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It is unclear whether invasive intraductal papillary mucinous neoplasm (IPMN) has different clinical and prognostic characteristics, beyond histological factors, when compared to pancreatic ductal adenocarcinoma (PDAC).compare prognostic features of resected PDAC and invasive IPMN METHODS: A retrospective study of patients resected for PDAC or invasive IPMN realized at Humanitas Cancer Center's Pancreatic Surgery Unit, Milan, Italy, between 2010 and 2016. Data recorded included patient demographics, onset symptoms, preoperative health status, tumor features, histology and surgical characteristics. Overall survival was estimated using Kaplan-Meier and prognostic factors for survival were assessed by multivariate Cox regression.A total of 332 patients were included (PDAC, n = 289; invasive IPMN, n = 43). Patients with invasive IPMN had better overall survival than PDAC patients (median: 76.6 versus 25.6 months; 5-year OS rate: 65.4% vs. 14.2%; p 0.001). PDAC histology was associated with a significantly higher risk of death than IPMN (hazard ratio 1.815, 95% CI: 1.02, 3.24; p = 0.044). Survival was also worse with PDAC in early-stage disease (IA-IB-IIA, N0). In multivariate analysis, independent predictors of worse survival included perineural invasion, preoperative ASA physical status ≥3 and pain at diagnosis.Patients with IPMN had a better prognosis than PDAC patients, regardless of disease stage.

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Better understanding of pancreatic diseases, including pancreatic ductal adenocarcinoma (PDAC), is an urgent medical need, with little advances in preoperative differential diagnosis, preventing rational selection of therapeutic strategies. The clinical management of pancreatic cancer patients would benefit from the identification of variables distinctively associated with the multiplicity of pancreatic disorders. We investigated, by 1H nuclear magnetic resonance, the metabolomic fingerprint of pancreatic juice (the biofluid that collects pancreatic products) in 40 patients with different pancreatic diseases. Metabolic variables discriminated PDAC from other less aggressive pancreatic diseases and identified metabolic clusters of patients with distinct clinical behaviors. PDAC specimens were overtly glycolytic, with significant accumulation of lactate, which was probed as a disease-specific variable in pancreatic juice from a larger cohort of 106 patients. In human PDAC sections, high expression of the glucose transporter GLUT-1 correlated with tumor grade and a higher density of PD-1+ T cells, suggesting their accumulation in glycolytic tumors. In a preclinical model, PD-1+ CD8 tumor–infiltrating lymphocytes differentially infiltrated PDAC tumors obtained from cell lines with different metabolic consumption, and tumors metabolically rewired by knocking down the phosphofructokinase (Pfkm) gene displayed a decrease in PD-1+ cell infiltration. Collectively, we introduced pancreatic juice as a valuable source of metabolic variables that could contribute to differential diagnosis. The correlation of metabolic markers with immune infiltration suggests that upfront evaluation of the metabolic profile of PDAC patients could foster the introduction of immunotherapeutic approaches for pancreatic cancer.

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ObjectivePancreatic ductal adenocarcinomas (PDACs) include heterogeneous mixtures of low-grade cells forming pseudoglandular structures and compact nests of high-grade cells organised in non-glandular patterns. We previously reported that low-grade PDAC cells display high expression of interferon regulatory factor 1 (IRF1), a pivotal transcription factor of the interferon (IFN) system, suggesting grade-specific, cell-intrinsic activation of IFN responses. Here, we set out to determine the molecular bases and the functional impact of the activation of IFN-regulated responses in human PDACs.DesignWe first confirmed the correlation between glandular differentiation and molecular subtypes of PDAC on the one hand, and the expression of IRF1 and IFN-stimulated genes on the other. We next used unbiased omics approaches to systematically analyse basal and IFN-regulated responses in low-grade and high-grade PDAC cells, as well as the impact of IRF1 on gene expression programmes and metabolic profiles of PDAC cells.ResultsHigh-level expression of IRF1 in low-grade PDAC cells was controlled by endodermal lineage-determining transcription factors. IRF1-regulated gene expression equipped low-grade PDAC cells with distinctive properties related to antigen presentation and processing as well as responsiveness to IFN stimulation. Notably, IRF1 also controlled the characteristic metabolic profile of low-grade PDAC cells, suppressing both mitochondrial respiration and fatty acid synthesis, which may in part explain its growth-inhibiting activity.ConclusionIRF1 links endodermal differentiation to the expression of genes controlling antigen presentation and processing as well as to the specification of the metabolic profile characteristic of classical PDAC cells.

Introduction: Poorly differentiated neuroendocrine carcinomas (NECs) are characterized by aggressive clinical course and poor prognosis. No reliable prognostic markers have been validated to date; thus, the definition of a specific NEC prognostic algorithm represents a clinical need. This study aimed to analyze a large NEC case series to validate the specific prognostic factors identified in previous studies on gastro-entero-pancreatic and lung NECs and to assess if further prognostic parameters can be isolated. Methods: A pooled analysis of four NEC retrospective studies was performed to evaluate the prognostic role of Ki-67 cut-off, the overall survival (OS) according to primary cancer site, and further prognostic parameters using multivariable Cox proportional hazards model and machine learning random survival forest (RSF). Results: 422 NECs were analyzed. The most represented tumor site was the colorectum (n = 156, 37%), followed by the lungs (n = 111, 26%), gastroesophageal site (n = 83, 20%; 66 gastric, 79%) and pancreas (n = 42, 10%). The Ki-67 index was the most relevant predictor, followed by morphology (pure or mixed/combined NECs), stage, and site. The predicted RSF response for survival at 1, 2, or 3 years showed decreasing survival with increasing Ki-67, pure NEC morphology, stage III–IV, and colorectal NEC disease. Patients with Ki-67 Conclusion: The most effective parameters to predict OS for NEC patients could be Ki-67, pure or mixed/combined morphology, stage, and site.

Intratumor morphological heterogeneity predicts clinical outcomes of pancreatic ductal adenocarcinoma (PDAC). However, it is only partially understood at the molecular level and devoid of clinical actionability. In this study we set out to determine the gene regulatory networks and expression programs underpinning intra-tumor morphological variation in PDAC. To this aim, we identified and deconvoluted at single cell level the molecular profiles characteristic of morphologically distinguishable clusters of PDAC cells that coexisted in individual tumors. We identified three major morpho-biotypes that co-occurred in various proportions in most PDACs: a glandular biotype with classical epithelial ductal features; a biotype with abortive ductal structures and expressing a partial epithelial-to-mesenchymal transition program; and a poorly differentiated biotype showing partial neuronal lineage priming and absence of both ductal features and basement membrane. The identification of PDAC morpho-biotypes may help improve patient stratification and therapeutic schemes taking into account the spectrum of actionable targets expressed by coexisting tumor components.

