Germline homozygosity and allelic imbalance of HLA-I are common in esophagogastric adenocarcinoma and impair the repertoire of immunogenic peptides.

BACKGROUND: The individual HLA-I genotype is associated with cancer, autoimmune diseases and infections. This study elucidates the role of germline homozygosity or allelic imbalance of HLA-I loci in esophago-gastric adenocarcinoma (EGA) and determines the resulting repertoires of potentially immunogenic peptides. METHODS: HLA genotypes and sequences of either (1) 10 relevant tumor-associated antigens (TAAs) or (2) patient-specific mutation-associated neoantigens (MANAs) were used to predict good-affinity binders using an in silico approach for MHC-binding (www.iedb.org). Imbalanced or lost expression of HLA-I-A/B/C alleles was analyzed by transcriptome sequencing. FluoroSpot assays and TCR sequencing were used to determine peptide-specific T-cell responses. RESULTS: We show that germline homozygosity of HLA-I genes is significantly enriched in EGA patients (n=80) compared with an HLA-matched reference cohort (n=7605). Whereas the overall mutational burden is similar, the repertoire of potentially immunogenic peptides derived from TAAs and MANAs was lower in homozygous patients. Promiscuity of peptides binding to different HLA-I molecules was low for most TAAs and MANAs and in silico modeling of the homozygous to a heterozygous HLA genotype revealed normalized peptide repertoires. Transcriptome sequencing showed imbalanced expression of HLA-I alleles in 75% of heterozygous patients. Out of these, 33% showed complete loss of heterozygosity, whereas 66% had altered expression of only one or two HLA-I molecules. In a FluoroSpot assay, we determined that peptide-specific T-cell responses against NY-ESO-1 are derived from multiple peptides, which often exclusively bind only one HLA-I allele. CONCLUSION: The high frequency of germline homozygosity in EGA patients suggests reduced cancer immunosurveillance leading to an increased cancer risk. Therapeutic targeting of allelic imbalance of HLA-I molecules should be considered in EGA.

Low B-cell content is associated with a CD73-low tumour microenvironment and unfavourable prognosis in classic Hodgkin lymphoma.

B-cell content in the tumour microenvironment (TME) of classic Hodgkin lymphoma (HL) is known to be associated with prognosis. Here we demonstrate that whole slide image analysis using routinely available slides predicts outcomes in patients treated with ABVD in a prospective trial with a high B-cell content being associated with a favourable prognosis. B cells in the TME did not correlate with B cells in peripheral blood. In the TME maturation, stages of B cells (naive and memory) were consistent. However, we detected down-regulation of CD73 in HL with low B cells suggestive of an antibody-independent function of B cells in the TME of HL.

In-hospital outcomes following percutaneous versus surgical intervention in the treatment of aortic stenosis and concomitant coronary artery disease.

INTRODUCTION AND OBJECTIVES: Concomitant coronary artery disease (CAD) is prevalent among aortic stenosis patients; however the optimal therapeutic strategy remains debated. We investigated periprocedural outcomes among patients undergoing transcatheter aortic valve implantation with percutaneous coronary intervention (TAVI/PCI) vs surgical aortic valve replacement with coronary artery bypass grafting (SAVR/CABG) for aortic stenosis with CAD. METHODS: Using discharge data from the Spanish National Health System, we identified 6194 patients (5217 SAVR/CABG and 977 TAVI/PCI) between 2016 and 2019. Propensity score matching was adjusted for baseline characteristics. The primary outcome was in-hospital all-cause mortality. Secondary outcomes were in-hospital complications and 30-day cardiovascular readmission. RESULTS: Matching resulted in 774 pairs. In-hospital all-cause mortality was more common in the SAVR/CABG group (3.4% vs 9.4%, P <.001) as was periprocedural stroke (0.9% vs 2.2%; P=.004), acute kidney injury (4.3% vs 16.0%, P <.001), blood transfusion (9.6% vs 21.1%, P <.001), and hospital-acquired pneumonia (0.1% vs 1.7%, P=.001). Permanent pacemaker implantation was higher for matched TAVI/PCI (12.0% vs 5.7%, P <.001). Lower volume centers (< 130 procedures/y) had higher in-hospital all-cause mortality for both procedures: TAVI/PCI (3.6% vs 2.9%, P <.001) and SAVR/CABG (8.3 vs 6.8%, P <.001). Thirty-day cardiovascular readmission did not differ between groups. CONCLUSIONS: In this large contemporary nationwide study, percutaneous management of aortic stenosis and CAD with TAVI/PCI had lower in-hospital mortality and morbidity than surgical intervention. Higher volume centers had less in-hospital mortality in both groups. Dedicated national high-volume heart centers warrant further investigation.

