Percentage Of Positive Tumor Cells Research Articles

PAX5 and CD70 are expressed in thymic carcinoma but not in atypical thymoma (WHO type B3 thymoma): an immunohistochemical analysis of 60 cases

AimsThymic carcinoma and atypical thymoma (WHO type B3 thymoma) are unusual tumours the separation of which may be challenging in small biopsies. Both tumours consist of epithelioid tumour cells that...

Potential imaging targets in primary head and neck squamous cell carcinoma and lymph node metastases

PurposeTo investigate glycoprotein nonmetastatic melanoma protein B (GPNMB) and vascular endothelial growth factor (VEGF) as potential fluorescent imaging markers by comparing their protein expression to epidermal growth factor receptor (EGFR). Materials and methodsThirty-eight paired samples of untreated head and neck squamous cell carcinoma (HNSCC) primary tumours (PT) and corresponding synchronous lymph node metastases (LNM) were selected. After immunohistochemical staining, expression was assessed and compared by the percentage of positive tumour cells. Data were analysed using the Mann-Whitney test, effect sizes (ESr) and Spearman's correlation coefficient (r). ResultsGPNMB expression was observed in 100 % of PT, and median 80 % (range 5–100 %) of tumour cells, VEGF in 92 % and 60 % (0–100 %), EGFR in 87 % and 60 % (0–100 %) respectively. In corresponding LNM, GPNMB expression was observed in 100 % of LNM and median 90 % (20–100 %) of tumour cells, VEGF in 87 % and 65 % (0–100 %), and EGFR in 84 % and 35 % (0–100 %). A positive correlation was found between expression in PT and LNM for GPNMB (r = 0.548) and EGFR (r = 0.618) (p < 0.001), but not for VEGF (r = −0.020; p = 0.905). GPNMB expression was present in a higher percentage of tumour cells compared to EGFR in PT (p = 0.015, ESr = −0.320) and in LNM (p < 0.001, ESr = −0.478), while VEGF was not (p = 1.00, ESr = −0.109 and − 0.152, respectively). ConclusionGPNMB expression is higher than EGFR in untreated HNSCC PT and corresponding LNM, while VEGF expression is comparable to EGFR. GPNMB is a promising target for fluorescent imaging in HNSCC.

Abstract 3629: Prevalence of claudin18.2 expression in gastric/gastroesophageal junction adenocarcinoma among patients in TranStar101 and TranStar102 clinical trials

Abstract Background: Claudin18.2 (CLDN18.2) is a tight junction protein highly specific to gastric mucosa, and a validated target for gastric cancer (GC) treatment. Immune checkpoint therapy targeting PD-1 combined with chemotherapy has been approved as the first line therapy of GC. Understanding the expression profiles of CLDN18.2 and PD-L1 could guide the development of combination therapies to maximize the benefits of these two agents. This study investigated the prevalence of CLDN18.2 expression in gastric/gastroesophageal junction adenocarcinoma (G/GEJC) screening samples from studies Transtar101 (NCT04396821 in US) and TranStar102 (NCT04495296 in China), and its correlation with various clinical characteristics and PD-L1 expression. Methods: CLDN18.2 expression in formalin-fixed, paraffin-embedded (FFPE) G/GEJC tissue samples was prospectively detected by an immunohistochemistry-based LDT using an in-house anti-CLDN18.2 antibody (Clone14G11) on the Leica Bond III stainer. CLDN18.2 expression was assessed by scoring the staining intensity (0, 1+, 2+, 3+) and the percentage of positive tumor cells. Positive CLDN18.2 expression is defined as the cutoff at ≥10% of tumor cell with ≥1+ staining intensity for this evaluation. PD-L1 expression was assessed by combined positive score (CPS) using Agilent’s PD-L1 IHC 28-8 pharmDx. Both assays were conducted in CAP/CLIA certified LabCorp central lab. Results: 547 G/GEJC patient samples had CLDN18.2 results as part of the screening procedures for the clinical trials. Of these patients (454 GC/93 GEJC), 439 (80%) were Asian, 29 (5%) were Caucasian, 2 (0.4%) were other ethnic group, and 77 (14%) were not recorded; 434 (79%) were primary tumors and 113 (21%) were metastasis; 201 (37%) were core needle biopsies (CNB), 108 (20%) were surgical resections (SR) and 238 (44%) had no information. 311 (57%) samples had positive CLDN18.2 expressions (≥10%/≥1+). No significant difference in CLDN18.2 positive rates were found between TranStar101 and TranStar102 studies (p=0.801), Asian and Caucasian (p=0.612), GC and GEJC (p=0.373), primary and metastatic specimens (p=0.055) or CNBs and SRs (p=0.715). Out of 83 TranStar102 specimens that had both CLDN18.2 and PD-L1 results, 15 (18%) had PD-L1 CPS≥5, 59 (71%) had positive CLDN18.2, and 10 (15%) had both positive CLDN18.2 and PD-L1 CPS≥5. No correlation (p=0.393) was observed between PD-L1 scores (CPS&amp;lt;5 or CPS≥5) and CLDN18.2 expression (≥10%/≥1+ or &amp;lt;10%/≥1+). Conclusions: Data suggested CLDN18.2 expression levels were independent of PD-L1 status, and support the use of Transcenta 14G11 antibody for CLDN18.2 detection regardless of sample collection methods, location, and patient demographics. An anti-CLDN18.2 companion diagnostic device based on 14G11 is being developed (CLDN18.2 IHC 14G11 pharmDx, Agilent Technologies, Inc.). Citation Format: Li Shen, Carol Mao, Alan Lin, Ying Gu, Jenny Milata, Lijuan Zhang, Chuan Qi, Jenny Yao, Steven Yu, Changjun Yue, Lin Shen, Yelena Janjigian, Xueming Qian, Wen-I Chang, Caroline Germa. Prevalence of claudin18.2 expression in gastric/gastroesophageal junction adenocarcinoma among patients in TranStar101 and TranStar102 clinical trials [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 3629.

