To detect the expression of INSM1, SOX11, Syn, CgA, CD56, β-catenin, and CD99 in 56 cases of PNET, 42 cases of SPN, 16 cases of ductal adenocarcinoma (DACC) and 8 cases of acinar cell carcinoma (ACC) by immunohistochemistry. The application value of combination of INSM1 and SOX11 was compared with conventional markers (Syn, CgA, CD56, β-catenin, and CD99) in diagnosis and differential diagnosis of PNET and SPN.

RESULTS

(1) In the 56 cases of PNET, the positive signals of INSM1 were located in the tumor and islet nucleus, the positive expression rate in the tumor tissues was 91.07% (51/56), whereas the signal was absent in 42 cases of SPN, 16 cases of DACC and 8 cases of ACC, and there were significant statistical difference between PNET with SPN, DACC, and ACC respectively (P < 0.001). (2) The positive signals of SOX11 were located in the tumor nucleus, with the positive expression rate was 92.86% (39/42) in SPN, however, the positive expression rate of SOX11 was 8.93% (5/56) in PNET, which included 3 cases of G1 and 2 cases of G3 types of PNET, the SOX11 positive signal was absent in 16 cases of DACC, 8 cases of ACC and peritumoral nomal pancreatic tissue, and the differences were statistically significant of positive rate between SPN with PNET, DACC and ACC, respectively (P < 0.001). (3) The sensitivity of INSM1(+)/SOX11(-) immunophenotype for PNET was 85.71%, vs. CD56 (57.14%), the difference was statistically significant (P=0.001); vs. Syn (80.36%) and CgA (71.43%), the difference was no statistically significant (P>0.05). The specificity of INSM1(+)/SOX11(-) for PNET was 100.00%, vs. Syn (42.86%) and CD56 (47.62%), the difference was statistically significant (P < 0.001); vs. CgA (92.86%), the difference was no statistically significant (P>0.05). The sensitivity of INSM1(-)/SOX11(+) immunophenotype for SPN was 92.86%, vs. β-catenin (90.48%) and CD99 (85.71%), the difference was no statistically significant (P>0.05). The specificity of INSM1(-)/SOX11(+) for SPN was 96.43%, vs. CD99 (48.21%), the difference was statistically significant (P < 0.001); vs. β-catenin (100.00%), the difference was no statistically significant (P>0.05). (4) The positive expression of INSM1 and SOX11 in PNET and SOX11 were not correlated with clinicopathological parameters (age, gender, tumor size, location, grade, and metastasis) (P>0.05).

CONCLUSION

The positive expression patterns of INSM1 and SOX11 in PNET and SPN respectively are conductive to distinguish the both tumors. The combination of both take precedence over some corresponding conventional immunohistochemical markers in terms of sensitivity and specificity.

Observational study of surgical resection in small non-functional pancreatic neuroendocrine tumors: AS SEER-based study

The potential benefits of surgical resection for small non-functional pancreatic neuroendocrine tumors (NF-PNETs) in terms of survival remain uncertain. This study aimed to evaluate the impact of surgical treatment on patients with NF-PNETs. Using SEER data, we identified 1102 patients from 2004 to 2015 with well and moderately differentiated pancreatic neuroendocrine tumors (PNETs). The associations between continuous variables and receipt of surgery were assessed using Wilcoxon rank-sum tests. Kaplan-Meier survival curves for OS were compared using the log-rank test. We compared outcomes in patients who received surgical resection with those in patients who did not, using a univariable Cox model with inverse probability weighting according to the propensity score and propensity-score matching. Among the cohort of 1102 patients, a majority of 965 individuals (87%) underwent surgical intervention. Upon conducting univariate analysis, we observed that surgical treatment significantly prolonged patients' survival [HR = 0.41, 95% CI [0.26-0.65] P < 0.001]. However, the old [HR = 3.27, 95% CI (2.24-4.76), P 0.001], male gender [HR = 1.82, 95% CI (1.23-2.68), P = 0.003], and moderately well-differentiated factors [HR = 1.71, 95% CI (1.04-2.80), P = 0.034] were found to potentially decrease patients' survival time. In the multivariate analysis, male gender [HR = 1.73, 95% CI (1.15-2.61), P = 0.009] and the old factor [HR = 3.52, 95% CI (2.33-5.31), P < 0.001] emerged as influential predictors with higher hazard ratios. Notably, surgical treatment remained a significant factor associated with improved overall survival [HR = 0.53, 95% CI (0.33-0.84), P = 0.007]. Propensity-score matching and inverse probability weighting were employed as analytical techniques. The univariate analysis results showed favorable outcomes in the weight group [HR = 0.48, 95% CI (0.29-0.78), P = 0.003] and matched group [HR = 0.44, 95% CI (0.22-0.85), P = 0.015], respectively. Survival analysis further confirmed that surgical treatment contributed to increased overall survival (log rank, P < 0.05) in both the matching and weight groups. Patients diagnosed with small, non-functioning pancreatic neuroendocrine tumors who undergo surgical intervention exhibit improved overall survival (OS) outcomes. Therefore, surgery is strongly recommended for this patient population.

