Aggressive Clinicopathological Features Research Articles

EXTH-07. UNRAVELING THE ROLE OF SHH SIGNALING PATHWAY IN RETINOBLASTOMA

Abstract Retinoblastoma (RB) is a pediatric cancer affecting the retina, often requiring surgical removal of one or both eyes due to the limited effectiveness of current treatments. There is an urgent need for advanced therapeutic strategies capable of effectively eliminating tumors, thereby obviating the need for surgical removal of eyes in affected children. Achieving this goal requires a deeper understanding of the cellular and molecular mechanisms governing RB initiation and progression. Using a transgenic mouse model, we identified the crucial role of the Shh signaling pathway in Rb1 mutation-induced tumorigenesis, highlighting its potential as a novel therapeutic target for RB treatment. We have observed frequent overexpression of Shh signaling proteins (SHH, GLI1, and GLI2) in human RB, correlating with aggressive clinicopathological features. GLI2 overexpression is necessary for Rb1 deletion-induced RB tumor initiation in mouse retinal progenitor cells (RPCs). These mouse intraocular tumors accurately replicate human RB at both cellular and molecular levels. Additionally, Shh pathway activation extends to normal retinal cells adjacent to human RB tumors, suggesting the involvement of Shh signaling in RB-microenvironment interactions. Importantly, our studies have identified a novel small molecular inhibitor targeting the Shh pathway, effectively inhibiting RB growth in vitro and in vivo by targeting both tumor cells and the tumor microenvironment (TME). The proposed research aims to provide unprecedented insights into the role of SHH signaling pathway in RB initiation and progression and the supporting communication network between RB tumors and TME. These outcomes have the potential to treat RB effectively while improving the well-being of young individuals with RB and those at risk of RB.

High CTLA-4 gene expression is an independent good prognosis factor in breast cancer patients, especially in the HER2-enriched subtype

BackgroundBreast cancer (BC) is the most common cancer in women and the leading cause of cancer-related death worldwide. This heterogeneous disease has been historically considered a non-immunogenic type of cancer. However, recent advances in immunotherapy have increased the interest in knowing the role of the immune checkpoints (IC) and other immune regulation pathways in this neoplasia.MethodsIn this retrospective study, we evaluated the correlation of mRNA expression of CTLA-4, PDCD1 (PD1), CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3), JAK2, and FOXO1 with clinicopathological factors and BC patient’s outcome by real-time quantitative polymerase chain reaction (qPCR).ResultsOur results showed that immunoregulatory gene expression depends on BC immunophenotype being CTLA-4 and PDCD1 (PD1) overexpressed on triple-negative/basal-like (TN/BL) and luminal B/HER2-positive phenotypes, respectively, and CD276 (B7-H3), JAK2 and FOXO1 associated with both luminal A and luminal B/HER2-negative tumors. In addition, we found that these genes can also be related to aggressive and non-aggressive clinicopathological characteristics in BC. Finally, survival analysis showed that CTLA-4 expression levels emerge as a significant independent factor of good prognosis in BC patients, especially in the HER2-enriched subtype.ConclusionConsidering all these data, we can conclude that the expression of immunoregulatory genes depends on tumor phenotype and has potential clinical implications in BC patients.

The role of adjuvant endocrine treatment in ER+, PR−, HER2− early breast cancer: a retrospective study of real-world data