Simple Summary In this manuscript, we offer an integrated molecular analysis of 44 combined large cell neuroendocrine carcinomas (CoLCNECs) in order to deepen the knowledge about these rare histotypes and to clarify their relationship with lung cancers. In the present state of research, molecular studies are still scant, consisting of small and heterogeneous cohorts, and the genomic landscape is poorly characterized. This study shows that CoLCNECs constitute a standalone group of neuroendocrine neoplasm, with three different molecular profiles, two of which overlap with pure LCNEC or adenocarcinoma. CoLCNECs can be considered an independent histologic category with specific genomic and transcriptomic features, different and therefore not comparable to other lung cancers. Indeed, in addition to a histological re-evaluation of lung cancer classification, our study may help to develop a new diagnostic approach for novel and personalized treatments in CoLCNECs. Background: Combined large cell neuroendocrine carcinoma (CoLCNEC) is given by the association of LCNEC with adeno or squamous or any non-neuroendocrine carcinoma. Molecular bases of CoLCNEC pathogenesis are scant and no standardized therapies are defined. Methods: 44 CoLCNECs: 26 with adenocarcinoma (CoADC), 7 with squamous cell carcinoma (CoSQC), 3 with small cell carcinoma (CoSCLC), 4 with atypical carcinoid (CoAC) and 4 napsin-A positive LCNEC (NapA+), were assessed for alterations in 409 genes and transcriptomic profiling of 20,815 genes. Results: Genes altered included TP53 (n = 30), RB1 (n = 14) and KRAS (n = 13). Targetable alterations included six KRAS G12C mutations and ALK-EML4 fusion gene. Comparison of CoLCNEC transcriptomes with 86 lung cancers of pure histology (8 AC, 19 ADC, 19 LCNEC, 11 SCLC and 29 SQC) identified CoLCNEC as a separate entity of neuroendocrine tumours with three different molecular profiles, two of which showed a non-neuroendocrine lineage. Hypomethylation, activation of MAPK signalling and association to immunotherapy signature specifically characterized each of three CoLCNEC molecular clusters. Prognostic stratification was also provided. Conclusions: CoLCNECs are an independent histologic category. Our findings support the extension of routine evaluation of KRAS mutations, fusion genes and immune-related markers to offer new perspectives in the therapeutic management of CoLCNEC.

In a previous study on esophageal adenocarcinoma (EAC) cases submitted to surgery (without neoadjuvant treatment), an algorithm (EACGSE classification) 1 based on morphologic distinctions provided significant prognostic impact. Tumor budding is a specific type of invasive growth pattern and was found to be an important prognostic parameter in gastrointestinal cancers. 2–3 We aimed to evaluate the prevalence of budding in glandular adenocarcinomas and its impact on survival. The EAC cohort classified according to EACGSE 1 was included in the study: among the different histotypes, 215 cases, classified as well (WD) and poorly (PD) differentiated glandular adenocarcinomas, were considered. Tumor budding was defined as single cells or clusters of up to four cells at the invasive margin. Budding was grouped according to ITBCC 2 into Bd1 (0-4 buds), Bd2 (5-9 buds), and Bd3 (10 or more buds). Furthermore, the most prognostically relevant cut off for bud number in EAC was defined by ROC analysis. Cancer specific survival analyses were performed using the Kaplan–Meier method and Cox regression analyses. Tumor budding was assessed in one hotspot (a field measuring 0.785 mm2) at the invasive front and ROC analysis identified 8 buds per field cut off as the most informative in relation to survival. By using this cut off, frequency of budding was higher in glandular PD (84/124,68%) cases than in WD ones (7/91,8%, p Tumor budding showed a prognostically negative impact in glandular EACs. The 8 buds per field cut off appears to provide the best prognostic discriminant. Tumor budding assessment should be added to the identification of other prognostic factors already described in the same series (stage, histotype and vascular invasion). 1

The incidence of esophageal adenocarcinoma (EAC) has constantly risen in western countries over the past decades, often diagnosed at advanced stage and with a five-year survival around 20%1. In a previous study on EAC cases submitted to surgery (without neoadjuvant treatment) an algorithm (EACGSE classification)2 based on morphologic distinctions provided a significant prognostic impact. We aimed to evaluate the molecular basis underlying these differences, to improve patient management. The EAC cohort classified according to EACGSE2 was included in the study. Genomic DNA was available from formalin fixed paraffin embedded surgical specimens for 207 cases. The cases were sequenced for 26 cancer-related genes (panel #226722257; IDT) with high coverage on NextSeq500 (Illumina). Data analysis was performed using a dedicated pipeline3. 245 cases were analyzed for SMAD4 immunostaining (IHC). Loss of SMAD4 immunostaining was reported as % of negative tumor cells (at least 35% of neoplastic cells). TP53 was the most frequently altered gene (134/207 cases with at least one mutation). The presence of TP53 missense variants was associated to a poor cancer-specific survival (CSS) in the high-risk cases (glandular poorly differentiated, mucinous invasive, diffuse anaplastic, mixed) according to EACGSE2 (P=0.0005). A significant correlation was observed for TP53 truncative variants and loss of SMAD4 staining (P=0.008). Actually, SMAD4 loss was observed in 85/245 (35%) of all EAC cases analyzed via immunostaining. SMAD4 loss correlated with poor CCS (P=0.007) and disease-free survival (P=0.002) in EACGSE high-risk cases. TP53 missense mutations correlated to poor outcomes (CSS) in high-risk cases, TP53 truncative mutations were associated to SMAD4 loss. SMAD4 loss itself resulted a frequent event in EAC and correlated with lower CCS and disease-free survival in high-risk cases. Therefore, we were able to correlate EAC histological classification, clinical outcomes and molecular phenotypes. Validation in independent samples is warranted to corroborate these findings. References 1. Coleman et al. Gastroenterology2018;154:390–405. 2. Fiocca et al. Cancers 2021;13:5211. 3. Isidori et al. CTG 202011:e00202.

