Fetal gut cell-like differentiation in esophageal adenocarcinoma defines a rare tumor subtype with therapeutically relevant claudin-6 positivity and SWI/SNF gene alteration.

Esophageal adenocarcinoma (EAC) is one of the deadliest tumor entities worldwide, with a 5-year survival rate of less than 25%. Unlike other tumor entities, personalized therapy options are rare, partly due to the lack of knowledge about specific subgroups. In this publication, we demonstrate a subgroup of patients with EAC in a large screening cohort of 826 patients, characterized by specific morphological and immunohistochemical features. This subgroup represents approximately 0.7% (6/826) of the total cohort. Morphological features of this subgroup show a striking clear cytoplasm of the tumour cells and the parallel existence of rare growth patterns like yolk sac-like differentiation and enteroblastic differentiation. Immunohistochemistry reveals expression of the fetal gut cell-like proteins Sal-like protein 4 (SALL4), claudin-6, and glypican 3. Interestingly, we find a correlation with alterations of SWI/SNF-complex associated genes, which are supposed to serve as tumor suppressor genes in various tumour entities. Our results suggest a possible implication of rare tumour subtypes in the WHO classification for EACs according to the classification for gastric cancer. Furthermore, claudin-6 positive tumors have shown promising efficacy of CAR T cell therapy in the recently published BNT-211-01 trial (NCT04503278). This represents a personalized therapeutic option for this tumor subtype.

Correlation of primary tumor volume and histopathologic response following neoadjuvant treatment of esophageal adenocarcinoma.

INTRODUCTION: In esophageal cancer, histopathologic response following neoadjuvant therapy and transthoracic esophagectomy is a strong predictor of long-term survival. At the present, it is not known whether the initial tumor volume quantified by computed tomography (CT) correlates with the degree of pathologic regression. METHODS: In a retrospective analysis of a consecutive patient cohort with esophageal adenocarcinoma, tumor volume in CT prior to chemoradiotherapy or chemotherapy alone was quantified using manual segmentation. Primary tumor volume was correlated to the histomorphological regression based on vital residual tumor cells (VRTC) (Cologne regression scale, CRS: grade I, >50% VRTC; grade II, 10-50% VRTC; grade III, <10% VRTC and grade IV, complete response without VRTC). RESULTS: A total of 287 patients, 165 with neoadjuvant chemoradiotherapy according to the CROSS protocol and 122 with chemotherapy according to the FLOT regimen, were included. The initial tumor volume for patients following CROSS and FLOT therapy was measured (CROSS: median 24.8 ml, IQR 13.1-41.1 ml, FLOT: 23.4 ml, IQR 10.6-37.3 ml). All patients underwent an Ivor-Lewis esophagectomy. 180 patients (62.7 %) were classified as minor (CRS I/II) and 107 patients (37.3 %) as major or complete responder (CRS III/IV). The median tumor volume was calculated as 24.2 ml (IQR 11.9-40.3 ml). Ordered logistic regression revealed no significant dependence of CRS from tumor volume (OR = 0.99, p-value = 0.99) irrespective of the type of multimodal treatment. CONCLUSION: The initial tumor volume on diagnostic CT does not aid to differentiate between potential histopathological responders and non-responders to neoadjuvant therapy in esophageal cancer patients. The results emphasize the need to establish other biological markers of prediction.

Tumour area infiltration and cell count in endoscopic biopsies of therapy-naive upper GI tract carcinomas by QuPath analysis: implications for predictive biomarker testing.

