Aberrant Expression Of E-cadherin Research Articles

Comprehensive characterization of invasive mammary carcinoma with lobular features: integrating morphology and E-cadherin immunohistochemistry patterns.

Breast cancer treatment prioritizes molecular subtypes over histologic types. However, considering the unique biological behavior of invasive lobular carcinoma (ILC), its diagnosis is crucial for patient management. Therefore, this study aimed to review breast cancer cases, focusing on the E-cadherin patterns and lobular morphology of cases misclassified in the original reports. A comprehensive review was conducted on 481 breast cancer biopsy cases diagnosed as invasive breast carcinoma of no special type (IBC-NST) or ILC with E-cadherin staining. These cases were categorized into six groups based on tumor morphology (ductal/lobular) and E-cadherin expression pattern (membranous/loss/aberrant): (1) ductal/membranous, (2) lobular/loss, (3) lobular/aberrant, (4) mixed, (5) ductal/loss or aberrant, and (6) lobular/membranous. In 211 cases (43.8%), an E-cadherin pattern indicating ILC (loss and aberrant) was observed alongside lobular morphology, representing 5.52% of all breast cancer biopsies during the relevant period. Moreover, 181 cases (37.6%) showed a membranous pattern with ductal morphology, 4 (0.8%) were mixed IBC-NST and ILC, and 85 (17.7%) exhibited discordance between morphology and E-cadherin expression. Notably, only 25.9% (15/58) of cases in group 3, characterized by aberrant E-cadherin patterns, were initially diagnosed as ILC, highlighting a significant diagnostic discrepancy. In group 6, where membranous E-cadherin pattern was present with lobular morphology, only 3.4% (2/58) were diagnosed as ILC in the original reports, indicating diagnostic challenges in morphology and immunohistochemistry discordance. Similarly, in group 5, which had ductal morphology with loss or aberrant E-cadherin expression, the initial diagnosis rate of IBC-NST was 33.3% (9/27), reflecting the complexities in interpreting discordant cases. In real-world practice, diagnosing ILC often heavily depends on E-cadherin results. This study emphasizes the need for diagnostic clarification in cases with discordance between morphology and E-cadherin patterns.

Abstract 202: Spry1 targeting enhances E-cadherin expression in cutaneous melanoma

Abstract Background: Cutaneous melanoma (CM) is a very aggressive malignancy that still represents the deadliest form of skin cancer. About 50% of CM harbors the activating BRAFV600 mutation which exerts most of the oncogenic effects through the MAPK signaling pathway. In the last years, a number of MAPK modulators have been identified, including Spry1. In this context, we have recently reported that Spry1 knockdown (Spry1KO) reduced the expression of several markers of epithelial-mesenchymal transition (EMT) both in vitro and in vivo. Loss of E-cadherin is a hallmark of EMT in CM, and the presence of aberrant E-cadherin expression in CM is usually associated with a significantly worse overall survival. Based on these premises, in this study we wondered to explore whether Spry1 influences EMT through the modulation of E-cadherin expression. Material and Methods: SPRY1 gene was knocked-out using the CRISPR strategy in BRAF wild-type (wt) and in BRAF-mutant CM cell lines. By using in vitro and in vivo models, the effects of Spry1KO on E-cadherin expression and localization was investigated through RNA-sequencing (RNA-seq), quantitative real-time PCR, western blot, and immunofluorescence analyses. To gain insight into Spry1 interactome, immunoprecipitation coupled to mass spectrometry (IP-MS) was performed. Results and Discussion: E-cadherin mRNA and protein levels were significantly increased both in vitro and in vivo in Spry1KO clones. In addition, immunofluorescence analysis revealed a sustained redistribution of E-cadherin to the plasma membrane following Spry1 loss, thus confirming that Spry1 plays a role in EMT in CM. E-cadherin requires p120-catenin (p120) to maintain cell adhesion and functional adherens junctions. Indeed, p120 dysregulation results in the rapid turnover of E-cadherin complexes. Intriguingly, IP-MS analyses identified several Spry1 protein partners, including p120. Although a number of functional studies are still ongoing, preliminary western blot analysis of cytosolic and mitochondrial proteins indicated that Spry1 and p120 were mostly located in mitochondria. Conclusion: Spry1 reduced E-cadherin expression in vitro and in vivo. Starting from preliminary data, we hypothesized that Spry1-p120 interaction might influence E-cadherin distribution over the plasma membrane. Citation Format: Barbara Montico, Giorgio Giurato, Roberto Guerrieri, Annamaria Salvati, Francesca Colizzi, Lorena Baboci, Luca Sigalotti, Alessia Covre, Michele Maio, Agostino Steffan, Tuula Anneli Nyman, Alessandro Weisz, Maurizio Mongiat, Eva Andreuzzi, Elisabetta Fratta. Spry1 targeting enhances E-cadherin expression in cutaneous melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 202.