Abstract 2866: NAPRTsilencing in rhabdomyosarcoma confers therapeutic vulnerabilities to NAD+depletion

Abstract Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma among children, and new treatments are needed to improve survival. Cells primarily synthesize nicotinamide adenine dinucleotide (NAD) through the Preiss-Handler and Salvage pathways driven by nicotinic acid phosphoribosyltransferase (NAPRT) and nicotinamide phosphoribosyltransferase (NAMPT), respectively. NAMPT inhibitors (NAMPTi) have been tested in clinical trials, but their efficacy has been limited by (a) lack of appropriate biomarkers for patient selection, and (b) significant dose-limiting toxicities (DLTs), including myelosuppression and retinal toxicity, although the latter has been described only in preclinical studies. Previous work from our group indicates that loss of NAPRT expression by tumor-specific promoter CpG island methylation may provide a novel biomarker for sensitivity to NAMPTi in a variety of tumors. Here, we sought to determine if RMS harbors NAPRT silencing that confers a synthetic lethal interaction with NAMPTi. We probed methylation data within the Cancer Dependency Map (DepMap) and found a high frequency of NAPRT gene promoter hypermethylation in RMS models. Predicted NAPRT silencing was confirmed at the protein level by western blot in a panel of RMS cell lines. In vitro growth delay assays demonstrated that NAPRT-silenced cells are exquisitely sensitive to NAMPTi even in the presence of nicotinic acid (NA) supplementation, while NAPRT-expressing cells were completely rescued. This sensitivity to NAMPTi was further mirrored by changes in NAD levels. In vivo, NAMPTi induced significant tumor regression in a NAPRT-silenced RMS xenograft model. To further establish the translational relevance, NAPRT protein expression in a TMA of 51 human RMS tumors was assessed via IHC staining using a newly validated NAPRT monoclonal antibody (4A5D7). Based on a semi-quantitative scoring system accounting for the percentage of positive tumor cells and staining intensity, 28% of RMS samples demonstrated loss of NAPRT protein expression. Overall, these data suggest that NAPRT loss may serve as a therapeutic target in RMS by inducing a synthetic lethal interaction with NAD+ depleting agents. Future studies in patient-derived xenograft (PDX) models will determine the optimal cut-off of NAPRT expression that portends NAMPTi sensitivity, paving the way for the development of biomarker-driven clinical trials in RMS. Ongoing studies will also evaluate the efficacy of combining NAMPTi with existing cytotoxic and DNA damaging chemotherapy in these difficult-to-treat tumors. Citation Format: Sophia J. Zhao, Katelyn J. Noronha, Prateek Bhardwaj, Karlie N. Lucas, Ranjini K. Sundaram, Collin D. Heer, Raffaella Morotti, Josh Spurrier, Mitch Raponi, Ranjit S. Bindra, Juan C. Vasquez. NAPRTsilencing in rhabdomyosarcoma confers therapeutic vulnerabilities to NAD+depletion [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 2866.

HER-3 surface expression increases in advanced colorectal cancer representing a potential therapeutic target

HER-3 (also known as ErbB-3) is a human epidermal growth factor receptor tyrosine kinases family member, and its expression in CRC (colorectal cancer) tissues was previously associated with poor prognosis. In this study, HER-3 expression was analyzed by immunohistochemistry in two cohorts of early and advanced metastatic CRC patients. The first cohort included 180 patients diagnosed with CRC in absence of lymph nodes or distant metastases (Stage I and Stage II), while the second was obtained from 53 advanced metastatic CRC patients who developed synchronous (SM) and metachronous (MM) liver metastases. In the first early-stage CRC cohort, 86 out of 180 (47.8%) tumors showed membranous expression of HER-3, with a mean percentage of positive tumor cells of 25.7%; conversely, in advanced metastatic CRC primary tumors, HER-3 was detected in all specimens, with a mean percentage of positive tumor cells of 76.1%. Kaplan–Meier curves showed that in the advanced metastatic CRC group, patients with HER-3high tumors had a significantly lower Cancer-Specific Survival (CSS) rate compared to patients with HER-3low tumors (p = 0.021). Importantly, this worse CSS rate was observed only in the MM subgroup of patients with HER-3high tumors (p = 0.002). Multivariate analysis confirmed that high HER-3 expression represents a significant and strong risk factor for death in patients developing MM liver metastases (Hazard Ratio = 64.9; 95% Confidence Interval, 4.7–886.6; p = 0.002). In addition, using a specific anti-HER-3 antibody-drug conjugate, named EV20/MMAF, we showed that HER-3 + CRC cells can be efficiently targeted in vitro and in vivo. Overall, this study confirms that surface HER-3 is highly expressed in CRC and reveals that HER-3 expression increases in metastatic CRC patients compared to early stage. Importantly, the results suggest that HER-3 has a prognostic and therapeutic value in patients developing MM liver metastases.