Guidelines regulate how many (tumour-bearing) tissue particles should be sampled during gastric cancer biopsy to obtain representative results in predictive biomarker testing. Little is known about how well these guidelines are applied, how the number of tissue particles correlates with the actual tumour-infiltrated area and how many absolute tumour cells are captured. The study included endoscopic biopsies of untreated carcinomas of the upper gastrointestinal (GI)-tract during the 2016-2020 review period. Archival (H&E)-stained histological sections were digitised and the tumour areas were manually annotated. The tumour-bearing tissue area and absolute carcinoma cell count per case were determined by image analysis and compared with a reference primary surgical specimen. Biopsies from 253 patients were analysed. The following mean values were determined: (a) tumour tissue particle number: 6.5 (range: 1-25, standard deviation (SD) = 3.33), (b) number of tumour-bearing tissue particles: 4.7 (range: 1-20, SD = 2.80), (c) tumour-infiltrated area: 7.5 mm2 (range: 0.18-59.46 mm2, SD = 6.67 mm2), (d) absolute tumour cell count: 13,492 (range: 193-92,834, SD = 14,185) and (e) tumour cell count in a primary surgical specimen (tumour size: 6.7 cm): 105,200,176. The guideline-recommended tissue particle count of 10 was not achieved in 208 patients (82.2%) and the required tumour-bearing tissue particle count of 5 was not achieved in 133 patients (52.6%). Tissue particle count, tumour-infiltrated area and tumour cell count were only weakly correlated. Most cases featured an infiltrated area ≥ 4.5 mm2 (156, 61.7%). Cases with more tissue particles showed only a moderate increase in infiltrated area and tumour cells compared to cases with fewer particles. Biopsies are often used to determine predictive biomarkers, particularly Her2/neu and PD-L1. Diagnostic standards to ensure representative material have been suggested in guidelines to reduce false-negative predictions. However, the real-world practice seems to substantially deviate from recommended standards. To the best of our knowledge, this is the first systematic study describing the relationships between endoscopic tissue fragment number, actual infiltrated tumour area and carcinoma cell number. The data question the tissue particle number as a quality assessment parameter. We advocate histopathological reports indicating on which basis statements on therapy-relevant biomarkers were made. Digital pathology has the potential to objectively quantify the tissue for documentation, quality assessment and future clinical studies.

Syndecan­1 expression is an independent favourable prognostic marker in oesophageal adenocarcinoma and represents a potential therapeutic target.

Because of the poor prognosis of oesophageal adenocarcinoma (EAC), there is an urgent need for additional therapeutic approaches. Syndecan-1 (CD138) is a cell-surface heparan sulphate that is overexpressed in multiple myeloma cells and several carcinomas. Specific drugs targeting CD138 [e.g. antibody-linked drug conjugates (ADCs)] are currently being assessed; however, the significance and implication of CD138 expression in EAC is mostly unknown. In the present study, CD138 expression was assessed using immunohistochemistry, and its association with histopathological parameters and ERBB2 (Her2/neu) amplification status in patients treated with primary resection and neoadjuvant (radio-)chemotherapy was investigated. Of the 723 cases of EAC included, 232 tumours (32.1%) expressed CD138, with 96 tumours displaying strong expression (13.3%). Patients with CD138-positive tumours had less invasive carcinoma, fewer lymph mode metastases and a significantly longer overall survival (OS) than patients with CD138-negative tumours (P=0.002). In multivariate analysis, strong CD138 expression was an independent favourable prognostic factor (P=0.02). Patients who received neoadjuvant CROSS (carboplatin, paclitaxel and intensity modulated radiotherapy) therapy and had CD138-positive tumours lived significantly longer (P=0.04). In tumours without Her2/neu amplification, CD138 expression was associated with a longer OS (P=0.02). In conclusion, CD138 in cancer is already used as a target for ADCs, such as indatuximab ravtansine, the effectiveness of which depends on the extent of CD138 on tumour cells. This indicates that CD138 is also a predictive, therapeutically relevant biomarker. Regardless of the favourable prognostic effect of CD138 in EAC, there is an urgent clinical need for personalized therapeutics in relapse. Future clinical trials now need to show how effective the corresponding ADCs are in CD138-positive EACs.

The tight junction protein claudin 6 is a potential target for patient-individualized treatment in esophageal and gastric adenocarcinoma and is associated with poor prognosis.

BACKGROUND: The prognosis of esophageal adenocarcinoma (EAC) and gastric adenocarcinoma (GAC) remains poor, and new therapeutic approaches are urgently needed. Claudin 6 (CLDN6) is an oncofetal antigen that is largely absent in healthy tissues and upregulated in several cancers, making it a promising therapeutical target. In this study, the expression of CLDN6 was assessed in an large Caucasian EAC and GAC cohort. METHODS: RNA-Seq data from 89 EACs and 371 GACs were obtained from The Cancer Genome Atlas project and EAC/GAC cases were stratified by CLDN6 mRNA expression based on a survival-associated cutoff. For groups with CLDN6 expression above or below this cutoff, differential gene expression analyses were performed using DESeq, and dysregulated biological pathways were identified using the Enrichr tool. Additionally, CLDN6 protein expression was assessed in more than 800 EACs and almost 600 GACs using a CLDN6-specific immunohistochemical antibody (clone 58-4B-2) that is currently used in Phase I/II trials to identify patients with CLDN6-positive tumors (NCT05262530; NCT04503278). The expression of CLDN6 was also correlated with histopathological parameters and overall survival (OS). RESULTS: EACs and GACs with high CLDN6 mRNA levels displayed an overexpression of pathways regulating the cell cycle, DNA replication, and receptor / extracellular matrix interactions. CLDN6 protein expression was associated with shorter OS in EAC and GAC, both in treatment-naïve subgroups and cohorts receiving neoadjuvant therapy. In multivariate analysis, CLDN6 protein expression was an independent adverse prognostic factor in EAC associated with a shorter OS (HR: 1.75; p = 0.01) and GAC (HR: 2.74; p = 0.028). CONCLUSIONS: High expression of CLDN6 mRNA is associated with the dysregulation of distinct biological pathways regulating cell growth, proliferation, and cell-matrix interactions. Clinically, the expression of CLDN6 protein is a valuable adverse prognostic marker in EAC and GAC.