Immunohistochemical markers in predicting behavior of bladder urothelial carcinoma.

Bladder cancer is the 5th most prevalent cancer among Iranian men. Finding prognostic markers to predict behavior of this cancer can help us to choose the best treatment for patients from the first place. We aimed to evaluate the correlation of immunohistochemical markers with tumor stage, grade and prognosis of disease. In this study, we reassessed the specs of proven UC among Iranian patients. Sixty specimens were collected, contained of 30 low grade and 30 high grade urothelial carcinomas. All slides were assessed by immunohistochemistry study for p21, p27, Her-2/neu, E-cadherin, and CD10. Data were analyzed by SPSS 18.0 and a p-value < 0.05 was considered significant. We evaluated 60 patients in this study with mean age of 66±11 years and majority of them are men. High expression of p27 showed significant correlation with LGUC (P=0.030). HGUC related with high expression of Her-2/neu, CD10 and aberrant expression of E-Cadherin (P<0.0001). Aberrant E-Cadherin and high expression of CD10 are associated with higher tumor stage (P=0.000). CD10 intensity was the only immunohistochemical markers to predict prognosis (P=0.010). In the present study, CD10 intensity is the only marker that directly predicts the prognosis. The higher intensity leads to poor prognosis (recurrence or metastasis). More studies must be done in this aspect to resolve the controversies and clarify the role of immunohistochemical markers in predicting BC behaviors.

Tanshinone I attenuates gastric precancerous lesions by inhibiting epithelial mesenchymal transition through the p38/STAT3 pathway

BackgroundGastric precancerous lesions (GPLs) are omens for gastric cancer (GC), which developing with a series of pathological changes of gastric mucosa. Reversing epithelial-mesenchymal transition (EMT) in gastric mucosa is the main approach to restrain GPLs from evolving into cancer. Tanshinone I (Tan-I), the active ingredients of traditional Chinese herb Salvia miltiorrhiza, has exhibited anticancer effect. PurposeTo investigate the effect and mechanism of Tan-I in intervening GPLs, and provide a new therapeutic strategy for prevention of GC. MethodsGastric mucosal epithelial cells were treated with the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) to construct MNNG-induced cell (MC cell) of gastric mucosa that undergoing EMT process. Then, this study explored the effect and mechanism of Tan-I in vitro. Subsequently, this study constructed GPL mice to clarify the exact efficacy and mechanism of Tan-I on GPLs. ResultsTan-I inhibited MC cell proliferation, invasion and migration. Simultaneously, the aberrant expression of E-cadherin and N-cadherin were reversed. Tan-I attenuated inflammation by reducing the release of nitric oxide, TNFα and IL-1β. Tan-I reversed the EMT and inflammatory processes by regulating p38 and STAT3. ConclusionThis study showed that Tan-I inhibited the progression of GPLs by reversing the EMT process and reducing inflammation by restraining the p38/STAT3 signaling pathway.

Ovarian Clear Cell Carcinoma and Markers of Epithelial-Mesenchymal Transition (EMT): Immunohistochemical Characterization of Tumor Budding.

Tumor budding, largely considered a manifestation of epithelial-mesenchymal transition (EMT) is an established prognostic marker for several cancers. In a recent study, tumor budding was associated with poor clinical outcomes in early-stage ovarian clear cell carcinoma. Here, we evaluated the immune expression of 3 proteins shown to be associated with EMT (E-cadherin, β-catenin, and glypican-3) in 72 primary tumors of ovarian clear cell carcinoma with median follow-up of 39.47mo. E-cadherin and β-catenin expression was further evaluated in tumor buds in 29 (40%) cases. In the tumor mass, diffuse membranous expression of E-cadherin and β-catenin was seen in 83% (60/72) and 81% (58/72) cases, respectively. Nuclear accumulation of E-cadherin was seen in 7 (10%) cases, while none of the cases showed nuclear β-catenin expression. Glypican-3 expression was diffuse in 33.3% (24/72), patchy in 29.2% (21/72), and absent in 37.5% (27/72) cases. Evaluation of tumor buds showed aberrant patterns of expression (complete loss/cytoplasmic accumulation/diminished, discontinuous incomplete membranous staining) of E-cadherin in 29/29 (100%) and of β-catenin in 26/29 (90%) cases. E-cadherin, β-catenin, and glypican-3 expression in the main tumor mass had no association with stage, lymph node status, recurrent/progressive disease, status at last follow-up, survival and histopathologic features ( P >0.05). Our finding of aberrant expression of both E-cadherin and β-catenin in tumor buds indicates involvement of Wnt signaling pathway/EMT in tumor budding and outlines its significance as a prognostic marker especially for early-stage ovarian clear cell carcinoma.

