Pancreatic neuroendocrine tumors are a heterogeneous group of rare clinical tumors, which can be classified into functional pancreatic neuroendocrine tumor (insulinoma is the most common) and noninsulinoma. Insulinoma and noninsulinoma have different mutation profiles. In noninsulinoma, ATRX/DAXX mutation is associated with alternative lengthening of telomeres-positive phenotype and positively correlated with poor prognosis. Copy number variation is also a prognostic marker for a high risk of recurrence. Scholars have used epigenetics as well as a multiomics approach (combining epigenetics, metabolomics, proteomics, etc) to molecularly type noninsulinoma, and there are huge differences in molecular expression and patient prognosis between different groups. In this manuscript, we summarize the published studies that utilized genome, epigenome, transcriptome, and proteome data to classify noninsulinoma.

Although pancreatic neuroendocrine tumors (PanNETs) are less common than other pancreatic tumors, they show significant differences in clinical behavior, genetics, and treatment responses. The understanding of the molecular pathways of PanNETs has gradually improved with advances in sequencing technology. Mutations in MEN1 (the most frequently varied gene) may result in the deletion of the tumor suppressor menin, affecting gene regulation, DNA repair, and chromatin modification. Changes in ATRX and DAXX involve chromatin remodeling, telomere stability and are associated with the alternative lengthening of telomeres (ALT) pathway and aggressive tumors. VHL mutations emphasize the roles of hypoxia and angiogenesis. Mutations in PTEN, TSC1/TSC2, and AKT1-3 often disrupt the mTOR pathway, complicating the genetic landscape of PanNETs. Understanding these genetic alterations and their impact on the PI3K/AKT/mTOR axis help to investigate new targeted therapies, which in turn can improve patient prognosis. This review aims to clarify PanNET pathogenesis through key mutations and their clinical relevance.

Pancreatic neuroendocrine neoplasms (pNENs) are rare and heterogeneous tumors arising from neuroendocrine cells, representing approximately 10 % of all Gastro-Entero-Pancreatic neuroendocrine neoplasms. While most pNENs are sporadic, a subset is associated with genetic syndromes such as multiple endocrine neoplasia type 1 (MEN1) or von Hippel-Lindau disease (VHL). pNENs are further classified into functioning and non-functioning tumors, with distinct clinical behaviors, prognoses, and treatment approaches. This review explores genetic and environmental biomarkers that influence the risk, prognosis, and therapeutic responses in pNENs. The epidemiology of pNENs reveals an increasing incidence, primarily due to advancements in imaging techniques. Genetic factors play a pivotal role, with germline mutations in MEN1, VHL, and other genes contributing to familial pNENs. Somatic mutations, including alterations in the mTOR pathway and DNA maintenance genes such as DAXX and ATRX, are critical in sporadic pNENs. These mutations, along with epigenetic dysregulation and transcriptomic alterations, underpin the diverse clinical and molecular phenotypes of pNENs. Emerging evidence suggests that epigenetic changes, including DNA methylation profiles, can stratify pNEN subtypes and predict disease progression. Environmental and lifestyle factors, such as diabetes, smoking, and chronic pancreatitis, have been linked to an increased risk of sporadic pNENs. While the association between these factors and tumor progression is still under investigation, their potential role in influencing therapeutic outcomes warrants further study. Advances in systemic therapies, including somatostatin analogs, mTOR inhibitors, and tyrosine kinase inhibitors, have improved disease management. Biomarkers such as Ki-67, somatostatin receptor expression, and O6-methylguanine-DNA methyltransferase (MGMT) status are being evaluated for their predictive value. Novel approaches, including the use of circulating biomarkers (NETest, circulating tumor cells, and ctDNA) and polygenic risk scores, offer promising avenues for non-invasive diagnosis and monitoring. Despite these advancements, challenges remain, including the need for large, well-annotated datasets and validated biomarkers. Future research should integrate multi-omics approaches and leverage liquid biopsy technologies to refine diagnostic, prognostic, and therapeutic strategies. Interdisciplinary collaborations and global consortia are crucial for overcoming current limitations and translating research findings into clinical practice. These insights hold promise for improving prevention, early detection, and tailored treatments, ultimately enhancing patient outcomes.

This study aimed to evaluate potential difference in clinicopathological characteristics, prognosis as well as the genetic bases between insulinomas and non-functional pancreatic neuroendocrine neoplasms (NF-PNENs).

We analyzed data from 241 patients who underwent resection for PNENs measuring 1-2 ​cm at West China Hospital between 2002 and 2020.

NF-PNENs were more likely to show lymph node involvement (P ​< ​0.001), perineural invasion (P ​= ​0.025), and a more advanced tumor grade (P ​< ​0.001). In multivariate analysis, NF-PNENs, when combined with lymph node metastasis and WHO G2/G3 grading, independently decreased recurrence-free survival [hazard ratio (HR), 4.72; P ​= ​0.014]. Whole exome sequencing revealed that most of the top 20 somatic mutated genes (90 ​%, 36/40) between insulinomas and NF-PNENs are different. Besides, all copy number variant (CNV) patterns were present in NF-PNENs, whereas insulinomas were more likely to exhibit CNV amplification.

Insulinomas and small NF-PNENs exhibit distinct tumor biology, prognosis, and genetic backgrounds, which may inform changes in surgical management and postoperative follow-up strategies for these patients.