Perianal fistula represents one of the most disabling manifestations of Crohn's Disease (CD) due to complete destruction of the affected mucosa, which is replaced by granulation tissue and associated with changes in tissue organization. To date, the molecular mechanisms underlying perianal fistula formation are not well defined. Here, we dissected the tissue changes in the fistula area and addressed whether a dysregulation of extracellular matrix (ECM) homeostasis can support fistula formation.Surgical specimens from perianal fistula tissue and the surrounding region of fistulizing CD were analyzed histologically and by RNA sequencing (RNA-seq). Genes significantly modulated were validated by RT-PCR, WB, and immunofluorescence assays. The effect of the protein product of TNF-stimulated gene-6 (TSG-6) on cell morphology, phenotype and ECM organization was investigated with endogenous Lentivirus-induced over-expression of TSG-6 in Caco-2 cells and with exogenous addition of recombinant human TSG-6 protein (rhTSG-6) to primary fibroblasts from region surrounding fistula. Proliferative and migratory assays were performed.A markedly different organization of ECM was found across fistula and surrounding fistula regions with an increased expression of integrins and metalloproteinases (MMPs) and hyaluronan (HA) staining in the fistula, associated with increased newly synthesized collagen fibers and mechanosensitive proteins. Among dysregulated genes associated with ECM, TNFAI6 (gene encoding for TSG-6) was as significantly upregulated in the fistula compared to area surrounding fistula, where it promoted the pathological formation of complexes between heavy chains (HCs) from inter-alpha-inhibitor and HA responsible for the formation of a crosslinked ECM. There was a positive correlation between TSG-6 expression and expression of mechanosensitive genes in fistula tissue. The over-expression of TSG-6 in Caco-2 cells promoted migration, epithelial mesenchymal transition (EMT), transcription factor SNAIL and hyaluronan synthase (Has) levels; while in fibroblasts, isolated from the area surrounding the fistula, it promoted an activated phenotype. Moreover, the enrichment of an HA scaffold with rhTSG-6 protein promoted collagen release, increase of SNAIL, ITGA4, ITGA42B, and PTK2B genes, the latter being involved in the transduction of responses to mechanical stimuli.By mediating changes in the ECM organization, TSG-6 triggers the EMT transcription factor SNAIL through the activation of mechanosensitive proteins. These data point to regulators of ECM as new potential targets for the treatment of CD perianal fistula.

Neuroendocrine neoplasms (NENs) of the major and minor ampulla are rare diseases with clinico-pathologic features distinct from non-ampullary-duodenal NENs. However, they have been often combined and the knowledge on prognostic factors specific to ampullary NENs (Amp-NENs) is limited. The aim of this study was to identify factors associated with metastatic potential and patient prognosis in Amp-NENs. We clinically and histologically investigated an international series of 119 Amp-NENs, comprising 93 ampullary neuroendocrine tumors (Amp-NETs) and 26 neuroendocrine carcinomas (Amp-NECs). Somatostatin-producing tubulo-acinar NET represented the predominant Amp-NET histologic subtype (58 cases, 62%, 12 associated with type 1 neurofibromatosis). Compared to Amp-NETs, Amp-NECs arose in significantly older patients and showed a larger tumor size, a more frequent small vessel invasion, a deeper level of invasion and a higher rate of distant metastasis, and, importantly, a tremendously worse disease-specific patient survival. In Amp-NETs, the WHO grade proved to be a strong predictor of disease-specific survival (hazard ratio: 12.61, p 60 years, small vessel invasion, pancreatic invasion, and distant metastasis at diagnosis. Although nodal metastatic disease was not associated with survival by itself, patients with > 3 metastatic lymph nodes showed a worse outcome in comparison with the remaining Amp-NET cases with lymphadenectomy. Tumor epicenter in the major ampulla, small vessel invasion, and tumor size > 16 mm were independent predictors of nodal metastases in Amp-NETs. In conclusion, we identified prognostic factors, which may eventually help guide treatment decisions in Amp-NENs.

Summary The first part of this overview on non-neoplastic esophagus is focused on gastro-esophageal reflux disease (GERD) and Barrett’s esophagus. In the last 20 years much has changed in histological approach to biopsies of patients with gastro-esophageal reflux disease. In particular, elementary histologic lesions have been well defined and modality of evaluation and grade are detailed, their sensitivity and specificity has been evaluated and their use has been validated by several authors. Also if there is not a clinical indication to perform biopsies in patient with GERD, the diagnosis of microscopic esophagitis, when biopsies are provided, can be performed by following simple rules for evaluation which allow pathologists to make the diagnosis with confidence. On the other hand, biopsies are required for the diagnosis of Barrett’s esophagus. This diagnosis is the synthesis of endoscopic picture (which has to be provided with the proper description on extent and with adequate biopsies number) and histologic pattern. The current guidelines and expert opinions for the correct management of these diagnosis are detailed.

Aim: Regorafenib may be active in different cancer types. This Phase II trial included patients with various refractory cancer types treated with regorafenib. Here, we report the results of the pancreatic adenocarcinoma cohort. Methods: The primary end point was progression-free survival (PFS) rate at 8 weeks; further investigation of regorafenib would be warranted with a PFS rate ≥50%. Results: A total of 20 patients were enrolled. The best response was stable disease in four patients (20%). The 8-week PFS rate was 25% with a median PFS of 1.7 months (95% CI: 1.5–2.0). A total of 13 patients (65%) experienced grade 3–4 treatment-related adverse events. Conclusion: The study did not meet its primary end point. Further investigation of regorafenib monotherapy in this setting is not recommended. Clinical Trial Registration: NCT02307500

The different oncological outcomes of invasive intraductal papillary mucinous neoplasm (I-IPMN) and pancreatic ductal adenocarcinoma (PDAC) are debated. This study aimed to compare disease recurrence patterns and histopathological characteristics in patients with resected I-IPMN and PDAC.Consecutive patients undergoing surgical resection for stage I-III I-IPMN or PDAC between 2010 and 2016 were retrospectively analyzed. Patients treated with neoadjuvant therapy or resected for Tis neoplasia were excluded. All surgical specimens were re-staged according to AJCC-8th-edition.A total of 330 patients were included, of whom 43 had I-IPMN and 287 had PDAC. Median follow-up time was 26.7 (1.3-92.3) months and estimated median disease-free survival (DFS) was 60.3 months (47.2-73.4) for I-IPMN and 23.8 (19.3-28.2) months for PDAC (p 0.001). During follow-up, 32.6% of I-IPMN and 67.9% of PDAC patients experienced recurrence (p 0.001). The sites of first recurrence were the lungs (38.5% vs 13.1%, p = 0.027), liver (28.6% vs 45.0%, p = 0.180) and local (15.4% vs 36.6%, p = 0.101) for I-IPMN and PDAC, respectively. At multivariate analysis, I-IPMN histology remained an independent predictive factor for longer DFS (OR 0.528, CI 95% 0.278-1.000, p = 0.050), regardless of stage or adjuvant chemotherapy. I-IPMN and PDAC differed in rates of neuroinvasion (51.2% vs 97.2%) and positive lymph node status (N+) (46.5% vs 82.7%), especially in patients with lower T status.I-IPMN showed a different recurrence pattern compared to PDAC, with a higher lung tropism, and longer DFS. This different biological behavior is associated with lower rates of neuroinvasion and nodal involvement, especially in early-stage disease.