Endometrial carcinomas with dyshesive, eosinophilic, and vacuolated (histiocyte-like) tumor cells: a reactive-like phenotype associated with aggressive behavior.

Herein, we present a clinicopathological and molecular analysis of four cases of endometrial carcinoma (EC) diffusely exhibiting dyshesive cells with wide eosinophilic and vacuolated cytoplasm (histiocyte-like tumor cells, HLTCs). We compared these HLTCs to similar cells found in microcystic, elongated and fragmented (MELF) pattern (n = 20) or after neoadjuvant chemotherapy (NAC) (n = 5). The four cases were endometrioid, serous, clear cell, and gastric-type; all were at FIGO stage ≥ III. HLTCs showed an epithelial Müllerian phenotype and at least focal CK20, HNF1β, and CK5/6 expression, with aberrant e-cadherin and β-catenin expression; two cases were MMR-deficient, and one was p53-abnormal; all were POLE wild type. MELF-associated and NAC-associated HLTCs showed similar morphological/immunophenotypical features. However, MELF-associated HLTCs were mainly intraglandular and inflammation-associated, did not form a distinct tumor component, and showed no relationship with lymph node metastases. In conclusion, different histotypes of EC may show a prominent HLTC component, which shows peculiar morphological/immunophenotypical features and appears associated with aggressive behavior.

34P Validation of a new scoring system for molecular subtyping of gastric cancer

Molecular classification of gastric cancer may potentially provide tailored treatment options by predicting survival outcomes and patients’ response to therapy. In our prior study by Setia et al. [Modern Patho 29.7 (2016): 772-784], we identified five groups of gastric cancers based on Epstein–Barr virus (EBV) positivity, microsatellite instability (MSI), aberrant E-cadherin, and p53 expression (normal/aberrant). The aim of this study was to validate the association between these molecular subtypes and the prognosis of patients with gastric cancer from Romania. The molecular classification was reproduced in a retrospective cohort of 121 resected gastric cancers at Fundeni Clinical Institute, Bucharest. EBER in situ hybridization, p53, microsatellite instability, and E-cadherin expression were analyzed using immunohistochemical, RT-PCR and in situ hybridization techniques. EBV-positive gastric cancers represented 30% of the cases (n=36); microsatellite instable adenocarcinoma constituted 9% of the cases (n=11); aberrant expression of E-cadherin was identified in 17% (n=20) while aberrant p53 expression was noted in 34% (n=42) of the gastric cancers. The remaining patients with normal p53 expression represent 10% (n=12) of total cases. The MSI high subtype was associated with a significantly more favorable prognosis while gastric cancers with aberrant E-cadherin expression had the least favorable prognosis (log-rank, p=0.001). Patients with EBV cancer subtype had superior median overall survival compared to those with aberrant E-cadherin expression (p=0.04). The proposed molecular classification successfully stratified patients by survival. Our results demonstrated a trend for superior survival in the MSIhigh subtype and EBV-positive gastric adenocarcinomas. These data warrant further validation of this scoring system and the role of anti-tumor immunity in MSI-high and EBV-positive subtypes.

The role of E-Cadherin expression in primary site of breast cancer

PurposeThe tumour’s ability to metastasize is the major cause for fatal outcomes in cancer diseases. In breast cancer, aberrant E-Cadherin expression has been linked to invasiveness and poor prognosis.MethodWe assessed expression of E-Cadherin by immunohistochemistry in primary tumour tissue from 125 female breast cancer patients. Staining intensities were analysed using the immunoreactive score (IRS). We investigated E-Cadherin expression and its associations with clinicopathological parameters (age, tumour size, lymph node status, grade, hormone receptors, Her2 Status) as well as with recurrence and survival.ResultsIncreased, rather than aberrant E-Cadherin expression was found and was associated with poor outcome (p = 0.046). Our data show an association between elevated E-Cadherin in primary tumour tissue and an unfavourable negative prognosis in patients.ConclusionThis association was somehow unexpected as loss of E-Cadherin has long been regarded as a prerequisite for development of invasiveness and metastases. Our findings support the notion that E-Cadherin promotes, rather than suppresses, development of metastasis and invasiveness.