Purpose: Estrogen receptor-positive (ER+), progesterone receptor-negative (PR-) and human epidermal growth factor receptor 2-negative (HER2−) breast cancer (BC) often developed resistance to endocrine treatment (ET). We aimed to explore (1) the different clinicopathological features between ER+/PR+/HER2- and ER+/PR-/HER2- BC, and (2) whether ER+/PR-/HER2- early BC patients could benefit from adjuvant ET. Methods: All patients treated for ER+/HER2- early BC who underwent surgery between 2010 and 2021 from a BC database in China were retrospectively examined. The cases followed up for less than six months were excluded. Results: The records of ER+/PR+/HER2- (n = 10843) and ER+/PR-/HER2- BC (n = 1193) cases were reviewed, with median follow-up times of 35.8 and 47.0 months, respectively. Compared with ER+/PR+/HER2- cases, ER+/PR-/HER2- BC occurred more in postmenopausal women (73.1% vs. 52.9%, p = 0.000) and were more likely to be T > 2 cm (40.6% vs. 37.6%, p = 0.048) and Ki67 > 20%+ (48.1% vs. 36.9%, p = 0.000). However, ER+/PR-/HER2- cases had fewer nodal involvement (32.9% vs. 36.9%, p = 0.000). Approximately 82.2% (981/1193) of ER+/PR-/HER2- patients received ET, while approximately 17.8% (212/1193) did not. Compared to patients did not receive adjuvant ET, the ET group had similar disease-free survival (DFS) (HR = 1.33, 95% confidence interval (CI): 0.68–2.59, p = 0.444) and overall survival (OS) (HR = 1.17, 95%CI: 0.37–3.68, p = 0.799). 65.7% of recurrent ER+/PR-/HER2- patients experienced distant relapse (65.7% vs. 48.2% (for ER+/PR + cases), p = 0.011). By comparison, recurrent ER+/PR+/HER2- patients were more likely to experience only local relapse (31.6% vs. 14.9% (for ER+/PR- cases), p = 0.007). Conclusions: ER+/PR-/HER2- BC was a special subtype with aggressive clinicopathological features and more tend to have distant metastasis rather than nodal involvement or local relapse. ER+/PR-/HER2- early BC did not seem to benefit from adjuvant ET.

IL-33/ST2 Signaling and its Correlation with Macrophage Heterogeneity and Clinicopathologic Features in Human Intrahepatic Cholangiocarcinoma.

IL-33/ST2 signaling plays crucial roles in the development and progression of various human malignancies. However, its significance in intrahepatic cholangiocarcinoma (ICC) still remains unclear. This study aimed to investigate the expression of IL-33/ST2 signaling and its correlations with macrophage heterogeneity and ICC patients' clinicopathologic features. The expression of different phenotype macrophage markers and IL-33/ST2 signalingrelated markers was detected. The correlation between L-33/ST2 signaling and different phenotype macrophage markers as well as ICC patients' clinicopathologic data was evaluated. Massive heterogeneous cancer cells and PAS-positive cells were observed in tumor tissues. CD68-positive cells accumulated in tumor tissues and expression of both M1 phenotype markers and M2 phenotype macrophage markers was higher in tumor samples than para-carcinoma samples. However, M2 phenotype macrophages represented the dominant macrophage population in ICC tissues. Plasma levels of IL-33, ST2, and MIF were evidently enhanced in ICC patients compared to healthy controls. IL-33/ST2 signaling-related markers exhibited a massive increase in tumor samples than para-carcinoma samples. IL-33 and ST2 expression in ICC tissues was positively associated with M1 and M2 phenotype macrophages. Plasma levels of IL-33, ST2, and MIF were correlated with the diameter of tumor lesions, lymph node metastasis, TNM stage, and tumor differentiation degree. Multivariate analysis demonstrated IL-33 expression to exhibit a correlation with the diameter of tumor lesions, lymph node metastasis, and TNM stage. Additionally, there was a relationship observed between ST2, MIF expression, and diameter of tumor lesions plus TNM stage. IL-33/ST2 signaling exhibited a positive relationship with macrophage heterogeneity in ICC tissues, and upregulated levels of IL-33, ST2, and MIF were associated with aggressive clinicopathologic characteristics. These findings may provide promising diagnostic biomarkers and potential therapeutic strategies for ICC patients targeting IL-33/ST2 signaling.

USP4 promotes PTC progression by stabilizing LDHA and activating the MAPK and AKT signaling pathway.

Ubiquitin-specific protease 4 (USP4) has been identified as a promising oncogenic factor implicated in various human malignancies. However, the exact biological functions and underlying mechanisms of USP4 in the progression of papillary thyroid carcinoma (PTC) remain elusive. In this study, we observed a marked upregulation of USP4 expression in PTC tumor tissues. Elevated levels of USP4 were significantly correlated with aggressive clinicopathological features and poor prognosis. Functional assays for loss-of-function demonstrated that silencing USP4 hindered the proliferation of PTC cells. Furthermore, our investigation revealed a specific interaction between USP4 and lactate dehydrogenase A (LDHA), wherein USP4 played a crucial role in stabilizing LDHA protein levels via deubiquitination in PTC cells. Notably, this study demonstrated that USP4 promotes PTC proliferation by modulating the MAPK and AKT signaling pathways. In summary, our findings elucidate the critical involvement of the USP4/LDHA axis in driving PTC progression through the modulation of MAPK and AKT pathways, thereby identifying USP4 as a potential therapeutic target for the treatment of PTC.