Putting pancreatic adenocarcinoma (PAAD) screening into perspective for high-risk individuals could significantly reduce cancer morbidity and mortality. Previous studies have profiled somatic mutations in PAAD. In contrast, the prevalence of mutations in PAAD predisposition genes has not been defined, especially in the Asian population. Using a multi-tier cohort design and whole genome/exome sequencing, we create a comprehensive germline mutation map of PAAD in 1,123 Chinese cancer patients in comparison with 11 pan-ethnic studies. For well-known pathogenic/likely pathogenic germline variants, Chinese patients exhibit overlapping but distinct germline mutation patterns comparing with Western cohorts, highlighted by lower mutation rates in known PAAD genes including BRCA1, BRCA2, ATM, CDKN2A, and CHEK2, and distinct mutations in CFTR, RAD51D, FANCA, ERCC2, and GNAS exclusive to Chinese patients. CFTR emerges as a top candidate gene following loss of heterozygosity analysis. Using an integrative multi-omics and functional validation paradigm, we discover that deleterious variants of uncertain significance may compromise CFTR's tumor suppressor function, and demonstrate the clinical relevance by using patient derived organoids for drug screen. Our multifaceted approach not only deepens the knowledge of population differences in PAAD germline mutations but also unveils potential avenues for targeted therapeutic interventions.

The classification of neuroendocrine neoplasms has evolved significantly. In the current World Health Organization (WHO) classification, well-differentiated grade 3 neuroendocrine tumors (G3-NETs) are distinguished from poorly-differentiated neuroendocrine carcinomas (NECs) based on morphology despite using the same proliferation indices, which poses diagnostic challenges. This review aims to assist pathologists in making an accurate diagnosis, which is crucial for patient management as G3-NETs and NECs have different prognoses and chemotherapy responses.

A literature review and meta-analyses were conducted to summarize current knowledge of G3-NETs and NECs, focusing on histopathologic and genetic characteristics.

Grade 3 neuroendocrine tumors and NECs are distinct entities with differences in histopathology, genetics, and clinical presentations. Grade 3 neuroendocrine tumors have a lower Ki-67 proliferation index and tumor mutational burden compared to NECs. Distinct gene mutations and pathways have been identified in G3-NETs and NECs, offering potential for developing a diagnostic gene panel. The 2022 WHO classification recognizes the use of immunohistochemistry for somatostatin receptors 2/5, TP53, Rb, Menin, P27, ATRX, and DAXX to distinguish G3-NETs and NECs. In particular, TP53 and ATRX immunohistochemistry may be useful in routine diagnostics.

Specific immunohistochemistry and genetic tests should be developed and incorporated into the classification to reliably distinguish G3-NETs from NECs.

Neuroendocrine tumors (NETs) are a diverse group of malignancies that can occur in various organs, with a notable prevalence in the lungs and gastrointestinal tract, which are the focus of this Review. Although NETs are rare in individual organs, their incidence has increased over recent decades, highlighting the urgent need for current classification systems to evolve by incorporating recent advances in the understanding of NET biology. Several omics studies have revealed molecular subtypes, which, when integrated into existing classification frameworks, may provide more clinically relevant insights for patients with NETs. This Review examines recent progress in elucidating the biology of NETs, with a particular emphasis on the tumor microenvironment and cells of origin. The existence of different cells of origin, which may contribute to distinct molecular groups, along with profiles of immune infiltration - despite being generally low - could explain the emergence of more aggressive cases and the potential for metastatic progression. Given the molecular heterogeneity of NETs and the diversity of their microenvironments and different cells of origin, there is an urgent need to develop morphomolecular classification systems. Such systems would make it possible to better characterize tumor progression, identify new therapeutic targets, and, ultimately, guide the development of personalized therapies.

Molecular studies have shown alternative lengthening to telomeres (ALT) to be an important prognostic biomarker of shorter relapse-free survival (RFS) for patients with pancreatic neuroendocrine tumors (PanNETs) and other neoplasms. However, the preferred method of detecting ALT in tissue is by fluorescence in situ hybridization (FISH), which has several clinical limitations. These issues necessitate the creation of a chromogenic ALT assay that can be easily implemented into routine practice. A chromogenic in situ hybridization (CISH) assay was developed using genetically modified osteosarcoma cell lines, 20 normal pancreata, 20 ALT-positive PanNETs, and 20 ALT-negative PanNETs. Thereafter, it was validated on a multiinstitutional cohort of 360 surgically resected PanNETs and correlated with multiple clinicopathologic features, RFS, and FISH results. Separately, 109 leiomyosarcomas (LMS) were evaluated by both CISH and FISH, and, similarly, the prognostic significance of ALT status was assessed. Upon optimization, ALT-CISH was identified in 112 of 360 (31%) primary PanNETs and was 100% concordant with FISH testing. ALT correlated with several adverse prognostic findings and distant metastasis (all P < .004). The 5-year RFS for patients with ALT-positive PanNETs was 35% as compared with 94% for ALT-negative PanNETs. By multivariate analysis, ALT was an independent prognostic factor for shorter RFS. Similarly, ALT was associated with shorter RFS in patients with LMS and, analogous to PanNETs, a negative, independent prognostic factor. ALT-CISH was developed and validated in not only PanNETs but also sarcomas, specifically LMS. CISH testing has multiple advantages over FISH that facilitate its widespread clinical use in the detection of ALT and prognostication of patients with diverse neoplasms.