Morphological, clinical and molecular characteristics in ARID1a­deficient microsatellite­stable oesophageal adenocarcinoma.

Publications describe the relevance of the AT-rich interactive domain-containing protein 1A (ARID1a) mutation in gastric adenocarcinoma, which occurs predominantly in the microsatellite instable (MSI)- and Epstein-Barr virus (EBV)-associated subtypes. It is unclear whether potential therapeutic, prognostic or morphologic descriptions are not epiphenomena of MSI (or EBV). Since personalised therapeutics are largely lacking for oesophageal adenocarcinoma (EAC), clinical trials investigating the efficacy of these therapeutics specifically in this subgroup are useful. To the best of our knowledge, this was the first study analysing the relevant tumour subset of microsatellite-stable (MSS) EAC with loss of function of ARID1a. A total of 875 patients with EAC and data from The Cancer Genome Atlas (TCGA) were analysed. Statistical analyses associating previously known molecular characteristics of the present tumour cohort, overall survival, morphological growth patterns and tumour heterogeneity issues were considered. Subsequently, 10% of EAC were ARID1a-deficient, the majority of which were MSS (7.5%). There was no characteristic growth pattern. Approximately 60% of tumours were PD-L1 positive to varying degrees. TP53 mutations occurred together with ARID1a defective EAC in the present cohort and in the TCGA collective. The extent of 7.5% MSS-EAC with ARID1a loss was unaffected by neoadjuvant therapy. ARID1a loss was often detected to be homogeneous (92%). ARID1a loss is not an epiphenomenon of MSI in EAC. The high homogeneity of ARID1a loss tumour clones could be considered an argument for the effectiveness of potential therapeutics. Since the majority of genomic ARID1a alterations result in protein loss, immunohistochemistry is a useful screening technique, especially in the absence of morphological characteristics.

Artificial intelligence for tumour tissue detection and histological regression grading in oesophageal adenocarcinomas: a retrospective algorithm development and validation study.

BACKGROUND: Oesophageal adenocarcinoma and adenocarcinoma of the oesophagogastric junction are among the most common malignant epithelial tumours. Most patients receive neoadjuvant therapy before complete tumour resection. Histological assessment after resection includes identification of residual tumour tissue and areas of regressive tumour, data which are used to calculate a clinically relevant regression score. We developed an artificial intelligence (AI) algorithm for tumour tissue detection and tumour regression grading in surgical specimens from patients with oesophageal adenocarcinoma or adenocarcinoma of the oesophagogastric junction. METHODS: We used one training cohort and four independent test cohorts to develop, train, and validate a deep learning tool. The material consisted of histological slides from surgically resected specimens from patients with oesophageal adenocarcinoma and adenocarcinoma of the oesophagogastric junction from three pathology institutes (two in Germany, one in Austria) and oesophageal cancer cohort of The Cancer Genome Atlas (TCGA). All slides were from neoadjuvantly treated patients except for those from the TCGA cohort, who were neoadjuvant-therapy naive. Data from training cohort and test cohort cases were extensively manually annotated for 11 tissue classes. A convolutional neural network was trained on the data using a supervised principle. First, the tool was formally validated using manually annotated test datasets. Next, tumour regression grading was assessed in a retrospective cohort of post-neoadjuvant therapy surgical specimens. The grading of the algorithm was compared with that of a group of 12 board-certified pathologists from one department. To further validate the tool, three pathologists processed whole resection cases with and without AI assistance. FINDINGS: Of the four test cohorts, one included 22 manually annotated histological slides (n=20 patients), one included 62 sides (n=15), one included 214 slides (n=69), and the final one included 22 manually annotated histological slides (n=22). In the independent test cohorts the AI tool had high patch-level accuracy for identifying both tumour and regression tissue. When we validated the concordance of the AI tool against analyses by a group of pathologists (n=12), agreement was 63·6% (quadratic kappa 0·749; p<0·0001) at case level. The AI-based regression grading triggered true reclassification of resected tumour slides in seven cases (including six cases who had small tumour regions that were initially missed by pathologists). Use of the AI tool by three pathologists increased interobserver agreement and substantially reduced diagnostic time per case compared with working without AI assistance. INTERPRETATION: Use of our AI tool in the diagnostics of oesophageal adenocarcinoma resection specimens by pathologists increased diagnostic accuracy, interobserver concordance, and significantly reduced assessment time. Prospective validation of the tool is required. FUNDING: North Rhine-Westphalia state, Federal Ministry of Education and Research of Germany, and the Wilhelm Sander Foundation.

