Tumour budding is a strong and independent prognostic factor in pancreatic cancer

Prognostic significance of tumour budding in noncolorectal gastrointestinal tract and pancreatobiliary tract: a systematic review and meta-analysis

Tumour budding shows promise as a prognostic factor in various cancers, but its widespread application is hindered by the lack of large, validated studies and standardized criteria. This meta-analysis aims to review and examine the prognostic role of tumour budding specifically in noncolorectal gastrointestinal and pancreatobiliary tract cancers, broadening our perspective on its clinical relevance. The literature review was conducted through PubMed, Embase, and Web of Science from inception till 20 February 2023. Pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated to assess the relation between tumour budding and clinicopathologic features, as well as overall survival. Each study was evaluated using the Newcastle-Ottawa Scale and both heterogeneity and publication bias were analysed. In this meta-analysis of 57 studies across various cancer types, multivariate HR revealed worse overall survival in oesophageal squamous cell carcinoma (HR 3.34 [95% CI 2.21-5.04]), gastric adenocarcinoma (2.03 [1.38-2.99]), pancreatic ductal adenocarcinoma (2.56 [2.02-3.25]), and biliary tract adenocarcinoma (3.11 [2.46-3.93]) with high-grade tumour budding. Additionally, high-grade tumour budding consistently correlated with adverse clinicopathological features, including lymph node metastasis, lymphovascular invasion, and distant metastasis without any observed inverse association. High heterogeneity was noted. Our study suggests that tumour budding is a valuable prognostic marker in various cancers. Nonetheless, standardized criteria tailored to specific organ types are necessary to enhance its clinical utility.

The radiomorphological appearance of the invasive margin in pancreatic cancer is associated with tumor budding

PURPOSE

Pancreatic cancer (PDAC) is characterized by infiltrative, spiculated tumor growth into the surrounding non-neoplastic tissue. Clinically, its diagnosis is often established by magnetic resonance imaging (MRI). At the invasive margin, tumor buds can be detected by histology, an established marker associated with poor prognosis in different types of tumors.

METHODS

We analyzed PDAC by determining the degree of tumor spiculation on T2-weighted MRI using a 3-tier grading system. The grade of spiculation was correlated with the density of tumor buds quantified in histological sections of the respective surgical specimen according to the guidelines of the International Tumor Budding Consensus Conference (n = 28 patients).

RESULTS

64% of tumors revealed intermediate to high spiculation on MRI. In over 90% of cases, tumor buds were detected. We observed a significant positive rank correlation between the grade of radiological tumor spiculation and the histopathological number of tumor buds (rs = 0.745, p < 0.001). The number of tumor buds was not significantly associated with tumor stage, presence of lymph node metastases, or histopathological grading (p ≥ 0.352).

CONCLUSION

Our study identifies a readily available radiological marker for non-invasive estimation of tumor budding, as a correlate for infiltrative tumor growth. This finding could help to identify PDAC patients who might benefit from more extensive peripancreatic soft tissue resection during surgery or stratify patients for personalized therapy concepts.

Comparison of mismatch repair and immune checkpoint protein profile with histopathological parameters in pancreatic, periampullary/ampullary, and choledochal adenocarcinomas

BACKGROUND

Pancreatic, periampullary/ampullary, and choledochal adenocarcinomas are aggressive malignancies with a poor prognosis. Immune checkpoint blockade is a promising treatment option for several tumor types. H long terminal repeat-associating 2 (HHLA2), which is analogous to programmed death-ligand 1 (PD-L1), is a recently discovered member of the B7/cluster of differentiation 28 family and is expressed in many malignancies.

AIM

To analyze the expression of HHLA2 and its association with the pathologic biomarkers that predict sensitivity to immunotherapy.

METHODS

Ninety-two adenocarcinoma cases located in the pancreas, ampulla, and distal common bile duct were identified. This study assessed 106 pancreaticoduodenectomy and distal/total pancreatectomy samples that were delivered to Ankara City Hospital between 2019 and 2021. Immunohistochemistry was conducted to examine the expression of DNA mismatch repair (MMR), PD-L1, and HHLA2 proteins.

RESULTS

Patients with high HHLA2 expression had a higher mean age than those with low expression. Low HHLA2 expression was associated with high perineural invasion. HHLA2 expression was low in pathological stage T3 (pT) 3 cases and high in pathological stage T1, T2, and T4 cases. There was no correlation between HHLA2 expression and the expression of MMR proteins and PD-L1.

CONCLUSION

Evaluation of HHLA2 expression in microsatellite stable and PD-L1-negative tumors may be useful for predicting the response of individuals to immunotherapy and may serve as a novel therapeutic target for immunotherapy in advanced-stage disease.

Tumor budding to investigate local invasion, metastasis, and prognosis of head and neck carcinoma: A systematic review

The aim of this systematic review is to shed light on the role of tumor budding (TB) in the biology, behavior, and prognosis of head and neck squamous cell carcinoma (HNSCC). A search was run in PubMed, Scopus, and Embase databases following PRISMA guidelines. After full-text screening and application of inclusion/exclusion criteria, 36 articles were included. Several investigations support the prognostic role of TB, which might play a role in selecting rational treatment strategies. To achieve this goal, further research is needed for greater standardization in TB quantification. Although TB is not included as a negative prognostic factor in the current management guidelines, it might be reasonable to consider a closer follow-up for HNSCC cases with high histopathological evidence of TB.

Invasive features of superficial oesophageal squamous cell carcinoma-analysis of risk factors for lymph node metastasis

There are currently no studies that have examined the clinicopathological factors in detail, including the histological images of the invasive front, and the risk of lymph node metastasis (LNM) in superficial oesophageal squamous cell carcinoma (SESCC). This study aimed to develop an algorithm that contributes to a better assessment of the risk of LNM and recurrence in SESCC. Clinicopathological factors, such as submucosal (SM) invasion distance, were examined in 88 surgically resected cases of SESCC. An SM invasion distance of 600 μm was the statistically best customer value for LNM (p = 0.0043). To obtain a histological image of the invasive front, we evaluated modified tumour budding (MBD) by modifying the number of tumour foci constituent cells and foci in tumour budding. We also evaluated the smallest number of tumour foci. Using these factors, we developed an algorithm to predict the risk of LNM. The best algorithm was created using an SM invasion distance of 600 μm and an index of 5 or more foci consisting of five or fewer tumour cells in the MBD (MBD5 high-grade ≥ 5), which was also significantly associated with recurrence-free survival (p = 0.0305). Further study of the algorithm presented in this study is expected to improve the quality of life of patients by selecting appropriate additional treatments after endoscopic resection and appropriate initial treatment for SESCC.

Emerging Prognostic and Predictive Factors in Pancreatic Cancer

Pancreatic cancer is a lethal disease with increasing incidence and high recurrence rates and is currently resistant to conventional therapies. Moreover, it displays extensive morphologic and molecular intratumoral and intertumoral heterogeneity and a mostly low mutational burden, failing to induce significant antitumor immunity. Thus, immunotherapy has shown limited effect in pancreatic cancer, except in rare tumors with microsatellite instability, constituting <1% of the cases. Currently, new methods, including single-cell and single-nucleus RNA sequencing, have refined and expanded the 2-group molecular classification based on bulk RNA sequencing (classical and basal-like subtypes), identifying hybrid forms and providing us with a comprehensive map of the tumor cell subsets that drive gene expression during tumor evolution, simultaneously giving us insight into therapy resistance and metastasis. Additionally, deeper profiling of the tumor microenvironment of pancreatic cancer by using spatial analyses and multiplex imaging techniques has improved our understanding of the heterogeneous distribution of both adaptive and innate immune components with their protumor and antitumor properties. By integrating host immune response patterns, as defined by spatial transcriptomic and proteomic analysis and multiplex immunofluorescence, with molecular and morphologic features of the tumors, we can increasingly understand the genetic, immunologic, and morphologic background of pancreatic cancer and recognize the potential predictors for different treatment modalities.