Aberrant expression of E-cadherin in infiltrating ductal and lobular breast carcinomas and its correlation with clinicopathological parameters – A hospital-based study

Introduction: Breast carcinoma is one of the commonest malignant tumours in women, leading topremature deaths and morbidity. E-cadherin is a 120kDa calcium-dependent transmembraneglycoprotein encoded by the CDH1 gene located on chromosome 16q21 and is expressed in mostepithelial cells. Loss of E Cadherin expression implies cell discohesion and favours metastasis.Materials and Methods: A total of 30 cases of breast carcinomas were studied, over two years.Histological grade and type were assessed by staining the paraffin-embedded sections with H &amp; E.Using IHC technique, E-cadherin antigen was retrieved by Heat-Induced Epitome Retrieval method,and immunostaining was scored semiquantitatively. Cases were grouped as ‘preserved,’ whenpositivity was strong membranous, and occurred in more than 75% of the neoplastic epithelial cellsand ‘aberrant’ in all the remaining cases. Results: E-cadherin was found to be preserved in 46.7%of all the breast carcinomas and aberrant in 51.7% of invasive ductal carcinomas (IDC) alone, while100% of invasive lobular carcinomas showed aberrant expression. No significant correlation wasfound with E-cadherin grading and histological type of carcinoma, histopathological grade orinvolvement of deep surgical margin. Conclusion: Differentiation between invasive ductal andinvasive lobular carcinoma based on the loss of E-cadherin has to be done cautiously given itsaberrant expression in ductal carcinomas as well.

Integrated clinicopathological and immunohistochemical analysis of gastric adenocarcinoma with hepatoid differentiation: an exploration of histogenesis, molecular characteristics, and prognostic markers

In addition to hepatoid adenocarcinoma (HAC), gastric adenocarcinoma with enteroblastic differentiation (GAED) and common adenocarcinoma (COM) could also show hepatoid differentiation, which presents a poor prognosis. To elucidate the histogenesis and development of gastric cancer with hepatoid differentiation, we identified 55 cases by histological morphology and a panel of markers, including α-fetoprotein (AFP), Glypican 3 (GPC3) and SALL4, then clinicopathological parameters, pathomorphological characteristics, mucin phenotypes, molecular features, Immunoscore and survival analysis were assessed. A mixture of three types (COM+GAED+HAC) was most commonly observed in the same case, and typical transitions between each histological subtype were frequently seen. Hyaline globule and pink amorphous substance were often present. HER2 was amplified in 21.8% of cases. All the tumors showed intestinal phenotype (69.1%) and mixed gastric/intestinal phenotype (30.9%)and were all defined to chromosomal instable (CIN)/genomically stable (GS) group. Considering that 83.6% cases presented TP53 gene mutation phenotype and 61.8% cases showed ≥10% aberrant E-cadherin expression, the precise molecule classification is ambiguous. Survival analysis showed that patients with high SALL4 expression, high preoperative serum AFP level, or low Immunoscore had a significantly poor overall survival (OS). Moreover, SALL4, HER2, and Immunoscore had an independent influence on OS. In conclusion, we suggest that the development of gastric adenocarcinoma with hepatoid differentiation might a continuously progressive profile: from intestinal-type COM adenocarcinoma to GAED and then HAC. CIN/GS subtypes might be where they belonged. SALL4, HER2, and Immunoscore may be potential therapeutic targets.

Salivary Duct Carcinoma With Rhabdoid Features-No or Aberrant Expression of E-cadherin and Genetic Changes in CDH1: Immunohistochemical and Genetic Analyses of 17 Cases.

Salivary duct carcinoma is a relatively uncommon malignancy of the salivary glands; however, it frequently occurs as a carcinomatous component of carcinoma ex pleomorphic adenoma. We previously reported salivary duct carcinoma with rhabdoid features (SDCRF) as an extremely rare subtype of salivary duct carcinoma, and that it occurred as a salivary counterpart of pleomorphic lobular carcinoma of the breast (PLCB). We collected new cases of SDCRF for this study, in which we examined a total of 17 cases immunohistochemically and genetically. As it is known that PLCB exhibits loss of or aberrant E-cadherin expression and carries nonsense/missense mutations in or deletion of the CDH1 gene, we examined the CDH1 gene status of our SDCRF cases. All of the examined SDCRF cases involved the diffuse proliferation of large ovoid cells with eosinophilic cytoplasm and eccentric nuclei, which displayed reduced cell-cell adhesion. Most cases were positive for pan-cytokeratin, androgen receptor, gross cystic disease fluid protein-15, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1, and WI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 4, whereas they were negative for vimentin. No and decreased/cytoplasmic E-cadherin expression was observed in 11 and 4 of 17 cases, respectively, whereas no and decreased/cytoplasmic β-catenin expression were observed in 10 and 5 of 17 cases, respectively. Among the 11 cases that could be genetically analyzed, a nonsense mutation (1 case), missense mutations (6 cases), and insertions (1 case) were detected in the CDH1 gene. In conclusion, we propose that SDCRF is the salivary counterpart of PLCB due to its morphology and immunophenotype, and the genetic status of CDH1.

