Search

Uroplakin 3B (Upk3b) is involved in stabilizing and strengthening the urothelial cell layer of the bladder. Based on RNA expression studies, Upk3b is expressed in a limited number of normal and tumor tissues. The potential use of Upk3b as a diagnostic or prognostic marker in tumor diagnosis has not yet been extensively investigated. A tissue microarray containing 17,693 samples from 151 different tumor types/subtypes and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. In normal tissues, Upk3b expression was largely limited to mesothelial cells, urothelial umbrella cells, and amnion cells. In tumor tissues, Upk3b was detectable in only 17 of 151 (11.3%) of tumor types. Upk3b expression was most frequent in mesotheliomas (82.1% of epithelioid and 30.8% of biphasic) and in urothelial tumors of the urinary bladder, where the positivity rate decreased from 61.9% in pTaG2 (low grade) to 58.0% in pTaG3 (high grade) and 14.6% in pT2-4 cancers. Among pT2-4 urothelial carcinomas, Upk3b staining was unrelated to tumor stage, lymph node status, and patient prognosis. Less commonly, Upk3b expression was also seen in Brenner tumors of the ovary (10.8%), as well as in four other subtypes of ovarian cancer (0.9–10.6%). Four additional tumor entities showed a weak to moderate Upk3b positivity in less than 5% of cases. In summary, Upk3b immunohistochemistry is a useful diagnostic tool for the distinction of mesotheliomas from other thoracic tumors and the visualization of normal mesothelial and umbrella cells. [ABSTRACT FROM AUTHOR]

Background: Epithelial splicing regulatory protein 1 (ESRP1) and 2 (ESRP2) regulate alternative splicing events of various pre-mRNAs. Some of these targets play a role in cancer-associated processes, including cytoskeleton reorganization and DNA-repair processes. This study was undertaken to estimate the impact of ESRP1 and ESRP2 alterations on prostate cancer patient prognosis.Methods: A tissue microarray made from 17,747 individual cancer samples with comprehensive, pathological, clinical and molecular data was analyzed by immunohistochemistry for ESRP1 and ESRP2.Results: Nuclear staining for ESRP1 was seen in 38.6% (36.0% low, 2.6% high) of 12,140 interpretable cancers and in 41.9% (36.4% low, 5.3% high) of 12,962 interpretable cancers for ESRP2. Nuclear protein expression was linked to advanced tumor stage, high Gleason score, presence of lymph node metastasis, early biochemical recurrence, and ERG-positive cancers (p < 0.0001 each). Expression of ESRPs was significantly linked to 11 (ESRP1)/9 (ESRP2) of 11 analyzed deletions in all cancers and to 8 (ESRP1)/9 (ESRP2) of 11 deletions in ERG-negative cancers portending a link to genomic instability. Combined ESRPs expression analysis suggested an additive effect and showed the worst prognosis for cancers with high ESRP1 and ESRP2 expression. Multivariate analyses revealed that the prognostic impact of ESRP1, ESRP2 and combined ESRP1/ESRP2 expression was independent of all established pre- and postoperative prognostic features.Conclusions: Our data show a striking link between nuclear ESRP expression and adverse features in prostate cancer and identifies expression of ESRP1 and/or ESRP2 as independent prognostic markers with a potential for routine application. [ABSTRACT FROM AUTHOR]