Characteristics and outcomes of percutaneous coronary interventions in patients with spontaneous coronary artery dissection. A study from the administrative minimum data set of the Spanish National Health System.

Background: Coronary revascularization in patients with spontaneous coronary artery dissection (SCAD) is challenging. Indications and results of percutaneous coronary interventions (PCI) in SCAD patients are not well established. Aim: To assess indications and results of PCI in SCAD. Methods: The minimum basic data set of the Spanish National Health System (years 2016-2019) was used to identify 804 episodes of acute myocardial infarction (AMI) and SCAD, with a crude in-hospital mortality rate of 3%. Of these, 368 (46.8%) patients were revascularized with PCI during admission whereas 436 (54.2%) were managed conservatively. Results: Revascularization and in-hospital mortality rates both declined over the study period (p for trend both < 0.05). SCAD patients treated with PCI were older, more frequently male, and had higher frequency of diabetes, ST-segment elevation AMI and cardiogenic shock, compared to patients managed conservatively. The crude in-hospital mortality rate was higher in patients treated with PCI (4.9% vs. 1.4%; p = 0.004). However, after adjusting by propensity score (223 pairs) the in-hospital mortality rate was similar in the two groups (Adj OR: 1.21; 95%CI: 0.30-1.57; p = 0.76). Readmissions at 30-days were higher in patients managed conservatively (7.1 vs. 1.6%, p < 0.001) and this difference was maintained after propensity score adjustment (Adj average treatment effect: 2% vs. 12.2%; OR: 0.15; 95%CI: 0.04-0.45; p < 0.001). Conclusion: Revascularization is frequently used in unselected patients with AMI and SCAD but its use is declining. Patients with SCAD treated with PCI have a higher in-hospital mortality but this appears to be explained by their adverse baseline clinical characteristics.

Spontaneous coronary artery dissection in Spain: a study using the minimum data set of the Spanish National Health System.

INTRODUCTION AND OBJECTIVES: Spontaneous coronary artery dissection (SCAD) is a rare cause of acute myocardial infarction (AMI). We sought to compare the results on in-hospital mortality and 30-day readmission rates among patients with AMI-SCAD vs AMI due to other causes (AMI-non-SCAD). METHODS: Risk-standardized in-hospital mortality (rIMR) and risk-standardized 30-day readmission ratios (rRAR) were calculated using the minimum dataset of the Spanish National Health System (2016-2019). RESULTS: A total of 806 episodes of AMI-SCAD were compared with 119 425 episodes of AMI-non-SCAD. Patients with AMI-SCAD were younger and more frequently female than those with AMI-non-SCAD. Crude in-hospital mortality was lower (3% vs 7.6%; P<.001) and rIMR higher (7.6±1.7% vs 7.4±1.7%; P=.019) in AMI-SCAD. However, after propensity score adjustment (806 pairs), the mortality rate was similar in the 2 groups (AdjOR, 1.15; 95%CI, 0.61-2,2; P=.653). Crude 30-day readmission rates were also similar in the 2 groups (4.6% vs 5%, P=.67) whereas rRAR were lower (4.7±1% vs 4.8%±1%; P=.015) in patients with AMI-SCAD. Again, after propensity score adjustment (715 pairs) readmission rates were similar in the 2 groups (AdjOR, 1.14; 95%CI, 0.67-1.98; P=.603). CONCLUSIONS: In-hospital mortality and readmission rates are similar in patients with AMI-SCAD and AMI-non-SCAD when adjusted for the differences in baseline characteristics. These findings underscore the need to optimize the management, treatment, and clinical follow-up of patients with SCAD.

Post-transplant Malignancies Show Reduced T-cell Abundance and Tertiary Lymphoid Structures as Correlates of Impaired Cancer Immunosurveillance.