Dissecting the inflammatory tumor microenvironment of esophageal adenocarcinoma: mast cells and natural killer cells are favorable prognostic factors and associated with less extensive disease.

PURPOSE: Esophageal adenocarcinoma (EAC) remains a challenging and lethal cancer entity. A promising target for new therapeutic approaches, as demonstrated by the success of immune checkpoint inhibitors, are tumor-associated immune cells and the tumor microenvironment (TME). However, the understanding of the TME in esophageal cancer remains limited and requires further investigation. METHODS: Over 900 EAC samples were included, including patients treated with primary surgery and neoadjuvant (radio-)chemotherapy. The immune cell infiltrates of mast cells (MC), natural killer cells (NK cells), plasma cells (PC), and eosinophilic cells (EC) were assessed semi-quantitatively and correlated with histopathological parameters and overall survival (OS). RESULTS: A high presence of all four immune cell types significantly correlated with a less extensive tumor stage and a lower frequency of lymph node metastasis, and, in case of NK cells, with less distant metastasis. The presence of MC and NK cells was favorably associated with a prolonged OS in the total cohort (MC: p < 0.001; NK cells: p = 0.004) and patients without neoadjuvant treatment (MC: p < 0.001; NK cells: p = 0.01). NK cells were a favorable prognostic factor in the total cohort (p = 0.007) and in the treatment-naïve subgroup (p = 0.04). Additionally, MC were a favorable prognostic factor in patients with lymph node metastasis (p = 0.009). CONCLUSION: Our results indicate a complex and important role of mast cells, NK cells, and the other assessed immune cells in the tumor microenvironment of EAC. Therefore, they are one further step to a better understanding of the immune cell environment and the potential therapeutic implications in this cancer entity.

FGFR2-amplified tumor clones are markedly heterogeneously distributed in carcinomas of the upper gastrointestinal tract.

BACKGROUND: FGFR2 is a therapy-relevant target in tumors of the upper gastrointestinal tract (GIT), and clinical trials are currently underway to test the efficacy of FGFR2 inhibitors. Tumor heterogeneity is one of the relevant causes of treatment failure. Almost nothing is known about the heterogeneous distribution of FGFR2-amplified clones in adenocarcinomas of the upper GIT. PATIENTS AND METHODS: To assess FGFR2 gene copy number alteration and intratumoral heterogeneity of upper GIT adenocarcinomas, we analyzed 893 patient-derived formalin-fixed paraffin-embedded tumor specimens, including primary operated and neoadjuvant-treated tumors (462 gastric carcinomas and 429 esophageal adenocarcinomas) as well as complementary lymph node and distant metastasis by fluorescence in situ hybridization. RESULTS: Twenty-six gastric tumors (5.6%) and 21 esophageal adenocarcinomas (4.9%) showed FGFR2 amplification. Overall, 93% of gastric carcinomas and 83% of esophageal carcinomas showed heterogeneous amplification. FGFR2 amplification was found in different histological growth patterns, including intestinal and diffuse type according to the Lauren classification. In the primary gastric carcinoma group, FGFR2 amplification was associated with poor prognosis (p = 0.005). CONCLUSION: Homogeneous FGFR2 amplification in tumors of the upper GIT is the exception. This has highly relevant implications in the nature of FGFR2 diagnostics (sufficient tumor cell number, determination of amplification at metastasis versus primary tumor, etc.) and on the response probability of appropriate inhibitors. It is relevant that the often poorly treatable and aggressive subtype of diffuse carcinomas (poorly cohesive carcinomas) also shows FGFR2 amplification and that an individualized therapy option with FGFR2 inhibitors could be an option in this group.

Identifying a core symptom set triggering radiological and endoscopic investigations for suspected recurrent esophago-gastric cancer: a modified Delphi consensus process.