TERT mutations and aggressive histopathologic characteristics of radioiodine-refractory papillary thyroid cancer.

Radioiodine (RI) ablation following thyroid-stimulating hormone suppression is an effective treatment for papillary thyroid cancer (PTC), typically leading to favorable outcomes. However, RI-refractory tumors exhibit aggressive behavior and poor prognoses. Recent studies highlight the role of genetic abnormalities in PTC signaling pathways, including the activation of telomerase reverse transcriptase (TERT), and the correlation of mutations with adverse outcomes. This study analyzed mutations in BRAF V600E and the TERT-promoter genes, comparing clinicopathological features between RI-refractory and RI-responsive PTCs. Among 82 RI-refractory patients, formalin-fixed, paraffin-embedded tissues from initial surgeries were available for 26. Another 89 without distant metastasis over 5 years formed a matched RI-responsive control group. Histopathologically, RI-refractory PTCs showed increased frequencies of small tumor clusters without fibrovascular cores, hobnail features, and a high height-to-width ratio of tumor cells. These tumors were more likely to exhibit necrosis, mitosis, lymph node metastasis, extrathyroidal extension, and involvement of resection margins. TERT-promoter mutations were statistically significantly associated with these aggressive clinicopathologic features. Immunohistochemically, decreased expression of sodium iodide symporter and thyroglobulin stimulating hormone receptor proteins was common in RI-refractory PTCs, along with lower levels of oncogenic proteins such as vascular endothelial cell growth factor, vascular endothelial cell growth factor receptor 2, and nuclear factor kappa-light-chain-enhancer of activated B cells. Total loss of PTEN expression was occasionally observed. In contrast, all cases tested positive for cytoplasmic β-catenin. RI-refractory PTCs are linked to TERT mutations and exhibit specific aggressive histopathologic features, particularly in tumor centers.

Elevated expression of Aurora-A/AURKA in breast cancer associates with younger age and aggressive features.

Aurora kinase A (AURKA) is reported to be overexpressed in breast cancer. In addition to its role in regulating cell cycle and mitosis, studies have reported AURKA involvements in oncogenic signaling in suppressing BRCA1 and BRCA2. We aimed to characterize AURKA protein and mRNA expression in a breast cancer cohort of the young, investigating its relation to clinico-pathologic features and survival, and exploring age-relatedAURKA-associated biological processes. Aurora kinase A immunohistochemical staining was performed on tissue microarrays of primary tumors from an in-house breast cancer cohort (n = 355) with information on clinico-pathologic data, molecular markers, and long and complete follow-up. A subset of the in-house cohort (n = 127) was studied by the NanoString Breast Cancer 360 expression panel for exploration of mRNA expression. METABRIC cohorts < 50 years at breast cancer diagnosis (n = 368) were investigated for differentially expressed genes and enriched gene sets in AURKA mRNA high tumors stratified by age. Differentially expressed genes and gene sets were investigated using network analyses and g:Profiler. High Aurora kinase A protein expression associated with aggressive clinico-pathologic features, a basal-like subtype, and high risk of recurrence score. These patterns were confirmed using mRNA data. High AURKA gene expression demonstrated independent prognostic value when adjusted for traditional clinico-pathologic features and molecular subtypes. Notably, high AURKA expression significantly associated with reduced disease-specific survival within patients below 50 years, also within the luminal A subtype. Tumors of high AURKA expression showed gene expression patterns reflecting increased DNA damage activation and higher BRCAness score. Our findings indicate higher AURKA expression in young breast cancer, and associations between high Aurora-A/AURKA and aggressive tumor features, including higher tumor cell proliferation, and shorter survival, in the young. Our findings point to AURKA as a marker for increased DNA damage and DNA repair deficiency and suggest AURKA as a biomarker of clinical relevance in young breast cancer.

Prognostic and Clinical Significance of the Proliferation Marker MCM7 in Breast Cancer.