Efficacy of endoscopic ultrasound-guided tissue acquisition for solid pancreatic lesions 20 mm or less in diameter suspected as neuroendocrine tumors or requiring differentiation

BACKGROUND

For non-functioning pancreatic neuroendocrine tumors (pNETs) ≤ 20 mm, most guidelines consider follow-up observations as an option; however, the various treatment strategies are defined by size alone, even though the Ki-67 index is important for malignancy grading. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is the standard for the histopathological diagnosis of solid pancreatic lesions; however, recent results for small lesions remain unclear. Therefore, we examined the efficacy of EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation and the non-increase rate in tumor size in follow-up cases.

METHODS

We retrospectively analyzed data of 111 patients (median age = 58 years) with lesions ≤ 20 mm suspected as pNETs or requiring differentiation who underwent EUS-TA. All patients underwent specimen evaluation by rapid onsite evaluation (ROSE).

RESULTS

EUS-TA led to a diagnosis of pNETs in 77 patients (69.4%) and tumors other than pNETs in 22 patients (19.8%). The histopathological diagnostic accuracy of EUS-TA was 89.2% (99/111) overall, 94.3% (50/53) for 10-20 mm lesions, and 84.5% (49/58) for ≤ 10 mm lesions, with no significant difference in diagnostic accuracy (p = 0.13). The Ki-67 index was measurable in all patients with a histopathological diagnosis of pNETs. Among 49 patients with a diagnosis of pNETs who were followed up, one patient (2.0%) showed tumor enlargement.

CONCLUSIONS

EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation is safe and has adequate histopathological diagnostic accuracy, suggesting that follow-up observations of pNETs with a histological pathologic diagnosis are acceptable in the short term.

Precision radiotherapy using MR-linac for pancreatic neuroendocrine tumors in MEN1 patients (PRIME): a protocol for a phase I-II trial, and systematic review on available evidence for radiotherapy of pNETs

Background

Surgical resection is the standard of care for the treatment of pancreatic neuro-endocrine tumors (pNETs) in patients with Multiple Endocrine Neoplasia Type 1 (MEN1). However, surgery can cause significant short- and long-term morbidity. Magnetic resonance-guided radiotherapy (MRgRT) is a potential effective treatment with little side effects. With traditional radiotherapy techniques, irradiation of pancreatic tumors to high dose levels was hampered by poor visibility of the tumor during treatment. MRgRT uses onboard MRI to guide the treatment, thereby enabling delivery of ablative irradiation doses to the tumor, while sparing surrounding tissues. In this study, we describe results from a systematic review assessing efficacy of radiotherapy in pNET and present the protocol of the PRIME study.

Methods

PubMed, Embase and Cochrane Library were searched for articles assessing efficacy and side effects of radiotherapy for the treatment of pNETs. Risk of bias was assessed using the ROBINS-I Risk of Bias Tool for observational studies. Descriptive statistics were used to describe results of included trials.

Results

Four studies comprising of 33 patients treated by conventional radiotherapy were included. Despite the heterogeneity of studies, radiotherapy appeared to be effective for the treatment of pNETs with most patients responding (45.5%) or stabilizing (42.4%) in tumor size.

Conclusion and trial design

Due to the limited literature available and concerns about damage to surrounding tissue, conventional radiotherapy is currently little used for pNETs. The PRIME study is a phase I-II trial with a single arm prospective cohort study design, investigating the efficacy of MRgRT in MEN1 patients with pNET. MEN1 patients with growing pNETs with a size between 1.0 and 3.0 cm without malignant features are eligible for inclusion. Patients are treated with 40 Gy in 5 fractions on the pNET, using online adaptive MRgRT on a 1.5T MR-linac. The primary endpoint is the change in tumor size at MRI 12 months follow-up. Secondary endpoints include radiotoxicity, quality of life, endocrine and exocrine pancreas function, resection rate, metastatic free and overall survival. When MRgRT is found effective with low radiotoxicity, it could reduce the need for surgery for pNET and preserve quality of life.

Systematic Review Registration

PROSPERO https://clinicaltrials.gov/, (CRD42022325542).

Efficacy and toxicity of anti-vascular endothelial growth receptor tyrosine kinase inhibitors in patients with neuroendocrine tumours - A systematic review and meta-analysis

AIM

Although anti-vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors (RTKIs) have been tested in patients with neuroendocrine tumours (NETs) over the last two decades, no study to date has benchmarked efficacy and toxicity of these drugs in this patient population.

METHODS

All phase II and phase III studies of anti-VEGF RTKIs in patients with NETs, published between January 1, 2000 andJuly 31, 2021, across major trial databases, were searched in August 2021 for relevant studies. The primary objectives of the meta-analysis were to compare objective response rate (ORR) and progression-free survival (PFS) between patients with pancreatic NETs (pNETs) and extra-pancreatic NETs (epNETs), and the incidence rate ratio (IRR) of adverse events between patients receiving anti-VEGF RTKIs and control.

RESULTS

1611 patients were available for the meta-analysis; 1194 received anti-VEGF RTKIs. ORR in pNETs was 18% (95% confidence interval (CI) 13-25%), while ORR in epNETs was 8% (95% CI 5-12%); test for differences between pNETs and epNETs (x12 = 8.38, p < .01). Median PFS in pNETs was 13.9 months (95% CI 11.43-16.38 months), while median PFS in epNETs was 12.71 months (95% CI 9.37-16.05 months); test for differences between pNETs and epNETs (x12 = .35, p = .55). With regards to common grade 3/4 adverse events , patients who received anti-VEGF RTKIs were more likely to experience hypertension (IRR 3.04, 95% CI 1.63-5.65) and proteinuria (IRR 5.79, 95% CI 1.09-30.74) in comparison to those who received control.