Gastroenteropancreatic neuroendocrine tumours (GEP-NETs), which may be hormone secreting (e.g., gastrinomas and insulinomas) or non-secreting (also known as non-functioning NETs) are associated with severe morbidity and have a median overall survival of 75-124 months. Studies have highlighted the importance of epigenetic mechanisms in GEP-NETs pathogenesis, with the most frequently mutated genes being the epigenetic regulators, MEN1, DAXX, and ATRX. However, the consequences of these aberrant epigenetic mechanisms are poorly understood. The calcium sensing receptor (CASR), a G protein coupled-receptor, is epigenetically silenced in cancers, and therefore we examined its role in GEP-NET subtypes. Using RNA-Scope and quantitative PCR analyses in two independent tumour cohorts from Europe (n = 18 patients) and the USA (n = 46 patients) we showed that CASR mRNA is almost completely absent in gastrinomas, insulinomas and non-functioning pancreatic NETs. Furthermore, immunohistochemical staining confirmed a significant reduction in CaSR protein expression in all GEP-NET subtypes, compared to normal islets. DNA methylationEPIC and ATAC-seq analyses in the pancreatic NET cell line QGP-1 showed the CaSR promoter was both hypermethylated and in a region of closed chromatin. Furthermore, transfection of wild type CaSR into QGP-1 cells decreased cell viability, in keeping with the CaSR having a role in cellular proliferation. In summary, our study reveals that CaSR expression is decreased in GEP-NETs and that this reduced expression is likely due to DNA methylation and chromatin changes. Moreover, we demonstrate that transfection of the CaSR into a PNET cell line reduces cell viability, thereby indicating that the CaSR acts as a tumour suppressor in this tumour type.

Functioning pancreatic neuroendocrine tumors (PanNETs) represent a subset of PanNETs that cause symptoms due to hormonal activity. Insulinoma is the most common functioning PanNET type. Mutations in the alpha thalassemia/mental retardation X-linked (ATRX) and death domain-associated protein (DAXX) genes result in genomic instability. ATRX/DAXX mutations and associated alternative lengthening of telomeres (ALT) are common in non-functioning PanNETs and associated with aggressive tumor behavior. Recent reports have shown that ATRX/DAXX mutations and ALT are also present in functioning PanNETs. In this review, we summarize the literature addressing ATRX/DAXX mutations and ALT in functioning PanNETs and discuss the clinical relevance with regard to distinguishing aggressive and indolent functioning tumors. ATRX/DAXX gene mutations and/or ALT have been reported in insulinoma, glucagonoma, gastrinoma, VIPoma and calcitoninoma. In insulinoma, the presence of ATRX/DAXX mutations and ALT are associated with aggressive behavior and could therefore be used as prognostic biomarkers. Although ATRX/DAXX mutation and ALT assessment may currently not be the standard of care in routine diagnostic pathology practice, the use of DAXX/ATRX immunohistochemistry at least can be encouraged not only for non-functioning but also for functioning PanNETs.

Astrocytoma is a rare tumour of the central nervous system that often manifests with non-specific clinical symptoms and lacks distinct histological features. There is a pressing need for further understanding of the clinicopathological and molecular characteristics of astrocytoma. Identifying mutant genes can aid in reliable and early diagnosis, as well as provide insights for the development of targeted therapies.

This study aims to investigate the clinicopathologic and molecular characteristics of astroblastoma. A total of four patients diagnosed with astroblastoma were included in the analysis. Clinical features, histological findings, and immunohistochemistry results were reviewed and analyzed. Genetic alterations were identified using fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS), followed by patient follow-up.

The study included four female patients, ranging in age from 8 to 44 years. One patient had a tumour in the right parietal lobe, while the other three had tumours in the spinal cord. Histology is usually characterized by pseudorosettes of astroblasts and hyalinization of blood vessels. These tumors showed a growth pattern similar to traditional intracranial astroblastoma, and the histological manifestations of the four patients were all high-grade, showing features of high-density areas of tumor cells or necrosis. Immunohistochemical staining revealed that all four patients expressed OLIG2, EMA, and vimentin, while three patients also expressed GFAP and S-100. The Ki-67 positivity index was approximately 15% in three cases and 10% in one case. Fluorescence in situ hybridization (FISH) using break-apart probes showed EWRS1 breaks in three patients and MN1 breaks in one. Further DNA or RNA-targeted biallelic sequencing identified an EWSR1(Exon1-7)-BEND2(Exon2-14) fusion in case 1, and an EWSR1(Exon1-7)-BEND2(Intergenic) fusion in case 2. In case 3, an EWSR1(Exon1-7)-NUDT10(Intergenic) fusion was present, and in case 4, an MN1(Exon1)-BEND2(Exon2) fusion was identified. The EWSR1-NUDT10 gene fusion is a new fusion type in astroblastoma. The patients were followed up for 76.5, 17.6, 33.7, and 61.3 months, respectively. Three cases experienced tumour recurrences at the spinal cord site, with multiple recurrences in case 4.

Our study unveiled the distinctive clinicopathological and molecular mutational characteristics of astrocytoma, while also identifying rare mutated genes. Additionally, the detection of MN1 or EWSR1 gene fusion through FISH or next-generation sequencing can provide valuable insights into the molecular mechanisms and aid in the differential diagnosis of astrocytoma.