Endoscopic and histologic remission (HR) are key therapeutic targets in the management of ulcerative colitis (UC). The aim of this study was to evaluate the reproducibility of the Paddington International virtual ChromoendoScopy ScOre (PICaSSO), a virtual chromoendoscopy score originally validated by use of the iSCAN platform, with the narrow-band imaging (NBI), linked-color imaging (LCI), and blue-laser imaging (BLI) platforms.We evaluated endoscopic activity using the Mayo Endoscopic Score (MES), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and PICaSSO in 159 UC patients (78 NBI and 81 BLI/LCI) who underwent colonoscopy in 2 tertiary referral centers. HR was defined by the Robarts Histopathology Index (RHI) and the Nancy Histologic Index (NHI). Receiver operating characteristic curves were plotted to evaluate endoscopic scores for the prediction of HR. Intraclass correlation coefficients (ICC) between endoscopists were evaluated.PICaSSO had an ICC of 0.825 when the NBI and BLI/LCI cohorts were combined, higher than MES and UCEIS. The correlation between PICaSSO and RHI and NHI was 0.83 and 0.79 in the NBI cohort and between 0.63 and 0.65 in LCI/BLI. In the NBI cohort, the accuracy of MES, UCEIS, and PICaSSO was 0.936, 0.897, and 0.808 for HR measured by RHI and 0.897, 0.885, and 0.821 by NHI, respectively. In the BLI/LCI cohort, the accuracy of MES, UCEIS, LCI PICaSSO and BLI PICaSSO was 0.765, 0.778, 0.827, and 0.79 to predict HR with RHI and NHI, respectively.The PICaSSO score can be consistently and accurately reproduced with NBI and LCI/BLI and therefore can be applied to all virtual electronic chromoendoscopy platforms.

Trans-duodenal ampullectomy (TDA) is a surgical option for the treatment of selected ampullary neoplasms. The aim of this study was to evaluate our experience with TDA for the treatment of ampullary neoplasms, focusing on indications, technical aspects, and short- and long-term outcomes. All TDAs for ampullary neoplasms performed between January 2010 and December 2018 at our institution were retrospectively evaluated. Patients had ampullary neoplasms with low-grade dysplasia or in situ carcinoma (Tis) not suitable for an endoscopic approach, ampullary carcinoma unfit for pancreaticoduodenectomy (PD), or ampullary neuroendocrine G1-tumours. Thirty-six patients were included in the study: 9 (25.0%) with neoplasms with low-grade dysplasia, 4 (11.1%) with G1 neuroendocrine tumours and 23 (63.9%) with Tis or invasive carcinoma. Mean operative time was 252.5 min. Overall and severe (Clavien–Dindo > IIIa) morbidity rate was 44.4% and 13.9%, respectively. No 90-day mortality was observed. At follow-up, no deaths were observed and local recurrence rate was 11.1% for patients with ampullary adenomas with low-grade dysplasia. Among four patients with neuroendocrine neoplasms, only one developed recurrence (pulmonary). Tis, T1 and T2 lesions were found in 16 (69.6%), 2 (8.7%) and 5 (21.7%) patients, respectively: recurrence occurred in 3 patients with Tis lesions (one malignant), no patients with T1 neoplasms and 2 patients with T2 lesions (3 patients had a survival of > 3 years). TDA is a feasible and effective surgical procedure for the treatment of ampullary adenomas with low-grade dysplasia when endoscopic approach is contraindicated or has failed. For lesions with evidence of malignancy, TDA seems to be an oncological safe procedure for Tis ampullary cancer and a good palliative procedure for patients unfit for PD. Moreover, TDA may be appropriate for the treatment of G1 ampullary neuroendocrine neoplasms. A large multicentre study of TDA for early ampullary cancers is needed.

Background: One of the controversial issues in the diagnosis of pancreatic neuroendocrine tumours (pNETs) is the accurate prediction of their clinical behaviour. Objectives: The aim of the study was to evaluate the role of endoscopic ultrasound (EUS) biopsy in the diagnosis and grading of pNETs in a certified ENETS Center. Methods: A prospectively maintained database of EUS biopsy procedures was retrospectively reviewed to identify all consecutive patients referred to a certified ENETS Center with a suspicion of pNET between June 2014 and April 2017. The cytological and/or histological specimens were stained and the Ki-67 labeling index was evaluated. In patients undergoing surgery, the grade obtained with EUS-guided biopsy was compared with the final histological grade. The grade was evaluated according to the 2017 WHO classifications and grading. Results: The study population included 59 patients. EUS biopsy material reached an adequacy of 98.3% and was adequate for Ki-67 evaluation in 84.7% of cases. Twenty-nine patients (49.2%) underwent surgery. Of these, 25 patients had Ki-67 evaluated on EUS biopsy: the agreement between EUS biopsy grading and surgical specimen grading was 84%. Conclusion: EUS biopsy is an accurate method for the diagnosis and grading of pNETs based on the WHO 2017 Ki-67 labelling scheme.

Background Transition to digital pathology usually takes months or years to be completed. We were familiarizing ourselves with digital pathology solutions at the time when the COVID-19 outbreak forced us to embark on an abrupt transition to digital pathology. Objective The aim of this study was to quantitatively describe how the abrupt transition to digital pathology might affect the quality of diagnoses, model possible causes by probabilistic modeling, and qualitatively gauge the perception of this abrupt transition. Methods A total of 17 pathologists and residents participated in this study; these participants reviewed 25 additional test cases from the archives and completed a final psychologic survey. For each case, participants performed several different diagnostic tasks, and their results were recorded and compared with the original diagnoses performed using the gold standard method (ie, conventional microscopy). We performed Bayesian data analysis with probabilistic modeling. Results The overall analysis, comprising 1345 different items, resulted in a 9% (117/1345) error rate in using digital slides. The task of differentiating a neoplastic process from a nonneoplastic one accounted for an error rate of 10.7% (42/392), whereas the distinction of a malignant process from a benign one accounted for an error rate of 4.2% (11/258). Apart from residents, senior pathologists generated most discrepancies (7.9%, 13/164). Our model showed that these differences among career levels persisted even after adjusting for other factors. Conclusions Our findings are in line with previous findings, emphasizing that the duration of transition (ie, lengthy or abrupt) might not influence the diagnostic performance. Moreover, our findings highlight that senior pathologists may be limited by a digital gap, which may negatively affect their performance with digital pathology. These results can guide the process of digital transition in the field of pathology.