Background: TFAP2D is a transcription factor important for modulating gene expression in embryogenesis. Its expression and prognostic role in prostate cancer has not been evaluated. Methods: Therefore, a tissue microarray containing 17,747 prostate cancer specimens with associated pathological, clinical, and molecular data was analyzed by immunohistochemistry to assess the role of TFAP2D. Results: TFAP2D expression was typically increased in prostate cancer as compared to adjacent non-neoplastic glands. TFAP2D staining was considered negative in 24.3% and positive in 75.7% of 13,545 interpretable cancers. TFAP2D staining was significantly linked to advanced tumor stage, high classical and quantitative Gleason grade, lymph node metastasis, and a positive surgical margin (p ≤ 0.0045). TFAP2D positivity was more common in ERG fusion positive (88.7%) than in ERG negative cancers (66.8%; p < 0.0001). Subset analyses in 3776 cancers with and 4722 cancers without TMPRSS2:ERG fusion revealed that associations with tumor phenotype and patient outcome were largely driven by the subset of ERG negative tumors. Multivariate analysis did not identify TFAP2D protein expression levels as a robust independent prognostic parameter. Positive TFAP2D immunostaining was significantly associated with 10 of 11 previously analyzed chromosomal deletions in ERG negative cancers (p ≤ 0.0244 each) indicating that elevated TFAP2D expression parallels genomic instability in prostate cancer. Conclusion: These data demonstrate that TFAP2D protein overexpression is linked to prostate cancer progression and genomic instability in ERG negative prostate cancers. [ABSTRACT FROM AUTHOR]

Cytokeratin 20 (CK20) expression is limited to umbrella cells in the normal urothelium. Since CK20 is often upregulated in neoplastic urothelial cells including dysplasia and carcinoma in situ, immunohistochemical CK20 analysis is often used for the assessment of bladder biopsies. CK20 expression is a feature of luminal bladder cancer subtype, but its prognostic relevance is disputed. In this study, we investigated CK20 on >2700 urothelial bladder carcinomas in a tissue microarray format by immunohistochemistry. Cytoplasmic and membranous CK20 staining was seen in 1319 (51.8%) cancers. The fraction of CK20 positive and especially strongly positive cases increased from pTaG2 low grade (44.5% strongly positive) and pTaG2 high grade (57.7%) to pTaG3 high grade (62.3%; p = 0.0006) but was lower in muscle-invasive (pT2–4) carcinomas (51.1% in all pTa vs. 29.6% in pT2–4; p < 0.0001). Within pT2–4 carcinomas, CK20 positivity was linked to nodal metastasis and lymphatic vessel invasion (p < 0.0001 each) and to venous invasion (p = 0.0177). CK20 staining was unrelated to overall patient survival if all 605 pT2–4 carcinomas were jointly analyzed but subgroup analyses revealed a significant association of CK20 positivity with favorable prognosis in 129 pT4 carcinomas (p = 0.0005). CK20 positivity was strongly linked to the expression of GATA3 (p < 0.0001), another feature of luminal bladder cancer. The combined analysis of both parameters showed best prognosis for luminal A (CK20+/GATA3+, CK20+/GATA3-) and worst outcome for luminal B (CK20−/GATA3+) and basal/squamous (CK20−/GATA3-) in pT4 urothelial carcinomas (p = 0.0005). In summary, the results of our study demonstrate a complex role of CK20 expression in urothelial neoplasms including neoexpression in pTa tumors, a subsequent loss of CK20 expression in a subset of tumors progressing to muscle-invasion, and a stage dependent prognostic role in muscle-invasive cancers. [ABSTRACT FROM AUTHOR]

Uroplakin 1A (Upk1a) protein is relevant for stabilizing and strengthening urothelial cells and helps to prevent them from rupturing during bladder distension. Based on RNA expression data Upk1a is expressed in a limited number of normal tissues and tumors. To comprehensively evaluate the potential diagnostic and prognostic utility of Upk1a immunohistochemistry, a tissue microarray containing 6929 samples from 115 different tumor types and subtypes and 608 samples of 76 different normal tissue types was analyzed. Upk1a positivity was found in 34 (29.6 %) different tumor types including 9 (7.8 %) tumor types with at least one strongly positive case. The highest rates of Upk1a positivity were seen in various subtypes of urothelial neoplasms (42.6–98 %) including Brenner tumors of the ovary (64.9 %) followed by neoplasms of the thyroid (10.4–33.3 %). In urothelial tumors, Upk1a staining predominated at the cell membranes and staining intensity was often moderate to strong. In thyroidal neoplasms the staining was mostly purely cytoplasmic and of low to moderate intensity. Upk1a positivity was also seen in up to 15 % of cases in 25 additional tumor categories but the staining intensity was often cytoplasmic and the intensity was usually judged as weak and only rarely as moderate. Within non-invasive (pTa) tumors, the Upk1a positivity rate decreased from 94 % in pTa G2 (low grade) to 90.1 % in pTa G3 (p = 0.012) and was even lower in muscle-invasive carcinomas (41.5 %; p < 0.0001 vs pTaG3). Within muscle invasive carcinomas, Upk1a expression was unrelated to nodal metastasis (p > 0.05) and patient outcome (p > 0.05). In conclusion, Upk1a immunohistochemistry is a potentially useful and specific diagnostic marker for the distinction of urothelial carcinomas from other neoplasms. However, its sensitivity is less than 50 % in muscle-invasive cancers because Upk1a expression decreases during grade and stage progression. [ABSTRACT FROM AUTHOR]