BACKGROUND: There is currently a lack of evidence-based guidelines regarding surveillance for recurrence after esophageal and gastric (OG) cancer surgical resection, and which symptoms should prompt endoscopic or radiological investigations for recurrence. The aim of this study was to develop a core symptom set using a modified Delphi consensus process that should guide clinicians to carry out investigations to look for suspected recurrent OG cancer in previously asymptomatic patients. METHODS: A web-based survey of 42 questions was sent to surgeons performing OG cancer resections at high volume centers. The first section evaluated the structure of follow-up and the second, determinants of follow-up. Two rounds of a modified Delphi consensus process and a further consensus workshop were used to determine symptoms warranting further investigations. Symptoms with a 75% consensus agreement as suggestive of recurrent cancer were included in the core symptom set. RESULTS: 27 surgeons completed the questionnaires. A total of 70.3% of centers reported standardized surveillance protocols, whereas 3.7% of surgeons did not undertake any surveillance in asymptomatic patients after OG cancer resection. In asymptomatic patients, 40.1% and 25.9% of centers performed routine imaging and endoscopy, respectively. The core set that reached consensus, consisted of eight symptoms that warranted further investigations included; dysphagia to solid food, dysphagia to liquids, vomiting, abdominal pain, chest pain, regurgitation of foods, unexpected weight loss and progressive hoarseness of voice. CONCLUSION: There is global variation in monitoring patients after OG cancer resection. Eight symptoms were identified by the consensus process as important in prompting radiological or endoscopic investigation for suspected recurrent malignancy. Further randomized controlled trials are necessary to link surveillance strategies to survival outcomes and evaluate prognostic value.

Long-Term Outcome After Histopathological Complete Response with and Without Nodal Metastases Following Multimodal Treatment of Esophageal Cancer.

BACKGROUND: This study analyzed the long-term survival after pathological complete response (pCR) with and without nodal metastases and associated recurrence following multimodal treatment of esophageal cancer. The recurrence pattern after pCR is of importance for different postoperative surveillance strategies. METHODS: A cohort of 890 patients with esophageal cancer received neoadjuvant therapy followed by transthoracic esophagectomy. Only patients with pCR of the primary tumor with and without nodal metastasis were analyzed. A clinicopathological database was set up and completed with long-term follow up information on recurrent disease. RESULTS: The specimen of 201 patients (23%) demonstrated pCR, 84% without (ypT0N0) and 16% with residual nodal disease (ypT0N+). For ypT0N0 patients, the 5-year overall survival was significantly higher than for patients with metastatic nodes (77% vs. 24%) (p < 0.0001). Sixty-eight percent of patients had no evidence of tumor recurrence, whereas 32% had proven relapse. For patients with and without tumor recurrence, 5-year survival rates were 14% and 93%, respectively (p < 0.0001). For patients with recurrent disease, median survival time was 27 for locoregional, 44 for distant, and 24 months for combined recurrence (p = 0.302). In the multivariable Cox-regression analysis, node-positive disease predicted both locoregional and metastatic recurrence. CONCLUSIONS: Pathological CR offers long-term survival in patients without nodal metastases but outcome significantly deteriorates with the presence of nodal metastases. Follow-up recommendations may therefore be adopted in patients with pCR. Furthermore, "watch-and-wait" surveillance strategies with suspected clinical complete response have to be considered with caution.

There is no correlation between a delayed gastric conduit emptying and the occurrence of an anastomotic leakage after Ivor-Lewis esophagectomy.

INTRODUCTION: Esophagectomy is the gold standard in the surgical therapy of esophageal cancer. It is either performed thoracoabdominal with a intrathoracic anastomosis or in proximal cancers with a three-incision esophagectomy and cervical reconstruction. Delayed gastric conduit emptying (DGCE) is the most common functional postoperative disorder after Ivor-Lewis esophagectomy (IL). Pneumonia is significantly more often in patients with DGCE. It remains unclear if DGCE anastomotic leakage (AL) is associated. Aim of our study is to analyze, if AL is more likely to happen in patients with a DGCE. PATIENTS AND METHODS: 816 patients were included. All patients have had an IL due to esophageal/esophagogastric-junction cancer between 2013 and 2018 in our center. Intrathoracic esophagogastric end-to-side anastomosis was performed with a circular stapling device. The collective has been divided in two groups depending on the occurrence of DGCE. The diagnosis DGCE was determined by clinical and radiologic criteria in accordance with current international expert consensus. RESULTS: 27.7% of all patients suffered from DGCE postoperatively. Female patients had a significantly higher chance to suffer from DGCE than male patients (34.4% vs. 26.2% vs., p = 0.040). Pneumonia was more common in patients with DGCE (13.7% vs. 8.5%, p = 0.025), furthermore hospitalization was longer in DGCE patients (median 17 days vs. 14d, p < 0.001). There was no difference in the rate of type II anastomotic leakage, (5.8% in both groups DGCE). All patients with ECCG type II AL (n = 47; 5.8%) were treated successfully by endoluminal/endoscopic therapy. The subgroup analysis showed that ASA ≥ III (7.6% vs. 4.4%, p = 0.05) and the histology squamous cell carcinoma (9.8% vs. 4.7%, p = 0.01) were independent risk factors for the occurrence of an AL. CONCLUSION: Our study confirms that DGCE after IL is a common finding in a standardized collective of patients in a high-volume center. This functional disorder is associated with a higher rate of pneumonia and a prolonged hospital stay. Still, there is no association between DGCE and the occurrence of an AL after esophagectomy. The hypothesis, that an DGCE results in a higher pressure on the anastomosis and therefore to an AL in consequence, can be refuted. DGCE is not a pathogenetic factor for an AL.