The correlation of e-cadherin expression with the modified gleason score and the grade group of prostatic adenocarcinoma

Background: E-cadherin is a cell adhesion molecule, its downregulation is associated with poorly differentiated tumors in many organs, and its loss is associated with adverse behavior of many tumors. Objectives: This study aims to find a correlation between E-cadherin status, the Grade Group, and the modified Gleason score in core biopsies obtained from prostatic carcinoma. Materials and Methods: This study is a retrospective and prospective cross-sectional study that was conducted on (50) paraffin blocks obtained from core biopsies of prostatic carcinoma. E-cadherin status was correlated with the Grade Group and the modified Gleason score. The E-cadherin staining pattern was also examined for its correlation with perineural invasion. Chi-square was used to determine the correlation between E-cadherin staining pattern on the one hand and the modified Gleason score, Grade Group, and perineural invasion on the other hand and P < 0.5% was considered as significant. Results: Only six patients (12%) fall in Grade Group 1 and according to the modified Gleason score, most patients had high scores. Regarding E-cadherin expression, 24 cases (48%) had aberrant E-cadherin expression, while the rest 26 cases (52%) had a complete strong membranous expression. Statistically, there was a significant correlation between aberrant E-cadherin expression and increasing grade according to the modified Gleason score and Grade Group with P values of 0.032% and 0.022%, respectively. In 24 patients (48%), perineural invasion was detected half of them had aberrant E-cadherin expression which was statistically notsignificant when both the parameters (perineural invasion and aberrant E-cadherin expression) are tested against the modified Gleason score and the Grade Group (P = 0.71%). Conclusion: Aberrant E-cadherin expression is associated with increasing modified Gleason score and Grade Group but has no significant correlation with perineural invasion.

Correlation between E-Cadherin and Hormone Receptor Status among Breast Cancer Patients.

To determine the association between E-cadherin expression and hormone receptors status in patients with breast cancer. Cross-sectional study. Department of Medical Oncology, Jinnah Postgraduate Medical Centre, Karachi, Pakistan, from March to December 2019. Two hundred and forty-eight women, aged 18-65 years with histologically proven diagnosis of breast carcinoma, were included in the study. Immunohistochemistry (IHC) staining was performed for the evaluation of E-Cadherin expression and status of hormonal receptors [Estrogen receptor (ER), Progesterone receptor (PR) and HER-2-neu]. The positive homogeneous pattern of staining for the cellular membranes is considered normal. The non-homogeneous or the heterogeneous pattern of the cytoplasm and membrane, represented aberrant E-cadherin expression (loss of E-cadherin expression). SPSS version 23 was used to analyse data. The results of IHC showed that 82.7% of the tumours were E-cadherin positive, 65.7% were ER positive, 62.9% were PR positive and 29.4% were HER 2 positive. A normal pattern of immunostaining of E-cadherin for the membranes is seen in hormone receptor positive and young patients with low grade tumour. Aberrant E-cadherin expression (loss of E-Cadherin)was noticed inHER 2 negative, postmenopausal women with high grade large size tumour(p<0.05). The study showed that there is significant association between E-cadherin expression and hormone receptor status, HER2-neu, menopausal status, age of patients, grade of tumour and size of tumour. Key Words: E-cadherin, Hormone receptors, Breast carcinoma, ER, PR and HER 2.

Aberrant Expression of E-cadherin, N-cadherin, and P-cadherin in Clear Cell Renal Cell Carcinoma: Association With Adverse Clinicopathologic Factors and Poor Prognosis.