Histopathological and Immunohistochemical Prognostic Factors in High-Grade Non-Endometrioid Carcinomas of the Endometrium (HG-NECs): Is It Possible to Identify Subgroups at Increased Risk?

In the present study, potential histopathological and immunohistochemical prognostic markers were investigated. Consecutive cases of high-grade non-endometrioid carcinoma (HG-NEC) of the endometrium were considered. Each surgical specimen was routinely processed; the most significant block was selected for immunohistochemistry and tested for ER, PR, ki67, p53, E-cadherin, β-catenin, Bcl-2 and cyclin D1. For each immunomarker, the percentage of positive tumor cells was evaluated (%) and dichotomized as low and high according to the distribution in the study population. Follow-up was collected for disease-free survival (DFS) and overall survival (OS). Thirty-three cases were eligible: 19 resulted in FIGO I-II; 14 resulted in FIGO III-IV. Twelve patients suffered a recurrent disease (mean follow-up 24.6 months); 8 patients died of the disease (mean follow-up 26.6 months). Women with recurrent disease demonstrated a significantly higher Bcl2% (35.84 ± 30.96% vs. 8.09 ± 11.56%; p = 0.0032) while DOD patients had higher ki67% (75 ± 13.09% vs. 58.6 ± 19.97%; p = 0.033) and Bcl2% of border significance (34.37 ± 34.99% vs. 13 ± 17.97%; p = 0.078). As expected, FIGO III-IV had a worse DFS (HR = 3.34; 95% CI: 1.1-10.99; p = 0.034) and OS (HR = 5.19; 95% CI: 1.27-21.14; p = 0.0217). Bcl-2-high patients (Bcl2 > 10%) demonstrated a significantly worse DFS (HR = 9.11; 95% CI: 2.6-32.4; p = 0.0006) and OS (HR = 7.63; 95% CI: 1.7-34; p = 0.0084); moreover, PR low patients (PR ≤ 10%) had significantly worse DFS (HR = 3.74; 95% CI: 1.2-11.9; p = 0.02). HG-NEC represents a heterogeneous group of endometrial aggressive neoplasms with a worrisome prognosis, often at an advanced stage at presentation. Bcl-2 and PR may represent promising markers to identify a subgroup of patients having an even worse prognosis requiring a careful and close follow-up.

Claudin-4 Expression in the Distinction of Mammary and Extramammary Paget Disease From Morphologic Mimics: Diagnostic Utility and Pitfalls.

Claudin-4 Expression in the Distinction of Mammary and Extramammary Paget Disease From Morphologic Mimics: Diagnostic Utility and Pitfalls.

High expression of Talin-1 is associated with tumor progression and recurrence in melanoma skin cancer patients

BackgroundTalin-1 as a component of multi-protein adhesion complexes plays a role in tumor formation and migration in various malignancies. This study investigated Talin-1 in protein levels as a potential prognosis biomarker in skin tumors.MethodsTalin-1 was evaluated in 106 skin cancer (33 melanomas and 73 non-melanomas skin cancer (NMSC)) and 11 normal skin formalin-fixed paraffin-embedded (FFPE) tissue samples using immunohistochemical technique on tissue microarrays (TMAs). The association between the expression of Talin-1 and clinicopathological parameters, as well as survival outcomes, were assessed.ResultsOur findings from data minings through bioinformatics tools indicated dysregulation of Talin-1 in mRNA levels for skin cancer samples. In addition, there was a statistically significant difference in Talin-1 expression in terms of intensity of staining, percentage of positive tumor cells, and H-score in melanoma tissues compared to NMSC (P = 0.001, P < 0.001, and P < 0.001, respectively). Moreover, high cytoplasmic expression of Talin-1 was found to be associated with significantly advanced stages (P = 0.024), lymphovascular invasion (P = 0.023), and recurrence (P = 0.006) in melanoma cancer tissues. Our results on NMSC showed a statistically significant association between high intensity of staining and the poor differentiation (P = 0.044). No significant associations were observed between Talin-1 expression levels and survival outcomes of melanoma and NMSC patients.ConclusionOur observations showed that higher expression of Talin1 in protein level may be significantly associated with more aggressive tumor behavior and advanced disease in patients with skin cancer. However, further studies are required to find the mechanism of action of Talin-1 in skin cancers.

TOMM20 as a Potential Prognostic Biomarker in Chordoma: Results From a High-Volume, Single-Center Study.

As few large studies identify correlative biomarkers in chordoma, our objective was to use our large, single-center chordoma tumor bank to identify novel signaling pathways. Clinical and pathologic data for 73 patients with chordoma were retrospectively collected. Tumor microarrays were built from 61 archived chordoma specimens; immunohistochemistry for TOMM20, TIGAR, and MCT1 were performed; and semiquantitative analysis of staining intensity and percentage of positive tumor cells was performed. Average composite scores of MCT1, TIGAR, and TOMM20 expression were compared by disease status and anatomic location. Higher expression of TOMM20 was seen in recurrent and metastatic chordomas compared with primary lesions. Comparing composite scores of primary lesions in patients with primary disease only vs those with recurrent disease showed that TIGAR and TOMM20 expressions are significantly higher in primary lesions, followed by a history of recurrence. A TOMM20 composite score of greater than or equal to 3 significantly decreased overall survival (hazard ratio [HR], 5.83) and recurrence-free survival (HR, 8.95). Identifying novel signaling pathways that promote chordoma growth and recurrence is critical for developing targeted therapy for chordoma. TOMM20 may be a biomarker associated with chordoma disease progression.