Short- and long-term follow-up of patients with non-neoplastic esophageal perforation.

PURPOSE: Esophageal perforation is associated with high morbidity and mortality. In addition to surgical treatment, endoscopic endoluminal stent placement and endoscopic vacuum therapy (EVT) are established methods in the management of this emergency condition. Although health-related quality of life (HRQoL) is becoming a major issue in the evaluation of any therapeutic intervention, not much is known about HRQoL, particularly in the long-term follow-up of patients treated for non-neoplastic esophageal perforation with different treatment strategies. The aim of this study was to evaluate patients' outcome after non-neoplastic esophageal perforation with focus on HRQoL in the long-term follow-up. METHODS: Patients treated for non-neoplastic esophageal perforation at the University Hospital Cologne from January 2003 to December 2014 were included. Primary outcome and management of esophageal perforation were documented. Long-term quality of life was assessed using the Gastrointestinal Quality of Life Index (GIQLI), the Health-Related Quality of Life Index (HRQL) for patients with gastroesophageal reflux disease (GERD), and the European Organization for Research and Treatment of Cancer (EORTC) questionnaires for general and esophageal specific QoL (QLQ-C30 and QLQ-OES18). RESULTS: Fifty-eight patients were included in the study. Based on primary treatment, patients were divided into an endoscopic (n = 27; 46.6%), surgical (n = 20; 34.5%), and a conservative group (n = 11; 19%). Short- and long-term outcome and quality of life were compared. HRQoL was measured after a median follow-up of 49 months. HRQoL was generally reduced in patients with non-neoplastic esophageal perforation. Endoscopically treated patients showed the highest GIQLI overall score and highest EORTC general health status, followed by the conservative and the surgical group. CONCLUSION: HRQoL in patients with non-neoplastic esophageal perforation is reduced even in the long-term follow-up. Temporary stent or EVT is effective and provides a good alternative to surgery, not only in the short-term but also in the long-term follow-up.

Voltage-gated calcium currents in human dorsal root ganglion neurons.

ABSTRACT: Voltage-gated calcium channels in sensory neurons underlie processes ranging from neurotransmitter release to gene expression and remain a therapeutic target for the treatment of pain. Yet virtually all we know about voltage-gated calcium channels has been obtained through the study of rodent sensory neurons and heterologously expressed channels. To address this, high voltage-activated (HVA) Ca2+ currents in dissociated human and rat dorsal root ganglion neurons were characterized with whole-cell patch clamp techniques. The HVA currents from both species shared basic biophysical and pharmacological properties. However, HVA currents in human neurons differed from those in the rat in at least 3 potentially important ways: (1) Ca2+ current density was significantly smaller, (2) the proportion of nifedipine-sensitive currents was far greater, and (3) a subpopulation of human neurons displayed relatively large constitutive current inhibition. These results highlight the need to for the study of native proteins in their native environment before initiating costly clinical trials.

[Fast-track Rehabilitation after Oesophagectomy]. / Fast-Track-Rehabilitation nach Ösophagektomie.

The multimodal and interprofessional concept of fast-track rehabilitation ("enhanced recovery after surgery", ERAS) is generally applicable to transthoracic oesophagectomy, but is associated with two special features as compared to other oncological procedures. Due to the high comorbidity of oesophageal cancer patients, fast-track pathways have to be considered as one component of perioperative management and cannot be separated from prehabilitation with preoperative conditioning of single organ dysfunctions. Since gastric reconstruction causes a high prevalence of delayed gastric conduit emptying (DGCE), early and sufficient postoperative oral feeding is not easily feasible. There is currently no generally accepted algorithm for the postoperative nutritional management as well as for the prophylaxis/treatment of DGCE. Fast-track prehabilitation does not influence the mortality rate in specialised centres. At present, it is not clear whether a fast-track pathway helps to reduce postoperative morbidity. After modified fast-track rehabilitation, hospital discharge is possible from the 8th postoperative day.