Aberrant expression of cadherins is known to be associated with tumor aggression. However, their role in clear cell renal cell carcinoma (CCRCC) is not well elucidated. This study investigated the expression of epithelial cadherin (E-cadherin), neural cadherin (N-cadherin), and placental cadherin (P-cadherin) in CCRCC, and assessed their prognostic significance and clinicopathologic association. We enrolled 254 patients with CCRCC who underwent radical or partial nephrectomy. E-cadherin, N-cadherin, and P-cadherin expression was evaluated by immunohistochemistry in a tissue microarray. Low E-cadherin expression was associated with larger tumor size, lymphovascular invasion, higher pT stage, lymph node and distant metastasis, and higher stage. High N-cadherin expression was significantly associated with larger tumor size, higher nuclear grade, and tumor necrosis. P-cadherin expression was found to be significantly associated with higher nuclear grade, distant metastasis, and higher stage. Univariate analysis revealed that aberrant expression of the 3 cadherins was significantly related to shorter overall survival (OS). Loss of E-cadherin, high P-cadherin expression, and higher stage were independent prognostic factors for OS. For recurrence-free survival, lymphovascular invasion, high P-cadherin expression, and higher stage were independent prognostic factors. Cadherin switch was significantly associated with aggressive clinicopathologic factors and poor outcomes. Aberrant expression of E-cadherin, N-cadherin, and P-cadherin was associated with adverse clinicopathologic factors and worse OS. Low E-cadherin and high P-cadherin expression were significantly associated with distant metastasis and independent prognostic factors. Therefore, cadherin expression may be used as a prognostic marker and therapeutic target, and cadherin switch plays an important role in CCRCC progression.

Integrated assessment of PD-L1 expression and molecular classification facilitates therapy selection and prognosis prediction in gastric cancer.

PurposeTargeting the PD-1/PD-L1 pathway has emerged as a novel therapy for cancer. To identify rational candidates for anti-PD-1/PD-L1 immunotherapy in gastric cancer (GC), the abundance of PD-L1 expression was evaluated on a kind of biomarker-based molecular classification for shaping prognosis and treatment planning.MethodsOne hundred and sixty-five GCs were classified into five subgroups using immunohistochemistry (IHC) and in situ hybridization (ISH) methods, based on a panel of seven markers (MLH1, PMS2, MSH2, MSH6, E-cadherin, P53, and Epstein-Barr virus mRNA). The expression of PD-L1 in GC tissues was analyzed immunohistochemically.ResultsThe five categories (Epstein–Barr virus positivity, microsatellite instability, aberrant E-cadherin, aberrant P53 expression, and normal P53 expression) correspond to the reported molecular subgroups for similar proportions and clinicopathologic characteristics. Survival analysis indicated that subgroups with aberrant E-cadherin expression independently predicted a worse prognosis in GC patients (HR=2.51, P=0.010). The clinical and prognostic profiles produced by this stratification in nonintestinal-type GC were distinguishable from those in intestinal-type. Although PD-L1 was not a significant prognostic factor, that more frequent presence of PD-L1-positive in microsatellite instability tumors than other subtypes (P<0.010) hinted at a prolonged clinical course. Moreover, the lowest level of PD-L1 but the highest of Her2 was observed in the group of aberrant P53, namely it was suggested that there was a negative correlation between PD-L1 and Her2 overexpression.ConclusionDifferent molecular subtypes in GC may have a tendency to react differently to anti-PD-L1/PD-1 immunotherapy or anti-Her2 therapy. A combination of PD-L1 expression and this cost-effective classification strategy would be helpful for predicting prognosis and promoting personalized therapy in clinical practice.

Impact of adjuvant treatment according to gastric cancer molecular subtypes.

e15513 Background: The four subtypes of gastric adenocarcinoma (GC) identified by the Cancer Genome Atlas project (TCGA) have different molecular signatures and prognosis. Several centers have tried to classify GC using immunohistochemistry (IHC) and in situ hybridization (ISH), examining the tumors according to Epstein–Barr virus (EBV) status, microsatellite instability (MSI), aberrant E-cadherin expression and TP53 status. Here we aim to verify the impact of adjuvant/perioperative chemotherapy (ACT/PCT) or adjuvant chemoradiation (CRT) according to the molecular subtypes profile. Methods: We retrospectively reviewed all GC patients who underwent gastrectomy and D2-lymphadenectomy at our institution from a prospective collected medical database. Deficient DNA mismatch repair (dMMR), E-cadherin and p53 were evaluated by IHC for determining the MSI, genomically stable (GS) and chromosomal instability (CIN, with and without p53 aberrant) subtypes, respectively. EBV positivity was detected by ISH. Results: Among the 178 stage II/III patients included, 67 had surgery alone, 47 received ACT/PCT and 64 CRT. 16 had aberrant E-cadherin (GS, 9%), 33 dMMR (MSI, 18.5%), 74 aberrant p53 expression (CIN p53-aberrant, 41.6%), 104 normal p53 expression (CIN p53-normal, 58.4%) and 18 EBV-positivity (EBV, 10.1%). Two or more altered status were present in GC of 16 patients. When analyzed independently, Kaplan-Meier survival analysis showed that EBV, dMMR, CIN p53-normal and GS subtypes did not obtain any benefit of ACT/PCT or CRT in disease free survival (DFS) (p = 0.71; p = 0.33; p = 0.41; p = 0.21, respectively). Meantime, those treatments impact positively in DFS for EBV-negative, proficient MMR and non-GS (p = 0.01; p = 0.007; p = 0.01). CIN subtype with p53 aberrant obtained most benefit for ACT/PCT or CRT (p &lt; 0.001). Conclusions: In accordance with other studies we achieved no benefit for adjuvant chemotherapy in patients with EBV, dMMR and GS GC subtypes. Patients with p53 aberrant expression had greater benefit for ACT/PCT or CRT. This simple method of classification can potentially help to tailor adjuvant treatment.