Artificial Intelligence in Digital Pathology for Bladder Cancer: Hype or Hope? A Systematic Review

Bladder cancer (BC) diagnosis and prediction of prognosis are hindered by subjective pathological evaluation, which may cause misdiagnosis and under-/over-treatment. Computational pathology (CPATH) can identify clinical outcome predictors, offering an objective approach to improve prognosis. However, a systematic review of CPATH in BC literature is lacking. Therefore, we present a comprehensive overview of studies that used CPATH in BC, analyzing 33 out of 2285 identified studies. Most studies analyzed regions of interest to distinguish normal versus tumor tissue and identify tumor grade/stage and tissue types (e.g., urothelium, stroma, and muscle). The cell's nuclear area, shape irregularity, and roundness were the most promising markers to predict recurrence and survival based on selected regions of interest, with >80% accuracy. CPATH identified molecular subtypes by detecting features, e.g., papillary structures, hyperchromatic, and pleomorphic nuclei. Combining clinicopathological and image-derived features improved recurrence and survival prediction. However, due to the lack of outcome interpretability and independent test datasets, robustness and clinical applicability could not be ensured. The current literature demonstrates that CPATH holds the potential to improve BC diagnosis and prediction of prognosis. However, more robust, interpretable, accurate models and larger datasets-representative of clinical scenarios-are needed to address artificial intelligence's reliability, robustness, and black box challenge.

Proposal of a grading system for squamous cell carcinoma of the lung - the prognostic importance of tumour budding, single cell invasion, and nuclear diameter

The prognostic markers of lung squamous cell carcinoma (LSCC) are less investigated. The aim of our study was to evaluate tumour budding (TB), minimal cell nest size, nuclear diameter (ND), and spread through air spaces (STAS) among patients with resected LSCC, semi-quantitatively. Furthermore, we aimed to identify a grading system for the best prognostic stratification of LSCC. Patients who underwent surgical resection at the Department of Surgery, University of Szeged between 2010 and 2016 were included. Follow-up data were collected from medical charts. Morphological characteristics were recorded from histologic revision of slides. Kaplan-Meier analysis, log rank test and Cox proportional-hazards model, ROC curve analysis, and intraclass correlation were utilised. Altogether 220 patients were included. In univariate analysis, higher degree of TB, infiltrative tumour border, larger ND, the presence of single cell invasion (SCI) and STAS were associated with adverse prognosis. Based on our results, we proposed an easily applicable grading scheme focusing on TB, ND, and SCI. In multivariate analysis, the proposed grading system (pOS < 0.001, pRFS < 0.001) and STAS (pOS = 0.008, pRFS < 0.001) were independent prognosticators. Compared to the previously introduced grading systems, ROC curve analysis revealed that the proposed grade had the highest AUC values (AUCOS: 0.83, AUCRFS: 0.78). Each category of the proposed grading system has good (ICC: 0.79-0.88) reproducibility. We validated the prognostic impact of TB, SCI, ND, and STAS in LSCC. We recommend a reproducible grading system combining TB, SCI, and ND for proper prognostic stratification of LSCC patients. Further research is required for validation of this grading scheme.

Correlation of Bony Invasion With Nodal Metastasis, Pattern of Invasion and Survival in Oral Squamous Cell Carcinoma: A Retrospective Analysis of 122 Primary Cases From Oral Cancer Centre of South India

Background Oral squamous cell carcinoma (OSCC) is considered to be the most common epithelial malignant neoplasm of the oral cavity. Despite advancements in diagnosis and therapeutics the clinical outcome of the disease has not improved much which may be attributed to tumor biology and heterogeneity. Bone invasion by cancer cells is currently staged as a moderately advanced disease. However, many low-grade carcinomas such as verrucous carcinoma and carcinoma cuniculatum show body invasion but less nodal metastases and better overall survival. The present study was orchestrated to analyze if bone invasion in OSCC has any impact on regional nodal metastases and survival. Materials and methods A total of 122 cases of OSCC who underwent excision and neck dissection were retrieved and included. These cases were then divided into two study groups. Group I comprised 56 OSCC cases with bone involvement and 66 cases with no bony involvement. The bone invasion was correlated with nodal metastases, survival and pattern of invasion. Statistical analysis was done using SPSS software (IBM Corp., Armonk, NY, USA). Results There was no statistically significant correlation between bone invasion with either nodal metastases or pattern of invasion, however, the worst pattern of invasion (WPOI)-4,5 showed a statistically higher incidence of nodal involvement in OSCC. No statistical difference was noted in overall survival between the two groups. Conclusion The worst pattern of invasion and not bone involvement, depicts nodal metastases in OSCC and thus, deserves consideration while staging and treatment planning.

Association between the expression levels of ADAMTS16 and BMP2 and tumor budding in hepatocellular carcinoma

Tumor budding (TB) has become a crucial factor for predicting the malignancy grade and prognostic outcome for multiple types of solid cancer. Studies have investigated the prognostic value of TB in hepatocellular carcinoma (HCC). However, its molecular mechanism in HCC remains unclear. To the best of our knowledge, the present study was the first to compare the expression of differentially expressed genes (DEGs) between TB-positive (TB-pos) and TB-negative HCC tissues. In the present study, total RNA was extracted from 40 HCC tissue specimens and then sequenced. According to Gene Ontology (GO) functional annotation, upregulated DEGs were markedly associated with embryonic kidney development-related GO terms, which suggested that the TB process may at least partly mimic the process of embryonic kidney development. Subsequently, two genes, a disintegrin and metalloproteinase domain with thrombospondin motifs 16 (ADAMTS16) and bone morphogenetic protein 2 (BMP2), were screened and verified through immunohistochemical analysis of HCC tissue microarrays. According to the immunohistochemical results, ADAMTS16 and BMP2 were upregulated in TB-pos HCC samples, and BMP2 expression was increased in budding cells compared with the tumor center. Additionally, through cell culture experiments, it was demonstrated that ADAMTS16 and BMP2 may promote TB of liver cancer, thus promoting the malignant progression of liver cancer. Further analysis revealed that ADAMTS16 expression was associated with necrosis and cholestasis, and BMP2 expression was associated with the Barcelona Clinic Liver Cancer stage and the vessels encapsulating tumor clusters. Overall, the findings of the present study provided insights into the possible mechanisms of TB in HCC and revealed potential anti-HCC therapeutic targets.

Tumor Budding Is an Independent Prognostic Factor in Pancreatic Adenocarcinoma and It Positively Correlates with PD-L1 Expression on Tumor Cells

Pancreatic adenocarcinoma is one of the leading causes of cancer-related death in developed countries. Only 15% of patients are candidates for radical surgery, and adequate prognostication may guide proper postsurgical management. We aimed to retrospectively assess the prognostic significance of the immunohistochemical expression of immune checkpoint receptors (PD-L1 and VISTA), markers of systemic inflammation, thrombosis in the tumor area, and the tumor budding in the group of 107 patients diagnosed with pancreatic adenocarcinoma in a single center. The high expression of PD-L1 on tumor cells (TCs) was associated with worse overall survival (OS, p = 0.041, log-rank). On the contrary, high PD-L1 or VISTA on tumor-associated immune cells (TAICs) was correlated with better OS (p = 0.006 and p = 0.008, respectively, log-rank). The joint status of PD-L1 on TCs and TAICs stratified patients into three prognostic groups. The cases with high-grade budding were characterized by higher PD-L1 expression on TCs (p = 0.008) and elevated systemic inflammatory markers. Moreover, budding was identified as the independent prognostic factor in multivariate Cox regression analysis (HR = 2.87; 95% CI = 1.75−4.68; p < 0.001). To conclude, the pattern of PD-L1 and VISTA expression was associated with survival in univariate analysis. Tumor budding accurately predicts outcomes in pancreatic cancer and should be incorporated into routine histopathological practice.

High expression of both desmoplastic stroma and epithelial to mesenchymal transition markers associate with shorter survival in pancreatic ductal adenocarcinoma

Desmoplastic stroma (DS) and the epithelial-to-mesenchymal transition (EMT) play a key role in pancreatic ductal adenocarcinoma (PDAC) progression. To date, however, the combined expression of DS and EMT markers, and their association with variations in survival within each clinical stage and degree of tumor differentiation is unknown. The purpose of this study was to investigate the association between expression of DS and EMT markers and survival variability in patients diagnosed with PDAC. We examined the expression levels of DS markers alpha smooth muscle actin (α-SMA), fibronectin, and vimentin, and the EMT markers epithelial cell adhesion molecule (EPCAM), pan-cytokeratin, and vimentin, by immunohistochemistry using a tissue microarray in a retrospective cohort of 25 patients with PDAC. The results were examined for association with survival by clinical stage and by degree of tumor differentiation. High expression of DS markers -α-SMA, fibronectin, and vimentin- was associated with decreased survival at intermediate and advanced clinical stages (p=0.006-0.03), as well as with both poorly and moderately differentiated tumor grades (p=0.01-0.02). Interestingly, the same pattern was observed for EMT markers, i.e., EPCAM, pan-cytokeratin, and vimentin (p=0.00008-0.03). High expression of DS and EMT markers within each clinical stage and degree of tumor differentiation was associated with lower PDAC survival. Evaluation of these markers may have a prognostic impact on survival time variation in patients with PDAC.