Recent pan-cancer analysis revealed the global pattern and potential aetiologies of copy number variation signatures in human cancers, particularly those derived from non-hematopoietic tissues. In sharp contrast, the generally low CNV burden in leukemia leaves the CNV landscape and variations largely unexplored, impeding understanding of CNV in leukemia development. Through a comprehensive compilation of public datasets, we constructed LeukAtlas ( https://ngdc.cncb.ac.cn/leukemia ), a user-friendly database encompassing 12,597 CNVs from 1446 AML samples across diverse subtypes and age groups, providing tools for multidimensional CNV analysis. Our analyses suggested the CNV levels significantly varied among AML patients. We discovered two previously unknown CNV patterns in adult AML patients, dominated by segmental LOH and/or minor gain, which have been shown to be associated with chromosomal instability in solid tumors. Additionally, we defined two potential new AML subgroups based on CNVs status, providing new stratification markers within the existing karyotype framework. Representing the most extensive CNV collection in AML, LeukAtlas is a valuable resource for exploring the role of CNVs in the pathogenesis and prognosis stratification of leukemia. Interrogation of this database uncovers novel subclasses with unique CNV profiles and reveals heterogeneous CNV patterns in AML, demonstrating the potential role of chromosomal instability in AML progression.

A recent prospective phase II study (ECOG-ACRIN E2211) demonstrated that MGMT deficiency was associated with a significant response to capecitabine and temozolomide (CAPTEM) in pancreatic neuroendocrine neoplasms (NENs); however, routine MGMT analysis in NENs was not recommended. Our study sought to demonstrate whether loss of MGMT protein expression is associated with improved overall survival (OS) in patients receiving CAPTEM for NENs from various tumor sites.

Paraffin-embedded tumor samples were evaluated by immunohistochemistry (IHC) using an MGMT monoclonal antibody. Intact MGMT protein expression (i.e., IHC positivity) was defined as any staining intensity (> 1+) in ≥ 36% of neoplastic cells according to an internal validation study. IHC and pyrosequencing for MGMT promotor methylation was performed in an independent cohort of 58 NENs. Real-world OS was extrapolated from insurance claims data with Kaplan-Meier estimates from the date of first CAPTEM administration to the last date of contact.

The study cohort included 80 patients (42 men and 38 women) with a median age of 57 years (range: 19-89). They had various NENs (33 pancreatic, 17 intestinal, 7 pulmonary, 8 other, and 15 of unknown origin) treated with CAPTEM. The median OS for the 48 patients with MGMT negative tumors was 31 months compared to 17.5 months for the 32 patients whose tumors were MGMT positive by IHC (HR: 1.75 [95% CI: 1.066-2.87] and p = 0.025). IHC results from the independent cohort of 58 NENs showed only 57% concordance with pyrosequencing results.

MGMT promotor status by IHC may be a clinically useful indicator that predicts improved OS for NENs treated with CAPTEM, but IHC does not reliably correlate with the findings of MGMT promoter methylation by pyrosequencing.

ATRX, DAXX, MEN1, and PTEN mutations are proposed drivers of pancreatic neuroendocrine tumor tumorigenesis and independent prognostic factors for metastasis and mortality. However, their implications after R0 resection remain debated. Thus, we sought to identify genomic signatures of pancreatic neuroendocrine tumor disease-specific mortality and recurrence after surgery for curative intent.

Pancreatic neuroendocrine tumor patients who underwent whole exome sequencing with available survival data were identified using cBioPortal. Clinicopathologic variables, genomics, and outcomes were analyzed.

Seventy patients who underwent R0 resection were identified. Forty-five of 70 patients were disease free at last follow-up, whereas 25 of 70 patients had disease-specific mortality or recurrent disease and therefore were categorized as part of the recurrent cohort. There were no significant differences in age (P = .245), sex (P = .201), or median follow-up (38.9 vs 33.7 months, P = .122) between groups. Clinicopathologically, the recurrent cohort had significantly greater tumor size (median 5.0 cm vs 3.2 cm, P = .012) and were more likely to have vascular invasion (88% vs 40%, P = .000), positive lymph nodes (68.0% vs 35.6%, P = .013), and metastatic disease (44% vs 4.4%, P < .000). For both cohorts, most tumors were well or moderately differentiated. Tumor mutation burden was greater in the recurrent cohort (median 0.77 vs 0.43 mutations/Mb, P = .004). DAXX mutations were more frequent in the recurrent cohort (36% vs 11%, P = .026) and in those with vascular invasion (51% vs 92%, P = .010).

Our analysis demonstrated the prognostic significance of DAXX mutations after curative-intent surgery. Future studies investigating DAXX mutations as a biomarker for aggressive features to guide treatment are warranted.

The purpose of this review is to outline the current knowledge on epidemiology, diagnosis and management of neuroendocrine neoplasms (NENs) that develop in the context of Von Hippel-Lindau (VHL) syndrome.