Objectives Tumor angiogenesis is an essential and complex process necessary for the growth of all tumors which represents a potential therapeutic target. Angiogenesis inhibitors targeting vascular endothelial growth factor (VEGF) or their receptor tyrosine kinases have been approved by the FDA. In thymic epithelial tumors (TET), targeted therapies have been sporadically applied due to their rarity. To ascertain the presence of potential therapeutic targets, we analyzed by immunohistochemistry the expression of angiogenesis-related biomarkers in a large series of TET arranged in Tissue Micro Arrays (TMA). Materials and methods We assessed by immunohistochemistry the expression of the possible molecular target of anti-angiogenic therapy, i.e. VEGFA, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, and PDGFRβ, in a TMA series of 200 TET collected in the framework of a multi-institutional collaborative project for Rare Diseases. Results When compared to the low-risk tumors, high-risk TET (B2, B3, carcinomas) contained higher proportion of cancer cells expressing VEGFA, VEGFC and VEGFD (P<0.001, P<0.001, and P<0.001) growth factors, and their receptors VEGFR1 (P=0.002), VEGFR2 (P=0.013), and VEGFR3 (P=0.041). No differences were observed in terms of PDGFRβ expression. Conclusions According to our data, it is possible to hypothesize the existence of multiple paracrine and/or autocrine loops in TET, particularly in the high-risk ones, involved in TET growth and progression. Anti-angiogenic agents, directed to inhibit these loops, are therefore to be considered as potential tools in advanced TET therapy. [ABSTRACT FROM AUTHOR]

Combined analysis of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) is often used for assessing the origin of metastatic cancer. To evaluate the diagnostic utility of CK7 and CK20, tissue microarrays containing 15,424 samples from 120 different tumor types and subtypes and 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. CK7 positivity was seen in 52% (8.7% weak, 5.9% moderate, 37% strong) and CK20 positivity in 23% (5.1% weak, 3.4% moderate, 15% strong) of interpretable tumors. Of 8390 positive tumors, 1181 (14%) showed positivity for CK7 and CK20, 5380 (64%) showed positivity for CK7 alone, and 1829 (22%) showed positivity for CK20 alone. CK20 predominated in gastrointestinal tract, urothelial and Merkel cell carcinomas. CK7 was usually negative in prostate cancer and colorectal cancer. Combined evaluation of CK7/CK20 revealed the best diagnostic utility in CK20 positive tumors, where CK7 negativity is often linked to colorectal origin while CK7 positivity argues for urothelial origin or mucinous ovarian cancer. Associations with unfavorable tumor features were found for cytokeratin 7 loss in breast cancer of no special type, urothelial and renal cell carcinomas, for CK7 overexpression in high-grade serous ovarian and gastric cancer, and for CK20 overexpression in urothelial carcinoma. CK20 loss was linked to MSI in gastric (p = 0.0291) and colorectal adenocarcinoma (p < 0.0001). These analyses provide comprehensive data on the frequency of CK7 and CK20 immunostaining - alone or in combination - in human cancers. These data facilitate interpretation of CK7/CK20 immunostaining in cancers. [ABSTRACT FROM AUTHOR]