SBA classification is still based on the location of the primary tumor, without genetic information. in the current study, an extensive genetic profile of SBA, was performed in order to identify and quantify targetable alterations for a future precision medicine in SBA. Clinical-pathological information for 24 patients affected by SBA were retrospectively reviewed. Whole genome analysis of the primary tumors was performed by the FOUNDATION Cdx technology. We carried out a functional enrichment analysis of the mutated genes with BioPlanet. Integrative clustering analysis revealed three distinct subtypes characterized by different genomic alterations. Cluster 1exhibited significant correlations with MSI status, high TMB, celiac disease and Jejunual site.We defined cluster 1 as “immunological subtype” (29.2% of patients). Driver mutations in this subtype suggest that 100% of patients may benefit from immunotherapy. Enrichment analysis of cluster 2 highlighted that the main affected pathway was that of homologous DNA pairing and strand exchange (16.7% of patients). We defined this cluster as “DNA Damage Repair (DDR) like”. On the basis of these driver molecular alterations, 100% of patients could benefit from PARPi. Finally, Cluster 3 had no significant correlations with clinical-pathological characteristics (54.1% of patients). Enrichment analysis revealed that this cluster has remarkable similarities with CRA genomic profile, so we defined it as “Colon-like”. SBA is a genetically distinct tumor entity and deep mutation heterogeneity indicates that different driver genes play a role in the biology of these tumors. The identification of clusters based on genetic profile suggest the possibility to go beyond chemotherapy in several patients.

High-grade Gastroenteropancreatic Neuroendocrine neoplasms (H-NENs) comprehend well-differentiated tumors (NET G3) and poorly differentiated carcinomas (NEC) with proliferative activity indexes as mitotic count (MC) &gt, 20 mitoses/10 HPF and Ki-67 &gt, 20%. At present, no specific therapy for H-NENs exists and the several evidences of microenvironment involvement in their pathogenesis pave the way for tailored therapies. Forty-five consecutive cases, with available information about T-cell, immune, and non-immune markers, from surgical pathology and clinical databases of 2 Italian institutions were immunostained for Arginase, CD33, CD163 and CD66 myeloid markers. The association between features was assessed by Spearman’s correlation coefficient. A unsupervised K-means algorithm was used to identify clusters of patients according to inputs of microenvironment features and the relationship between clusters and clinicopathological features, including cancer-specific survival (CSS), was analyzed. The H-NEN population was composed of 6 (13.3%) NET G3 and 39 (86.7%) NEC. Overall, significant positive associations were found between myeloid (CD33, CD163 and Arginase) and T/immune markers (CD3, CD4, CD8, PD-1 and HLA-I). Myeloid and T-cell markers CD3 and CD8 identified two clusters of patients from unsupervised K-means analysis. Cases grouped in cluster 1 with more myeloid infiltrates, T cell, HLA and expression of inhibitory receptors and ligands in the stroma (PD-1, PD-L1) had significantly better CSS than patients in cluster 2. Multivariable analysis showed that Ki-67 (&gt, 55 vs. &lt, 55, HR 8.60, CI 95% 2.61–28.33, p &lt, 0.0001) and cluster (1 vs. 2, HR 0.43, CI 95% 0.20–0.93, p = 0.03) were significantly associated with survival. High grade gastroenteropancreatic neuroendocrine neoplasms can be further classified into two prognostic sub-populations of tumors driven by different tumor microenvironments and immune features able to generate the framework for evaluating new therapeutic strategies.

Stage significantly affects survival of esophageal and esophago-gastric junction adenocarcinomas (EA/EGJAs), however, limited evidence for the prognostic role of histologic subtypes is available. The aim of the study was to describe a morphologic approach to EA/EGJAs and assess its discriminating prognostic power. Histologic slides from 299 neoadjuvant treatment-naïve EA/EGJAs, resected in five European Centers, were retrospectively reviewed. Morphologic features were re-assessed and correlated with survival. In glandular adenocarcinomas (240/299 cases—80%), WHO grade and tumors with a poorly differentiated component ≥6% were the most discriminant factors for survival (both p &lt, 0.0001), distinguishing glandular well-differentiated from poorly differentiated adenocarcinomas. Two prognostically different histologic groups were identified: the lower risk group, comprising glandular well-differentiated (34.4%) and rare variants, such as mucinous muconodular carcinoma (2.7%) and diffuse desmoplastic carcinoma (1.7%), versus the higher risk group, comprising the glandular poorly differentiated subtype (45.8%), including invasive mucinous carcinoma (5.7%), diffuse anaplastic carcinoma (3%), mixed carcinoma (6.7%) (CSS p &lt, 0.0001, DFS p = 0.001). Stage (p &lt, 0.0001), histologic groups (p = 0.001), age &gt, 72 years (p = 0.008), and vascular invasion (p = 0.015) were prognostically significant in the multivariate analysis. The combined evaluation of stage/histologic group identified 5-year cancer-specific survival ranging from 87.6% (stage II, lower risk) to 14% (stage IVA, higher risk). Detailed characterization of histologic subtypes contributes to EA/EGJA prognostic prediction.

Background: There is extreme heterogeneity in the available literature on the determination of R1 resection rate after pancreatoduodenectomy (PD), consequently, its prognostic role is still debated. The aims of this multicenter randomized study were to evaluate the effect of sampling and clearance definition in determining R1 rate after PD for periampullary cancer and to assess the prognostic role of R1 resection. Methods: PD specimens were randomized to Leeds Pathology Protocol (LEEPP) (group A) or the conventional method adopted before the study (group B). R1 rate was determined by adopting 0- and 1-mm clearance, the association between R1, local recurrence (LR) and overall survival (OS) was also evaluated. Results. One-hundred-sixty-eight PD specimens were included. With 0 mm clearance, R1 rate was 26.2% and 20.2% for groups A and B, respectively, with 1 mm, R1 rate was 60.7% and 57.1%, respectively (p &gt, 0.05). Only in group A was R1 found to be a significant prognostic factor: at 0 mm, median OS was 36 and 20 months for R0 and R1, respectively, while at 1 mm, median OS was not reached and 30 months. At multivariate analysis, R1 resection was found to be a significant prognostic factor independent of clearance definition only in the case of the adoption of LEEPP. Conclusions. The 1 mm clearance is the most effective factor in determining the R1 rate after PD. However, the pathological method is crucial to accurately evaluate its prognostic role: only R1 resections obtained with the adoption of LEEPP seem to significantly affect prognosis.