PURPOSE: An increased risk to develop cancer is one of the most challenging negative side effects of long-term immunosuppression in organ transplant recipients and impaired cancer immunosurveillance is assumed as underlying mechanism. This study aims to elucidate transplant-related changes in the tumor immune microenvironment (TME) of cancer. EXPERIMENTAL DESIGN: Data from 123 organ transplant recipients (kidney, heart, lung, and liver) were compared with historic data from non-immunosuppressed patients. Digital image analysis of whole-section slides was used to assess abundance and spatial distribution of T cells and tertiary lymphoid structures (TLS) in the TME of 117 tumor samples. Expression of programmed cell death 1 ligand 1 (PD-L1) and human-leucocyte-antigen class I (HLA-I) was assessed on tissue microarrays. RESULTS: We found a remarkably reduced immune infiltrate in the center tumor (CT) regions as well as the invasive margins (IM) of post-transplant cancers. These differences were more pronounced in the IM than in the CT and larger for CD8+ T cells than for CD3+ T cells. The Immune-score integrating results from CT and IM was also lower in transplant recipients. Density of TLS was lower in cancer samples of transplant recipients. The fraction of samples with PD-L1 expression was higher in controls whereas decreased expression of HLA-I was more common in transplant recipients. CONCLUSIONS: Our study demonstrates the impact of immunosuppression on the TME and supports impaired cancer immunosurveillance as important cause of post-transplant cancer. Modern immunosuppressive protocols and cancer therapies should consider the distinct immune microenvironment of post-transplant malignancies.

The effect of weekends and public holidays on the care of acute coronary syndrome in the Spanish National Health System.

INTRODUCTION AND OBJECTIVES: To analyze whether admission on weekends or public holidays (WHA) influences the management (performance of angioplasty, percutaneous coronary intervention [PCI]) and outcomes (in-hospital mortality) of patients hospitalized for acute coronary syndrome in the Spanish National Health System compared with admission on weekdays. METHODS: Retrospective observational study of patients admitted for ST-segment elevation myocardial infarction (STEMI) or for non-ST-segment elevation acute coronary syndrome (NSTEACS) in hospitals of the Spanish National Health system from 2003 to 2018. RESULTS: A total of 438 987 episodes of STEMI and 486 565 of NSTEACS were selected, of which 28.8% and 26.1% were WHA, respectively. Risk-adjusted models showed that WHA was a risk factor for in-hospital mortality in STEMI (OR, 1.05; 95%CI,1.03-1.08; P < .001) and in NSTEACS (OR, 1.08; 95%CI, 1.05-1.12; P < .001). The rate of PCI performance in STEMI was more than 2 percentage points higher in patients admitted on weekdays from 2003 to 2011 and was similar or even lower from 2012 to 2018, with no significant changes in NSTEACS. WHA was a statistically significant risk factor for both STEMI and NSTEACS. CONCLUSIONS: WHA can increase the risk of in-hospital death by 5% (STEMI) and 8% (NSTEACS). The persistence of the risk of higher in-hospital mortality, after adjustment for the performance of PCI and other explanatory variables, probably indicates deficiencies in management during the weekend compared with weekdays.

Reverted exhaustion phenotype of circulating lymphocytes as immune correlate of anti-PD1 first-line treatment in Hodgkin lymphoma.

While classical Hodgkin lymphoma (HL) is highly susceptible to anti-programmed death protein 1 (PD1) antibodies, the exact modes of action remain controversial. To elucidate the circulating lymphocyte phenotype and systemic effects during anti-PD1 1st-line HL treatment we applied multicolor flow cytometry, FluoroSpot and NanoString to sequential samples of 81 HL patients from the NIVAHL trial (NCT03004833) compared to healthy controls. HL patients showed a decreased CD4 T-cell fraction, a higher percentage of effector-memory T cells and higher expression of activation markers at baseline. Strikingly, and in contrast to solid cancers, expression for 10 out of 16 analyzed co-inhibitory molecules on T cells (e.g., PD1, LAG3, Tim3) was higher in HL. Overall, we observed a sustained decrease of the exhausted T-cell phenotype during anti-PD1 treatment. FluoroSpot of 42.3% of patients revealed T-cell responses against ≥1 of five analyzed tumor-associated antigens. Importantly, these responses were more frequently observed in samples from patients with early excellent response to anti-PD1 therapy. In summary, an initially exhausted lymphocyte phenotype rapidly reverted during anti-PD1 1st-line treatment. The frequently observed IFN-y responses against shared tumor-associated antigens indicate T-cell-mediated cytotoxicity and could represent an important resource for immune monitoring and cellular therapy of HL.

T-cells of invasive candidiasis patients show patterns of T-cell-exhaustion suggesting checkpoint blockade as treatment option.