A simple modification of the cell block technique for cultured cells grown in different conditions and suitable for the construction of tissue micro arrays (TMA) is described. The application of mechanical stirring during clot formation allows the uniform dispersion of cells in the fibrin mesh, thus increasing the final volume of the embedded material of evenly distributed cells. This technique is easily applied to spheres—obtained from cell lines cultured under appropriate conditions—that are enriched in stem cells. The possibility of constructing TMA using cell lines (grown in adherence and as spheres) and samples of the corresponding tumors or normal tissues may allow the direct comparison of original tumors with in vitro-expanded cell lines. [ABSTRACT FROM AUTHOR]

Tissue micro array ( TMA) is widely used in cancer research in search of new predictive and prognostic markers. Colon cancer is known to be heterogeneous and the present study addresses some methodological aspects using cores of different size and analysing markers with different cellular distribution. We selected 61 paraffin-embedded tissue blocks representing patients diagnosed with Dukes B colon cancer. Two 1 mm and two 2 mm cores were taken from both the centre and the invasive front of the tumour respectively. The immunostaining included MLH1, MSH2, PMS2, p53, COX-2, TIMP and Betacatenin. Twenty-five percent of the cores taken from paraffin blocks less than 0.5 cm was lost and the total loss was 8%. The homogeneous stains ( MLH1, MSH2 and PMS2) all showed high agreement between TMA and whole tissue stains (kappa = 0.96,1 and 1 respectively). The COX-2, p53 and Betacatenin illustrated moderate to high agreement (kappa = 0.54-0.9) whereas TIMP-1 had the lowest score (kappa 0.19-0.25). The application of TMA in Dukes B colon cancer has several pitfalls and depends substantially on the immunohistochemical marker in question. Therefore a validation study seems justified before applying large scale TMA in this setting. [ABSTRACT FROM AUTHOR]

Abstract: Within the concert of immune reactions against tumour cells cytotoxic and regulatory T-cells are of utmost importance. Several studies revealed contradictory results on this issue. We therefore focused on functional expression patterns and localization of tumour-infiltrating T-lymphocytes in non-small cell lung cancer (NSCLC) and their impact on patient''s survival. 232 curatively operated NSCLC patients were included. After histological reevaluation and construction of tissue-multi-arrays immunohistochemical doublestains for CD3/CD8 and CD4/CD25 were performed to evaluate the total number of T-cells and their subsets of cytotoxic and activated T-cells. Additionally, the localization of the lymphocytes was included in the analysis. Hereby, T-cells within the tumour stroma were regarded as stromal, those among cancer cells as intraepithelial. The number of lymphocytes differed significantly between the histological subtypes being most prominent in large cell carcinomas. Survival analysis showed that high numbers of stromal T-lymphocytes are of beneficial prognostic influence in NSCLC patients. This also proved to be an independent prognostic factor in adenocarcinomas. Thus, in a large and well characterized cohort of NSCLC this is the first study to determine the prognostic value of stromal T-lymphocytes, as these are an independent prognosticator in NSCLC especially in adenocarcinomas whereas intraepithelial T-cells are not. [Copyright &y& Elsevier]