KRAS mutations characterize pancreatic cell transformation from the earliest stages of carcinogenesis, and are present in >95% of pancreatic ductal adenocarcinoma (PDAC) cases. In search of novel biomarkers for the early diagnosis of PDAC, we identified the proteins secreted by the normal human pancreatic cell line (HPDE) recently transformed by inducing the overexpression of the KRASG12V oncogene. We report a proteomic signature of KRAS-induced secreted proteins, which was confirmed in surgical tumor samples from resected PDAC patients. The putative diagnostic performance of three candidates, Laminin-C2 (LAMC2), Tenascin-C (TNC) and Pentraxin-3 (PTX3), was investigated by ELISA quantification in two cohorts of PDAC patients (n = 200) eligible for surgery. Circulating levels of LAMC2, TNC and PTX3 were significantly higher in PDAC patients compared to the healthy individuals (p < 0.0001). The Receiver Operating Characteristics (ROC) curve showed good sensitivity (1) and specificity (0.63 and 0.85) for LAMC2 and PTX3, respectively, but not for TNC, and patients with high levels of LAMC2 had significantly shorter overall survival (p = 0.0007). High levels of LAMC2 and PTX3 were detected at early stages (I–IIB) and in CA19-9-low PDAC patients. In conclusion, pancreatic tumors release LAMC2 and PTX3, which can be quantified in the systemic circulation, and may be useful in selecting patients for further diagnostic imaging.

BackgroundSerous cysto-adenoma (SCA) is a rare benign neoplasm of the pancreas. SCA can mimic other pancreatic lesions, such as neuroendocrine tumours. 68Gallium-DOTA-peptide Positron Emission Tomography (PET) is able to image in vivo the over-expression of the somatostatin receptors, playing an important role for the identification of neuroendocrine neoplasms.Case presentationWe reported a case of 63-year-old man,with a solid lesion of 7 cm of diameter of the body–tail of the pancreas. Two fine-needle-aspirations (FNA) were inconclusive. A 68Ga-DOTA-peptide PET-CT revealed a pathological uptake of the pancreatic lesion. The diagnosis of a pancreatic neuroendocrine neoplasm was established and a laparoscopic distal splenopancreatectomy and cholecystectomy was performed. Final histopathological report revealed the presence of a micro-cystic SCA.ConclusionsThe current case firstly reports a pancreatic SCA showing increased radiopharmaceutical uptake at 68Ga-DOTA-peptide PET-CT images. This unexpected finding should be taken into account during the diagnostic algorithm of a pancreatic lesion, in order to minimize the risk of misdiagnosis and overtreatment of SCA.

BACKGROUND Transition to digital pathology usually takes months or years to be completed. We were familiarizing ourselves with digital pathology solutions at the time when the COVID-19 outbreak forced us to embark on an abrupt transition to digital pathology. OBJECTIVE The aim of this study was to quantitatively describe how the abrupt transition to digital pathology might affect the quality of diagnoses, model possible causes by probabilistic modeling, and qualitatively gauge the perception of this abrupt transition. METHODS A total of 17 pathologists and residents participated in this study; these participants reviewed 25 additional test cases from the archives and completed a final psychologic survey. For each case, participants performed several different diagnostic tasks, and their results were recorded and compared with the original diagnoses performed using the gold standard method (ie, conventional microscopy). We performed Bayesian data analysis with probabilistic modeling. RESULTS The overall analysis, comprising 1345 different items, resulted in a 9% (117/1345) error rate in using digital slides. The task of differentiating a neoplastic process from a nonneoplastic one accounted for an error rate of 10.7% (42/392), whereas the distinction of a malignant process from a benign one accounted for an error rate of 4.2% (11/258). Apart from residents, senior pathologists generated most discrepancies (7.9%, 13/164). Our model showed that these differences among career levels persisted even after adjusting for other factors. CONCLUSIONS Our findings are in line with previous findings, emphasizing that the duration of transition (ie, lengthy or abrupt) might not influence the diagnostic performance. Moreover, our findings highlight that senior pathologists may be limited by a digital gap, which may negatively affect their performance with digital pathology. These results can guide the process of digital transition in the field of pathology.

Background Duodenal adenocarcinoma (DA) is a rare yet aggressive malignancy, with increasing incidence in the last decades. Its low frequency has hampered a thorough understanding of the pathogenesis of the disease and of its biology, limiting the identification of tailored therapeutic options. A large body of evidence has clearly shown the clinical relevance of immune cells in solid tumors, correlating immune features with post-surgical prognosis. The aim of this study was to analyze the immune contexture in a cohort of duodenal adenocarcinomas surgically resected at our Institution and define its correlation with clinical variables. Methods Tissue slides from paraffin-embedded tumor specimens of 15 consecutive DA and 3 adenomas that underwent a pancreaticoduodenectomy in our center between 2010 to 2018 were immunohistochemically stained. The density (percentage of immune reactive area, IRA%) of immune markers CD45RO, CD8, CD20, IL-17, PD-1, CD68 was quantified by computer-assisted image analysis. Demographic, clinical, histopathological data were collected. Results In our population, median IRA % (IQR) of immune subsets was respectively CD45RO-TILs 2.19 (2.14), CD8-TIL 0.42 (0.81), CD20-TILs 0.22 (0.51), CD20-TLT 2.84 (4.64), CD68-TAM 2.19 (1.56), IL17+ cells 0.39 (0.39), PD1-TILs 0.19 (0.41). The median follow-up was 47.5 (22.4–63.3) months. At statistical analysis, the density of CD8-TILs inversely correlated with lymph node ratio (p = 0.013), number of metastatic lymph nodes (p = 0.019), and was lower in N+ adenocarcinomas compared to N0 (1.07 vs 0.29; p = 0.093), albeit not significantly. Stratifying patients for the N status, the density of CD8-TILs decreased with the increasing of the N stage (p = 0.065) and was lower in patients who experienced recurrence and died for the disease (0.276 vs 0.641; p = 0.044). Notably, also CD68-TAM distribution was different in patients who had recurrence versus patients who did not (1.028 vs 2.276; p = 0.036). Conclusions Immune cells showed variable expression in correlation with common prognostic factors, suggesting T cell infiltration may play a protective role towards lymphatic spread of disease and nodal metastatization. Furthermore, T cell density and macrophage infiltration were associated to a lower risk of recurrence and disease related death. A multicentric approach may be indicated to allow analysis of larger cohorts of patients, potentially increasing the power of our observations.

Summary Several pathological conditions, other than gastro-esophageal reflux disease and its complications, can affect the esophagus. While some of these can present with unspecific lesions (i.e. ulcers and epithelial damage) and require clinico-pathological correlation for diagnosis (i.e. drug-induced esophagitis and corrosive esophagitis) other conditions show distinctive histological lesions which enable the pathologist to reach the diagnosis (i.e. some specific infectious esophagites and Crohn’s disease). In this context eosinophilic esophagitis is the condition which has been increasingly studied in the last two decades, while lymphocytic esophagitis, a relatively new entity, still represents an enigma. This overview will focus on and describe histologic lesions which allow pathologists to differentiate between these conditions.