Pancreatic NENs develop in 8-17% of VHL patients (vPNENs) and are mostly multi-focal, cystic and non-functioning. Surgical resection is recommended for vPNENS > 3 cm that exhibit higher metastatic potential or in tumors with short doubling time while in the 20% of cases with metastatic disease the HIF-2 A inhibitor belzutifan is considered a promising option. Pheochromocytomas arising in VHL type 2 are often bilateral and have a noradrenergic phenotype while they are associated with increased risk of recurrence. High-specific activity [131I]-MIBG and sunitinib are the treatment options with the highest level of evidence whereas studies on belzutifan are evolving. Life-long surveillance and management in the context of a multidisciplinary team are suggested to achieve the best clinical outcome.

An amplicon-based targeted next-generation sequencing (NGS) assay for the detection of gene fusions in sarcomas was developed, validated, and implemented. This assay can detect fusions in targeted regions of 138 genes and BCOR internal tandem duplications. This study reviews our experience with testing on the first 652 patients analyzed. Gene fusions were detected in 238 (36.5%) of 652 cases, including 83 distinct fusions in the 238 fusion-positive cases, 10 of which had not been previously described. Among the 238 fusion-positive cases, the results assisted in establishing a diagnosis for 137 (58%) cases, confirmed a suspected diagnosis in 66 (28%) cases, changed a suspected diagnosis in 25 (10%) cases, and were novel fusions with unknown clinical significance in 10 (4%) cases. Twenty-six cases had gene fusions (ALK, ROS1, NTRK1, NTRK3, and COL1A1::PDGFB) for which there are targetable therapies. BCOR internal tandem duplications were identified in 6 (1.2%) of 485 patients. Among the 138 genes in the panel, 66 were involved in one or more fusions, and 72 were not involved in any fusions. There was little overlap between the genes involved as 5'-partners (31 different genes) and 3'-partners (37 different genes). This study shows the clinical utility of a next-generation sequencing gene fusion detection assay for the diagnosis and treatment of sarcomas.

Gastroenteropancreatic neuroendocrine tumors (NET) often metastasize to the liver. Although curative liver resection provides a favorable prognosis for patients with neuroendocrine liver metastasis (NELM), with a 5-year survival rate of 70-80%, recurrence is almost inevitable, mainly in the remnant liver. In Western countries, liver transplantation (LT) has been performed in patients with NELM, with the objective of complete removal of macro- and micro-NELMs. However, prognosis had been unsatisfactory, with 5-year overall survival and recurrence-free survival rates of approximately 50 and 30%, respectively. In 2007, the Milan criteria were proposed as indications for LT for NELM. The criteria included: (1) confirmed histology of NET-G1 or G2; (2) a primary tumor drained by the portal system and all extrahepatic diseases removed with curative resection before LT; (3) liver involvement ≤50%; (4) good response or stable disease for at least 6 months before LT; (5) age ≤ 55 years. A subsequent report demonstrated outstanding LT outcomes for NELM within the Milan criteria, with 5-year overall survival and recurrence rates of 97 and 13%, respectively. In Japan, living donor LT (LDLT) for NELM has been performed sporadically in only 16 patients by 2021 in Japan; however, no consensus has been reached on the indications or perioperative management of LDLT. This article presents the outcomes of these 16 patients who underwent LDLT in Japan and reviews the literature to clarify optimal indications and perioperative management of LDLT for NELM in the era of novel multimodal treatments.

Determining the primary origin of non-organ-confined neuroendocrine tumors (NETs) for accurate diagnosis and management. Neuroendocrine tumors are rare neoplasms with diverse clinical behaviors. Determining their primary origin remains challenging in cases of non-organ-confined NETs. This study explores the histogenesis of a retroperitoneal, non-functional NET localized between the duodenum and pancreatic head, utilizing advanced molecular diagnostics to elucidate its probable primary source.

Initial diagnostic methods, including imaging and histopathology, failed to resolve the tumor's origin. The tumor was subjected to single-cell RNA sequencing (scRNA-seq) and whole exome sequencing (WES). Publicly available transcriptomic datasets from pancreatic and small intestine NETs were used to develop and validate a molecular gene signature for tissue-of-origin identification.

The gene signature distinguished pancreatic and small intestine NETs with high accuracy. The tumor cells presented a molecular profile consistent with a pancreatic origin, likely derived from ectopic pancreatic tissue.

This case demonstrates the value of integrating scRNA-seq and WES for the molecular characterization of complex NETs. Identifying the tumor's pancreatic origin informed a targeted management approach, avoiding unnecessary systemic treatment and underscoring the potential of single-cell approaches in personalized oncology.

Pancreatic neuroendocrine neoplasms (pNENs) are the second most common pancreatic malignancy. While most cases are sporadic, a small proportion is associated with genetic syndromes, such as Multiple Endocrine Neoplasia (MEN), Von Hippel-Lindau Syndrome (VHL), Neurofibromatosis Type 1 (NF1), and Tuberous Sclerosis Complex (TSC). This review aims to use pNENs as a clue to reveal the full spectrum of disease, providing a comprehensive understanding of diagnosis. It aids in promptly identifying abnormalities in other organs, recognizing familial genetic mutations, and achieving personalized treatment.

Pancreatic neuroendocrine tumors (PNETs) exhibit a wide range of behavior from localized disease to aggressive metastasis. A comprehensive transcriptomic profile capable of differentiating between these phenotypes remains elusive.

Use machine learning to develop predictive models of PNET metastatic potential dependent upon transcriptomic signature.