Discoveries in Pancreatic Physiology and Disease Biology Using Single-Cell RNA Sequencing

Transcriptome analysis is used to study gene expression in human tissues. It can promote the discovery of new therapeutic targets for related diseases by characterizing the endocrine function of pancreatic physiology and pathology, as well as the gene expression of pancreatic tumors. Compared to whole-tissue RNA sequencing, single-cell RNA sequencing (scRNA-seq) can detect transcriptional activity within a single cell. The scRNA-seq had an invaluable contribution to discovering previously unknown cell subtypes in normal and diseased pancreases, studying the functional role of rare islet cells, and studying various types of cells in diabetes as well as cancer. Here, we review the recent in vitro and in vivo advances in understanding the pancreatic physiology and pathology associated with single-cell sequencing technology, which may provide new insights into treatment strategy optimization for diabetes and pancreatic cancer.

Reappraisal of Grading in Intestinal-Type Sinonasal Adenocarcinoma: Tumor Budding as an Independent Prognostic Parameter

Since sinonasal intestinal-type adenocarcinomas (ITAC) show resemblance to colorectal adenocarcinomas, we aimed to investigate novel prognostic factors of outcome, with particular focus on the role of tumor budding (TB). Retrospective clinico-pathological single-institution study on consecutive ITAC patients between 1996 and 2020. Histopathological parameters including conventional subtypes and TB features (low, intermediate, high) were evaluated with the aid of pancytokeratin (AE1/AE3) immunohistochemical staining. Parameters were correlated to clinical data and outcome. A total of 31 ITAC patients were included. Overall, 19/31 patients (61.3%) presented with stage III/IV disease. Presence of lymph node or distant metastases was rare (1/31 patient, 3.2%). Treatment protocols consisted of tumor resection in 30/31 patients (96.8%) and primary radiochemotherapy in 1/31 patient (3.2%). Adjuvant radiation therapy was conducted in 20/30 surgically treated patients (66.7%). The 3- and 5-year overall survival (OS) was 83.9% and 78.3% and the 3- and 5-years disease-specific survival (DSS) 83.7% % and 78.5%, respectively. The presence of intermediate/high TB (defined as ≥ 5 buds) was associated with both, worse DSS (log rank p = 0.03) and OS (log rank p = 0.006). No patient with low TB revealed progressive disease or died of the disease. No association between TB and tumor stage or conventional tumor subtype was found. Tumor budding seems to be an independent prognostic factor of worse outcome in ITAC.

Prognostic significance of tumour budding, tumour-stroma ratio and desmoplastic stromal reaction in gall bladder carcinoma

AIMS AND METHODS

The prognostic role of tumour budding (TBd) and its interaction with the stromal microenvironment has gained a lot of attention recently, but remains unexplored in gall bladder cancer (GBC). We aimed to study the interrelationship of TBd by International Tumour Budding Consensus Conference scoring system, tumour-stroma ratio (TSR) and desmoplastic stromal reaction (DSR) with the conventional clinicopathological prognostic factors, mortality and overall survival (OS) in 96 patients of operated GBC.

RESULTS

Higher age, high TNM stage, lymphovascular and perineural invasion, positive resection margins, higher TBd score, low TSR and immature DSR were significantly associated with worse OS. However, on multivariate analysis, only metastases, positive resection margins and TSR <50% proved to be independent prognostic factors. The TBd score of stroma-rich tumour group (6.40±4.69) was significantly higher than that of stroma-poor group (2.77±3.79, p≤0.001). The TBd score of immature and intermediate DSR groups was significantly higher than that of mature group (p≤0.001 and p=0.002, respectively). There was a strong interobserver agreement for TBd score, TSR and type of DSR (Cohen's Kappa=0.726 to 0.864, p≤0.001). Stroma-rich tumours were significantly associated with immature DSR and fibrotic DSR with high TSR (p≤0.001).

CONCLUSION

A high TBd, low TSR and immature DSR were significantly associated with several high-risk clinicopathological parameters and poor OS in GBC. These novel, simple, reproducible and cost-effective parameters may be included in the routine reporting checklist for GBC as additional prognostic parameters that can substratify the high-risk patients.

Tumor Budding Score Is a Strong and Independent Prognostic Factor in Patients With Pancreatic Ductal Adenocarcinoma: An Evaluation of Whole Slide Pathology Images of Large Sections

OBJECTIVE

We aimed to develop the tumor budding (TB) score and to explore the association between the TB score and overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

In this retrospective study, 130 consecutive patients with PDAC underwent surgical resection between July 2016 and March 2019. The location and counts of TB were assessed based on the digitalized whole slide hematoxylin and eosin images. The TB score was achieved using the Cox regression equation. The cutoff point for the TB score was determined by X-tile. Univariate and multivariate Cox regression models were used to analyze the association between the TB score and OS.

RESULTS

The TB score was 0.49 (range = 0-1.08), and the best cutoff for the TB score was 0.62. The duration of survival in individuals with a low TB score [median = 21.8 months, 95% confidence interval (CI) = 15.43-25.50] was significantly longer than that in those with a high TB score (median = 11.33 months, 95% CI = 9.8-14.22). Univariate analysis revealed that the TB score was significantly associated with OS [hazard ratio (HR) = 2.71, 95% CI = 1.48-4.96, p = 0.001]. Multivariate analysis revealed a strong and independent association between the TB score and OS (HR = 2.35, 95% CI = 1.27-4.33, p = 0.03). The high TB score group had a 2.14 times higher mortality than the low TB score group.

CONCLUSION

The TB score is strongly and independently associated with the risk of OS in PDAC.

Epithelial to Mesenchymal Transition: Key Regulator of Pancreatic Ductal Adenocarcinoma Progression and Chemoresistance

Simple Summary

Pancreatic ductal adenocarcinoma’s (PDAC) dismal prognosis is associated with its aggressive biological behavior and resistance to chemotherapy. Epithelial to mesenchymal transition (EMT) has been recognized as a key driver of PDAC progression and development of drug resistance. EMT is a transient and reversible process leading to transdifferentiation of epithelial cells into a more mesenchymal phenotype. It is regulated by multiple signaling pathways that control the activity of a transcription factors network. Activation of EMT in pre-invasive stages of PDAC has been accused for early dissemination. Furthermore, it contributes to the development of intratumoral heterogeneity and drug resistance. This review summarizes the available data regarding signaling networks regulating EMT and describes the integral role of EMT in different aspects of PDAC pathogenesis.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies, characterized by aggressive biological behavior and a lack of response to currently available chemotherapy. Emerging evidence has identified epithelial to mesenchymal transition (EMT) as a key driver of PDAC progression and a central regulator in the development of drug resistance. EMT is a reversible transdifferentiation process controlled by complex interactions between multiple signaling pathways such as TGFb, Wnt, and Notch, which converge to a network of specific transcription factors. Activation of EMT transcriptional reprogramming converts cancer cells of epithelial differentiation into a more mesenchymal phenotypic state. EMT occurrence in pre-invasive pancreatic lesions has been implicated in early PDAC dissemination. Moreover, cancer cell phenotypic plasticity driven by EMT contributes to intratumoral heterogeneity and drug tolerance and is mechanistically associated with the emergence of cells exhibiting cancer stem cells (CSCs) phenotype. In this review we summarize the available data on the signaling cascades regulating EMT and the molecular isnteractions between pancreatic cancer and stromal cells that activate them. In addition, we provide a link between EMT, tumor progression, and chemoresistance in PDAC.

A novel self-learning framework for bladder cancer grading using histopathological images

In recent times, bladder cancer has increased significantly in terms of incidence and mortality. Currently, two subtypes are known based on tumour growth: non-muscle invasive (NMIBC) and muscle-invasive bladder cancer (MIBC). In this work, we focus on the MIBC subtype because it has the worst prognosis and can spread to adjacent organs. We present a self-learning framework to grade bladder cancer from histological images stained by immunohistochemical techniques. Specifically, we propose a novel Deep Convolutional Embedded Attention Clustering (DCEAC) which allows for the classification of histological patches into different levels of disease severity, according to established patterns in the literature. The proposed DCEAC model follows a fully unsupervised two-step learning methodology to discern between non-tumour, mild and infiltrative patterns from high-resolution 512 × 512 pixel samples. Our system outperforms previous clustering-based methods by including a convolutional attention module, which enables the refinement of the features of the latent space prior to the classification stage. The proposed network surpasses state-of-the-art approaches by 2-3% across different metrics, reaching a final average accuracy of 0.9034 in a multi-class scenario. Furthermore, the reported class activation maps evidence that our model is able to learn by itself the same patterns that clinicians consider relevant, without requiring previous annotation steps. This represents a breakthrough in MIBC grading that bridges the gap with respect to training the model on labelled data.