Comparison of GATA-3, Mammaglobin and GCDFP-15 Expression in Primary, Metastatic and Triple Negative Breast Carcinomas: An Indian Scenario.

Mammaglobin and GCDFP-15 are traditional immunohistochemistry (IHC) markers utilized to recognize metastasis of breast carcinoma in an unknown primary. GATA-3 is increasingly being used as a marker of primary breast origin. This study was done to evaluate and compare GATA-3 with GCDFP-15 and Mammaglobin in invasive primary including metastatic and triple negative breast carcinomas. Immunohistochemistry for GATA-3, GCDFP-15 and Mammaglobin was applied on 100 cases of primary breast carcinomas, including 20 triple negative cases and 30 cases of metastatic breast carcinomas. Staining scores were given for each marker by multiplying the percentage of positive tumor cells by the intensity of staining (1+, 2+ or 3+), with scores ranging from 0 to 300. Staining score of 1 or more was considered positive. GATA-3 was expressed in 92% of primary, 80% of metastatic and 60% of triple negative breast carcinomas, with an average staining score of 270. Mammaglobin was expressed in 68% of primary, 56.6% of metastatic and 25% of triple negative breast carcinomas, with an average staining score of 180. GCDFP-15 was expressed in 48% of primary, 26.6% of metastatic and 05% of breast carcinomas, with an average staining score of 60. GATA-3 demonstrated to have higher staining score (average of 270) than other two markers in maximum number of cases. GATA-3 has a higher sensitivity and increased staining scores in primary breast carcinomas, metastatic breast carcinomas as well as in triple negative breast carcinomas.

The Mutually Mediated Chloride Intracellular Channel Protein 1 (CLIC1) Relationship between Malignant Cells and Tumor Blood Vessel Endothelium Exhibits a Significant Impact on Tumor Angiogenesis, Progression, and Metastasis in Clear Cell Renal Cell Carcinoma (ccRCC).

Background: Overexpression of chloride intracellular channel protein 1 (CLIC1) in tumor cells has been confirmed, but it has received less attention in the tumor blood vessel endothelium. Aim: The assessment of CLIC1 expression in ccRCC tumor blood vessels and its relationship with TNM parameters and tumor cell CLIC1 expression. Methods: CLIC1 immunostaining in ccRCC was evaluated in 50 cases in both malignant cells and tumor blood vessels (CLIC1 microvessel density-CLIC1-MVD) and was correlated with TNM staging parameters. Results: CLIC1-MVD was observed in approximately 65% of cases, and CLIC1 co-localization in both tumor and endothelial cells was observed in 59% of cases. ccRCC was classified into four groups (Classes 0−3) based on the percentage of positive tumor cells, with each group including sub-groups defined by CLIC1 expression in the endothelium. Class 3 (60−100% positive tumor cells) had the highest CLIC1-MVD, with an impact on T and M parameters (p value = 0.007 for T, and p value = 0.006 for M). For cases with CLIC1 intracellular translocation, there was a strong correlation between CLIC1-MVD and M (p value < 0.001). Conclusions: Co-expression of ccRCC tumor and endothelial cells promotes tumor progression and metastasis and should be investigated further as a potential therapeutic target for ccRCC and other human malignancies.

CD19 Expression by IHC Alone Is Not a Predictor of Response to Loncastuximab Tesirine: Results from the LOTIS-2 Clinical Trial and Quantitative Systems Pharmacology Modeling

Introduction: CD19 is a clinically-validated target for the treatment of B-cell malignancies, and several CD19-targeted therapies have received approval, including chimeric antigen receptor T-cell (CAR-T) therapy, antibody-drug conjugates (ADCs), monoclonal antibodies, and bispecific agents. However, the optimal sequencing of these treatments has not yet been clarified. Loncastuximab tesirine (loncastuximab tesirine-lypl; Lonca) is an ADC comprising an anti-CD19 antibody conjugated to a pyrrolobenzodiazepine (PBD) dimer cytotoxin, indicated for relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) after ≥2 systemic treatments. Prior CAR-T therapy does not preclude a response to Lonca, and responses were also observed in patients who received CAR-T therapy post-Lonca. The present analysis was performed to determine the contribution of CD19 expression to responses in patients treated with Lonca. Methods: CD19 expression determined by immunohistochemistry (IHC) was evaluated in a cohort of patients enrolled in the LOTIS-2 clinical trial (NCT03589469) with available tissue samples obtained after their last anti-cancer systemic therapy and prior to Lonca. IHC was performed using the LE-CD19 antibody (DAKO), and expression was analyzed using the BenchMark ULTRA platform (Ventana). CD19 expression was assessed by semiquantitative scoring of both the percentage of positive tumor cells and the H-Score (semiquantitative assessment of the percentage of CD19 positive cells and staining intensity). Quantitative Systems Pharmacology (QSP) modeling was used to predict response to Lonca and to test hypotheses regarding patient-specific covariates. Results: The cohort included patients with any prior systemic therapies (n = 59), including patients who received CAR-T as the last therapy prior to biopsy (n = 9). Responses to Lonca were seen in patients across all levels of CD19 expression, including patients with extremely low or no detectable CD19 expression at baseline and extremely low H-Scores. On the basis of the QSP modeling, patients are anticipated to achieve disease response to Lonca with CD19 tumor cell-surface densities as low as 1,000 molecules/cell (Figure 2). Conclusions: Response to Lonca was observed in R/R DLBCL patients with very low CD19 tumor expression as measured by IHC. QSP modeling predicts that CD19 expression level by IHC is not predictive of response to Lonca, whereas the addition of CD19 surface density improves the response prediction. Patients responded to Lonca with estimated tumor cell surface densities as low as 1,000 molecules/cell, normally below the level of IHC detection. Our findings indicate that Lonca is an effective treatment option for patients with R/R DLBCL following ≥ 2 lines of treatment, even in patients expected to have a low level of CD19 expression. These results serve as a basis for future studies addressing sequencing of CD19-targeted agents. Funding: ADC Therapeutics SA; medical writing: CiTRUS Health Group. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Oncogenic JAK2/STAT Signaling Molecules Activation Is Associated with PD-L1 Upregulation in Acute Myeloid Leukemia