RNA-sequencing data were analyzed from 95 surgically resected primary PNETs in an international cohort. Two cohorts were generated with equally balanced metastatic PNET composition. Machine learning was used to create predictive models distinguishing between localized and metastatic tumors. Models were validated on an independent cohort of 29 formalin-fixed, paraffin-embedded samples using NanoString nCounter®, a clinically available mRNA quantification platform.

Gene expression analysis identified concordant differentially expressed genes between the 2 cohorts. Gene set enrichment analysis identified additional genes that contributed to enriched biologic pathways in metastatic PNETs. Expression values for these genes were combined with an additional 7 genes known to contribute to PNET oncogenesis and prognosis, including ARX and PDX1. Eight specific genes (AURKA, CDCA8, CPB2, MYT1L, NDC80, PAPPA2, SFMBT1, ZPLD1) were identified as sufficient to classify the metastatic status with high sensitivity (87.5-93.8%) and specificity (78.1-96.9%). These models remained predictive of the metastatic phenotype using NanoString nCounter® on the independent validation cohort, achieving a median area under the receiving operating characteristic curve of 0.886.

We identified and validated an 8-gene panel predictive of the metastatic phenotype in PNETs, which can be detected using the clinically available NanoString nCounter® system. This panel should be studied prospectively to determine its utility in guiding operative vs nonoperative management.

To investigate incidence, treatment patterns and outcomes of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) in the United States. The 2019 National Cancer Database was searched for adult GEP-NEN patients. Main outcomes included overall and site-specific incidence, treatment patterns, and overall survival (OS). Overall survival was evaluated using averaged Cox regression. 86,324 GEP-NEN patients were included (6.33% of all GEP malignancies). From 2004 to 2016, annual GEP-NEN cases increased (n = 4,010 to n = 9,379), largely driven by low-stage, low-grade disease. Most patients received surgery, either alone (72.9%) or in combination with systemic therapy (4.9%). Longest overall survival (OS) was evident in patients with low stage and low grade GEP-NEN of the small intestine and rectum (p < 0.001). Patients undergoing surgical resection demonstrated longest OS. The addition of systemic therapy was most effective in high stage G3 NEN. Having higher income (≥$63,333) and private insurance or Medicare, but not Medicaid, was associated with improved survival. GEP-NEN incidence increases, likely due to improved detection and diagnosis. Treatment patterns have evolved to follow the latest international guidelines and site-specific improvement in survival is noted. In addition to disease specific factors, insurance access and socioeconomic factors emerged as potential targets for improving outcomes.

Background: Neuroendocrine neoplasms are a rare and heterogeneous group of neoplasms. Small-sized (≤2 cm) pancreatic neuroendocrine tumors (PanNETs) are of particular interest as they are often associated with aggressive behavior, with no specific prognostic or progression markers.

This article describes a clinical case characterized by a progressive growth of nonfunctional PanNET requiring surgical treatment in a patient with a germline FANCD2 mutation, previously not reported in PanNETs. The patient underwent whole exome sequencing and single-cell RNA sequencing.

The patient underwent surgical treatment. We confirmed the presence of the germline mutation FANCD2 and also detected the germline mutation WNT10A. The cellular composition of the PanNET was analyzed using single-cell sequencing, and the main cell clusters were identified. We analyzed the tumor genomics, and used the data to define the effect the germline FANCD2 mutation had.

Analysis of the mutational status of patients with PanNET may provide additional data that may influence treatment tactics, refine the plan for monitoring such patients, and provide more information about the pathogenesis of PanNET. PanNET research using scRNA-seq data may help in predicting the effect of therapy on neuroendocrine cells with FANCD2 mutations.

Well-differentiated neuroendocrine tumor rarely occurs as a testicular primary tumor, accounting for less than 1% of all testicular cancers, and is rarely reported with sufficient molecular profiles. After searching our departmental database (2003-2023), two testicular primary well-differentiated neuroendocrine tumors were identified in a 35-year-old man and a 23-year-old man, respectively, both of whom had normal serum level of tumor markers. Both tumors grossly exhibited solid, yellow-tan, and homogeneous appearance and histologically displayed a mixture of growth patterns, including organoid, tubular, cribriform, nests, cords, and single cells, were composed of eosinophilic tumor cells with salt-and-pepper chromatin and indistinct cell borders. Immunoreactivity for chromogranin and synaptophysin were detected, with Ki-67 labeling 9% and 2% of tumor cells on counting of 500 tumor cells, respectively. There was no germ cell neoplasia in situ in the background testicular parenchyma. Furthermore, fluorescence in situ hybridization failed to identify the presence of isochromosome 12p in both tumors. A panel-based next-generation sequencing was done in one of tumors and showed no reportable pathogenic variants with a mutation burden of 0.5 mutations per megabase. Although elevated mitotic figures (up to 6 per 10 high power fields), lymphovascular invasion and marked nuclear pleomorphism were present in this tumor, there was no evidence of disease detected in this patient via Dotatate positron emission tomography/computed tomography scan after the surgery. This report expands the spectrum of testicular primary well-differentiated neuroendocrine tumor. Considering its rarity, it may pose a diagnostic challenge or pitfall in certain clinical circumstances. In addition, the literature pertaining to this entity is herein reviewed.

Evidence-based treatment decisions for advanced gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) require individualized patient-centered decision-making that accounts for patient and cancer characteristics.