Background: Formaldehyde (HCHO) is a gas (available as a 37% concentrated solution, stabilized with methanol). The 10% dilution (approximately 4% formaldehyde) has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, along with other USA agencies (CalEPA, RoC/NTP) on the carcinogenicity of formaldehyde for humans renders its substitution in Pathology Departments necessary since the annual use of formalin may exceed 3,500 liters for a medium-large laboratory. To achieve a "formalin-free laboratory" we tested straightforward-to-make fixatives along with registered reagents offered as formalin substitutes. Methods: More than two hundreds specimens were fixed in parallel with in-laboratory made fixatives PAGA (Polyethylenglycol, ethyl Alcohol, Glycerol, Acetic acid), two zinc-based fixatives (ZBF, Z7), and commerciallyavailable alternatives (RCL2 and CellBlock). Tissue micro arrays were used for morphological and immunohistochemical comparison. Extraction of RNA was carried out to evaluate preservation of nucleic acids. Results: Differences compared to formalin fixation were evident in alcohol-based fixatives, mainly restricted to higher stain affinity and considerable tissue shrinkage. Conversely, nuclear detail was superior with these alcohol-based formulas compared to formalin or glyoxale-based recipes. RNA extraction was superior for Z7, PAGA and RCL2 with regard to concentration but relatively comparable regarding quality. Conclusions: Abolition of the human carcinogen formaldehyde from pathology laboratories is possible even in contexts whereby commercial alternatives to formalin are unavailable or are too expensive for routine use, and aspiration devices are lacking or not adequately serviced. The use of known formulations, possibly with simple and not-noxious ("alimentary grade") constituents, comparable with registered proprietary products, may expand the search for the ideal fixative combining satisfactory morphology with improved preservation of nucleic acids and proteins as well as being easy and safe to dispose of. [ABSTRACT FROM AUTHOR]

Abstract: Although survival rates of colon cancer patients diagnosed at an early stage (T1-2N0M0; Dukes A) vary considerably according to the studies cited, several studies indicate development of distant metastases already occurring in a considerable percentage of these patients leading to the death of the patients. This particular high risk group cannot be identified properly as no marker exists to identify these patients. As the Wnt/Win pathway plays a crucial role in metastasis formation in colorectal carcinoma, we analysed whether the transcription factor brachyury critically involved in this pathway may predict metastasis formation in these patients. The expression of brachyury-homologous (T) was immunohistochemically analysed in 748 patients and the data were correlated with classical and newer prognostic markers in colorectal cancer. Early stages colorectal cancer patients (T1-2N0M0, Dukes A) showed a significantly decreased survival when brachyury was expressed in the tumour tissue while no correlation was observed in later tumour stages. Hence a subset of colorectal cancers exists in which the ability to metastasise is already present at early stages of tumour growth and this high risk group can now be detected by immunohistochemistry. [Copyright &y& Elsevier]

Abstract: In this study, the prognostic and/or predictive value of different proteins (cyclo-oxygenase 2 (COX-2), Ki67 and cleaved cytokeratin (CK) 18) and fibro-inflammatory changes which might be of importance for the response to treatment were evaluated using tissue micro arrays. Samples were obtained from a subset of 95 patients included in the European Organisation for Research and Treatment of Cancer 22921 clinical trial, which randomised patients with rectal cancer to one of four arms treated with preoperative radiotherapy with or without pre- and/or postoperative chemotherapy. From our results, we can conclude that the addition of preoperative chemotherapy to radiotherapy led to significantly less COX-2 upregulation, less proliferation and more inflammation, as was seen in the resection specimen as well as less invasion and metastasis. For COX-2, Ki67 or cleaved CK18, no predictive or prognostic value could be identified. However, the fibro-inflammatory reaction after preoperative radiochemotherapy correlated with T-downstaging and seems to be an important factor for response. [Copyright &y& Elsevier]

Abstract: A robust algorithm is presented for labeling rows and columns in an irregular array. The algorithm is based on hierarchical pattern matching to a local lattice, which is used as a template. Starting from the best local match, the pattern is expanded hierarchically to encompass the entire array. An application to labeling digitized images of an array of tissue sections mounted on a microscope slide is discussed. [Copyright &y& Elsevier]

