Paraffin-embedded Tissue Blocks Research Articles

Expression of human epidermal growth factor receptor 2 (HER2) in colorectal cancer and its correlation with clinicopathological characteristic among Jordanian patients

Abstract Introduction/Objective Human epidermal growth factor receptor 2 (HER2/neu) is a well-established therapeutic target in breast and gastric cancers. Currently HER2 expression is being considered in other solid tumors including colorectal cancer (CRC). We aimed to investigate HER2 expression in CRC among Jordanians and its association with clinicopathological variables. Methods/Case Report Formalin-fixed, paraffin-embedded tissue blocks of 69 CRC cases were retrieved with their clinicopathological data. Tissue microarray (TMA) were constructed and immunostained using anti-HER2/neu 4B5 monoclonal antibody (Ventana, Tucson, AZ). HER2 scoring was performed by two experienced pathologists using the HERACLES criteria (HER2 positivity: cases of (3+) in ≥10% of cells and FISH-positive equivocal cases). Fisher’s exact/Chi-square test was used to investigate the association between HER2 s and clinicopathological data such as age, gender, histological differentiation, node and metastasis (NM) stage, and tumor site. Survival analysis was evaluated using Kaplan–Meier curves. Results (if a Case Study enter NA) Any degree (score) of HER2/neu expression was seen in 43.5 % of the cases. In 25 (36.2%), 4 (5.8%) and 1 (1.5%) the HER2 score was 1+, 2+ and 3+ respectively. The rest of the cases, 39 (56.5%) were scored as 0. Two of the four cases with a score (2+) required ISH testing to confirm amplification which was not performed. No significant association was found between HER2/neu expression and clinicopathological parameters or with survival. However, survival analysis showed that combined 2+/ 3+ group tend to have worse overall (OS) and event -free survival than the (0/1+) group. Conclusion The prevalence of HER2 overexpression in CRC is low among Jordanian patients, with only 1.5% of the study sample exhibiting definite HER2 overexpression. This rate is lower than the 3-5% rate reported in general, however the small sample size and lack of FISH confirmation might have contributed to this low rate. There was a trend towards worse OS and EFS in HER2 positive cases

TP53 mutation status and consensus molecular subtypes of colorectal cancer in patients from Rwanda

BackgroundMutations in the TP53 tumor suppressor gene are well-established drivers of colorectal cancer (CRC) development. However, data on the prevalence of TP53 variants and their association with consensus molecular subtype (CMS) classification in patients with CRC from Rwanda are currently lacking. This study addressed this knowledge gap by investigating TP53 mutation status concerning CMS classification in a CRC cohort from Rwanda.MethodsFormalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained from 51 patients with CRC at the University Teaching Hospital of Kigali, Rwanda. Exons 4 to 11 and their flanking intron-exon boundaries in the TP53 gene were sequenced using Sanger sequencing to identify potential variants. The recently established immunohistochemistry-based classifier was employed to determine the CMS of each tumor.ResultsSequencing analysis of cancerous tissue DNA revealed TP53 pathogenic variants in 23 of 51 (45.1%) patients from Rwanda. These variants were predominantly missense types (18/23, 78.3%). The most frequent were c.455dup (p.P153Afs*28), c.524G > A (p.R175H), and c.733G > A (p.G245S), each identified in three tumors. Trinucleotide sequence context analysis of the 23 mutations (20 of which were single-base substitutions) revealed a predominance of the [C > N] pattern among single-base substitutions (SBSs) (18/20; 90.0%), with C[C > T]G being the most frequent mutation (5/18, 27.8%). Furthermore, pyrimidine bases (C and T) were preferentially found at the 5ʹ flanking position of the mutated cytosine (13/18; 72.2%). Analysis of CMS subtypes revealed the following distribution: CMS1 (microsatellite instability-immune) (6/51, 11.8%), CMS2 (canonical) (28/51, 54.9%), CMS3 (metabolic) (9/51, 17.6%), and CMS4 (mesenchymal) (8/51, 15.7%). Interestingly, the majority of TP53 variants were in the CMS2 subgroup (14/23; 60.1%).ConclusionOur findings indicate a high frequency of TP53 variants in CRC patients from Rwanda. Importantly, these variants are enriched in the CMS2 subtype. This study, representing the second investigation into molecular alterations in patients with CRC from Rwanda and the first to explore TP53 mutations and CMS classification, provides valuable insights into the molecular landscape of CRC in this understudied population.