Abstract PD7-05: Correlation of CDH1 alterations and aberrant E-cadherin expression in lobular carcinomas

Abstract Background: E-cadherin (ECAD), encoded by the CDH1 gene, is expressed in the majority of invasive ductal carcinomas (IDC). In contrast, ECAD expression is lost in ˜90% of invasive lobular carcinomas (ILC) due to genomic alterations of CDH1. Immunohistochemical (IHC) staining for ECAD has thus increasingly been utilized to differentiate between ductal and lobular lesions. This study examines the correlation between CDH1 mutation profile, morphology and ECAD IHC status in invasive breast carcinomas (BC). Methods: The Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) platform is a hybrid capture next-generation sequencing assay to detect somatic alterations in exons and selected introns of 468 cancer-related genes. Invasive BC tested from 1/2014 – 5/2018 which yielded a CDH1 alteration were identified and only cases with ECAD IHC results were included. Histologic features were extracted from pathology reports. All available H&amp;E/ECAD slides were reviewed by two pathologists to confirm the histology and immunophenotype. Results: CDH1 alterations were identified in 455 out of 4103 BC analyzed (11%) and ECAD IHC were available for 209 (46%) tumors. Most of the tumors were reported as ILC (70%, 147/209). The majority (77%, 161/209) were ECAD-negative but 23% (48/209) showed some ECAD staining. Table 1 summarizes the histologic subtypes and IHC results. Upon review of H&amp;E/ECAD slides in cases with ECAD staining, the histologic subtype was re-classified in 52% (25/48) of cases (Table 2). For ECAD-negative BC, at least 61% (98/161) of CDH1 alterations were truncating mutations (frameshift deletion 47/161, nonsense 51/161) and 39% (63/161) were variants of unknown significance (VUS). In cases with ECAD staining, 48% (23/48) of CDH1 alterations were truncating mutations (frameshift deletion 12/48, nonsense 11/48) however 52% (25/48) were VUS. Conclusion: In this study, 88% (141/161) of cases with negative ECAD staining and CDH1 alteration were classified as ILC, confirming the known observation that CDH1 alteration and loss of ECAD expression is relatively specific for a lobular phenotype. The correlation is, however, imperfect. A subset of BC (23%; 48/209) with CDH1 alteration still exhibits ECAD expression. Morphologically this subset consists of ILC in 60% (29/48), IMC in 25% (12/48) and IDC in 15% (7/48). Our preliminary findings suggest that aberrant ECAD expression can occur in BC with morphologic features of ILC due to certain CDH1 alterations that most likely result in non-functional ECAD complex. BC with histologic features of ILC should therefore not be re-classified as IDC/IMC based solely on the status of ECAD expression. Given that ILC is clinically distinct from IDC, correct classification based on morphological and molecular features is prudent. Table 1:Histologic subtypes and ECAD IHC ILC (n = 147)IDC (n = 13)IMC (n = 49)ECAD staining Negative141020Strong, diffuse4135Heterogenous0020Reduced/weak204IMC: invasive mammary with mixed ductal/lobular features Table 2:Morphologic review of cases with ECAD stainingECAD stainingOriginal DX (n)Morphology Review DX ILCIDCIMCStrong, diffuseILC (4)301 IDC (13)670 IMC (5)500HeterogenousIMC (20)10010Reduced/weakILC (2)200 IMC (4)301 Citation Format: Grabenstetter A, Mohanty AS, DeLair DF, Tan LK, Ross DS. Correlation of CDH1 alterations and aberrant E-cadherin expression in lobular carcinomas [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD7-05.

High Frequency of ERBB2 Activating Mutations in Invasive Lobular Breast Carcinoma with Pleomorphic Features.