CONCLUSIONS

Anti-VEGF RTKIs demonstrate anti-tumour effect in both pNETs and epNETs, supporting their development in both populations. These agents also appear to be safe in patients with NETs.

The road to systemic therapy in von Hippel-Lindau (VHL) disease: Are we there yet?

Pathogenic germline mutations in VHL gene cause von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary cancer syndrome associated with high penetrance of benign and malignant neoplasms, including clear cell renal cell carcinoma (ccRCC), central nervous system haemangioblastomas (CNS-HB), retinal angiomas, phaeochromocytomas and pancreatic neuroendocrine tumours (pNET). Management of VHL disease involves lifelong radiological and biochemical surveillance, often leading to repeat surgical intervention causing significant morbidity and mortality. Systemic therapy that prevents or reduces the need for surgical intervention could improve clinical outcomes and quality of life for affected individuals. Belzutifan is a second-generation small molecule hypoxia-inducible factor 2α (HIF-2α) inhibitor recently approved by US and UK regulators for the treatment of VHL (disease)-associated ccRCC, CNS-HB and pNET. While this is a welcome step forward, it is vital that we consider in what circumstances these drugs are recommended and how they fit into the overall management of VHL disease. In this personal view article, we reflect on the history of the use of systemic therapy in localised VHL disease and consider open questions relating to the use of HIF-2α inhibitors, including the need to involve medical oncologists in the multidisciplinary team moving forward. Indeed, VHL disease is the perfect paradigm for similar settings in the future.

Differential diagnosis between pancreatic solid pseudopapillary tumors and pancreatic neuroendocrine tumors based on contrast enhanced ultrasound imaging features

PURPOSES

To evaluate the application of contrast enhanced ultrasound (CEUS) in preoperatively differential diagnosis between pancreatic solid pseudopapillary tumors (SPTs) and pancreatic neuroendocrine tumors (pNETs).

PATIENTS AND METHODS

This retrospective study was approved by Institutional Review Board. Patients with surgical resection and histopathological diagnosis as SPTs and pNETs were included. All patients underwent B mode ultrasound (BMUS) and CEUS examinations within one week before surgical operation. On BMUS, the size, location, echogenicity, calcification, and margin of lesions were observed and recorded. On CEUS imaging, enhancement patterns, and enhancement degrees were recorded and analyzed. An independent t-test or Mann-Whitney U test was used for comparison between continuous variables. Chi-square test was used to compare the CEUS patterns.

RESULTS

From February 2017 to Dec 2022, patients diagnosed as SPTs (n = 39) and pNETs (n = 48) were retrospectively included. On BMUS, anechoic cystic changes (19/39, 48.72%) and hyperechoic calcification (14/39, 35.90%) are more commonly detected in SPTs (P = 0.000). On CEUS imaging, the majority of SPTs (27/39, 69.23%) showed hypo-enhancement in the arterial phase, while most of the pNETs (36/48, 75.00%) showed hyper- or iso-enhancement in the arterial phase (P = 0.000). In the venous phase, most of the SPTs (32/39, 82.05%) showed hypo-enhancement, while over half of pNETs (29/48, 60.42%) showed hyper- or iso-enhancement compared to pancreatic parenchyma (P = 0.001).

CONCLUSIONS

CEUS is a valuable and non-invasive imaging method to make preoperatively differential diagnoses between SPTs and pNETs.

Endoscopic Ultrasound-Guided Therapies in Patients with Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine neoplasms (PNETs) are rare but can be associated with significant morbidity and mortality. PNETs can be difficult to diagnose and have a propensity for metastasis before their diagnosis is established. To this end, many PNETs do not become apparent until late in their clinical course. Endoscopic ultrasound (EUS) has become the modality of choice for detecting these lesions due to its high tumor detection rate. Additionally, therapeutic techniques have arisen from EUS which allow for the treatment of PNETs. Overall, EUS has become a powerful diagnostic and therapeutic modality for addressing pancreatic lesions such as PNETs. In this perspective article, we provide an overview of the therapeutic potentials of EUS in the management of PNETs.

Characteristics of small pancreatic neuroendocrine tumors and risk factors for invasion and metastasis

BACKGROUND

The number of people with small pancreatic neuroendocrine tumors (pNETs) (tumors with a diameter less than or equal to 2 cm) is gradually increasing, but the selection of treatment strategy is still controversial. Our aim was to characterize small pNETs with a poor prognosis and to define the impact of aggressive small pNETs on survival and the risk factors for the development of invasive disease.

METHODS

Patients with pNETs diagnosed between 2004 and 2019 and a tumor diameter of 2 cm or less were selected from the SEER Registry. Kaplan-Meier survival analysis was used to identify the factors affecting patient survival, and binary logistic regression was used to identify the associated risk factors.