Artificial intelligence in urological oncology: An update and future applications

There continues to be rapid developments and research in the field of Artificial Intelligence (AI) in Urological Oncology worldwide. In this review we discuss the basics of AI, application of AI per tumour group (Renal, Prostate and Bladder Cancer) and application of AI in Robotic Urological Surgery. We also discuss future applications of AI being developed with the benefits to patients with Urological Oncology.

Pancreatic Cancers with High Grade Tumor Budding Exhibit Hallmarks of Diminished Anti-Tumor Immunity

Simple Summary

Pancreatic cancer, in its most common manifestation pancreatic ductal adenocarcinoma (PDAC), is a uniquely lethal disease with very limited treatment options and few prognostic biomarkers. Tumor budding is a proven independent, adverse prognostic factor in many tumor types including PDAC. Tumor buds can be detected histologically as single cancer cells or clusters of up to four cancer cells at the tumor invasive front. Tumor budding is biologically correlated to the induction of epithelial-mesenchymal transitions (EMT) and disease progression. In this study, we sought to investigate the immunological composition of tumors with high levels of tumor budding. We show that PDAC cases with a high grade of tumor budding display notably diminished anti-tumor immunity. These findings were further validated by gene expression analysis of PDAC cases from The Cancer Genome Atlas (TCGA). Our results provide insight on the immune escape mechanisms of tumor cells undergoing EMT. This offers the potential of designing novel treatments combining immunotherapies with EMT-targeted drugs.

Abstract

Tumor budding is associated with epithelial-mesenchymal transition and diminished survival in a number of cancer types including pancreatic ductal adenocarcinoma (PDAC). In this study, we dissect the immune landscapes of patients with high grade versus low grade tumor budding to determine the features associated with immune escape and disease progression in pancreatic cancer. We performed immunohistochemistry-based quantification of tumor-infiltrating leukocytes and tumor bud assessment in a cohort of n = 111 PDAC patients in a tissue microarray (TMA) format. Patients were divided based on the ITBCC categories of tumor budding as Low Grade (LG: categories 1 and 2) and High Grade (HG: category 3). Tumor budding numbers and tumor budding grade demonstrated a significant association with diminished overall survival (OS). HG cases exhibit notably reduced densities of stromal (S) and intratumoral (IT) T cells. HG cases also display lower M1 macrophages (S) and increased M2 macrophages (IT). These findings were validated using gene expression data from TCGA. A published tumor budding gene signature demonstrated a significant association with diminished survival in PDAC patients in TCGA. Immune-related gene expression revealed an immunosuppressive TME in PDAC cases with high expression of the budding signature. Our findings highlight a number of immune features that permit an improved understanding of disease progression and EMT in pancreatic cancer.

Joint Tumor Bud-MMP/TIMP Count at the Invasive Front Improves the Prognostic Evaluation of Invasive Breast Carcinoma

BACKGROUND

Tumor budding is a histological phenomenon consisting of the formation of small clusters of one to five undifferentiated malignant cells detached from the main tumor mass which are observed in the tumor stroma. In the present study, we investigated the prognostic significance of tumor budding in breast cancer and its relationship with the expressions of matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs).

METHODS

The number of buds was counted in whole-tissue sections from 153 patients with invasive ductal carcinomas who underwent a long follow-up period. In addition, an immunohistochemical study of MMP-9, -11, and -14 TIMP-1 and -2 expression by cell types at the invasive tumor front was carried out.

RESULTS

There was a wide variability in the number of buds among tumors, ranging from 0 to 28 (median = 5). Tumor budding count ≥ 4 was the optimal cut-off to predict both relapse-free and overall survival. High-grade tumor budding was associated with MMP/TIMP expression by cancer-associated fibroblasts. In addition, we found that the combination of tumor budding grade with MMP/TIMP expression by stromal cells, and especially with MMP-11 expression by mononuclear inflammatory cells, significantly improved the prognostic evaluation.

CONCLUSION

High-grade tumor budding is associated with a more aggressive tumor phenotype, which, combined with MMP/TIMP expression by stromal cells at the invasive front of the tumor, identifies patients with poor prognosis.

Reproducibility of tumor budding assessment in pancreatic cancer based on a multicenter interobserver study

Tumor budding has been reported to be an independent prognostic factor in pancreatic ductal adenocarcinoma (PDAC). Its use in daily diagnostics would improve the prognostic stratification of patients. We performed a multicenter interobserver study to test various budding assessment methods for their reproducibility. Two serial sections of 50 resected, treatment-naïve PDACs were stained for Hematoxylin and Eosin (H&E) and pancytokeratin. Tumor budding was scored by independent observers at five participating centers in Switzerland, Germany, and Canada. Pathologists assessed tumor budding on a digital platform comparing H&E with pancytokeratin staining in 10 high-power fields (10HPF) and one HPF hotspot (1HPF). Additionally, tumor budding was assessed in one H&E hotspot at × 20 magnification, as suggested by the International Tumor Budding Consensus Conference (ITBCC). Correlation coefficients for bud counts between centers ranged from r = 0.58648 to r = 0.78641 for H&E and from r = 0.69288 to r = 0.81764 for pancytokeratin. The highest interobserver agreement across all centers was observed for pancytokeratin 10HPFs (ICC = 0.6). ICC values were 0.49, 0.48, 0.41, and 0.4 for H&E in 1HPF hotspot, H&E in 10HPFs, pancytokeratin in 1HPF, and H&E in one hotspot at ×20, respectively (ITBCC method). This interobserver study reveals a range between moderately poor to moderate agreement levels between pathologists for the different tumor budding assessment methods in PDAC. Acceptable levels of agreement were reached with the pancytokeratin 10HPF method, which can thus be recommended for the assessment of tumor budding in PDAC resection specimens. To improve the levels of interobserver agreement, the implementation of machine learning applications should be considered.

The prognostic influence of tumour budding in Western patients with stage II colorectal cancer

BACKGROUND

Tumour budding (TB) refers to loss of tumour cohesiveness and is defined as isolated cells or a cell cluster of up to four tumour cells at the microscopic analysis. The International Tumour Budding Consensus Conference (ITBCC) in 2016 proposed a scoring system to standardise the pathology evaluation of TB in colorectal cancer (CRC) as high (H), intermediate (I) and low (L) TB.

OBJECTIVE

To evaluate the recurrence-free survival (RFS) of stage II CRC patients as per the ITBCC 2016 classification and associations between TB and clinical pathological features.

METHODS

Cases of stage II CRC undergoing surgery with available tumour tissue underwent central pathology review for TB. Prognostic factors, retrospectively retrieved from electronic medical charts, were evaluated in univariate and multivariate Cox regression analyses for RFS (primary end point).

RESULTS

Among 137 patients included, L-TB was observed in 107 (78.1%), I-TB in 21 (15.3%) and H-TB in 9 (6.6%). In a median follow-up of 69 months, the median RFS was 134 months, with 14 patients (10.2%) presenting with tumour recurrence: 10 (9.3%) with L-TB, 2 (9.5%) with I-TB and 2 (22.2%) with H-TB. Perineural invasion was more commonly seen in the H-TB group. In multivariate analysis, TB (H and I versus L; HR = 2.6; p = 0.059) and not receiving adjuvant chemotherapy (HR 3.7; p = 0.020) were independently associated with RFS. Adjuvant chemotherapy was associated longer RFS (HR = 3.7; p = 0.022).

CONCLUSION

In this series of Western patients, TB grade was associated with perineural invasion and increased risk of disease relapse.

The Tumor Microenvironment of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis along with rising incidence rates and will be responsible for many cancer deaths in the future [...].