OBJECTIVE: Recent data imply that strengthening host immunity by checkpoint inhibition improves outcome in invasive fungal infections (IFI), particularly in candidiasis. METHODS: To assess T-cell exhaustion in this context, we compared peripheral blood mononuclear cells (PBMCs) and serum samples of patients with invasive Candida albicans infection (IC, n = 21) to PBMCs or tumor-infiltrating lymphocytes (TILs) from cancer patients (n = 14) and PBMCs of healthy controls (n = 20). Type and differentiation of lymphocytes and expression of 29 immune-regulatory molecules were analyzed by flow cytometry. C. albicans specific responses were assessed by FluoroSpot (n = 8) and antibody measurement (n = 14). RESULTS: Fractions and phenotypes of lymphocyte subsets in PBMCs of IC patients were similar compared to PBMCs of controls, while they were different in TILs. PBMCs of patients with IC showed increased expression of immune-checkpoint molecules. The pattern of upregulated molecules was similar to TILs, but not present in PBMCs of control cancer patients. Fractions of T-cells expressing PD-1 and TIGIT were higher in IC patients that died. FluoroSpot analysis showed a Candida-specific IFN-y or IL-2 response in 5/8 patients, enhanced by addition of nivolumab in vitro. CONCLUSIONS: Together with preclinical data and preliminary evidence of clinical efficacy in mucormycosis, our results support clinical evaluation of immune-checkpoint inhibition in IFI treatment. TRIAL REGISTRATION: NCT04533087; retrospectively registered on August 31, 2020.

Immune responses against shared antigens are common in esophago-gastric cancer and can be enhanced using CD40-activated B cells.

BACKGROUND: Specific immune response is a hallmark of cancer immunotherapy and shared tumor-associated antigens (TAAs) are important targets. Recent advances using combined cellular therapy against multiple TAAs renewed the interest in this class of antigens. Our study aims to determine the role of TAAs in esophago-gastric adenocarcinoma (EGA). METHODS: RNA expression was assessed by NanoString in tumor samples of 41 treatment-naïve EGA patients. Endogenous T cell and antibody responses against the 10 most relevant TAAs were determined by FluoroSpot and protein-bound bead assays. Digital image analysis was used to evaluate the correlation of TAAs and T-cell abundance. T-cell receptor sequencing, in vitro expansion with autologous CD40-activated B cells (CD40Bs) and in vitro cytotoxicity assays were applied to determine specific expansion, clonality and cytotoxic activity of expanded T cells. RESULTS: 68.3% of patients expressed ≥5 TAAs simultaneously with coregulated clusters, which were similar to data from The Cancer Genome Atlas (n=505). Endogenous cellular or humoral responses against ≥1 TAA were detectable in 75.0% and 53.7% of patients, respectively. We found a correlation of T-cell abundance and the expression of TAAs and genes related to antigen presentation. TAA-specific T-cell responses were polyclonal, could be induced or enhanced using autologous CD40Bs and were cytotoxic in vitro. Despite the frequent expression of TAAs co-occurrence with immune responses was rare. CONCLUSIONS: We identified the most relevant TAAs in EGA for monitoring of clinical trials and as therapeutic targets. Antigen-escape rather than missing immune response should be considered as mechanism underlying immunotherapy resistance of EGA.

CD86+ Antigen-Presenting B Cells Are Increased in Cancer, Localize in Tertiary Lymphoid Structures, and Induce Specific T-cell Responses.

The role of B cells in antitumor immunity and their impact on emerging immunotherapies is increasingly gaining attention. B-cell effector functions include not only secretion of antibodies, but also presentation of antigens to T cells. A physiologic B-cell subset with immunostimulatory properties was described in humans, defined by a high expression of CD86 and downregulation of CD21. We used multicolor flow cytometry and IHC to elucidate abundance and spatial distribution of these antigen-presenting B cells (BAPC) in blood (peripheral blood mononuclear cells, PBMC) and tumor samples of 237 patients with cancer. Antigen-specific T-cell responses to cancer testis antigens were determined using tetramer staining and sorted BAPCs in FluoroSpot assays for selected patients. We found that BAPCs were increased in the tumor microenvironment of 9 of 10 analyzed cancer types with site-specific variation. BAPCs were not increased in renal cell carcinoma, whereas we found a systemic increase with elevated fractions in tumor-infiltrating lymphocytes (TIL) and PBMCs of patients with colorectal cancer and gastroesophageal adenocarcinoma. BAPCs were localized in lymphoid follicles of tertiary lymphoid structures (TLS) and were enriched in tumors with increased numbers of TLSs. BAPCs isolated from tumor-draining lymph nodes of patients with cancer showed increased percentages of tumor antigen-specific B cells and induced responses of autologous T cells in vitro. Our results highlight the relevance of BAPCs as professional antigen-presenting cells in tumor immunity and provide a mechanistic rationale for the observed correlation of B-cell abundance and response to immune checkpoint inhibition.