Summary Background and Aims: As obtaining adequate tissue on biopsy is critical for the detection of residual and recurrent intestinal metaplasia/dysplasia in Barrett’s esophagus (BE) patients undergone Barrett’s endoscopic eradication therapy (BET), we decided to compare the adequacy of biopsy specimens using jumbo versus standard biopsy forceps. Methods: This is a two-center study of patients’ post-radiofrequency ablation of dysplastic BE. After BET, jumbo (Boston Scientific©, Radial Jaw 4, opening diameter 2.8 mm) or standard (Boston Scientific©, Radial Jaw 4, opening diameter 2.2 mm) biopsy forceps were utilized to obtain surveillance biopsies from the neo-squamous epithelium. Presence of lamina propria and proportion of squamous epithelium with partial or full thickness lamina propria was recorded by two experienced gastrointestinal pathologists who were blinded. Squamous epithelial biopsies that contained at least two-thirds of lamina propria were considered ‘adequate’. Results: In a total of 211 biopsies from 55 BE patients, 145 biopsies (29 patients, 18 males, mean age 61 years, interquartile range [IQR] 33–83) were obtained using jumbo forceps and 66 biopsies (26 patients, all males, mean age 65 years, IQR 56–76) using standard forceps biopsies. Comparing jumbo versus standard forceps, the proportion of specimens with any subepithelial lamina propria was 51.7% versus 53%, P = 0.860 and the presence of adequate subepithelial lamina propria was 17.9% versus 9.1%, P = 0.096 respectively. Conclusions: Use of jumbo forceps does not appear to have added advantage over standard forceps to obtain adequate biopsy specimens from the neo-squamous mucosa post-ablation.

Summary Many tumors of endodermal origin are composed of highly secretory cancer cells that must adapt endoplasmic reticulum (ER) activity to enable proper folding of secreted proteins and prevent ER stress. We found that pancreatic ductal adenocarcinomas (PDACs) overexpress the myelin regulatory factor (MYRF), an ER membrane-associated transcription factor (TF) released by self-cleavage. MYRF was expressed in the well-differentiated secretory cancer cells, but not in the poorly differentiated quasi-mesenchymal cells that coexist in the same tumor. MYRF expression was controlled by the epithelial identity TF HNF1B, and it acted to fine-tune the expression of genes encoding highly glycosylated, cysteine-rich secretory proteins, thus preventing ER overload. MYRF-deficient PDAC cells showed signs of ER stress, impaired proliferation, and an inability to form spheroids in vitro, while in vivo they generated highly secretory but poorly proliferating and hypocellular tumors. These data indicate a role of MYRF in the control of ER homeostasis in highly secretory PDAC cells.

Background: Little information is available concerning prognostic factors for bronchopulmonary large cell neuroendocrine carcinomas (BP-LCNECs) and even less is known about combined LCNECs (Co-LCNECs). We investigated whether an integrated morphological, immunohistochemical, and molecular approach could be used for their prognostic evaluation. Methods: Morphological (including combined features), proliferative (mitotic count/Ki-67 index), immunohistochemical (napsin A, p40, TTF-1, CD44, OTP, SSTR2A, SSTR5, mASH1, p53, RB1, and MDM2), and genomic (TP53, RB1, ATM, JAK2, KRAS, and STK11) findings were analyzed in BP-LCNECs from 5 Italian centers, and correlated with overall survival (OS). The Ki-67 index was expressed as the percentage of positive cells in hot spots as indicated in the WHO 2019 Digestive System Tumors and, for Co-LCNECs, the Ki-67 index was evaluated only in the LCNEC component. Results: A total of 111 LCNECs were distinguished into 70 pure LCNECs, 35 Co-LCNECs (27 with adenocarcinoma [ADC] and 8 with squamous cell carcinoma [SqCC]), and 6 LCNECs with only napsin A immunoreactivity. The Ki-67 index cutoff at 55% evaluated in the neuroendocrine component was the most powerful predictor of OS (log-rank p = 0.0001) in all LCNECs; 34 cases had a Ki-67 index p = 0.0001) were also observed between pure and Co-LCNECs. A significant difference in OS was found between pure LCNECs-A and Co-LCNECs-A (p < 0.05) but not between pure LCNECs-B and Co-LCNECs-B. Co-LCNEC-ADC and LCNEC napsin A+ cases had longer OS than pure LCNEC and Co-LCNEC-SqCC cases (log-rank p = 0.0001). On multivariable analysis, tumor location, pure versus combined features, and napsin A, but no single gene mutation, were significantly associated with OS after adjustment for Ki-67 index and study center (p < 0.05). Conclusions: The Ki-67 proliferation index and the morphological characterization of combined features in LCNECs seem to be important tools for predicting clinical outcome in BP-LCNECs.

Better understanding of pancreatic diseases, including pancreatic ductal adenocarcinoma (PDAC), is an urgent medical need, with little advances in preoperative differential diagnosis, preventing rational selection of therapeutic strategies. The clinical management of pancreatic cancer patients would benefit from the identification of variables distinctively associated with the multiplicity of pancreatic disorders. We investigated, by 1H nuclear magnetic resonance, the metabolomic fingerprint of pancreatic juice (the biofluid that collects pancreatic products) in 40 patients with different pancreatic diseases. Metabolic variables discriminated PDAC from other less aggressive pancreatic diseases and identified metabolic clusters of patients with distinct clinical behaviors. PDAC specimens were overtly glycolytic, with significant accumulation of lactate, which was probed as a disease-specific variable in pancreatic juice from a larger cohort of 106 patients. In human PDAC sections, high expression of the glucose transporter GLUT-1 correlated with tumor grade and a higher density of PD-1+ T cells, suggesting their accumulation in glycolytic tumors. In a preclinical model, PD-1+ CD8 tumor–infiltrating lymphocytes differentially infiltrated PDAC tumors obtained from cell lines with different metabolic consumption, and tumors metabolically rewired by knocking down the phosphofructokinase (Pfkm) gene displayed a decrease in PD-1+ cell infiltration. Collectively, we introduced pancreatic juice as a valuable source of metabolic variables that could contribute to differential diagnosis. The correlation of metabolic markers with immune infiltration suggests that upfront evaluation of the metabolic profile of PDAC patients could foster the introduction of immunotherapeutic approaches for pancreatic cancer.