Tumour budding in solid cancers

Tumour budding is an emerging prognostic biomarker in colorectal cancer (CRC) and other solid cancers. Tumour buds are usually defined as isolated single cancer cells or clusters of up to four cancer cells located at the invasive tumour front. The prognostic value of tumour budding is now supported by a large body of evidence, whereas the utility of this phenotype as a predictive biomarker remains under investigation. The application of tumour budding indices in clinical practice requires a standardized scoring system that can be tailored to specific tumour types and clinical scenarios. In the context of CRC, tumour budding can be assessed according to the method agreed at the International Tumour Budding Consensus Conference (ITBCC) in 2016. Using the ITBCC scoring system, tumour budding is an independent predictor of lymph node metastasis in patients with pT1 CRC and of unfavourable survival in patients with stage II colon cancer. Regardless of the clinical scenario or tumour type, the assertion that 'the more tumour buds, the worse the clinical outcome' applies. In this Review, we provide an overview of tumour budding in solid cancers, highlighting the molecular and biological aspects of this phenomenon, including its associations with epithelial-mesenchymal transition and features of the tumour microenvironment. We also describe the available evidence demonstrating the value of tumour budding as a biomarker across various solid cancers.

Recurrence patterns of pancreatic cancer after pancreatoduodenectomy: systematic review and a single-centre retrospective study

BACKGROUND

Positive margins in pancreatoduodenectomy (PD) for pancreatic cancer, specifically the superior mesenteric artery (SMA) margin, are associated with worse outcomes. Local therapies targeting these margins could impact on recurrence. This study analysed recurrence-patterns to identify whether strategies to control local disease could have a meaningful impact.

METHODS

(I) Systematic review to define recurrence patterns and resection margin status. (II) Additional retrospective study of PD performed at our centre.

RESULTS

In the systematic review, 23/617 evaluated studies were included (n = 3815). Local recurrence was observed in 7-69%. SMA margin (6 studies) was positive in 15-35%. In the retrospective study (n = 204), local recurrence was more frequently observed with a positive SMA margin (66 vs.45%; p = 0.005). Furthermore, in a multivariate cox-proportional hazard model, only a positive SMA margin was associated with disease recurrence (HR 1.615; 95%CI 1.127-2.315; p = 0.009). Interestingly, median overall survival was 20 months and similar for patients who developed local only, metastases only or simultaneous recurrence (p = 0.124).

CONCLUSION

Local recurrence of pancreatic cancer is common and associated with similar mortality rates as those who present with simultaneous or metastatic recurrence. Involvement of the SMA margin is an independent predictor for disease progression and should be the target of future adjuvant local therapies.

Three-dimensional analysis of extrahepatic cholangiocarcinoma and tumor budding

Advances in tissue clearing and microscopy make it possible to study human diseases in three dimensions (3D). High-grade tumor budding is known to be associated with poor prognosis in various cancers; however, little is known about the 3D architecture of tumor budding. Using tissue clearing, we analyzed the 3D structure of tumor budding and E-cadherin expression in 31 extrahepatic cholangiocarcinomas. A total of 31 thick slabs (up to 5 mm) were harvested from surgically resected tumor tissue, including 27 hilar and 4 distal cholangiocarcinomas. Twenty-eight cases were adenocarcinoma, and three were undifferentiated carcinoma. After clearing, the tissues were immunolabeled with antibodies to cytokeratin 19 and to E-cadherin, and then visualized using light-sheet and confocal laser scanning microscopy. Tumor budding was evaluated in hematoxylin and eosin-stained sections (2D) using standard pathological criteria. Of the 31 cancers, 13 showed low-grade tumor budding and 18 showed high-grade tumor budding. First, 3D analysis revealed that the neoplastic cells in tumor buds of adenocarcinoma were typically not individual islands of cells, but rather tips of attenuated protrusions connected to the main tumor. Second, adenocarcinomas with low-grade tumor budding were composed predominantly of tubules that only focally form cords at the periphery. By contrast, adenocarcinomas with high-grade tumor budding predominantly formed cords in both centers and peripheries of the tumors. Third, adenocarcinoma with low-grade tumor budding was characterized by a few short protrusions with few branches, whereas adenocarcinoma with high-grade tumor budding was characterized by longer protrusions with more branching. Finally, immunolabeling of E-cadherin was stronger in the center of the adenocarcinoma but decreased at the tips of protrusions. E-cadherin loss was more extensive in the protrusions of high-grade tumor budding than in the protrusions of low-grade tumor budding. Our findings suggest that tumor buds as seen in 2D are, in fact, cross-sections of attenuated but contiguous protrusions extending from the main tumor. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Can morphological features evaluated in oral cancer biopsies influence in decision-making? A preliminary study

Tumor budding (TB) is a promising prognostic marker in many cancers including oral squamous cell carcinoma. The evaluation of TB in preoperative diagnostic biopsies has been proven be possible; therefore, the association of TB with other morphological features can represent an important aid in the previous treatment decision. This study aims to evaluate TB in oral squamous cell carcinoma (OSCC) biopsies, assessing its association with other morphological characteristics of the sample. A total of 56 cases of OSCC were investigated. In hematoxylin and eosin-stained slides, morphological features including histopathological grading and mode of invasion were evaluated in the deep invasive front. Moreover, immunohistochemistry was performed with anti-multi-cytokeratin antibody helping in the identification of TB, which was graded as low-intensity or no TB and high-intensity TB. Descriptive and bivariate analyses were performed, and the level of significance was set at 5%. The tongue was the most-affected site with 29 (51.7 %) tumors. The predominant mode of invasion (27-48.2 %) was by groups of neoplastic cells without clear boundaries. Of the cases investigated, 37 (66.1 %) were high-intensity TB, which was associated with the mode of invasion of the tumors (p < 0.05). All cases with the worst mode of invasion showed high-intensity TB. Preliminary results showed the potential of morphological features, such as TB and mode of invasion, evaluated in diagnostic specimens of OSCC, aiding in the treatment decision to select patients who could benefit from more-aggressive treatments.

Tumour budding and its clinical implications in gastrointestinal cancers

Tumour budding in colorectal cancer has become an important prognostic factor. Represented by single cells or small tumour cell clusters at the invasion front of the tumour mass, these tumour buds seem to reflect cells in a ‘hybrid’ state of epithelial–mesenchymal transition, and evidence indicates that the presence of these entities is associated with lymph node metastasis, local recurrence and distant metastatic disease. The International Tumour Budding Consensus Conference (ITBCC) has highlighted a scoring system for the reporting of tumour budding in colorectal cancer, as well as different clinical scenarios that could affect patient management. Other organs are not spared: tumour budding has been described in numerous gastrointestinal and non-gastrointestinal cancers. Here, we give an update on ITBCC validation studies in the context of colorectal cancer and the clinical implications of tumour budding throughout the upper gastrointestinal and pancreatico-biliary tract.

LINC00261 Is Differentially Expressed in Pancreatic Cancer Subtypes and Regulates a Pro-Epithelial Cell Identity

Pancreatic adenocarcinoma (PDAC) is one of the major causes of cancer-associated deaths worldwide, with a dismal prognosis that has not significantly changed over the last decades. Transcriptional analysis has provided valuable insights into pancreatic tumorigenesis. Specifically, pancreatic cancer subtypes were identified, characterized by specific mutations and gene expression changes associated with differences in patient survival. In addition to differentially regulated mRNAs, non-coding RNAs, including long non-coding RNAs (lncRNAs), were shown to have subtype-specific expression patterns. Hence, we aimed to characterize prognostic lncRNAs with deregulated expression in the squamous subtype of PDAC, which has the worst prognosis. Extensive in silico analyses followed by in vitro experiments identified long intergenic non-coding RNA 261 (LINC00261) as a downregulated lncRNA in the squamous subtype of PDAC, which is generally associated with transforming growth factor β (TGFβ) signaling in human cancer cells. Its genomic neighbor, the transcription factor forkhead box protein A2 (FOXA2), regulated LINC00261 expression by direct binding of the LINC00261 promoter. CRISPR-mediated knockdown and promoter knockout validated the importance of LINC00261 in TGFβ-mediated epithelial–mesenchymal transition (EMT) and established the epithelial marker E-cadherin, an important cell adhesion protein, as a downstream target of LINC00261. Consequently, depletion of LINC00261 enhanced motility and invasiveness of PANC-1 cells in vitro. Altogether, our data suggest that LINC00261 is an important tumor-suppressive lncRNA in PDAC that is involved in maintaining a pro-epithelial state associated with favorable disease outcome.

Neoadjuvant chemotherapy followed by curative-intent surgery for perihilar cholangiocarcinoma based on its anatomical resectability classification and lymph node status

Background

The prognosis of patients with perihilar cholangiocarcinoma have been unsatisfactory. We established new anatomical resectability classification for patients with localized perihilar cholangiocarcinoma and performed neoadjuvant chemotherapy followed by curative-intent surgery based on its resectability classification and lymph node status to improve prognosis. This study aimed to clarify the long-term outcomes and validation of our strategy.