Background: Characterisation of molecular alterations of pleomorphic lobular carcinoma (PLC), an aggressive subtype of invasive lobular carcinoma (ILC), have not been yet completely accomplished. Methods: To investigate the molecular alterations of invasive lobular carcinoma with pleomorphic features, a total of 39 tumour samples (in situ and invasive lesions and lymph node metastases) from 27 patients with nuclear grade 3 invasive lobular carcinomas were subjected to morphological, immunohistochemical and massive parallel sequencing analyses. Results: Our observations indicated that invasive lobular carcinomas with pleomorphic features were morphologically and molecularly heterogeneous. All cases showed absence or aberrant expression of E-cadherin and abnormal expression of β-catenin and p120. CDH1 (89%), PIK3CA (33%) and ERRB2 (26%) were the most common mutated genes. ERBB2 mutations preferentially affected the tyrosine-kinase activity domain, being the most frequent the targetable mutation p.L755S (57%). We also observed higher frequency of mutations in ARID1B, KMT2C, MAP3K1, TP53 and ARID1A in PLC than previously reported in classic ILC. Alterations related to progression from in situ to invasive carcinoma and/or to lymph node metastases included TP53 mutation, amplification of PIK3CA and CCND1 and loss of ARID1A expression. Conclusions: The high frequency of ERBB2 mutations observed suggests that ERBB2 mutation testing should be considered in all invasive lobular carcinomas with nuclear grade 3.

Ezrin and E-cadherin expression profile in cervical cytology: a prognostic marker for tumor progression in cervical cancer

BackgroundCervical cancer (CC) is the fourth cause of mortality by neoplasia in women worldwide. The use of immunomarkers is an alternative tool to complement currently used algorithms for detection of cancer, and to improve selection of therapeutic schemes. Aberrant expression of Ezrin and E-cadherin play an important role in tumor invasion. In this study we analyzed Ezrin and E-cadherin expression in liquid-based cervical cytology samples, and evaluated their potential use as prognostic immunomarkers.MethodsImmunocytochemical staining of Ezrin and E-cadherin was performed in cervical samples of 125 patients. The cytological or histological diagnostic was performed by Papanicolaou staining or H&E staining, respectively. HPV genotyping was determined using INNO-LIPA Genotyping Extra kit and the HPV physical status by in situ hybridization. Ezrin expression in HaCaT, HeLa and SiHa cell lines was determined by immunocytochemistry, immunofluorescence and Western blot.ResultsHigh Ezrin expression was observed in cervical cancer samples (70%), samples with multiple infection by HR-HPV (43%), and samples with integrated viral genome (47%). High Ezrin expression was associated with degree of SIL, viral genotype and physical status. In contrast, low E-cadherin expression was found in cervical cancer samples (95%), samples with multiple infection by HR-HPV/LR-HPV (87%) and integrated viral genome (72%). Low E-cadherin expression was associated with degree of SIL and viral genotype. Interestingly, Ezrin nuclear staining was associated with degree of SIL and viral genotype. High Ezrin expression, high percent of nuclear Ezrin and low E-cadherin expression behaved as risk factors for progression to HSIL and cervical cancer.ConclusionsEzrin and E-cadherin expression profile in cervical cytology samples could be a potential prognostic marker, useful for identifying cervical lesions with a high-risk of progression to cervical cancer.

Aberrant expression of STYK1 and E-cadherin confer a poor prognosis for pancreatic cancer patients.

Previous studies showed that aberrant Serine/threonine/tyrosine kinase 1 (STYK1, also known as NOK) or/and E-cadherin were involved in the progression of some types of human cancers. However, whether they contributed to the development of pancreatic cancer was unknown. Here, we investigated the prognostic significance of aberrant STYK1 and E-cadherin in pancreatic cancer. Our results showed that STYK1 expression increased while E-cadherin decreased in pancreatic cancer tissues compared with normal pancreas tissues. STYK1 level was positively correlated with lymph node metastasis and clinical stage in pancreatic cancer patients. E-cadherin expression was inversely correlated with STYK1 expression in pancreatic cancer tissue samples. Patients with high STYK1 and low E-cadherin expression had the worst prognosis. In addition, STYK1 knockdown in pancreatic cancer cell lines inhibited cell proliferation, enhanced cell apoptosis, induced cell cycle arrest, and prohibited cell migration, while STYK1 over-expression showed the opposite effects. Silencing STYK1 also increased E-cadherin expression and inhibited epithelial-to-mesenchymal transition (EMT) and p-p38 expression in vitro. Over-expression had showed the opposite trends, and treatment with p38 inhibitor, SB203580, could reverse the trends. Thus, STYK1 repressed E-cadherin expression and promoted EMT, mediated by p38 MAPK signaling pathway, which was the possible mechanism for STYK1-mediated pancreatic cancer cell proliferation and migration. In summary, our results showed that STYK1 might be a prognostic marker for pancreatic cancer patients and might be a novel strategy for the treatment of pancreatic cancer.