Background: Increased evidence suggests the PD-1/PD-L1 axis is involved in the oncogenesis of myeloid neoplasms through promoting cancer immune escape, which suggests potential benefits by blockade of this axis in these neoplasms by immune checkpoint inhibitors. However, the ongoing clinical trials on PD-1/PD-L1 blocker in MDS/AML have reported controversial results, unlike the promising therapeutic efficacy shown in solid tumors. Identifying reliable biomarkers and scoring of PD-L1 expression and targeting the subgroup of patients who might benefit the most from PD-1/PD-L1 blockade are promising directions. Janus kinase 2 (JAK2) pathway activation has been shown to enhance PD-L1 expression in malignancies by in vitro studies. Here, we investigated PD-L1 expression associated with JAK2/STAT oncogenic pathway in AML patients using the combined positive score (CPS) algorithm. Methods: Immunohistochemical staining (IHC) for PD-L1 and pSTAT3 was performed on the marrow biopsies of 31 AML patients (39 cases), including 11 patients (17 cases) with JAK2/STAT mutation and 20 patients (22 cases) with wild-type JAK2/STAT. For PD-L1 IHC, the cases were evaluated for variable staining intensity (weak, moderate, strong) and membrane staining pattern (partial, complete) in tumor and mononuclear immune cells. The PD-L1 CPS was calculated by summing the number of all PD-L1-stained cells and dividing by the total number of tumor cells, multiplied by 100. The pSTAT3 was evaluated by percentage of positive tumor cells among the total tumor cells. The status of JAK2 / STAT mutations and other molecular abnormalities was evaluated by next generation sequencing (NGS) study. Results: Among patients of JAK2/STAT mutations, nine with JAK2 V617F exon 14 mutations, one with JAK2 I540-E543delinsRG exon 12 mutation and one with STAT5B N642H mutation. Evaluation of PD-L1 expression by IHC revealed four major cell staining patterns in our study cohort: 1. Negative (Figure 1A); 2. Partial weak membrane staining (Figure 1B, CPS<10); 3. Partial-complete, weak-moderate membrane staining (Figure 1C, CPS≥10); 4. Complete, moderate-strong membrane staining (Figure 1D, CPS≥10). Patterns 3-4 were classified as positive PD-L1 staining with a CPS cut-off of 10 (CPS≥10). Comparison of the PD-L1 CPS score in the JAK2/STAT wild-type versus the JAK2/STAT mutant groups revealed significantly higher PD-L1 CPS score in the JAK2/STAT mutant group (Figure 1K, P<0.0001, CPS≥10). One patient showed wild-type JAK2 at initial AML diagnosis. At two subsequent relapses, gain of JAK2 exon 12 (I540-E543delinsRG) mutation with increased VAF from 17% to 41% was detected. Interestingly, PD-L1 expression was correspondingly increased with CPS from 25 to 75 in these subsequent biopsies (Figure 1E, F). In another case with wild-type JAK2, STAT5B N642H mutation was detected and strong PD-L1 expression with CPS of 80 was obtained (Figure 1G). To address if JAK2/STAT3 axis is involved in PD-L1 upregulation, we assessed STAT3 phosphorylation by IHC in JAK2 wild-type and mutated groups. The results revealed significantly increased p-STAT3 expression in the JAK2 mutant compared with the wild-type cases, supporting the idea that oncogenic JAK2 mutation leads to STAT3 phosphorylation (Figure 1H-J). Furthermore, p-STAT3 expression showed a significant positive correlation with the PD-L1 CPS score (Figure 1H, r=0.8663, P<0.0001). Conclusion: In the AML patients with oncogenic JAK2 or its downstream signaling molecule STAT5B mutations, there is significantly enhanced PD-L1 expression. In addition, we proposed that the PD-L1 CPS positivity cut-off score of 10 being used as a quantitative measure of PD-L1 expression in this heterogeneous myeloid neoplasm. In the patient with relapsing AML, PD-L1 expression showed a positive correlation with increased JAK2 mutant VAF. Independent of the oncogenic JAK2 mutation, PD-L1 expression upregulation was also noted with STAT5B N642H mutation. Lastly, we demonstrated enhanced p-STAT3 expression in JAK2 mutant cases and a positive correlation between p-STAT3 and PD-L1 expression. Taken together, these data support the model that JAK2/STAT pathway activation is associated with PD-L1 upregulation in AML patients (Figure 1I), together with the proposed PD-L1 CPS cut-off of 10, can serve as scanning biomarkers to select relevant subgroups of AML patients for PD-1/PD-L1 immunotherapeutic study. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Utility of TRPS-1 immunohistochemistry in diagnosis of metastatic breast carcinoma in cytology specimens