Cancer-specific immune evasion and substantial heterogeneity within cancer types provide evidence for personalized immunotherapy.

The immune response against cancer is orchestrated by various parameters and site-dependent specificities have been poorly investigated. In our analyses of ten different cancer types, we describe elevated infiltration by regulatory T cells as the most common feature, while other lymphocyte subsets and also expression of immune-regulatory molecules on tumor-infiltrating lymphocytes showed site-specific variation. Multiparametric analyses of these data identified similarities of renal and liver or lung with head and neck cancer. Co-expression of immune-inhibitory ligands on tumor cells was most frequent in colorectal, lung and ovarian cancer. Genes related to antigen presentation were frequently dysregulated in liver and lung cancer. Expression of co-inhibitory molecules on tumor-infiltrating T cells accumulated in advanced stages while T-cell abundance was related to enhanced expression of genes related to antigen presentation. Our results promote evaluation of cancer-specific or even personalized immunotherapeutic combinations to overcome primary or secondary resistance as major limitation of immune-checkpoint inhibition.

In-hospital outcomes of mechanical complications in acute myocardial infarction: Analysis from a nationwide Spanish database.

BACKGROUND: Mechanical complications represent an important cause of mortality in myocardial infarction (MI) patients. This is a nationwide study performed to evaluate possible changes in epidemiology or prognosis of these complications with current available strategies. METHODS: Information was obtained from the minimum basis data set of the Spanish National Health System, including all hospitalizations for acute myocardial infarction (AMI) from 2010 to 2015. Risk-standardized in-hospital mortality ratio was calculated using multilevel risk adjustment models. RESULTS: A total of 241,760 AMI episodes were analyzed, MI mechanical complications were observed in 842 patients: cardiac tamponade in 587, ventricular septal rupture in 126, and mitral regurgitation due to papillary muscle or chordae tendineae rupture in 155 (there was more than one complication in 21 patients). In-hospital mortality was 59.5%. On multivariate adjustment, variables with significant impact on in-hospital mortality were: age (OR 1.06; 95% CI 1.04-1.07; p < 0.001), ST-segment elevation AMI (OR 2.91; 95% CI 1.88-4.5; p < 0.001), cardiogenic shock (OR 2.35; 95% CI 1.66-3.32; p < 0.001), cardio-respiratory failure (OR 3.48; 95% CI 2.37-5.09; p < 0.001), and chronic obstructive pulmonary disease (OR 1.85; 95% CI 1.07-3.20; p < 0.001). No significant trends in risk-adjusted in-hospital mortality were detected (IRR 0.997; p = 0.109). Cardiac intensive care unit availability and more experience with mechanical complications management were associated with lower adjusted mortality rates (56.7 ± 5.8 vs. 60.1 ± 4.5; and 57 ± 6.1 vs. 59.9 ± 5.6, respectively; p < 0.001). CONCLUSIONS: Mechanical complications occur in 3.5 per thousand AMI, with no significant trends to better survival over the past few years. Advanced age, cardiogenic shock and cardio-respiratory failure are the most important risk factors for in-hospital mortality. Higher experience and specialized cardiac intensive care units are associated with better outcomes.

Microwave ablation enhances tumor-specific immune response in patients with hepatocellular carcinoma.