RESULTS

A total of 3261 patients with pNETs were enrolled in the study. Both older and younger patients benefited from surgery. Regional invasion occurred in 10% of the patients, and distant metastases occurred in 9% of the patients, but in both categories, those who underwent surgery had better survival outcomes than those who did not. There was no difference in survival between patients with a tumor diameter of 1-2 cm and those with a tumor diameter of less than 1 cm, and there was no difference in survival between patients with functional and nonfunctional small pNETs. However, the survival of patients with pNETs in the head of the pancreas was worse than that of patients with tumors in other parts of the pancreas. Survival was worse in elderly patients and in those with poorly differentiated and undifferentiated tumors. Lymphatic metastasis, regional invasion, and distant metastasis all worsened the prognosis of patients. The presence or absence of neuroendocrine function, the degree of tumor differentiation, and the location of the tumor were associated with the risk of lymphatic metastasis and regional invasion; the risk factors for distant metastasis were associated with the degree of differentiation and tumor location.

CONCLUSION

The pNETs ≤ 2 cm in diameter could be still aggressive, and patient prognosis worsens after invasive disease develops. Attention to the characteristics of aggressive tumors can improve patient survival.

Quantitative contrast-enhanced endoscopic ultrasound in pancreatic ductal adenocarcinoma and pancreatic neuroendocrine tumors: can we predict survival using perfusion parameters? A pilot study

AIM

Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) parameters may be used to predict prognosis of pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (pNET). The aim of this study was to investigate the association between several perfusion parameters on CEH-EUS performed before treatment and survival outcome in patients with PDAC or pNET.

MATERIAL AND METHODS

Thirty patients with PDAC or pNET who underwent CEH-EUS and EUS-guided fine needle aspiration (EUS-FNA) were included. Quantitative analysis of tumor vascularity was performed using time-intensity curve (TIC) analysis-derived parameters, obtained from processing CEH-EUS recordings with a commercially available software (VueBox). Cox proportional hazards models were used to determine associations with survival outcome.

RESULTS

Median overall survival (OS) for PDAC patients was 9.61 months (95% CI: 0.1-38.7) while the median OS for pNET patients was 15.81 months (95% CI: 5.8-24.75. In a multivariate model for OS, a lower peak enhancement (HR=1.76, p=0.02) and a lower wash-in area under the curve (HR=1.06, p=0.001) were associated with worse survival outcome for patients with PDAC.

CONCLUSIONS

CEH-EUS parameters may be used as a surrogate to predict PDAC aggressiveness and survival before treatment. After validation by large-scale studies, CEH-EUS perfusion parameters have the potential to be used in pretreatment risk stratification of patients with PDAC and in evidence-based clinical decision support.

Clinical characteristics of 662 patients with pancreatic neuroendocrine tumors receiving antitumoral therapy

Pancreatic neuroendocrine neoplasia constitute an important subentity of the gastroenteropancreatic neuroendocrine neoplasms accounting for up to 15% of all neuroendocrine neoplasm. Prognosis and oncological behavior of pancreatic neuroendocrine tumors (pNETs) is extremely heterogenous and dependent on the specific tumor stage and differentiation. However, systematic data on the specific epidemiology of pNET are scarce. We identified 662 patients with pNET within the Oncology Dynamics database (IQVIA). Patients were derived from 4 European countries (Germany, France, UK, Spain), 3 Asian countries (Japan, China, South Korea) and 2 South American countries (Mexico and Brazil) and with regard to major patient and tumor related characteristics including patients' age, sex, tumor stage, tumor grading, and differentiation. The mean age of the study cohort was 62 years (SD 12 years) with 53.9.1% of all patients being male. The majority of patients had an Eastern co-operative of Oncology Group 1 performance status (63.3%). The most common Union international contre le cancer tumor stage was stage IV (85%) with liver metastases (89.0%) representing the most common site of extra-pancreatic tumor manifestation. The majority of all patients displayed well or moderate tumor differentiation (9.6% of patients had a Ki-67 expression below 2%. 67.6% of pNET patients had a Ki-67 expression between 2 and 20% and 22.8% of patients showed an expression above 20%). At time point of diagnoses, 93.1% of patients were classified as inoperable. Of note, 93.9 % of patients received systemic anti-tumoral therapy in palliative intention, while treatment was administered in 1.4 % of cases in neoadjuvant and in 4.7% of cases in in an adjuvant setting. Biological therapy was applied to 39.4% of patients, followed by targeted therapies (31.4%) and chemotherapy. Pancreatic neuroendocrine neoplasia are diagnosed in advanced tumor stages, globally. Systemic treatment was the most commonly used treatment modality. Such data may help to better understand the specific epidemiology of pNET worldwide.