Minichromosome maintenance complex component 7 (MCM7) plays an essential role in proliferation and DNA replication of cancer cells. However, the expression and prognostic significance of MCM7 in breast cancer (BC) remain to be defined. In this study, we aimed to evaluate the role of MCM7 in BC. We conducted immunohistochemistry staining of MCM7 in 1,156 operable early-stage BC samples and assessed MCM7 at the transcriptomic levels using publicly available cohorts (n = 13,430). MCM7 expression was evaluated and correlated with clinicopathological parameters including Ki67 labelling index and patient outcome. At the transcriptomic level, there was a significant association between high MCM7 mRNA levels and shorter patient survival in the whole cohort and in luminal BC class but not in the basal-like molecular subtype. High MCM7 protein expression was detected in 43% of patients and was significantly associated with parameters characteristic of aggressive tumour behaviour. MCM7 was independently associated with shorter survival, particularly in oestrogen receptor-positive (luminal) BC. MCM7 stratified luminal tumours with aggressive clinicopathological features into distinct prognostic groups. In endocrine therapy-treated BC patients, high MCM7 was associated with poor outcome, but such association disappeared with administration of adjuvant chemotherapy. Patients with high expression of Ki67 and MCM7 showed worst survival, while patients with double low expression BC showed the best outcome compared with single expression groups. The current findings indicate that MCM7 expression has a prognostic value in BC and can be used to identify luminal BC patients who can benefit from adjuvant chemotherapy.

Mesothelin expression correlates with elevated inhibitory immune activity in patients with colorectal cancer

The expression of the protein Mesothelin (MSLN) is highly variable in several malignancies, including colorectal cancer (CRC), and high levels are associated with aggressive clinicopathological features and worse patient survival. Colorectal cancer is both a common and deadly cancer; being the third most common in incidence and second most common cause of cancer-related death. While systemic therapy remains the primary therapeutic option for most patients with stage IV (metastatic; m) CRC, their disease eventually becomes treatment refractory, and 85% succumb within 5 years. Microsatellite-stable (MSS) CRC tumors, which constitute more than 90% of patients with mCRC, are generally refractory to immunotherapeutic interventions. In our current work, we characterize MSLN levels in CRC, specifically correlating expression with clinical outcomes in relevant CRC subtypes, and explore how MSLN expression impacts the status of immune activation and suppression in the peritumoral microenvironment. Higher MSLN expression is prevalent in CMS1 and CMS4 CRC subtypes and correlates with higher gene mutation rates across the patient cohorts. Further, MSLN-high patients exhibit increased M1/M2 macrophage infiltration, PD-L1 staining, immune-inhibitory gene expression, enrichment in inflammatory, TGF-β, IL6/JAK/STAT3, IL2/STAT5 signaling pathways, and mutation in KRAS and FBXW7. Together, these results suggest that MSLN protein is a potential target for antigen-specific therapy and supports investigation into its tumorigenic effects to identify possible therapeutic interventions for patients with high MSLN expressing MSS CRC.

Association of aberrant expression of CD39 with the outcome of patients with cholangiocarcinoma.

93 Background: Cholangiocarcinoma is defined as a kind of malignant tumor originating from bile ducts. Due to the lack of effective diagnostic and treatment methods, the prognosis of cholangiocarcinoma is dismal. Accumulating evidence indicates that CD39 could promote the progression of several types of cancer. However, the biological function and the underlying mechanism of CD39 in cholangiocarcinoma have not been well investigated. Methods: Quantitative reverse transcription PCR (RT-qPCR), western blot (WB), and immunohistochemistry staining was used to evaluate the expression level of CD39 in cholangiocarcinoma. Kaplan-Meier and Cox hazard ratio regression analyses were implicated to evaluate the prognostic significance of CD39. Cell counting kit-8 (CCK-8) was carried out to evaluate the proliferative capacity, while transwell assay was used to detect the migration and invasion ability. In addition, B-NDG mice were used for the in vivo assay. The potential protein binding with the CD39 was identified through co-immunoprecipitation. Results: We observed that CD39 was aberrantly expressed in the tumor tissue and cholangiocarcinoma cell lines. Our analysis indicated that the high expression level of CD39 correlated with aggressive clinicopathological characteristics, and CD39 was identified as an independent poor prognostic factor in cholangiocarcinoma. In addition, our in vitro and in vivo data indicated that the knockdown of CD39 could suppress the proliferation, migration, invasion ability, and the epithelial-mesenchymal transition (EMT) process of cholangiocarcinoma. Opposite results were observed when CD39 was overexpressed. Mechanistically, CD39 could bind with Annexin A2 (ANXA2), which influences the phosphorylation level of ANXA2 at the Tyr24 site, thereby promoting the activation of PI3K/AKT signaling, which resulted in the biological change in cholangiocarcinoma. Conclusions: Our data indicated that CD39 was overexpressed in the tumor tissue. Meanwhile, CD39 was identified as an independent prognostic factor of poor overall survival for patients withcholangiocarcinoma. In terms of the biological role of CD39, our data indicated that CD39 promoted the progression and metastasis of cholangiocarcinoma through binding with ANXA2, and through activating the PI3K/AKT signaling. In brief, CD39 is a potential prognostic factor and therapeutical target for cholangiocarcinoma.