Thermal ablative therapies are standard treatments for localized hepatocellular carcinoma (HCC). In addition to local tumor destruction, ablation leads to abscopal effects in distant lesions most likely mediated by an anti-tumor immune response. Although microwave ablation (MWA) is increasingly substituting other ablative techniques, its systemic immunostimulatory effects are poorly studied. We analyzed tumor-specific immune responses in peripheral blood of HCC patients after thermal ablation with regard to T cell responses and disease outcome. While comprehensive flow cytometric analyses in sequential samples of a prospective patient cohort (n = 23) demonstrated only moderate effects of MWA on circulating immune cell subsets, fluorospot analyses of specific T cell responses against seven tumor-associated antigens (TTAs) revealed de-novo or enhanced tumor-specific immune responses in 30% of patients. This anti-tumor immune response was related to tumor control as Interferon-y and Interleukin-5 T cell responses against TAAs were more frequent in patients with a long-time remission (> 1 year) after MWA (7/16) compared to patients suffering from an early relapse (0/13 patients) and presence of tumor-specific T cell response (IFN-y and/or IL-5) was associated to longer progression-free survival (27.5 vs. 10.0 months). Digital image analysis of immunohistochemically stained archival HCC samples (n = 18) of patients receiving combined MWA and resection revealed a superior disease-free survival of patients with high T cell abundance at the time of thermal ablation (37.4 vs. 13.1 months). Our data demonstrates remarkable immune-related effects of MWA in HCC patients and provides additional evidence for a combination of local ablation and immunotherapy in this challenging disease.

Tumor and microenvironment response but no cytotoxic T-cell activation in classic Hodgkin lymphoma treated with anti-PD1.

Classic Hodgkin lymphoma (cHL) is the cancer type most susceptible to antibodies targeting programmed cell death protein 1 (PD1) and is characterized by scarce Hodgkin and Reed-Sternberg cells (HRSCs), perpetuating a unique tumor microenvironment (TME). Although anti-PD1 effects appear to be largely mediated by cytotoxic CD8+ T cells in solid tumors, HRSCs frequently lack major histocompatibility complex expression, and the mechanism of anti-PD1 efficacy in cHL is unclear. Rapid clinical responses and high interim complete response rates to anti-PD1 based first-line treatment were recently reported for patients with early-stage unfavorable cHL treated in the German Hodgkin Study Group phase 2 NIVAHL trial. To investigate the mechanisms underlying this very early response to anti-PD1 treatment, we analyzed paired biopsies and blood samples obtained from NIVAHL patients before and during the first days of nivolumab first-line cHL therapy. Mirroring the rapid clinical response, HRSCs had disappeared from the tissue within days after the first nivolumab application. The TME already shows a reduction in type 1 regulatory T cells and PD-L1+ tumor-associated macrophages at this early time point of treatment. Interestingly, a cytotoxic immune response and a clonal T-cell expansion were not observed in the tumors or peripheral blood. These early changes in the TME were distinct from alterations found in a separate set of cHL biopsies at relapse during anti-PD1 therapy. We identify a unique very early histologic response pattern to anti-PD1 therapy in cHL that is suggestive of withdrawal of prosurvival factors, rather than induction of an adaptive antitumor immune response, as the main mechanism of action.

B cells in esophago-gastric adenocarcinoma are highly differentiated, organize in tertiary lymphoid structures and produce tumor-specific antibodies.

Tumor-infiltrating lymphocytes (TILs) are correlated to prognosis of several kinds of cancer. Most studies focused on T cells, while the role of tumor-associated B cells (TABs) has only recently gained more attention. TABs contain subpopulations with distinct functions, potentially promoting or inhibiting immune responses. This study provides a detailed analysis of TABs in gastro-esophageal adenocarcinoma (EAC). Flow cytometric analyses of single cell suspensions of tumor samples, mucosa, lymph nodes and peripheral blood mononuclear cells (PBMC) of EAC patients and healthy controls revealed a distinct B cell compartment in cancer patients. B cells were increased in tumor samples and subset-analyses of TILs showed increased proportions of differentiated and activated B cells and an enrichment for follicular T helper cells. Confocal microscopy demonstrated that TABs were mainly organized in tertiary lymphoid structures (TLS), which resemble lymphoid follicles in secondary lymphoid organs. A panel of 34 tumor-associated antigens (TAAs) expressed in EAC was identified based on public databases and TCGA data to analyze tumor-specific B cell responses using a LUMINEXTM bead assay and flow cytometry. Structural analyses of TLS and the detection of tumor-specific antibodies against one or more TAAs in 48.1% of analyzed serum samples underline presence of anti-tumor B cell responses in EAC. Interestingly, B cells were decreased in tumors with expression of Programmed Death Ligand 1 or impaired HLA-I expression. These data demonstrate that anti-tumor B cell responses are an additional and underestimated aspect of EAC. Our results are of immediate translational relevance to emerging immunotherapies.