At present, GATA binding protein 3 (GATA-3) is the most frequently used diagnostic immunohistochemical (IHC) marker for breast carcinoma (BC). However, it is not specific and has very low sensitivity for triple-negative BC (TNBC). SRY-box transcription factor 10 (SOX-10) and trichorhinophalangeal syndrome type 1 (TRPS-1) have been suggested for inclusion in the diagnostic workup of TNBC. TRPS-1 has not been established in cytology specimens as a diagnostic IHC marker for metastatic BC (MBC). Hence, in the present study we evaluated the utility of TRPS-1 in diagnosing MBC in cytology specimens. MBC cases diagnosed on cytology specimens from January to October 2020 were included in the present study. Only cases with hormonal status available and ≥20 tumor cells on cell blocks were included in the study. The cell blocks were assessed for TRPS-1, GATA-3, and SOX-10 IHC marker positivity (intensity and percentage of tumor cells). The results were correlated with the specimen type (fine needle aspiration [FNA] versus body fluid) and various BC prognostic subgroups. We analyzed 61 cases, including 33 body fluid and 28 FNA (13 lymph node, 10 bone, 2 liver, 2 soft tissue, and 1 lung) specimens. TRPS-1 had 97.2% positivity in ER/PR+ (estrogen receptor/progesterone receptor-positive) MBC compared with GATA-3, which had 100% positivity in the same group. TRPS-1 showed high positivity in 35 of 37 cases (94.6%) and intermediate positivity in 1 (2.6%) and was negative/low positive in 1 case (2.7%). In contrast, GATA-3 showed high positivity for all 37 cases (100%). SOX-10 showed positivity in only 1 of 37 cases (2.7%), with intermediate positivity. In the HER2+ (human epidermal growth factor receptor 2-positive) group, TRPS-1 showed high positivity in 5 of 7 cases (71.4%), intermediate positivity in 1 case (14.3%), and negativity in 1 case (14.3%). However, GATA-3 showed high positivity in 6 of 7 cases (85.7%) and negative/low positivity in 1 case (14.3%). SOX-10 was negative in all 7 cases. In TNBC, TRPS-1 showed high positivity in 16 of 17 cases (94%) and intermediate positivity in 1(5.9%), and GATA-3 showed high positivity in 9 (53%), intermediate positivity in 2 (11.8%), and low positive/negative in 6 of the 17 cases (35.3%). TRPS-1 expression was significantly higher than GATA-3 expression for the number of positive cases (P = 0.07), mean percentage of positive tumor cells (P=0.005), and intensity of reactivity (P = 0.005). SOX-10 expression was present in only 5 of 17 cases (29%), with a mean percentage of positivity in the tumor cells of 26.5% and intensity of 0.8. No differences were found in the IHC results between the different specimen types (FNA versus fluid) in any group. TRPS-1 is a highly sensitive new diagnostic IHC marker for breast carcinoma, with a similar positivity rate in ER/PR+ and HER2+ BC compared with GATA-3 and a higher positivity rate than GATA-3 and SOX-10 in TNBC in cytology specimens. In particular, when only a few clusters of tumor cells are present on the cell block, TRPS-1 can be highly useful, because its mean percentage of positive tumor cells and intensity are higher than those of other IHC markers.

Overexpression of cytoplasmic dynamin 2 is associated with worse outcomes in patients with clear cell renal cell carcinoma.

Dynamin 2 (DNM2) involved in tumor progression in various malignancies. For the first time, we evaluated DNM2 expression pattern, its association with clinicopathological characteristics and survival outcomes in RCC subtypes. We evaluated the DNM2 expression pattern in RCC tissues as well as adjacent normal tissue using immunohistochemistry on tissue microarray (TMA) slides. Our findings revealed increased DNM2 expression in RCC samples rather than in adjacent normal tissues. The results indicated that there was a statistically significant difference between cytoplasmic expression of DNM2 among subtypes of RCC in terms of intensity of staining, percentage of positive tumor cells, and H-score (P= 0.024, 0.049, and 0.009, respectively). The analysis revealed that increased cytoplasmic expression of DNM2 in ccRCC is associated with worse OS (log rank: P= 0.045), DSS (P= 0.049), and PFS (P= 0.041). Furthermore, cytoplasmic expression of DNM2 was found as an independent prognostic factor affecting DSS and PFS in multivariate analysis. Our results indicated that DNM2 cytoplasmic expression is associated with tumor aggressiveness and poor outcomes. DNM2 could serve as a promising prognostic biomarker and therapeutic target in patients with ccRCC.

Epidermal Growth Factor Receptor immunohistochemical expression in hepatocellular carcinoma without Epidermal Growth Factor Receptor exons 18-21 mutations.