Sex-specific prognostic effect of CD66b-positive tumor-infiltrating neutrophils (TANs) in gastric and esophageal adenocarcinoma.

BACKGROUND: Tumor-associated neutrophils (TANs) have recently been identified as a relevant component of the tumor microenvironment (TME) in solid tumors. Within the TME TANs mediate either tumor-promoting or tumor-inhibiting activities. So far, their prognostic relevance remains to be determined. This study aims to evaluate the prognostic relevance of TANs in different molecular subtypes of gastric and esophageal adenocarcinoma. METHODS: We analyzed a total of 1118 Caucasian patients divided into gastric adenocarcinoma (n = 458) and esophageal adenocarcinoma cohort (n = 660) of primarily resected and neoadjuvant-treated individuals. The amount of CD66b + TANs in the tumor stroma was determined using quantitative image analysis and correlated to both molecular, as well as clinical data. RESULTS: An accumulation of TANs in the tumor stroma of gastric carcinomas was associated to a significant favorable prognosis (p = 0.026). A subgroup analysis showed that this effect was primarily related to the molecular chromosomal instable subtype (CIN) of gastric carcinomas (p = 0.010). This was only observed in female patients (p = 0.014) but not in male patients (p = 0.315). The same sex-specific effect could be confirmed in adenocarcinomas of the esophagus (p = 0.027), as well as in female individuals after receiving neoadjuvant therapy (p = 0.034). CONCLUSIONS: Together, we show a sex-specific prognostic effect of TANs in gastric cancer within a Caucasian cohort. For the first time, we showed that this sex-specific prognostic effect of TANs can also be seen in esophageal cancer.

Optimized PD-L1 scoring of gastric cancer.

BACKGROUND: PD-1/PD-L1-Immunotherapy has been approved for gastric carcinoma. PD-L1 assessment by immunohistochemistry is the principle biomarker. Are biopsies able to map the actual PD-L1 status of the entire tumor? METHODS: Whole tumor slides of 56 gastric carcinoma were analyzed to determine the distribution of PD-L1 positive cells in the entire tumor areas. Tissue micro arrays with four cores of the tumor surface, which represents the endoscopically accessible biopsy zone, were built from the same tumors. The PD-L1 CPS value was determined separately for each core. Preoperative diagnostic biopsies were available for 22 of the tumors. PD-L1 prevalence, sensitivity and specificity were analyzed using the whole tumor slides as reference scores. Molecular subtyping was performed and related to the PD-L1 status. RESULTS: 27.3% of cases were PD-L1 negative (CPS < 1), 43.6% showed low PD-L1 expression (CPS ≥ 1 to < 5), 12.7% moderate (CPS ≥ 5 to < 10) and 16.4% strong expression (CPS ≥ 10). The biopsies showed best test characteristics if four surface biopsies were analyzed combined, i.e., the CPS was calculated across all four biopsies. The prevalence showed a distribution similar to the resection specimens, sensitivity was 0.73 and specificity 1.0. Using fewer surface biopsies decreased sensitivity and specificity and caused false-negative classifications. Compared to the TMAs, the preoperative biopsies showed reduced sensitivity (0.412). CONCLUSIONS: This is the first comprehensive study to optimize PD-L1 assessment in gastric cancer using endoscopically available tissue. The obtained PD-L1 prevalence is consistent with data of current clinical studies. Calculation of the test characteristics shows that surface biopsies can be indicative of the true PD-L1 status based on the resection specimen. However, an adequate number of biopsies is required. In this study, n = 4 biopsies yielded best results.

Y Chromosome Loss is a Frequent Event in Barrett's Adenocarcinoma and Associated with Poor Outcome.