Patients with non-functional metastatic G2 pancreatic neuroendocrine tumor benefit from palliative surgery: A 20-year single-center retrospective analysis

Pancreatic neuroendocrine tumor (pNET) is the most common subset (31.5%) of gastroenteropancreatic neuroendocrine tumor in China. Based on real-world data from a single center, the present study aimed to evaluate the influence of clinical characteristics, medical treatment and surgery on the survival of non-functional metastatic G2 pNET. In total, 114 metastatic non-functional G2 pNET patients, who were treated and followed up in the Department of Medical Oncology, Peking Union Medical College Hospital (PUMCH) from 2001 until 2019, were analyzed retrospectively. The primary endpoint, overall survival (OS), was calculated from the date of diagnosis to the date of death. The second endpoint, progression-free survival (PFS), was calculated from the date of diagnosis to the date of disease progression. Statistical data were analyzed to evaluate the effects of a clinical characteristic, medical treatment and surgery on OS and PFS. Sixty-nine (60.5%) patients were male and 87 (76.3%) were aged < 60 years. The liver was the most common metastatic organ, with a total of 84 cases (73.7%). With respect to surgery, 32 (28.1%) patients underwent radical surgery and 37 (32.5%) underwent palliative surgery. Survival analysis showed that the 5-year and 10-year survival rates were 79.36% and 70.0%, respectively. Univariate and multivariate Cox regression analyses suggested that both radical (p < .001/.003) and palliative surgery (p < .001/.002) significantly prolonged OS, as revealed by the Kaplan-Meier test (p < .001). Subgroup analysis showed that palliative resection also significantly improves the prognosis in patients with multiple liver metastases. However, the first-line systemic anti-tumor therapy option showed no statistical differences in the present study. Overall, patients with non-functional metastatic G2 pNET receiving palliative or radical surgery demonstrated significantly better survival. Prospective clinical trials are suggested to validate our findings.

Molecular classification and outcome of children with rare CNS embryonal tumors: results from St. Jude Children's Research Hospital including the multi-center SJYC07 and SJMB03 clinical trials

Methylation profiling has radically transformed our understanding of tumors previously called central nervous system primitive neuro-ectodermal tumors (CNS-PNET). While this marks a momentous step toward defining key differences, reclassification has thrown treatment into disarray. To shed light on response to therapy and guide clinical decision-making, we report outcomes and molecular features of children with CNS-PNETs from two multi-center risk-adapted studies (SJMB03 for patients ≥ 3 years; SJYC07 for patients < 3 years) complemented by a non-protocol institutional cohort. Seventy patients who had a histological diagnosis of CNS-PNET or CNS embryonal tumor from one of the new categories that has supplanted CNS-PNET were included. This cohort was molecularly characterized by DNA methylation profiling (n = 70), whole-exome sequencing (n = 53), RNA sequencing (n = 20), and germline sequencing (n = 28). Clinical characteristics were detailed, and treatment was divided into craniospinal irradiation (CSI)-containing (SJMB03 and SJMB03-like) and CSI-sparing therapy (SJYC07 and SJYC07-like). When the cohort was analyzed in its entirety, no differences were observed in the 5-year survival rates even when CSI-containing therapy was compared to CSI-sparing therapy. However, when analyzed by DNA methylation molecular grouping, significant survival differences were observed, and treatment particulars provided suggestions of therapeutic response. Patients with CNS neuroblastoma with FOXR2 activation (CNS-NB-FOXR2) had a 5-year event-free survival (EFS)/overall survival (OS) of 66.7% ± 19.2%/83.3% ± 15.2%, and CIC rearranged sarcoma (CNS-SARC-CIC) had a 5-year EFS/OS both of 57.1% ± 18.7% with most receiving regimens that contained radiation (focal or CSI) and multidrug chemotherapy. Patients with high-grade neuroepithelial tumor with BCOR alteration (HGNET-BCOR) had abysmal responses to upfront chemotherapy-only regimens (5-year EFS = 0%), but survival extended with salvage radiation after progression [5-year OS = 53.6% ± 20.1%]. Patients with embryonal tumor with multilayered rosettes (ETMR) or high-grade glioma/glioblastoma multiforme (HGG/GBM) did not respond favorably to any modality (5-year EFS/OS = 10.7 ± 5.8%/17.9 ± 7.2%, and 10% ± 9.0%/10% ± 9.0%, respectively). As an accompaniment, we have assembled this data onto an interactive website to allow users to probe and query the cases. By reporting on a carefully matched clinical and molecular cohort, we provide the needed insight for future clinical management.

Genetics of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (pNETs) represent a relatively rare disease; however, the incidence has been increasing during the last 2 decades. Next generation sequencing has greatly increased our understanding of driver mutations in pNETs. Sporadic pNETs have consistently presented with mutations in MEN1, DAXX/ATRX, and genes related to the mammalian target of rapamycin pathway. Inherited pNETs have traditionally been associated with multiple endocrine neoplasia type 1, von Hippel-Lindau syndrome, neurofibromatosis type 1, and tuberous sclerosis complex. The current review expands on the existing knowledge and the relevant updates on the genetics of pNETs.

Distinguishing pancreatic solid serous cystadenomas from nonfunctional pancreatic neuroendocrine tumors by computed tomography: A propensity score analysis