Methods

Between September 2010 and August 2018, 72 consecutive patients with perihilar cholangiocarcinoma were classified into three groups: Resectable (R = 29), Borderline resectable (BR = 23), and Locally advanced (LA = 20), based on the two factors of tumor vascular and biliary extension. R with clinically lymph node metastasis, BR, and LA patients received neoadjuvant chemotherapy using gemcitabine plus S-1.

Results

Forty-seven patients (65.3%) received neoadjuvant chemotherapy: R in 8, BR in 21, and 18 in LA, respectively. Fifty-nine patients (68.1%) underwent curative-intent surgery: R in 26, BR in 17, and LA in 6. Five-year disease-specific survival was 31.5% (median survival time: 33.0 months): 50.3% (not reached) in R, 30.0% (31.4 months) in BR, and 16.5% (22.5 months) in LA, which were relatively stratified. Among 49 patients with resection, disease-specific survival was 43.8% (57.0 months): 57.6% (not reached) in R, 41.0% (52.4 months) in BR, and 0% (49.4 months) in LA, which were significantly good prognosis compared to 23 patients without resection (17.2 months). Multivariate analysis identified preoperative high carcinoembryonic antigen levels (more than 8.5 ng/ml) and pT4 as independent poor prognostic factor of patients with resection.

Conclusion

Neoadjuvant chemotherapy based on resectability classification and lymph node status was feasible, and was considered efficacious in selected patients.

Validation of the International Tumor Budding Consensus Conference (ITBCC) 2016 recommendation in squamous cell carcinoma of the lung-a single-center analysis of 354 cases

There are no universally accepted grading systems in pulmonary squamous cell carcinoma (pSQCC). Recently, tumor budding, cell nest size, and spread through airspaces (STAS) have been proposed as grading scheme candidates. Tumor budding is a well-established independent prognostic factor in colorectal cancer. The International Tumor Budding Consensus Conference (ITBCC) provided consensus on scoring in 2016, albeit for colorectal cancers. Here, we aimed to validate the ITBCC method in pSQCC and evaluate additional proposed grading parameters. We analyzed a fully clinico-pathologically annotated Western single-center cohort of 354 consecutive primary resected pSQCC (resected 2000-2013). Patients with SQCC of other organs were excluded to reliably exclude lung metastases. We assessed conventional grading, keratinization, STAS, and tumor budding according to ITBCC recommendations, and correlated them with clinico-pathological parameters and survival. Tumor budding was low (0-4 buds/0.785 mm²) in 41%, intermediate (5-9 buds/0.785 mm²) in 30%, and high (≥10 buds/0.785 mm²) in 29% of cases (mean bud count = 7.45 (H&E), min = 0, max = 84). Cell nests of 1, 2-4, 5-15, >15 cells were present in 68%, 20%, 5%, 7%, respectively. We detected STAS in 33% of cases, desmoplasia in 68%. Tumor budding assessed as continuous and categorized variables was highly concordant between hematoxylin and eosin (H&E) and pancytokeratin (AE1/AE3) stained slides (P < 0.001) and significantly associated with tumor size, UICC/AJCC pT, pN, stage (all P < 0.001) and presence of mediastinal lymph node metastases (H&E: P = 0.028). Tumor budding was a significant prognostic parameter for overall, disease-specific, and progression-free survival (PFS) (all P < 0.001). ITBCC tumor budding categories were independent prognostic factors for overall survival (HR = 1.581; 95% CI 1.186-2.108; P = 0.002), disease-specific survival (HR = 1.710; 95% CI 1.111-2.632; P = 0.015), and PFS (HR = 1.457; 95% CI 1.123-1.890; P = 0.005). STAS or conventional tumor grade had no prognostic value. In conclusion, we confirm tumor budding as an independent prognostic marker in pSQCC and validate the ITBCC 2016 scoring recommendations in pSQCC.

Tumor budding as a prognostic factor in pancreatic ductal adenocarcinoma

In this retrospective study, we analyzed the association between tumor budding and perineural invasion as well as their prognostic role in pancreatic ductal adenocarcinoma. A total of N = 119 patients resected for pancreatic ductal carcinoma from 1996 to 2015 were included. Clinical and standard histopathological parameters were retrieved from the patient's records. One representative hematoxylin and eosin section from the tumor region was examined for perineural invasion and tumor budding using light microscopy. Tumor budding was assessed independently using two different methods: in the first approach, the number of buds was counted over three fields of 0.237 mm2 at 40-fold magnification; in the second approach, tumor budding was quantified according to the recommendation of the International Tumor Budding Consensus Conference (ITBCC) over a field of 0.785 mm2 at 20-fold magnification. Linear and logistic regression was applied to delineate association between perineural invasion, tumor budding, and other parameters; Kaplan-Meier and Cox regression were used in the survival analysis. Regardless of the quantification approach, high tumor budding was a significant negative prognostic factor in the univariable Cox regression (> 5 buds/0.237 mm2, hazard ratio (HR) 1.66, 95% confidence interval (CI) 1.06-2.61, p = 0.027; ≥ 10 buds/0.785 mm2, HR 1.68, 95% CI 1.07-2.64, p = 0.024). In the multivariable model adjusting for stage and standard histopathological parameters, lymph vessel invasion (HR = 2.43, 95% CI 1.47-4.03, p = 0.001) and tumor budding > 5 buds/0.237 mm2 (HR = 1.70, 95% CI 1.07-2.7, p = 0.026) were independent negative prognostic factors, while adjuvant therapy was a positive prognostic factor (HR = 0.54, 95% CI 0.33-0.86, p = 0.009). No significant prognostic value could be delineated for perineural invasion. In conclusion, tumor budding is an independent negative prognostic factor in pancreatic ductal adenocarcinoma associated with lymph node metastasis. The prognostic role of perineural invasion remains uncertain.

High tumor budding is a strong predictor of poor prognosis in the resected perihilar cholangiocarcinoma patients regardless of neoadjuvant therapy, showing survival similar to those without resection

Background

Tumor budding (TB) is used as an indicator of poor prognosis in various cancers. However, studies on TB in perihilar cholangiocarcinoma are still limited. We examined the significance of TB in resected perihilar cholangiocarcinoma with or without neoadjuvant therapy.

Methods

Seventy-eight patients who underwent surgical resection at our institution for perihilar cholangiocarcinoma from 2004 to 2017, (36 with neoadjuvant therapy), were enrolled in this study. TB was defined as an isolated cancer cell or clusters (< 5 cells) at the invasive front and the number of TB was counted using a 20 times objective lens. Patients were classified into two groups according to TB counts: low TB (TB < 5) and high TB (TB ≥5).

Results

In this 78 patient cohort, high TB was significantly associated with advanced tumor status (pT4: 50.0% vs 22.2%, p = 0.007, pN1/2: 70.8% vs 39.6%, p = 0.011, M1: 20.8% vs 1.9%) and higher histological grade (G3: 25.0% vs 5.7%, p = 0.014). Disease specific survival (DSS) in high TB was significantly inferior compared to that in low TB group (3-y DSS 14.5% vs 67.7%, p < 0.001). Interestingly, DSS in high TB showed similar to survival in unresected patients. In addition, high TB was also associated with advanced tumor status and poor prognosis in patients with neoadjuvant therapy. Multivariate analysis identified high TB as an independent poor prognostic factors for DSS (HR: 5.206, p = 0.001).

Conclusion

This study demonstrated that high TB was strongly associated with advanced tumor status and poor prognosis in resected perihilar cholangiocarcinoma patients. High TB can be a novel poor prognostic factor in resected perihilar cholangiocarcinoma regardless of neoadjuvant therapy.

Prognostic and predictive factors in pancreatic cancer

Pancreatic cancer is one of the leading causes of cancer death worldwide. Its high mortality rate has remained unchanged for years. Radiotherapy and surgery are considered standard treatments in early and locally advanced stages. Chemotherapy is the only option for metastatic patients. Two treatment regimens, i. e. the association of 5-fluorouracil- irinotecan-oxaliplatin (FOLFIRINOX) and the association of nab-paclitaxel with gemcitabine, have been shown to improve outcomes for metastatic pancreatic adenocarcinoma patients. However, there are not standardized predictive biomarkers able to identify patients who benefit most from treatments. CA19-9 is the most studied prognostic biomarker, its predictive role remains unclear. Other clinical, histological and molecular biomarkers are emerging in prognostic and predictive settings. The aim of this review is to provide an overview of prognostic and predictive markers used in clinical practice and to explore the most promising fields of research in terms of treatment selection and tailored therapy in pancreatic cancer.