BACKGROUND: The loss of the Y chromosome in various malignant diseases has been described previously. There are no reliable information on the actual frequency, significance and homogeneity of Y chromosome loss (LoY) in esophageal adenocarcinoma (EAC). METHODS: 400 male EAC including lymph-node metastases were analyzed with commercially available Y chromosome specific fluorescence in-situ probes. The results were correlated with molecular and immunohistochemical markers and clinicopathological aspects. RESULTS: The entire cohort (n = 400) showed a singular LoY of one chromosome arm in 1.0% (q-arm) and 2.8% (p-arm), complete LoY in 52.5%. LoY was strongly associated with shortened overall-survival (OS). Patients with preserved Y chromosome had a median OS of 58.8 months, patients with LoY an OS of 19.4 months (p < 0.001). Multivariate analysis showed LoY as an independent prognostic marker with a hazard ratio of 1.835 (95% CI 1.233-2.725). LoY correlated with TP53 mutations (p = 0.003), KRAS amplification (p = 0.004), loss of ARID1a (p = 0.045) and presence of LAG3 (p = 0.018). CONCLUSIONS: Loss of the Y chromosome is a very common phenomenon in EAC. The LoY is heterogeneously distributed within the tumor, but corresponding lymph node metastases frequently show homogeneous LoY, indicating a selection and metastasizing advantage with poor prognosis. To date, the male predominance of EAC (7-9:1) is unclear, so genetic explanatory models are favored. The LoY in EAC may be biologically and functionally relevant and additional genomic or functional analyses are needed.

Mesothelin expression in esophageal adenocarcinoma and squamous cell carcinoma and its possible impact on future treatment strategies.

BACKGROUND: Mesothelin is expressed at very low levels by normal mesothelial cells but is overexpressed in several human cancers. This makes mesothelin a promising target for immunotherapy. Limited data exist about mesothelin expression in esophageal carcinoma. In a current clinical trial, the highly potent anti-mesothelin antibody anetumab ravtansine is used in patients with mesothelin-positive tumors. Response rates are correlated with mesothelin expression (using the Ventana antibody) in tumor cells. No data are available on expression levels using the Ventana antibody. Most data have been generated using the Novocastra antibody. As patients are selected for clinical trials based on antibody staining of tumor samples, a comparison of these two available antibodies is crucial. METHODS: We analyzed 481 esophageal carcinomas [373 esophageal adenocarcinomas (EACs), 108 esophageal squamous cell carcinomas (ESCCs)] using two different monoclonal antibodies (Novocastra and Ventana) for mesothelin expression (low-mid and high-level expression, as used in one clinical trial). We also checked for the correlation of these results with clinical and molecular data. RESULTS: We revealed different staining results for both antibodies in EACs: Ventana: 53.6% (low expression: 25.3%; high expression: 28.3%) and Novocastra: 35.7% (low expression: 21.2%; high expression 14.5%). In ESCC we found comparable staining results: Ventana: 13.3% (low expression: 9.5%; high expression: 3.8%) and Novocastra: 13% (low expression: 11.1%; high expression: 1.9%). ARID1a-deficient EAC patients demonstrated significantly higher rates of mesothelin-positive tumors than ARID1a intact EAC patients. No correlations were found with other molecular alterations (TP53 mutation, ERBB2 amplification) or survival rates. CONCLUSION: To the best of our knowledge, this is the largest study analyzing the importance of mesothelin expression in esophageal carcinoma. This study revealed a significant number of mesothelin-positive esophageal carcinomas, especially adenocarcinomas. New therapeutic targets are urgently required to improve the outcome of patients with locally advanced or metastasized esophageal carcinoma. The inhibition of mesothelin can be a new attractive target.

Claudin 18.2 expression in esophageal adenocarcinoma and its potential impact on future treatment strategies.

The incidence of esophageal adenocarcinoma (EAC) has rapidly increased, particularly in the Western world. Despite improvements in perioperative treatments, the overall survival of patients remains low. Claudin 18.2 is a tight junction protein that is exclusively expressed in the gastric epithelia. However, following malignant transformation, gastric cancer metastases maintain this expression. Therefore, claudin 18.2 is a promising target for immunotherapy. Previous clinical trials have revealed improved anti-tumor activity in patients treated with an anti-claudin antibody by investigating the expression of claudin 18.2 in tumor cells. However, there is currently very limited data on the importance of claudin 18.2 expression in EAC. The present study analyzed the distribution of claudin 18.2 using immunohistochemistry in 485 patients with EAC, including their lymph node metastases. Additionally, these results were associated with clinical and molecular data. Claudin 18.2 was detected in 89/485 patients (18.4%). No correlations between expression and clinicopathological data (sex, age, pT stage, lymph node metastasis and grading) were observed. However, significantly decreased claudin 18.2 expression was observed in tumor types with upregulated human epidermal growth factor receptor 2 expression (P=0.036). Additionally, neoadjuvant treatment did not have any significant impact on claudin 18.2 expression (P=0.331). To the best of our knowledge, the present study is the largest systematic investigation of claudin 18.2 protein expression in EAC. The results obtained suggested that claudin 18.2 may serve as a promising therapeutic target in a substantial number of patients with EAC.