γδ T cells account for a large fraction of human intestinal intraepithelial lymphocytes (IELs) endowed with potent anti-tumor activities. However, little is known about their origin, phenotype and clinical relevance in colorectal cancer (CRC). To determine γδ IEL gut-specificity, homing and functions, γδ T cells were purified from human healthy blood, lymph nodes, liver, skin, intestine either disease-free or affected by CRC or generated from thymic precursors. The constitutive expression of NKp46 specifically identifies a new subset of cytotoxic Vδ1 T cells representing the largest fraction of gut-resident IELs. The ontogeny and gut-tropism of NKp46pos/Vδ1 IELs depends both on distinctive features of Vδ1 thymic precursors and gut-environmental factors. Either the constitutive presence of NKp46 on tissue-resident Vδ1 intestinal IELs or its induced-expression on IL-2/IL-15 activated Vδ1 thymocytes are associated with anti-tumor functions. Higher frequencies of NKp46pos/Vδ1 IELs in tumor-free specimens from CRC patients correlate with a lower risk of developing metastatic III/IV disease stages. Additionally, our in vitro settings reproducing CRC tumor-microenvironment inhibited the expansion of NKp46pos/Vδ1 cells from activated thymic precursors. These results parallel the very low frequencies of NKp46pos/Vδ1 IELs able to infiltrate CRC, thus providing new insights to either follow-up cancer progression or develop novel adoptive cellular therapies.

Differentiation of normal and tumor cells is controlled by regulatory networks enforced by lineage-determining transcription factors (TFs). Among them, TFs such as FOXA1/2 bind naïve chromatin and induce its accessibility, thus establishing new gene regulatory networks. Pancreatic ductal adenocarcinoma (PDAC) is characterized by the coexistence of well- and poorly differentiated cells at all stages of disease. How the transcriptional networks determining such massive cellular heterogeneity are established remains to be determined. We found that FOXA2, a TF controlling pancreas specification, broadly contributed to the cis-regulatory networks of PDACs. Despite being expressed in both well- and poorly differentiated PDAC cells, FOXA2 displayed extensively different genomic distributions and controlled distinct gene expression programs. Grade-specific functions of FOXA2 depended on its partnership with TFs whose expression varied depending on the differentiation grade. These data suggest that FOXA2 contributes to the regulatory networks of heterogeneous PDAC cells via interactions with alternative partner TFs.

Colorectal cancer (CRC) is one of the most malignant tumors worldwide. Stromal cells residing in the tumor microenvironment strongly contribute to cancer progression through their crosstalk with cancer cells and extracellular matrix. Here we provide the first evidence that CRC-associated lymphatic endothelium displays a distinct matrisome-associated transcriptomic signature, which distinguishes them from healthy intestinal lymphatics. We also demonstrate that CRC-associated human intestinal lymphatic endothelial cells regulate tumor cell growth via growth differentiation factor 11, a soluble matrisome component which in CRC patients was found to be associated with tumor progression. Our data provide new insights into lymphatic contribution to CRC growth, aside from their conventional role as conduits of metastasis.

Nodal involvement (actually categorized as positive or negative) is an important prognostic factor after surgery for pancreatic neuroendocrine neoplasms (pNENs). We aim to evaluate the predictive role of the number of nodal metastases after pancreatic resection for pNENs. We analyzed from a prospectively maintained database all pancreatic resections for nonmetastatic nonfunctioning pNENs performed in our institution from 2011 to 2016. According to the number of nodal metastases, enhancing the actual categorization, we distinguished the following: N0, no nodal metastases; N1, 1-3 metastatic lymph nodes; and N2, metastases in 4 or more regional lymph nodes. Recurrence and disease-free survival (DFS) were evaluated. The predictive value in terms of recurrence for each clinicopathological data, including the number of metastatic lymph nodes, was calculated. Univariate and multivariate analyses were conducted. 77 patients underwent pancreatic surgery for pNENs. N0, N1, and N2 resections were found in 52 (67.5%), 16 (20.8%), and 9 (11.7%) cases, respectively. Mean follow-up of the entire cohort was 48 (±25) months. The recurrence rate was 11.8%, and the mean time of recurrence was 12 (±14) months. DFS was 83.7 months (76.0 - 91.5). At a univariate analysis, factors associated with recurrence were mitotic count (OR 1.19, p=0.001), Ki67 value (OR 1.06, p=0.001), the presence of nodal metastases (OR 11.54, p=0.002), and metastases in 4 or more regional lymph nodes (N2) (OR 30.19, p=0.002). At a multivariate analysis, only mitotic count (OR 1.51, p=0.005) and N2 resection (OR 134.74, p=0.002) were found to be predictive factors of recurrence. The number of metastatic lymph nodes and mitotic count is the most significant predictive factors of recurrence after pancreatic surgery for nonmetastatic nonfunctioning pNENs.

Metastasis is facilitated by the formation of a "premetastatic niche," which is fostered by primary tumor-derived factors. Colorectal cancer (CRC) metastasizes mainly to the liver. We show that the premetastatic niche in the liver is induced by bacteria dissemination from primary CRC. We report that tumor-resident bacteria Escherichia coli disrupt the gut vascular barrier (GVB), an anatomical structure controlling bacterial dissemination along the gut-liver axis, depending on the virulence regulator VirF. Upon GVB impairment, bacteria disseminate to the liver, boost the formation of a premetastatic niche, and favor the recruitment of metastatic cells. In training and validation cohorts of CRC patients, we find that the increased levels of PV-1, a marker of impaired GVB, is associated with liver bacteria dissemination and metachronous distant metastases. Thus, PV-1 is a prognostic marker for CRC distant recurrence and vascular impairment, leading to liver metastases. Copyright © 2021 Elsevier Inc. All rights reserved.

In pancreatic neuroendocrine neoplasms (pNEN), size ≤2 cm and Ki-67 3% suggest indolent behavior, but no factor alone predicts prognosis. We investigated factors predictive of tumor progression in 80 pNENs surgically resected in a single Institution from 1995 to 2015. At multivariable analysis the only two independent variables related to PFS were Ki-67 (HR 2.97; 95%CI 1.26-7.02) and presence of synchronous liver metastases (HR 3.60; 95%CI 1.70-7.61). Using Ki-67 3% and M0 as reference, the HR for tumor progression was 3.21 (95%CI 1.18-8.74) for M0 patients with Ki-67 3-20%, 5.06 (2.29-11.2) for M1 patients with Ki-67 ≤ 20% and 24.3 (6.64-89.2) for those with Ki-67 20%. Tumor size (≤2 vs.2 cm) was not a predictive factor at any analysis. Intra-class correlation of Ki-67 values on pre-surgical biopsies vs. surgical specimens was 0.99 and Ki-67 classes were correctly identified in 97% of biopsies. Ki-67 and presence of liver metastases are the major prognostic factors in pNEN and identify different progression risks regardless of tumor size. Pre-surgical pNEN biopsy for Ki-67 assessment should be included in the evaluation of patients with 1-2 cm tumors to help in the decision on whether to perform surgical resection.

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