High-grade intratumoral tumor budding is a predictor for lymphovascular invasion and adverse outcome in stage II colorectal cancer

PURPOSE

Evaluation of tumor budding in colorectal cancer (CRC) may help to predict the tumors' metastatic potential and patients with an aggressive tumor, although not yet metastasized at time of surgery might benefit from adjuvant therapy.

METHODS

The degree of intratumoral tumor budding (ITB) was classified as low, intermediate, and high grade according to the recommendations of the International Tumor Budding Consensus Conference (ITBCC) 2016 on H&E and pankeratin-stained TMA sections from 1262 CRC, no special type (NST), including 655 stage II CRC and was correlated to clinicopathological data and overall survival.

RESULTS

Results show that higher ITB rates are significantly linked to higher tumor grade and stage, positive nodal status, lymphovascular invasion (P < 0.0001 each), absence of peritumoral lymphocytes, infiltrating type invasive tumor margin, left-sided cancer localization, and mismatch-repair proficient cancers (P < 0.05 each). In a cohort of 655 stage II CRC, ITB was associated with lymphovascular invasion (P = 0.0459) and adverse clinical outcome (P < 0.0001). In a multivariate analysis including tumor stage, tumor grade, lymphovascular invasion, ITB, and tumor localization, only low tumor stage (P = 0.0022) and absence of lymphovascular invasion (P = 0.0043) showed independent prognostic significance.

CONCLUSION

In conclusion, our findings argue towards a clinical utility of ITB as a prognostic biomarker in stage II colorectal cancer to define patients who might benefit from adjuvant therapy. ITB might be used as additional or surrogate marker in CRC in which peritumoral tumor budding is difficult to assess.

Tumor budding is an adverse prognostic marker in intestinal-type sinonasal adenocarcinoma and seems to be unrelated to epithelial-mesenchymal transition

Intestinal-type adenocarcinoma (ITAC) of sinonasal tract is a rare malignant tumor with strong morphological, immunophenotypical, and molecular similarities to colorectal adenocarcinoma (CRC). Tumor budding (TB) is a well-established adverse prognostic marker in CRC and some head and neck tumors, with features of epithelial-mesenchymal transition (EMT). The aim of this study was to assess TB in ITAC and to evaluate its possible association with EMT markers in this setting. We selected 32 surgically resected specimens of non-mucinous/non-signet ring ITAC and evaluated them for TB according to the international recommendations developed for CRC. The expression of the EMT markers E-cadherin, ZEB1, ZEB2, SLUG, and SNAIL was evaluated by immunohistochemistry (IHC). Results were stratified using clinical and follow-up data (2/32 patients had metastatic disease and 4/32 died of disease). We observed TB in 13/32 (40.6%) ITAC cases including the 7 patients with relapse (p = 0.0005) and the 4 patients dead of disease (p = 0.02). Lymphovascular invasion was associated with TB (p = 0.008). Absence of TB was associated with low ZEB2 expression (p = 0.003). No other association with EMT markers emerged. Occupational exposure to wood and leather dust was not related to the presence of TB. TB interobserver concordance was substantial (proportion of agreement = 87%; Cohen's kappa = 0.73). This work suggests that TB is associated with a worse prognosis in ITAC, but our findings do not seem to support the involvement of EMT in this specific setting. Further larger studies are needed to address this point.

RAC1B: A Guardian of the Epithelial Phenotype and Protector Against Epithelial-Mesenchymal Transition

The small GTPase Ras-related C3 botulinum toxin substrate 1B (RAC1B) has been shown to potently inhibit transforming growth factor (TGF)-β1-induced cell migration and epithelial-mesenchymal transition (EMT) in pancreatic and breast epithelial cells, but the underlying mechanism has remained obscure. Using a panel of pancreatic ductal adenocarcinoma (PDAC)-derived cell lines of different differentiation stages, we show that RAC1B is more abundantly expressed in well differentiated as opposed to poorly differentiated cells. Interestingly, RNA interference-mediated knockdown of RAC1B decreased expression of the epithelial marker protein E-cadherin, encoded by CDH1, and enhanced its TGF-β1-induced downregulation, whereas ectopic overexpression of RAC1B upregulated CDH1 expression and largely prevented its TGF-β1-induced silencing of CDH1. Conversely, knockdown of RAC1B, or deletion of the RAC1B-specific exon 3b by CRISPR/Cas-mediated genomic editing, enhanced basal and TGF-β1-induced upregulation of mesenchymal markers like Vimentin, and EMT-associated transcription factors such as SNAIL and SLUG. Moreover, we demonstrate that knockout of RAC1B enhanced the cells’ migratory activity and derepressed TGF-β1-induced activation of the mitogen-activated protein kinase ERK2. Pharmacological inhibition of ERK1/2 activation in RAC1B-depleted cells rescued cells from the RAC1B knockdown-induced enhancement of cell migration, TGF-β1-induced downregulation of CDH1, and upregulation of SNAI1. We conclude that RAC1B promotes epithelial gene expression and suppresses mesenchymal gene expression by interfering with TGF-β1-induced MEK-ERK signaling, thereby protecting cells from undergoing EMT and EMT-associated responses like acquisition of cell motility.

Prognostic significance of tumour budding assessed in gastric carcinoma according to the criteria of the International Tumour Budding Consensus Conference

AIMS

In this study, we aimed to independently evaluate the utility and prognostic value of tumour budding (TB) according to the International Tumour Budding Consensus Conference (ITBCC) criteria in a large and a well-characterised European gastric cancer (GC) cohort.

METHODS AND RESULTS

In 456 consecutive, surgically treated GCs, TB was assessed according to the ITBCC criteria and scored as Bd0 (no buds), Bd1 (one to four buds), Bd2 (five to nine buds) or Bd3 (≥10 buds). Cases with TB present were divided into low- (Bd1/Bd2) and high-budding (Bd3) groups. The TB score was analysed in relation to the clinicopathological parameters, overall survival (OS) and tumour-specific survival (TSS); 115 (25.2%) cases had no, 104 (22.8%) had low and 237 (52.0%) had high TB. The TB score correlated significantly with sex, Laurén phenotype, pT-, pN- and M categories, histological grade, R status; and lymph node ratio, lymphatic invasion, perineural invasion and HER2-, MET- and MSI status. In both total and intestinal-type early invasive GC (n = 57 and n = 41, respectively), significant associations between the presence and extent of TB and presence of lymph node metastasis were detected. Significant differences in OS and TSS between the TB groups were found; however, TB did not retain significance in multivariate models.

CONCLUSIONS

Our data show that the ITBCC criteria can be applied to GC. The data correlated significantly with the diverse clinicopathological characteristics, including patient outcome, and can help to standardise diagnostics and research into special histological features of malignant tumours in general and GC in particular.

RAS, Cellular Plasticity, and Tumor Budding in Colorectal Cancer

The high morbidity and mortality of colorectal cancer (CRC) remain a worldwide challenge, despite the advances in prevention, diagnosis, and treatment. RAS alterations have a central role in the pathogenesis of CRC universally recognized both in the canonical mutation-based classification and in the recent transcriptome-based classification. About 40% of CRCs are KRAS mutated, 5% NRAS mutated, and only rare cases are HRAS mutated. Morphological and molecular correlations demonstrated the involvement of RAS in cellular plasticity, which is related to invasive and migration properties of neoplastic cells. RAS signaling has been involved in the initiation of epithelial to mesenchymal transition (EMT) in CRC leading to tumor spreading. Tumor budding is the morphological surrogate of EMT and features cellular plasticity. Tumor budding is clinically relevant for CRC patients in three different contexts: (i) in pT1 CRC the presence of tumor buds is associated with nodal metastasis, (ii) in stage II CRC identifies the cases with a prognosis similar to metastatic disease, and (iii) intratumoral budding could be useful in patient selection for neoadjuvant therapy. This review is focused on the current knowledge on RAS in CRC and its link with cellular plasticity and related clinicopathological features.

A classification based on tumor budding and immune score for patients with hepatocellular carcinoma

Background: The role of immune profiling and tumor budding in hepatocellular carcinoma (HCC) remains largely unknown. This study evaluated the association between tumor budding and lymphocytic infiltration in HCC. Meanwhile, HCC patients were stratified based on tumor budding grade and immune score.