Gene Expression Profiles of AHNAK2, DCSTAMP, FN1, and TERT Correlate With Mutational Status and Recurrence in Papillary Thyroid Carcinoma.

Papillary thyroid carcinoma (PTC), the most common malignancy of follicular cell derivation, is generally associated with good prognosis. Nevertheless, it is important to identify patients with aggressive PTCs and unfavorable outcome. Molecular markers such as BRAFV600E mutation and TERT promoter mutations have been proposed for risk stratification. While TERT promoter mutations have been frequently associated with aggressive PTCs, the association of BRAFV600E mutation with increased recurrence and mortality is less clear and has been controversially discussed. The aim of the present study was to analyze whether differentially expressed genes can predict BRAFV600E mutations as well as TERT promoter mutations in PTCs. RNA sequencing identified a large number of differentially expressed genes between BRAFV600E and BRAFwildtype PTCs. Of those, AHNAK2, DCSTAMP, and FN1 could be confirmed in a larger cohort (n = 91) to be significantly upregulated in BRAFV600E mutant PTCs using quantitative RT-PCR. Moreover, individual PTC expression values of DCSTAMP and FN1 were able to predict the BRAFV600E mutation status with high sensitivity and specificity. The expression of TERT was detected in all PTCs harboring TERT promoter mutations and in 19% of PTCs without TERT promoter mutations. Tumors with both TERT expression and TERT promoter mutations were particularly associated with aggressive clinicopathological features and a shorter recurrence-free survival. Altogether, it will be interesting to explore the biological function of AHNAK2, DCSTAMP, and FN1 in PTC in more detail. The analysis of their expression patterns could allow the characterization of PTC subtypes and thus enabling a more individualized surgical and medical treatment.

Stanniocalcin-2 expression in glioblastoma - A novel prognostic biomarker: An observational study.

The objective of this study was to assess the prognostic relevance of Stanniocalcin-2 (STC2) expression, as determined via immunohistochemistry in tumor tissue, in a cohort of 83 patients diagnosed with glioblastoma who underwent maximal safe surgical resection followed by radiotherapy concurrent with adjuvant temozolomide. STC2 expression levels were categorized using a 3-tiered semiquantitative system: negative expression (level 0-), low expression (level 1+), and high expression (levels 2 + and 3+). Patients were categorized into 2 distinct groups according to their STC2 expression levels: negative STC2 (-/+) and positive STC2 (++/+++). The primary outcome measure was the relationship between STC2 expression and progression-free survival (PFS), with overall survival (OS) serving as the secondary endpoint. Kaplan-Meier survival analysis confirmed that patients exhibiting high STC2 expression had significantly shorter OS (8 vs 20 months, P < .001) and PFS (6 vs 18 months, P < .001) than those with low or negative STC2 expression. Multivariate analysis revealed that STC2 expression was an independent prognostic factor for both OS (hazard ratio: 0.4; 95% confidence interval: 0.2-0.8; P < .05) and PFS (hazard ratio: 0.3; 95% confidence interval: 0.2-0.4; P < .05) in patients with glioblastoma. Furthermore, elevated STC2 expression in GBM was correlated with several established aggressive clinicopathological characteristics, including advanced age (≥65 years), low ECOG PS (≥2), and isocitrate dehydrogenase mutation negativity. These findings underscore that heightened STC2 expression within the tumor tissue of GBM patients functions as an adverse prognostic marker, correlating with an elevated risk of progression and reduced OS. Therapeutic interventions targeting the AKT-mTOR, ERK1-2, and mitogen-activated protein kinase pathways as well as immune checkpoint inhibitors and vascular endothelial growth factor blockade, as well as potential forthcoming antibody-drug conjugates targeting the STC2 molecule, have the potential to broaden the scope of combined treatment strategies.

Clinical impact of EGFR and KRAS mutations in surgically treated unifocal and multifocal lung adenocarcinoma.

Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) are the two most common oncogenic drivers in lung adenocarcinoma, and their roles still need further exploration. Here we aimed to compare the clinical impact of EGFR and KRAS mutations on disease progression in resected unifocal and multifocal lung adenocarcinoma. Clinicopathologic and genomic data were collected for patients who underwent resection of lung adenocarcinoma from 2008 to 2022 at Stanford University Hospital. Retrospective review was performed in 241 patients whose tumors harbored EGFR (n=150, 62.2%) or KRAS (n=91, 37.8%) mutations. Clinical outcome was analyzed with special attention to the natural history of secondary nodules in multifocal cases wherein the dominant tumor had been resected. We confirm that compared with EGFR mutations, patients with KRAS mutations had more smokers, larger tumor size, higher TNM stage, higher positron emission tomography (PET)/computed tomography (CT) standard uptake value max, higher tumor mutation burden, and worse disease-free survival and overall survival on univariate analysis. For patients with multifocal pulmonary nodules, the median follow-up of unresected secondary nodules was 55 months. Secondary nodule progression-free survival (SNPFS) was significantly worse for patients with KRAS mutations than those with EGFR mutations (mean 40.3±6.6 vs. 67.7±6.5 months, P=0.004). Univariate analysis showed tumor size, tumor morphology, pathologic TNM stage, and KRAS mutations were significantly associated with SNPFS, while multivariate analysis showed only KRAS mutations were independently associated with worse SNPFS (hazard ratio 1.752, 95% confidence interval: 1.017-3.018, P=0.043). Resected lung adenocarcinomas with KRAS mutations have more aggressive clinicopathological features and confer worse prognosis than those with EGFR mutations. Secondary pulmonary nodules in multifocal cases with dominant KRAS-mutant tumors have more rapid progression of the secondary nodules.

Fusobacterium Detected in Barrett’s Esophagus and Esophageal Adenocarcinoma Tissues

We examined Fusobacterium nucreatum (F. nucleatum) and whole Fusobacterium species (Pan-fusobacterium) in non-neoplastic Barrett’s esophagus (BE) from patients without cancer (n = 67; N group), with esophageal adenocarcinoma (EAC) (n = 27) and EAC tissue (n = 22). F. nucleatum was only detectable in 22.7% of EAC tissue. Pan-fusobacterium was enriched in EAC tissue and associated with aggressive clinicopathological features. Amount of Pan-fusobacterium in non-neoplastic BE was correlated with presence of hital hernia and telomere shortening. The result suggested potential association of Fusobacterium species in EAC and BE, featuring clinicpathological and molecular features.

ETMR-25. UNRAVELING THE ROLE OF SHH SIGNALING PATHWAY IN RETINOBLASTOMA

Abstract BACKGROUND Retinoblastoma (RB) is a pediatric cancer affecting the retina, often requiring surgical removal of one or both eyes due to the limited effectiveness of current treatments. There is an urgent need for advanced therapeutic strategies capable of effectively eliminating tumors, thereby obviating the need for surgical removal of eyes in affected children. Achieving this goal requires a deeper understanding of the cellular and molecular mechanisms governing RB initiation and progression. METHODS Using a transgenic mouse model, we identified the crucial role of the Shh signaling pathway in Rb1 mutation-induced tumorigenesis, highlighting its potential as a novel therapeutic target for RB treatment. RESULTS We have observed frequent overexpression of Shh signaling proteins (SHH, GLI1, and GLI2) in human RB, correlating with aggressive clinicopathological features. GLI2 overexpression is necessary for Rb1 deletion-induced RB tumor initiation in mouse retinal progenitor cells (RPCs). These mouse intraocular tumors accurately replicate human RB at both cellular and molecular levels. Additionally, Shh pathway activation extends to normal retinal cells adjacent to human RB tumors, suggesting the involvement of Shh signaling in RB-microenvironment interactions. Importantly, our studies have identified a novel small molecular inhibitor targeting the Shh pathway, effectively inhibiting RB growth in vitro and in vivo by targeting both tumor cells and the tumor microenvironment (TME). CONCLUSIONS The proposed research aims to provide unprecedented insights into the role of SHH signaling pathway in RB initiation and progression and the supporting communication network between RB tumors and TME. These outcomes have the potential to treat RB effectively while improving the well-being of young individuals with RB and those at risk of RB.