Introduction: EGFR targeted therapies, have been proved beneficial for patients with HCC, nevertheless additional research on EGFR immunoexpresion and EGFR mutations is still needed, especially in population in which it has not been done yet. The aim of this study is to evaluate EGFR immunoexpression in HCC without EGFR exons 18-21 mutations and to evaluate its influence on survival in HCC patients in North Macedonia. Methods: We studied 31 cases of HCC for EGFR immunohistochemical expression and EGFR exons 18-21 mutations. The following clinical parameters were analyzed: Hepatitis B and C virus infection, presence of cirrhosis, tumor size, enlarged lymph nodes, metastases, alpha fetoprotein level and overall survival. Presence of the EGFR immunosignal (membranous and cytoplasmic) and the percentage of positive tumor cells in the entire tumor tissue specimen were semi-quantitatively determined. Results: Hepatitis B and C virus infection, tumor size, metastatic disease and EGFR immunoexpression have influence on patient's survival. No EGFR exons 18-21 mutations were detected in this group of HCCs. EGFR expression of 61%-80% in tumor tissue significantly influenced survival of the patients (p < 0.01). Multiple Cox regression confirmed tumor size of 5-10 cm (p < 0.05), tumor size > 10 cm (p < 0.01) and EGFR expression in range of 61% to 80% (p < 0.05) as independent survival predictors in patients with HCC. Conclusion: EGFR overexpression in range of 61% to 80% was an independent survival predictor in patients with HCC, implying that these patients could benefit from EGFR inhibition. However, the absence of EGFR mutations in exons 18-21 in any of the cases of this study suggest that single drug EGFR targeted therapy in patients with HCC may be insufficient.

Immunohistochemical analyses of paraffin-embedded sections after primary surgery or trimodality treatment in esophageal carcinoma

BackgroundThe microscopic tumor extension before, during or after radiochemotherapy (RCHT) and its correlation with the tumor microenvironment (TME) are presently unknown. This information is, however, crucial in the era of image-guided, adaptive high-precision photon or particle therapy. Materials and methodsIn this pilot study, we analyzed formalin-fixed paraffin-embedded (FFPE) tumor resection specimen from patients with histologically confirmed squamous cell carcinoma (SCC; n = 10) or adenocarcinoma (A; n = 10) of the esophagus, having undergone neoadjuvant radiochemotherapy followed by resection (NRCHT + R) or resection (R)]. FFPE tissue sections were analyzed by immunohistochemistry regarding tumor hypoxia (HIF-1α), proliferation (Ki67), immune status (PD1), cancer cell stemness (CXCR4), and p53 mutation status. Marker expression in HIF-1α subvolumes was part of a sub-analysis. Statistical analyses were performed using one-sided Mann-Whitney tests and Bland-Altman analysis. ResultsIn both SCC and AC patients, the overall percentages of positive tumor cells among the five TME markers, namely HIF-1α, Ki67, p53, CXCR4 and PD1 after NRCHT were lower than in the R cohort. However, only PD1 in SCC and Ki67 in AC showed significant association (Ki67: p = 0.03, PD1: p = 0.02). In the sub-analysis of hypoxic subvolumes among the AC patients, the percentage of positive tumor cells within hypoxic regions were statistically significantly lower in the NRCHT than in the R cohort across all the markers except for PD1. ConclusionIn this pilot study, we showed changes in the TME induced by NRCHT in both SCC and AC. These findings will be correlated with microscopic tumor extension measurements in a subsequent cohort of patients.

Association Between GATA3 and Histopathological and Immunohistochemical Parameters in Early-Infiltrating Breast Carcinomas

This study evaluated the frequency of GATA-binding protein 3 (GATA3) expression in early breast cancer and its relationship with histopathological and immunohistochemical parameters. GATA3 was analysed by immunohistochemistry in histological sections of tumors from 105 female patients, with histological diagnosis of invasive breast carcinoma (BC), at clinical stages I, II and IIIA, who underwent primary surgical treatment. GATA3 nuclear expression was determined as the percentage of positive tumor cells and further categorized as high (positive expression in more than 95% of cells) or non-high (negative or low positive expression in up to 95% of tumor cells). GATA3 expression was analysed according to the patient age, tumor and node pathological stage, histological type, histological and nuclear grade, lymphovascular invasion, and estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), human epidermal growth factor 2 (HER2) status, and Ki-67 expression. GATA3 expression was positive in 103 cases (98.1%). High expression was significantly associated with low histological and nuclear grade, positive hormonal receptors, and less proliferative activity based on Ki-67 expression. A prominent feature was that 94.7% of the ER-positive/HER2-negative cases presented high-GATA3 expression, as 94.0% of the tumors showing high-GATA3 were ER-positive. In ER-negative/HER2-positive or ER-negative/HER2- negative, high-GATA3 was present in 25% while 75% were non-high-GATA3 compared with ER-positive/HER2- negative (4.1%) and ER-positive/HER2-positive (20%). Proliferative activity in triple-negative breast cancer tended to be higher among tumors with low-GATA3, irrespective of AR expression. In the group of ER-positive/HER2-negative tumors only three cases were low-GATA3 (85% and 80%), both with high proliferative activity. High GATA3 expression is associated with favorable histopathologic and immunohistochemical BC prognostic factors.