Arginase-1 catalyzes the conversion of arginine to ornithine and urea. Because of its predominant expression in hepatocytes, it serves as a marker for hepatocellular carcinoma, although other tumor entities can also express arginase-1. To comprehensively determine arginase-1 expression in normal and neoplastic tissues, tissue microarrays containing 14,912 samples from 117 different tumor types and 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. In normal tissues, arginase-1 was expressed in the liver, the granular layer of the epidermis, and in granulocytes. Among tumors, a nuclear and cytoplasmic arginase-1 immunostaining was predominantly observed in hepatocellular carcinoma, where 96% of 49 cancers were at least moderately positive. Although 22 additional tumor categories showed occasional arginase immunostaining, strong staining was exceedingly rare in these entities. Staining of a few tumor cells was observed in squamous cell carcinomas of various sites. Staining typically involved maturing cells with the beginning of keratinization in these tumors and was significantly associated with a low grade in 635 squamous cell carcinomas of various sites (p = 0.003). Teratoma, urothelial carcinoma and pleomorphic adenomas sometimes also showed arginase expression in areas with squamous differentiation. In summary, arginase-1 immunohistochemistry is highly sensitive and specific for hepatocellular carcinoma if weak and focal staining is disregarded. [ABSTRACT FROM AUTHOR]

Mucin 5AC (MUC5AC) is a secreted gel-forming mucin which is expressed by mucus producing cells of several organs but can also be found in cancer cells of the ovary, pancreas, and gastrointestinal tract. This study aimed to characterize the expression of MUC5AC and its potential prognostic implications in different ovarian cancer subtypes. MUC5AC expression was analyzed by immunohistochemistry on a tissue microarray containing 603 ovarian cancers. MUC5AC was commonly expressed in mucinous (27/36; 75%) and endometrioid (12/39; 31%) carcinomas, whereas malignant mixed Mullerian tumors (2/27; 7%), high-grade serous (20/373; 5%) and clear cell carcinomas (1/28; 4%) were only rarely MUC5AC positive and also showed lower expression levels. MUC5AC positive endometroid carcinomas and high-grade serous carcinomas lacked lymph node metastases (p = 0.0495 and p = 0.0216) suggesting a more favorable prognosis. Deficient mismatch repair (dMMR), associated with a favorable prognosis in different cancer types, was found in 4/39 (10%) MUC5AC positive cancers but in only 5/375 (1%) of MUC5AC negative cancers (p = 0.0052). In subgroup analyses MUC5AC positive endometroid carcinomas more frequently showed dMMR (4/10; 40%) as opposed to MUC5AC negative endometroid carcinomas (3/23; 13%; p = 0.0932). In summary, the results of our study show that MUC5AC expression is associated with mucinous and endometrioid ovarian carcinomas, lack of nodal metastases and dMMR. MUC5AC expressing ovarian cancers should be evaluated for dMMR. [ABSTRACT FROM AUTHOR]

Background Targeting Her2 is highly established in cancers of the upper gastrointestinal tract, since clinical studies showed a survival benefit in Her2-positive gastric cancer. To date there is conflicting data concerning the impact of Her2 expression and gene amplification in esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the esophagus, gastroesophageal junction and stomach. The aim of this study was to analyze the expression and gene amplification of Her2 in EAC in correlation to clinical and pathological data to verify the prognostic impact. Methods We analyzed 506 patients with esophageal adenocarcinomas that underwent thoraco-abdominal esophagectomy between 1997 and 2013 using a tissue micro array (TMA) for the expression of Her2 by immunohistochemistry (IHC) according to the guidelines. Fluorescence-in-situ-hybridization (FISH) was performed for IHC score 2. The Her2-status was correlated with clinical and pathological data. Results Her2-positivity was found in 11.7% (n = 59) of all EAC (IHC score 3 + or IHC score 2 + with amplification) and demonstrated a significant better overall-survival (OS) in correlation to Her2-negative tumors (median OS 55.0 vs. 22.7 months, P  < 0.0001) (Figure below). Overexpression of Her2 was associated with lower tumor stages (pT1/pT2, P  = 0.038), absence of lymph node metastases (pN0/pN + , P  = 0.030) and was significantly associated with tubular and/or papillary tumor growth pattern (P  = 0.029). View large Download slide View large Download slide Conclusion We demonstrated a positive prognostic impact of Her2 expression and gene amplification in a large cohort of EAC, contrary to other solid malignancies including gastric cancer, but according to a large study of EAC from 2012. Her2-positive tumors significantly have a tubular and/or papillary tumor growth pattern, indicating a marker of differentiation in EAC. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]