STEM-06. THE ROLE OF SHH SIGNALING PATHWAY IN RETINOBLASTOMA INITIATION AND PROGRESSION

Abstract BACKGROUND Retinoblastoma is a rare childhood cancer of the retina that shows the biallelic loss of RB1 in nearly 95% of cases. It was reported that SHH pathway proteins, such as SHH, GLI1, and GLI2, are aberrantly high in human retinoblastoma, and high GLI2 expression is associated with aggressive clinicopathological features. Thus, we assessed whether activation of SHH pathway by overexpression of Gli2 or SMO induces the initiation of retinoblastoma. METHODS We generated a Cre-activated, Doxycycline (Dox)-controlled transgenic model to induce SMO or Gli2 expression in developing retina. In this transgenic mouse, expression of Smo or Gli2A is under the control of TRE, which permits temporal and spatial expression of Smo or Gli2A by administering/withdrawing doxycycline (DOX). RESULTS We fed the triple transgenic mice (Chx10-Cre/R26-LSL-rtTA/tetO-Smo or Chx10-Cre/R26-LSL-rtTA/tetO-Gli2A starting from E0 or P5. Our studies demonstrated that control littermates (Cre-) did not show any abnormalities, while mice with triple transgenes developed tumors in the bilateral eyes with 100% morbidity. The animals showed symptoms of leukocoria at P0-P3 or P25-p30 if the oncogenes were initiated at E0 or P5 respectively. The tumor cells were highly proliferative and expressed retina progenitor cell specific marker of Sox2, showing aberrant expression of pRB, CDK4/6, and CCND1. CONCLUSIONS Our results demonstrate that overexpressing Smo or Gli2 in Chx10+ cells induce rapid tumor formation in mouse retina. In future study, we plan to (i) investigate the impact of Shh pathway activation in RPCs on RB tumorigenesis within the context of Rb1 loss; (ii) define the molecular mechanisms underlying tumor initiation and progression; and (iii) evaluate whether targeting SHH pathway prevents or delays tumor initiation and progression using our Gli2-driven mouse model and patient-derived xenografts.

Prognostic significance and value of further classification of lymphovascular invasion in invasive breast cancer: a retrospective observational study

PurposeTo investigate the prognostic significance of lymphovascular invasion in invasive breast cancer and the value of using specific vascular endothelial markers to further classify lymphovascular invasion.MethodsWe collected 2124 patients with invasive breast cancer who were hospitalized at the First Hospital of Dalian Medical University from 2012 to 2020. Statistical methods were used to investigate the relationship between lymphovascular invasion and clinicopathological characteristics of breast cancer, and the correlation between lymphovascular invasion on overall survival (OS) and disease-free survival (DFS) of various categories of breast cancers. Immunohistochemical staining of breast cancer samples containing lymphovascular invasion using specific vascular endothelial markers D2-40 and CD34 was used to classify lymphovascular invasion and to investigate the relationship between lymphovascular invasion and breast cancer progression.ResultsThere was a high correlation between lymphovascular invasion and T stage, N stage and nerve invasion. Survival analyses showed that patients with lymphovascular invasion, especially luminal B, triple-negative, and Her-2 overexpression breast cancer patients, had poorer OS and DFS prognosis, and that lymphovascular invasion was an independent prognostic factor affecting OS and DFS in breast cancer. The immunohistochemical staining results showed that positive D2-40 staining of lymphovascular invasion was linked to the N stage and localized recurrence of breast cancer.ConclusionLymphovascular invasion is associated with aggressive clinicopathological features and is an independent poor prognostic factor in invasive breast cancer. Breast cancer localized recurrence rate and lymph node metastases are influenced by lymphatic vessel invasion. Immunohistochemical techniques should be added to the routine diagnosis of lymphovascular invasion.

Exploring the Link between BMI and Aggressive Histopathological Subtypes in Differentiated Thyroid Carcinoma-Insights from a Multicentre Retrospective Study.