Abstract 2691: Expression pattern and prognostic significance of HER family members and EGFRvIII in pancreatic cancer

Abstract Pancreatic cancer is one of the most aggressive, heterogeneous, and fatal types of human cancers. There is urgent need for discovery of biomarkers of prognostic significance, predictive value and as well as therapeutic targets in patients with pancreatic cancer. In this study, we examined the relative expression and prognostic significance of all HER family members and the type III EGFR mutant (EGFRvIII) in patients with pancreatic ductal adenocarcinoma (PDC). The expression levels of wild-type EGFR (wtEGFR), HER2, HER3, HER4 and EGFRvIII were determined in tumor specimens from 43 patients by immunohistochemistry using antibodies DAK-H1-WT, Neu 3B5, SP71, HFR1 and NBP2-50599 respectively. The staining was scored based on the percentage of positive tumor cells, the intensity (i.e. strong 3+, moderate 2+, weak 1+) and the cellular location of immunostaining (i.e. membranous, cytoplasmic or nuclear). The association between the expression level of the biomarkers and patient overall survival was evaluated using Chi-squared, Kaplan-Meier survival curves and log rank test. At cut-off value of above 5%, we found weak to moderate expression of wtEGFR, HER2, HER3, HER4 and EGFRvIII in 4.7%, 14%, 14%, 20.9% and 2.3% of the cases examined respectively. The cellular location of wtEGFR and HER2 was found to be predominantly cytoplasmic, HER-3 membranous and cytoplasmic whereas HER4 expression was found to be mainly nuclear. There was no statistically significant association between the expression level of these markers and patient overall survival. The expression levels of the above biomarkers were also evaluated in tissue microarrays (TMAs) from 40 cases of pancreatic ductal adenocarcinoma. Interestingly, at the same cut-off value, 62.5%, 75%, 0%, 55% and 5% of the TMAs were positive for wtEGFR, HER2, HER3, HER4 and EGFRvIII respectively. Overall, we found that the expression pattern of HER family members was heterogenous, and with EGFRvIII expression being very low in both whole tumor sections and TMAs from patients with pancreatic cancer. Taken together, our results provide support for more detailed studies of co-expression of all HER family members in a larger group of pancreatic cancer patients. Such studies should help to unravel their potential as targets for therapeutic interventions as well as their prognostic significance and predictive value for response to therapy. Citation Format: Tanzeel Khan, Said A. Khelwatty, Izhar Bagwan, Alan Seddon, Angus Dalgleish, Satvinder Mudan, Helmout Modjtahedi. Expression pattern and prognostic significance of HER family members and EGFRvIII in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2691.

Abstract 6261: Comparison of glycoprotein nonmetastatic melanoma protein b, epidermal growth factor receptor and vascular endothelial growth factor expression in head and neck squamous cell carcinoma, and untreated and residual lymph node metastases

Abstract Objective: To evaluate expression of the potential molecular imaging targets glycoprotein nonmetastatic melanoma protein B (GPNMB) and vascular endothelial growth factor (VEGF) in comparison to classical epidermal growth factor receptor (EGFR) in previously untreated head and neck cancer primary tumors and corresponding lymph node metastases, and in lymph node metastases after initial (chemo)radiotherapy. Methods: Primary tumors and lymph node metastases of 38 patients who underwent primary resection of head and neck squamous cell carcinoma (HNSCC) were selected. In addition, lymph node metastases from salvage surgery after (chemo)radiotherapy from 22 patients with HNSCC were selected. Immunohistochemical staining for EGFR, VEGF and GPNMB was performed, after which protein expression was scored using H-scores (percentage of positive tumor cells multiplied by staining intensity ranging from 0 to 2). Primary tumors and lymph node metastases with an H-score ≥5 were considered positive, after which sensitivity rates were calculated. Groups were compared using the Mann-Whitney U test for non-parametric data with post-hoc Bonferroni corrections. Results: In untreated primary HNSCC the sensitivity was 86.8% for EGFR (median H-score 60), 92.1% for VEGF (median 60), and 100% for GPNMB (median 100). In previously untreated lymph node metastases the sensitivity was 81.6% for EGFR (median 30), 86.8% for VEGF (median 65), and 100% for GPNMB (median 118). In lymph node metastases after initial (chemo)radiotherapy, sensitivity was 86.4% for EGFR (median 95) and 100% for GPMB (median 100). VEGF sensitivity could not reliably be evaluated in these lymph nodes due to nonspecific staining in all tissue slides. GPNMB expression was significantly higher compared to EGFR in untreated primary HNSCC (p = .009 and p &amp;lt; .001, respectively) and lymph node metastases (p &amp;lt; .001 for both). Conclusion: GPNMB shows better tumor-specific receptor expression in both sensitivity and H-scores compared to EGFR and VEGF in immunohistochemistry. VEGF performed comparable to EGFR in untreated HNSCC and lymph node metastases. GPNMB could therefore be a new potential imaging target based on these immunohistochemical results. Citation Format: Jeroen E. van Schaik, Bert van der Vegt, Saskia H. Hanemaaijer, Gyorgy B. Halmos, Max J. Witjes, Bernard F.A.M. van der Laan, Rudolf S. Fehrmann, Sjoukje F. Oosting, Boudewijn E. Plaat. Comparison of glycoprotein nonmetastatic melanoma protein b, epidermal growth factor receptor and vascular endothelial growth factor expression in head and neck squamous cell carcinoma, and untreated and residual lymph node metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6261.