Background Immunotherapy has grown to a rapidly advancing sphere of research on modern strategies for treatment of cancer. A well-known way of immunomodulation is the principle of immune checkpoints leading to a down-regulated immune response in tumor microenvironment. Recently, beside the PD1/PD-L1 pathway, several immunecheckpoint pathways have been found. However, almost nothing is known about the expression and the correlation as prognostic factor in esophageal adenocarcinoma. Methods Two tissue micro arrays (TMA) were construced, a multi-spot TMA with up to 8 spots from different tumor areas of 165 patients and a valdiation single-spot TMA of 620 patients with EAC. Immunehistochemistry analysis were performed for LAG3, Tim3, IDO, VISTA, MHC1, MHC2, CD3, CD8, CD20 and CD38 and correlated with clinico-pathological and survival data. Data were additionally correlated with molecular data like TP53 mutational and HER2-neu status. Results LAG3 was detectable in 13.5% of all tumors, VISTA in 40.2%, IDO in 57.9%, Tim3 in 36.3%. There was only minor intratumoral heterogeneity between the luminal and infiltration area of the tumor for all analyzed immunecheckpoints. LAG3 and VISTA expression on tumor infiltrating T-cells (TIL) was associated with superior overall-survival compared to LAG3 and VISTA negative tumors. In pT1/2 tumors, VISTA was found as excellent independent prognosticator identifiying long-term surivors in case of VISTA expression. High amount of CD3 positive TILs was also associated with a better OS than CD3 poor tumors. Conclusion We conducted an extensive analysis of the immunecheckpoint status and presecnce of TILs in EAC. To the best of our knowledge, this is the first report in a large patients cohort correlating the expression of LAG3, Tim3, IDO and VISTA in EAC. The prognostic impact of LAG3 and VISTA expression suggests potential promising targets for novel immune checkpoint inhibition therapies beyond the PD1/PD-L1 inhibition as it is already established in head and neck cancer and NSCLC. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]

Background: Intra-tumoral heterogeneity has been recently addressed in different types of cancer, including breast cancer. A concept describing the origin of intra-tumoral heterogeneity is the cancer stem-cell hypothesis, proposing the existence of cancer stem cells that can self-renew limitlessly and therefore lead to tumor progression. Clonal evolution in accumulated single cell genomic alterations is a further possible explanation in carcinogenesis. In this study, we addressed the question whether intra-tumoral heterogeneity can be reliably detected in tissue-micro-arrays in breast cancer by comparing expression levels of conventional predictive/prognostic tumor markers, tumor progression markers and stem cell markers between central and peripheral tumor areas.Methods: We analyzed immunohistochemical expression and/or gene amplification status of conventional prognostic tumor markers (ER, PR, HER2, CK5/6), tumor progression markers (PTEN, PIK3CA, p53, Ki-67) and stem cell markers (mTOR, SOX2, SOX9, SOX10, SLUG, CD44, CD24, TWIST) in 372 tissue-micro-array samples from 72 breast cancer patients. Expression levels were compared between central and peripheral tumor tissue areas and were correlated to histopathological grading. 15 selected cases additionally underwent RNA sequencing for transcriptome analysis.Results: No significant difference in any of the analyzed between central and peripheral tumor areas was seen with any of the analyzed methods/or results that showed difference. Except mTOR, PIK3CA and SOX9 (nuclear) protein expression, all markers correlated significantly (p < 0.05) with histopathological grading both in central and peripheral areas.Conclusion: Our results suggest that intra-tumoral heterogeneity of stem-cell and tumor-progression markers cannot be reliably addressed in tissue-micro-array samples in breast cancer. However, most markers correlated strongly with histopathological grading confirming prognostic information as expression profiles were independent on the site of the biopsy was taken. [ABSTRACT FROM AUTHOR]