Patients and methods: A total of 423 HCC patients were divided into training (n = 212) and validation (n = 211) cohort. Tumor slides from resected HCC samples were used for tumor budding assessment. A prognosis-relevant immune score was developed based on five types of immune cells out of eleven immune markers. A classification based on tumor budding grade and immune type was established (IS-TB type). To explore the association of IS-TB type and molecular alterations of HCC, 100 HCC samples and adjacent non-tumor tissues from 100 patients were investigated by whole-exome sequencing.

Results: Tumor budding was an independent adverse prognostic factor for OS and DFS in both of the training and validation cohorts (all P values <.05). The rate of high-grade tumor budding was significantly higher in HCC with immature stroma (P < .001), strong α-SMA expression (P = .005), non-steatotic tumors and non-fibrolamellar-HCC (P < .001). Additionally, tumor budding was related to both anti- and pro-tumor immune responses. Patients were classified into immune type A and immune type B according to the immune score. Based on tumor budding grade and immunotype, patients were classified into four subgroups: IS_A-TB_high (type I), IS_B-TB_high (type II), IS_A-TB_low (type III) and IS_B-TB_low (type IV). Patients with type III tumor had the best OS and DFS, whereas OS and DFS were the worst for cases with type II tumor. TP53 mutation was more frequent in IS-TB type I (IS_ATB_high) patients, while IS-TB type IV (IS_BTB_low) harbored high number of CTNNB1 mutation.

Conclusion: Tumor-immune cell interactions in HCC is heterogeneous. HCC classification based on tumor budding and immune score correlates with patient survival and molecular alterations. The defined subtypes may have significance for utilizing individualized treatment in patients with HCC.

Gemcitabine-induced epithelial-mesenchymal transition-like changes sustain chemoresistance of pancreatic cancer cells of mesenchymal-like phenotype

Growing body of evidence suggests that epithelial-mesenchymal transition (EMT) is a critical process in tumor progression and chemoresistance in pancreatic cancer (PC). The aim of this study was to analyze the role of EMT-like changes in acquisition of resistance to gemcitabine in pancreatic cells of the mesenchymal or epithelial phenotype. Therefore, chemoresistant BxPC-3, Capan-2, Panc-1, and MiaPaca-2 cells were selected by chronic exposure to increasing concentrations of gemcitabine. We show that gemcitabine-resistant Panc-1 and MiaPaca-2 cells of mesenchymal-like phenotype undergo further EMT-like molecular changes mediated by ERK-ZEB-1 pathway, and that inhibition of ERK1/2 phosphorylation or ZEB-1 expression resulted in a decrease in chemoresistance. Conversely, gemcitabine-resistant BxPC-3 and Capan-2 cells of epithelial-like phenotype did not show such typical EMT-like molecular changes although the expression of the tight junction marker occludin could be found decreased. In pancreatic cancer patients, high ZEB-1 expression was associated with tumor invasion and tumor budding. In addition, tumor budding was essentially observed in patients treated with neoadjuvant chemotherapy. These findings support the notion that gemcitabine treatment induces EMT-like changes that sustain invasion and chemoresistance in PC cells.

Clinical Scenarios Emerging from Combined Immunophenotypic, Molecular and Morphologic Analysis of Pancreatic Cancer: The Good, the Bad and the Ugly Scenario

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with increasing incidence and dismal prognosis. The composition of the immune cell infiltrates in the tumor microenvironment (TME) and the dynamic interplay between cancer- and immune cells can influence and/or be influenced by tumor-intrinsic characteristics like molecular profiles and tumor cell morphology. The combined analyses of pancreatic cancer by using morphologic, genetic, and immunologic features help us understand the significant heterogeneity of the TME and recognize the different mechanisms of immune evasion. Moreover, this information may lead to the identification of novel biomarkers for more precise patient stratification and therapy guidance.

Tumour microenvironment of pancreatic cancer: immune landscape is dictated by molecular and histopathological features

Pancreatic cancer is a lethal disease, with fewer than 7% of patients surviving beyond 5 years following diagnosis. Immune responses are known to influence tumour progression. The dynamic interaction between cancer cells and immune cells in the tumour microenvironment (TME) can not only result in, or be influenced by, different tumour characteristics, but it can also lead to diverse mechanisms of immune evasion. At present, there is much interest in classifying pancreatic cancer according to its morphologic, genetic and immunologic features in order to understand the significant heterogeneity of this tumour type. Such information can contribute to the identification of highly needed novel prognostic and predictive biomarkers, and can be used for accurate patient stratification and therapy guidance. This review focuses on the characteristics of the local immune contexture of pancreatic ductal adenocarcinoma and the interaction between tumour cells and immune cells within the TME, by simultaneously taking into account the histomorphologic and genetic features of the tumours. The emerging opportunities for approaches that could predict the most-effective therapeutic modalities towards more targeted, personalised treatments to improve patient care are also discussed.

Validation of the International Tumor Budding Consensus Conference (2016) recommendations in oral tongue squamous cell carcinoma

BACKGROUND

Tumor budding is a valuable prognostic marker in oral tongue squamous cell carcinoma (OTSCC) but lacks a standardized scoring system. The aim of this study was to evaluate the prognostic value of tumor budding for OTSCC patients based on the scoring system recommended by the International Tumor Budding Consensus Conference (ITBCC) 2016.

METHODS

Tumor budding was scored as ITBCC recommended in 255 patients with OTSCC. Then, associations between tumor budding and clinicopathologic parameters were examined. Among them, 136 patients with follow-up data available were used to evaluate overall survival (OS) by the Kaplan-Meier method. Prognostic value of tumor budding was assessed by Cox regression analysis. The inter-observer and intra-observer agreement was calculated by the kappa statistic.

RESULTS

Tumor budding score was associated with lymph node metastasis, differentiation, invasive pattern, lymphoid infiltrate, tumor relapse, invasive depth, and reduced OS in OTSCC patients. The Cox analysis showed high budding score was an independent prognostic factor in patients with all clinical stage and patients with clinical early-stage OTSCC. The high kappa values were achieved in intra-observer and inter-observer.

CONCLUSIONS

International Tumor Budding Consensus Conference scoring system is a simple, reliable, and reproducible method to measure tumor budding in OTSCC, which should be included in the routine pathological report.

Management of pancreatic head adenocarcinoma: From where to where?

Pancreatic head adenocarcinoma (PHAC) is one of the most aggressive malignancies, and it has low long-term survival rates. Surgery is the only option for long-term survival. The difficulties associated with PHAC include higher frequencies of regional or distant lymph node metastases and vascular involvement, and positive resection margins in pancreatic and retroperitoneal tissues. Radical resections increase margin negativity and life expectancy; however, the extend of the surgery applied is controversial. Thus, western and eastern centers may use different approaches. Multiorgan, peripancreatic nerve plexus, and vascular resections have been discussed in relation to radical surgery for pancreatic cancer as have the roles of neoadjuvant and adjuvant therapy regimens. Determining the appropriate limits for surgery, standardizing definitions and surgical techniques according to guidelines, and centralizing pancreatic surgery within high-volume institutions to reduce mortality and morbidity rates are among the most important issues to consider. In this review, we evaluate the basic concepts underlying and the roles of radical surgery for PHAC, and lymphadenectomy, nerve plexus, retroperitoneal tissue, vascular, and multivisceral resections, total pancreatectomy, and liver metastases are discussed.

Automated tumour budding quantification by machine learning augments TNM staging in muscle-invasive bladder cancer prognosis

Tumour budding has been described as an independent prognostic feature in several tumour types. We report for the first time the relationship between tumour budding and survival evaluated in patients with muscle invasive bladder cancer. A machine learning-based methodology was applied to accurately quantify tumour buds across immunofluorescence labelled whole slide images from 100 muscle invasive bladder cancer patients. Furthermore, tumour budding was found to be correlated to TNM (p = 0.00089) and pT (p = 0.0078) staging. A novel classification and regression tree model was constructed to stratify all stage II, III, and IV patients into three new staging criteria based on disease specific survival. For the stratification of non-metastatic patients into high or low risk of disease specific death, our decision tree model reported that tumour budding was the most significant feature (HR = 2.59, p = 0.0091), and no clinical feature was utilised to categorise these patients. Our findings demonstrate that tumour budding, quantified using automated image analysis provides prognostic value for muscle invasive bladder cancer patients and a better model fit than TNM staging.