To create an accessible guidance document to educate clinicians and patients on biomarkers informing prognosis and treatment in unresectable or metastatic GEP-NENs.

A multidisciplinary panel in-person workshop was convened to define methods. English language articles published from January 2016 to January 2023 in PubMed (MEDLINE) and relevant conference abstracts were reviewed to investigate prognostic and treatment-informing features in unresectable or metastatic GEP-NENs. Data from included studies were used to form evidence-based recommendations. Quality of evidence and strength of recommendations were determined using the Grading of Recommendations, Assessment, Development and Evaluations framework. Consensus was reached via electronic survey following a modified Delphi method.

A total of 131 publications were identified, including 8 systematic reviews and meta-analyses, 6 randomized clinical trials, 29 prospective studies, and 88 retrospective cohort studies. After 2 rounds of surveys, 24 recommendations and 5 good clinical practice statements were developed, with full consensus among panelists. Recommendations focused on tumor and functional imaging characteristics, blood-based biomarkers, and carcinoid heart disease. A single strong recommendation was made for symptomatic carcinoid syndrome informing treatment in midgut neuroendocrine tumors. Conditional recommendations were made to use grade, morphology, primary site, and urinary 5-hydroxyindoleacetic levels to inform treatment. The guidance document was endorsed by the Commonwealth Neuroendocrine Tumour Collaboration and the North American Neuroendocrine Tumor Society.

The study results suggest that select factors have sufficient evidence to inform care in GEP-NENs, but the evidence for most biomarkers is weak. This article may help guide management and identify gaps for future research to advance personalized medicine and improve outcomes for patients with GEP-NENs.

Present in all eukaryotic cells, the integrated stress response (ISR) is a highly coordinated signaling network that controls cellular behavior, metabolism, and survival in response to diverse stresses. The ISR is initiated when any 1 of 4 stress-sensing kinases (protein kinase R-like endoplasmic reticulum kinase [PERK], general control non-derepressible 2 [GCN2], double-stranded RNA-dependent protein kinase [PKR], heme-regulated eukaryotic translation initiation factor 2α kinase [HRI]) becomes activated to phosphorylate the protein translation initiation factor eukaryotic translation initiation factor 2α (eIF2α), shifting gene expression toward a comprehensive rewiring of cellular machinery to promote adaptation. Although the ISR has been shown to play an important role in the homeostasis of multiple tissues, evidence suggests that it is particularly crucial for the development and ongoing health of the pancreas. Among the most synthetically dynamic tissues in the body, the exocrine and endocrine pancreas relies heavily on the ISR to rapidly adjust cell function to meet the metabolic demands of the organism. The hardwiring of the ISR into normal pancreatic functions and adaptation to stress may explain why it is a commonly used pro-oncogenic and therapy-resistance mechanism in pancreatic ductal adenocarcinoma and pancreatic neuroendocrine tumors. Here, we review what is known about the key roles that the ISR plays in the development, homeostasis, and neoplasia of the pancreas.

High-grade or grade 3 epithelial neuroendocrine neoplasms (G3 NEN) are now divided into grade 3 well-differentiated neuroendocrine tumor (G3 NET) and neuroendocrine carcinoma (NEC), both defined by Ki-67 > 20% and/or > 20 mitoses per 2 mm2. NET and NEC are thought to be distinct tumors with different genetic profiles: NEC classically harbors co-alteration of TP53 and RB1, whereas NET genetics are site-dependent with frequent alterations in MEN1, ATRX, DAXX, and TSC1/2 in pancreatic NETs. Progression from NET to NEC is considered rare and is not well described. While both TP53 and RB1 alterations were initially thought to be rare in NET, recent work has demonstrated the former in up to 35% of high-grade G3 NET and the latter in rare high-grade NEN that progressed from NET. Here, we describe the clinical, pathologic, and molecular features associated with tumor evolution in a series of five patients that had low-grade NET that progressed to high-grade NEN with co-alteration of RB1 and TP53, similar to NEC. Morphology of the high-grade neoplasms remained well-differentiated in some cases despite RB1/TP53 co-alteration and had some NEC-like features in other cases. All five patients died of disease, with a mean overall survival of 41 months from the first metastatic disease and 12 months from acquisition of RB1/TP53 co-alteration. Our data demonstrate that low-grade NET can progress via the acquisition of both TP53 and RB1 alteration, similar to NEC, but whether this represents a transformation from NET to NEC remains unclear.