This study aims to evaluate the utility of calculated computed tomography (CT) attenuation value ratio (AVR) and enhancement pattern in distinguishing pancreatic solid serous cystadenomas (SCAs) from nonfunctional pancreatic neuroendocrine tumors (NF-pNETs). A total of 142 consecutive patients with 22 solid SCAs and 120 NF-pNETs confirmed by pathology were included in this retrospective study. All patients underwent preoperative contrast-enhanced CT and were categorized into 2 groups, solid SCA and NF-pNET groups. Patients with NF-pNETs were matched to patients with solid SCAs via propensity scores. AVR was measured and defined as: attenuation value of tumor/attenuation value of normal pancreas. AVR and enhancement pattern performance were assessed according to the discriminative abilities of patients. After matching, 29 patients were allocated to the NF-pNET group. Before matching, sex, age, and the peak enhanced value phase were significantly different between solid SCA and NF-pNET patients (P < .05). After matching, no significant difference was observed between both groups (P > .05). Solid SCAs AVRs were significantly smaller than NF-pNETs AVRs in all unenhanced, arterial, portal venous, and delayed phases (P < .05). Solid SCAs showed significantly more wash-in and wash-out enhancement patterns than NF-pNETs (P < .05). For unenhanced, arterial, portal venous, and delayed phases, and enhancement pattern, the area under the curve (AUC) values were 0.96, 0.72, 0.80, 0.85, and 0.86, respectively. Low AVR on unenhanced CT and wash-in and wash-out enhancement patterns were useful for differentiating solid SCAs from NF-pNETs and may be useful for clinical decisions, a clearer opinion will be formed with further studies to be conducted with larger patient numbers.

Modeling MEN1 with Patient-Origin iPSCs Reveals GLP-1R Mediated Hypersecretion of Insulin

Multiple endocrine neoplasia type 1 (MEN1) is an inherited disease caused by mutations in the MEN1 gene encoding a nuclear protein menin. Among those different endocrine tumors of MEN1, the pancreatic neuroendocrine tumors (PNETs) are life-threatening and frequently implicated. Since there are uncertainties in genotype and phenotype relationship and there are species differences between humans and mice, it is worth it to replenish the mice model with human cell resources. Here, we tested whether the patient-origin induced pluripotent stem cell (iPSC) lines could phenocopy some defects of MEN1. In vitro β-cell differentiation revealed that the percentage of insulin-positive cells and insulin secretion were increased by at least two-fold in MEN1-iPSC derived cells, which was mainly resulted from significantly higher proliferative activities in the pancreatic progenitor stage (Day 7–13). This scenario was paralleled with increased expressions of prohormone convertase1/3 (PC1/3), glucagon-like peptide-1 (GLP-1), GLP-1R, and factors in the phosphatidylinositol 3-kinase (PI3K)/AKT signal pathway, and the GLP-1R was mainly expressed in β-like cells. Blockages of either GLP-1R or PI3K significantly reduced the percentages of insulin-positive cells and hypersecretion of insulin in MEN1-derived cells. Furthermore, in transplantation of different stages of MEN1-derived cells into immune-deficient mice, only those β-like cells produced tumors that mimicked the features of the PNETs from the original patient. To the best of our knowledge, this was the first case using patient-origin iPSCs modeling most phenotypes of MEN1, and the results suggested that GLP-1R may be a potential therapeutic target for MEN1-related hyperinsulinemia.

The diagnostic value of intravoxel incoherent motion diffusion-weighted imaging for distinguishing nonhypervascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinomas

PURPOSE

To primarily evaluate the diagnostic performance of the monoexponential and intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) models for differentiating between nonhypervascular pancreatic neuroendocrine tumors (PNETs) and pancreatic ductal adenocarcinomas (PDACs).

METHODS

63 patients with PNETs (35 nonhypervascular PNETs and 28 hypervascular PNETs) and 164 patients with PDACs were retrospectively enrolled in the study and underwent multiple b-value DWI. Intraobserver and interobserver reliabilities of DWI parameters were assessed by using the intraclass correlation coefficient (ICC). The parameters of apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) of nonhypervascular PNETs were compared with PDACs and hypervascular PNETs using the independent sample t test or the Mann-Whitney U test. The diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

All DWI parameters values showed good to excellent intra- and interobserver agreements (ICC = 0.743-0.873). Nonhypervascular PNETs had significantly lower ADC and D, but significantly higher f than PDACs (P = 0.005, P < 0.001 and P < 0.001, respectively). ADC, D and f of nonhypervascular PNETs were lower than hypervascular PNETs (P = 0.001, <0.001 and 0.093, respectively). D* of nonhypervascular PNETs showed no statistically significant differences with PDACs and hypervascular PNETs (P = 0.809 and 0.420). D showed a higher area under the curve (AUC), followed by ADC and f (AUC = 0.885, 0.665 and 0.740, respectively) in differentiating nonhypervascular PNETs from PDACs.

CONCLUSION

Monoexponential and IVIM diffusion models are valuable to differentiate nonhypervascular PNETs from PDACs. D showed better performance than f and ADC.

Comprehensive Characterization of the Genomic Landscape in Chinese Pulmonary Neuroendocrine Tumors Reveals Prognostic and Therapeutic Markers (CSWOG-1901)

BACKGROUND

Pulmonary neuroendocrine tumors (pNETs) include typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung carcinoma (SCLC). The optimal treatment strategy for each subtype remains elusive, partly due to the lack of comprehensive understanding of their molecular features. We aimed to explore differential genomic signatures in pNET subtypes and identify potential prognostic and therapeutic biomarkers.

METHODS

We investigated genomic profiles of 57 LCNECs, 49 SCLCs, 18 TCs, and 24 ACs by sequencing tumor tissues with a 520-gene panel and explored the associations between genomic features and prognosis.