Obesity's role in thyroid cancer development is still debated, as well as its association with aggressive histopathological subtypes (AHSs). To clarify the link between Body Mass Index (BMI) and AHS of differentiated thyroid carcinoma (DTC), we evaluated patients who underwent thyroidectomy for DTC from 2020 to 2022 at four European referral centres for endocrine surgery. Based on BMI, patients were classified as normal-underweight, overweight, or obese. AHSs were defined according to 2022 WHO guidelines. Among 3868 patients included, 34.5% were overweight and 19.6% obese. Histological diagnoses were: 93.6% papillary (PTC), 4.8% follicular (FTC), and 1.6% Hürthle cell (HCC) thyroid carcinoma. Obese and overweight patients with PTC had a higher rate of AHSs (p = 0.03), bilateral, multifocal tumours (p = 0.014, 0.049), and larger nodal metastases (p = 0.017). In a multivariate analysis, BMI was an independent predictor of AHS of PTC, irrespective of gender (p = 0.028). In younger patients (<55 years old) with PTC > 1 cm, BMI predicted a higher ATA risk class (p = 0.036). Overweight and obese patients with FTC had larger tumours (p = 0.036). No difference was found in terms of AHS of FTC and HCC based on BMI category. Overweight and obese patients with PTC appear to be at an increased risk for AHS and aggressive clinico-pathological characteristics.

Low Mitotic Activity in Papillary Thyroid Cancer: A Marker for Aggressive Features and Recurrence.

The significance of low mitotic activity in papillary thyroid cancer (PTC) is largely undefined. We aimed to determine the behavioral landscape of PTC with low mitotic activity compared to that of no- and high-mitotic activity. A single-institution consecutive series of PTC patients from 2018-2022 was reviewed. Mitotic activity was defined as no mitoses, low (1-2 mitoses/2 mm2) or high (≥3 mitoses/2 mm2) per the World Health Organization. The 2015 American Thyroid Association risk stratification was applied to the cohort, and clinicopathologic features were compared between groups. For patients with ≥6 months follow-up, Cox regression analyses for recurrence were performed. 640 PTCs were included - 515 (80.5%) no mitotic activity, 110 (17.2%) low mitotic activity, and 15 (2.3%) high mitotic activity. Overall, low mitotic activity exhibited rates of clinicopathologic features including vascular invasion, gross extrathyroidal extension, and lymph node metastases in between those of no- and high-mitotic activity. PTCs with low mitotic activity had higher rates of intermediate- and high-risk ATA risk stratification compared to those with no mitotic activity (p < 0.001). Low mitotic activity PTCs also had higher recurrence rates (15.5% vs. 4.5%, p < 0.001). Low mitotic activity was associated with recurrence, independent of the ATA risk stratification (HR 2.96; 95% CI 1.28-6.87, p = 0.01). Low mitotic activity is relatively common in PTC and its behavior lies within a spectrum between no- and high-mitotic activity. Given its association with aggressive clinicopathologic features and recurrence, low mitotic activity should be considered when risk stratifying PTC patients for recurrence.

Survival impact of variant histology in patients with upper tract urothelial carcinoma after radical nephroureterectomy

ObjectiveTo investigate the prognostic impact of variant histology (VH) on survival outcomes in upper tract urothelial carcinoma (UTUC) patients after radical nephroureterectomy (RNU). Materials and methodsData from 635 UTUC patients who underwent RNU at our institution from May 2003 to June 2019 were retrospectively acquired and analyzed. After propensity score matching (PSM), we investigated the impact of VH on overall survival (OS) and cancer-specific survival (CSS) by using cumulative incidence plots with the log-rank test, Cox regression models, and competing risk regression models. ResultsOverall, 121 (19.1%) patients were diagnosed with VH, including 68 (10.7%) with squamous cell differentiation (SCD) and 28 (4.4%) with adenocarcinoma differentiation (AD). After PSM, the presence of VH was significantly associated with worse OS (HR 1.70, 95% CI 1.25–2.32) and CSS (HR 1.64, 95% CI 1.17–2.31) only in locally advanced UTUC patients (pT>2). In the subgroup analysis, SCD revealed inferior outcomes (OS: HR 1.81, 95% CI 1.28–2.57; CSS: HR 1.73, 95% CI 1.18–2.54) compared with pure urothelial carcinoma (pUC), whereas AD conferred comparable outcomes. In addition, compared with pUC patients, SCD patients with extensive squamous components had significantly decreased OS (HR 4.17, 95% CI 1.84–9.44) and CSS (HR 1.10, 95% CI 0.61–1.99), whereas those with regional squamous components had similar survival outcomes. ConclusionFor UTUC patients after RNU, the presence of VH is associated with aggressive clinicopathological features and inferior survival outcomes. However, the survival outcomes of localized UTUC patients (pT≤2) with VH, and patients with the AD or regional SCD subtype are comparable to those of patients with pUC.