Tumour evolution with acquisition of more aggressive disease characteristics is a hallmark of disseminated cancer. Metastatic pancreatic neuroendocrine tumours (PanNETs) in particular may progress from a low/intermediate to a high-grade disease. The aim of this work was to understand the molecular mechanisms underlying metastatic progression as well as PanNET transformation from a low/intermediate to a high-grade disease. We performed multi-omics analysis (genome/exome sequencing, total RNA-sequencing and methylation array) of 32 longitudinal samples from six patients with metastatic low/intermediate grade PanNET. The clonal composition of tumour lesions and underlying phylogeny of each patient were determined with bioinformatics analyses. Findings were validated in post-alkylating chemotherapy samples from 24 patients with PanNET using targeted next generation sequencing. We validate the current PanNET evolutionary model with MEN1 inactivation that occurs very early in tumourigenesis. This was followed by pronounced genetic diversity on both spatial and temporal levels, with parallel and convergent tumour evolution involving the ATRX/DAXX and mechanistic target of the rapamycin (mTOR) pathways. Following alkylating chemotherapy treatment, some PanNETs developed mismatch repair deficiency and acquired a hypermutational phenotype. This was validated among 16 patients with PanNET who had high-grade progression after alkylating chemotherapy, of whom eight had a tumour mutational burden >50 (50%). In comparison, among the eight patients who did not show high-grade progression, 0 had a tumour mutational burden >50 (0%; odds ratio 'infinite', 95% confidence interval 1.8 to 'infinite', p = 0.02). Our findings contribute to broaden the understanding of metastatic/high-grade PanNETs and suggests that therapy driven disease evolution is an important hallmark of this disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Aim: Pancreatic Neuroendocrine tumors (pNETs) are a heterogeneous group of neoplasms whose tumor biology is still little known. Thanks to next-generation sequencing, pathogenic mutations in base-excision-repair MUTYH gene and homologous recombination genes CHEK2 and BRCA2 seem to have a role in the development of pNETs.Research design & methods: We assumed that Homologous Recombination Deficiency (HRD) could be a critical pathogenetic mechanism for pNETs. We evaluated the HR status in a case series of 33 patients diagnosed with pNET at the Modena Cancer Center using the AmoyDX HRD Focus assay.Results: The AmoyDx test did not identify any HRD-positive patients (median GSS equal to 1.1, positive score: >50), and no pathogenic BRCA variants were detected. However, thanks to the SNP analysis, a consistent number of partial or complete single-copy deletions or duplications in several chromosomes.Conclusion: The AmoyDX HRD focus assay performed well on pancreatic samples, despite being originally designed for ovarian cancer and used on samples stored for over a year. Larger studies are needed to further assess the role of HRD assays in pNETs research.

In this editorial, a comment on the article by Díaz-López et al published in the recent issue of the 2024 is provided. We focus on the practical implications critical for providing a correct and complete diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) in the gastrointestinal system. The diagnosis of MiNEN begins with the recognition of neuroendocrine features in one component of a biphasic tumor. The non-neuroendocrine counterpart can be virtually represented by any neoplastic type, even though the most frequent histologies are glandular and squamous. However, qualification of the neuroendocrine component requires histological and immunohistochemical confirmation. Neuroendocrine tumors are characterized by a peculiar architectural organization and bland nuclei with granular "salt and pepper" chromatin. Although neuroendocrine carcinomas have multiple and variable presentations, they typically show a solid or organoid architecture. The histological aspect needs to be confirmed by immunohistochemistry, and a diagnosis is confirmed whenever the expression of keratin and neuroendocrine markers is observed. Once both histopathological and immunohistochemical features of neuroendocrine neoplasms are identified, it is important to consider the three major pitfalls of MiNEN diagnostics: (1) Entrapment of neuroendocrine non-neoplastic cells within the tumor mass; (2) Differential diagnosis with amphicrine neoplasms; and (3) Differential diagnosis of tumors that partially express neuroendocrine markers. According to the current guidelines for diagnosing digestive MiNEN, each component must represent at least 30% of the entire neoplastic mass. Although the high-grade histopathological subtype frequently determines disease prognosis, both components can significantly affect prognosis. Thus, if one of the components, either neuroendocrine or non-neuroendocrine, does not fulfill the volumetric criteria, the guidelines still encourage reporting it. These strict criteria are essential for correctly recognizing and characterizing digestive MiNENs. This task is essential because it has prognostic relevance and substantial potential value for guiding further studies in this field. In the future, systematic analyses should be performed to validate or reconsider the current 30% cutoff value.

Rectal neuroendocrine neoplasms (rNENs) are among the most frequent gastrointestinal neuroendocrine neoplasms and pose a serious challenge for clinical management. The size of the primary neoplasm is considered to be the most important predictor of disease progression, but the genetic alterations that occur during the progression of rNENs remain unknown. Here, we performed a comprehensive whole-exome sequencing study on 54 tumor-normal paired, formalin-fixed paraffin-embedded specimens from patients locally diagnosed with rNENs. Of these, 81.5% (n = 44) were classified as small-sized (≤2 cm) rNENs, while the remainder (18.5%, n = 10) were classified as large-sized (>2 cm) rNEN samples. Comparative analysis revealed marked disparities in the mutational landscape between small- and large-sized rNEN samples, and between large-sized rNEN samples with or without lymph node metastases. The high-confidence driver genes RHPN2, MUC16, and MUC4 were significantly mutated in both small- and large-sized rNEN specimens, whereas mutations in MAN2A1, and BAG2 were only identified in large-sized specimens diagnosed with lymph node metastases. Correspondingly, we observed that the mTOR and MAPK pathways were preferentially enriched in the large-sized rNEN specimens. Signature-based analysis revealed that mutational processes associated with defective DNA base excision repair (SBS30) significantly accumulated in large-sized rNEN samples with lymph node metastases, highlighting the important role of this mutagenic process in promoting rNEN progression. We further found that most rNEN subjects, regardless of tumor size, harbored at least one alteration with targeted therapeutic implications. Taken together, these results elucidate the genetic features associated with tumor size and lymphatic metastasis in rNEN patients, which will deepen our understanding of the genetic changes during rNEN progression and potentially directing improvements in rNEN treatment strategies.