RESULTS

Both LCNEC and SCLC displayed higher mutation rates for TP53, PRKDC, SPTA1, NOTCH1, NOTCH2, and PTPRD than TC and AC. Small cell lung carcinoma harbored more frequent co-alterations in TP53-RB1, alterations in PIK3CA and SOX2, and mutations in HIF-1, VEGF and Notch pathways. Large cell neuroendocrine carcinoma (12.7 mutations/Mb) and SCLC (11.9 mutations/Mb) showed higher tumor mutational burdens than TC (2.4 mutations/Mb) and AC (7.1 mutations/Mb). 26.3% of LCNECs and 20.8% of ACs harbored alterations in classical non-small cell lung cancer driver genes. The presence of alterations in the homologous recombination pathway predicted longer progression-free survival in advanced LCNEC patients with systemic therapy (P = .005) and longer overall survival (OS) in SCLC patients with resection (P = .011). The presence of alterations in VEGF (P = .048) and estrogen (P = .018) signaling pathways both correlated with better OS in patients with resected SCLC.

CONCLUSION

We performed a comprehensive genomic investigation on 4 pNET subtypes in the Chinese population. Our data revealed distinctive genomic signatures in subtypes and provided new insights into the prognostic and therapeutic stratification of pNETs.

Prognostic Factors of Small Non-Functional Pancreatic Neuroendocrine Tumors and the Risk of Lymph Node Metastasis: A Population-Level Study

BACKGROUND

Small non-functional neuroendocrine tumors (NF-PNETs) are a heterogeneous subset of tumors with controversy regarding their optimal management. We aimed to analyze the prognostic factors of patients with small NF-PNETs and create a risk score for lymph node metastasis (LNM).

METHODS

Data of 751 patients with NF-PNETs ≤ 2 cm were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate survival analysis was performed to analyze the prognostic factors. Logistic regression was used to identify risk factors for LNM.

RESULTS

Of the 751 patients, 99 (13.2%) were confirmed to have LNM. In multivariate survival analysis, LNM (hazard ratio [HR], 2.12; 95% CI, 1.04-4.32, p = 0.040) was independently associated with disease-specific survival. Logistic regression identified that tumor location in the head of the pancreas (odds ratio [OR], 4.33; 95% CI, 2.75-6.81; p < 0.001), size ≥ 1.5-2 cm (OR, 1.84; 95% CI, 1.17-2.87; p = 0.009), and grade III-IV (OR, 7.90; 95% CI, 1.79-34.90; p = 0.006) were independent risk factors of LNM. According to the OR value, the risk of LNM was scored as follows: a score of 1 for tumors located in the body/tail of the pancreas and 4 for those located in the head; a score of 1 for tumors <1 cm and 2 for those ≥1.5-2 cm; and a score of 1 for tumors with grade I-II and 8 for those with grade III-IV. Finally, the median score for this cohort was 4, with an interquartile range of 3-6. Therefore, patients were classified as three groups based on the risk score system: a total score of 1-3 for low risk, 4-6 for intermediate risk (OR, 2.98; 95% CI, 1.59-5.60; p = 0.001), and 7-14 for high risk (OR, 8.94; 95% CI, 4.50-17.7; p < 0.001), with an incidence of LNM 5.0%, 13.5%, and 31.8%, respectively (p < 0.001).

CONCLUSION

Surgical resection with regional lymphadenectomy is recommended for small NF-PNETs with malignant potential of LNM. A risk score for LNM based on tumor grade, location, and size may preoperatively predict LNM of small NF-PNETs and guide clinical practice.

International Validation of a Nomogram to Predict Recurrence after Resection of Grade 1 and 2 Nonfunctioning Pancreatic Neuroendocrine Tumors

BACKGROUND

Despite the low recurrence rate of resected nonfunctional pancreatic neuroendocrine tumors (NF-pNETs), nearly all patients undergo long-term surveillance. A prediction model for recurrence may help select patients for less intensive surveillance or identify patients for adjuvant therapy. The objective of this study was to assess the external validity of a recently published model predicting recurrence within 5 years after surgery for NF-pNET in an international cohort. This prediction model includes tumor grade, lymph node status and perineural invasion as predictors.

METHODS

Retrospectively, data were collected from 7 international referral centers on patients who underwent resection for a grade 1-2 NF-pNET between 1992 and 2018. Model performance was evaluated by calibration statistics, Harrel's C-statistic, and area under the curve (AUC) of the receiver operating characteristic curve for 5-year recurrence-free survival (RFS). A sub-analysis was performed in pNETs >2 cm. The model was improved to stratify patients into 3 risk groups (low, medium, high) for recurrence.

RESULTS

Overall, 342 patients were included in the validation cohort with a 5-year RFS of 83% (95% confidence interval [CI]: 78-88%). Fifty-eight patients (17%) developed a recurrence. Calibration showed an intercept of 0 and a slope of 0.74. The C-statistic was 0.77 (95% CI: 0.70-0.83), and the AUC for the prediction of 5-year RFS was 0.74. The prediction model had a better performance in tumors >2 cm (C-statistic 0.80).

CONCLUSIONS

External validity of this prediction model for recurrence after curative surgery for grade 1-2 NF-pNET showed accurate overall performance using 3 easily accessible parameters. This model is available via www.pancreascalculator.com.

OUP accepted manuscript

Background

Pancreatic neuroendocrine tumors (pNETs) are rare cancers with outcomes determined by multiple factors including grade, stage, and clinical presentation. In this study, we aimed to determine the prognosis of patients with pNETs using a large population-based database.

Materials and Methods

In this population-based study, we identified patients with pNETs from the SEER 18 registry (2000-2016) using a combination of ICD-O-3 and histology codes. We calculated age-adjusted incidence rates using SEER*Stat 8.3.5. In addition, we analyzed overall survival (OS) using the Kaplan-Meier method, and investigated prognostic factors using a multivariable Cox proportional hazards model.

Results

A total of 8944 pNETs patients were identified. Annual incidence rates increased from 0.27 to 1.00 per 100 000. This was largely explained by an increase in number of patients diagnosed with localized disease in more recent years (2012-2016). Median OS was 68 months (95% CI [64, 73]) and 5-year OS rates in localized, regional, and metastatic disease were 83%, 67%, and 28%, respectively. There was a significant improvement in OS for patients diagnosed between 2009 and 2016 (median OS 85 months) compared with those diagnosed between 2000 and 2008 (median OS 46 months) (HR 0.66; 95% CI [0.62, 0.70]). This improvement in OS was consistent across all stages.

Conclusions and Relevance

This study shows a steady increase pNETs incidence with notable stage migration to earlier stages in recent years. This increase in incidence is accompanied by a significant improvement in survival across different disease stages.

Metabolic Syndrome Is Associated with Impaired Survival after Surgery for Pancreatic Neuroendocrine Tumors

INTRODUCTION

Pancreatic neuroendocrine tumors (pNETs) are a heterogeneous group of neoplasms. Surgery is the only curative treatment option. However, our understanding of predictors of survival after surgery remains incomplete. The aim of the study was to evaluate metabolic syndrome (MetS) as a prognostic factor in pNET.

METHODS

In a retrospective single-center cohort study, we examined the influence of MetS in 120 patients with curative intended resection of pNETs on overall survival (OS), recurrence-free survival, and outcome after recurrence.

RESULTS

MetS was present in 32 patients (26.6%). Patients with MetS had an impaired OS after curative intended surgery compared to patients without MetS (median OS 72 months [95% CI 13.3-130.7] vs. not reached, p < 0.001). The shortest survival was observed in patients with MetS in the presence of oligometastatic disease at time of surgery. In a multivariable Cox regression analysis, MetS was identified as an independent risk factor for mortality (hazard ratio [HR] = 4.54, 95% CI [1.88-11.00], p = 0.01). In our dataset, MetS was not associated with tumor recurrence or recurrence-free survival. Nevertheless, in patients with recurrence, MetS was associated with shorter time to recurrence (median 3.4 months, 95% CI [2.48-4.24], vs. 20.1 months, 95% CI [10.8-29.49], p < 0.001), and poor outcome (HR = 5.03, 95% CI [1.25-20.20], p = 0.01).

CONCLUSIONS

We identified MetS as a negative prognostic factor after curative intended surgery for pNET. In particular, patients with oligometastatic disease might not benefit from extensive surgery in the presence of MetS. Furthermore, MetS had a strong impact on survival after recurrence.

Predicting Progression, Recurrence, and Survival in Pancreatic Neuroendocrine Tumors: A Single Center Analysis of 174 Patients

INTRODUCTION

The European Neuroendocrine Tumor Society, ENETS, reports variables of prognostic significance in pancreatic neuroendocrine tumors (PNET). However, studies have short follow-ups, and the optimal treatment remains controversial. We aimed to determine overall survival (OS), progression-free survival (PFS) after conservative treatment, and recurrence-free survival (RFS) after surgery and further to find predictors of aggressive PNET behavior to support treatment decisions.

METHODS

174 patients with PNET treated at Aarhus University Hospital from 2011 to 2021 were included in a retrospective cohort study. Patients were divided into surgically resected (SUR, n=91) and medically or conservatively treated (MED, n=83). Variables were tested in univariate and multivariate survival analysis. Median follow-up time was 3.4 years in the MED group and 4.5 years in the SUR group.

RESULTS

The 5-year OS was 95% and 65% for the SUR and MED groups, respectively. The 5-year RFS in the SUR group was 80% whereas the 5-year PFS in the MED group was 41%. Larger tumor size, Ki67 index, tumor grade, and stage were predictive of shorter OS, RFS, and PFS. Further, chromogranin A was a predictor of OS. Larger tumor size was associated with higher stage and grade. Only 1 of 28 patients with stage 1 disease and size ≤2 cm developed progression on a watch-and-wait strategy during a median follow-up of 36 months.

CONCLUSION

This study supported the ENETS staging and grading system to be useful to predict OS, PFS, and RFS in PNET. Further, our data support that small, localized, low-grade PNETS can be followed with active surveillance.

Biomarkers for prognosis in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) encompass a diverse group of malignancies marked by histological heterogeneity and highly variable clinical outcomes. We performed a systematic review on potential prognostic biomarkers in PNETs by searching the PubMed database. A total of 472 manuscripts were reviewed in detail, of which 52 multivariate studies met the inclusion criteria proposed by the Reporting Recommendations for Tumor Marker Prognostic Studies. These altogether analyzed 53 unique targets, and 36 of them were statistically associated with survival.