Homologous recombination deficiency gene panel analysis results in synchronous endometrial and ovarian cancers.

The objective of this study was to analyze the genetic alterations of tumors within the scope of the homologous recombination deficiency gene panel in patients diagnosed with synchronous endometrial ovarian cancer who have been followed for over 5 years using next-generation sequencing. DNA was isolated from the patient's formalin-fixed, paraffin-embedded tissue blocks. Next-generation sequencing was performed using the Illumina capture-based sequencing method. Samples were sequenced using the Sophia HR Solution DNA Kit. Seven patients were included in this study. The ratios of likely pathogenic (LP)/pathogenic (P) somatic mutations in ATM (serine/threonine kinase or Ataxia-telangiectasia mutated gene), BRCA2 (breast cancer type 2 susceptibility gene), BARD1 (BRCA1 associated RING domain 1), TP53 (tumor protein p53), BIRP1 (BRCA1-interacting helicase 1 gene), PALB2 (partner and localizer of BRCA2), and CHECK2 were 21 (48.8%), 8 (18.6%), 5 (11.6%), 3 (6.9%), 2 (4.6%), 2 (4.6%), and 2 (4.6%), respectively, in endometrium, and the ratios of somatic mutations in ATM, BRCA2, TP53, BARD1, RAD54L (DNA repair/recombination protein like), BIRP1, and RAD51D (RAD51 recombinase paralog D) were 24 (60%), 6 (15%), 5 (12.5%), 2 (5%), 2 (5%), 1 (2.5%), and 1 (2.5%), respectively, in ovary. In endometrioid-synchronous endometrial ovarian cancer cases, P/LP mutations were observed in ATM and CHECK2 genes in endometrium and ATM, BRCA2, and TP53 genes in ovary. In two non-endometrioid-synchronous endometrial ovarian cancer cases, CHEK2 (checkpoint kinase 2) mutations were observed in endometrium and ATM and TP53 mutations in ovary, whereas in one case, P/LP mutations in ATM and TP53 genes were common in both tissues. Pathogenic variations confirming the diagnosis of synchronous endometrial ovarian cancer with genetic alterations were identified in all but one case. ATM gene mutation emerged as the most common alteration and has a potential association with a favorable prognosis.

A Retrospective Study on the Expression of E-Cadherin in Endometrial Carcinoma.

E-cadherin is a cell adhesion molecule crucial for maintaining cellular integrity and survival. E-cadherin is the focus of this study, which aims to evaluate its immunohistochemical staining patterns in endometrial carcinoma (EC). Material and methods In this retrospective study, 25 formalin-fixed, paraffin-embedded tissue blocks of EC were retrieved from the Department of Pathology at Saveetha Medical College. These samples, collected between September 2020 and May 2023, were identified using unique histopathology numbers. Results The analysis revealed that E-cadherin expression decreased as the endometrial tissue progressed from normal to carcinoma. This reduction was more pronounced in cancers with greater depth of invasion and in more advanced stages compared to those with less invasive depth and earlier stages. Additionally, E-cadherin expression was higher in grade 1 tumors but became heterogeneous or negative in grade 3 tumors. Conclusion The downregulation of E-cadherin is likely due to disruptions in the cadherin-catenin complex, which is linked to the potential for local and distant metastasis in cancer. This study underscores the significance of cell adhesion molecule expression in predicting the prognosis of EC.

Evaluation of Periapical Granuloma and Radicular Cyst Regarding the Age, Gender and The Lesion Size

Background: Apical periodontitis (AP) is a common infectious disease characterized by inflammation and bone destruction in the periapical tissues due to microbial infection in the dental pulp . AP is the most frequent inflammatory lesion related to teeth, distinguished by a direct pathway to the bone marrow without epithelial barriers if the dental pulp becomes necrotic and infected. Materials and methods: Thirty paraffin embedded tissue blocks of radicular neck resected samples of 18 preapical granulomas and 12 radicular cysts were processed histopatholgically. Results: the mean patients’ age was 34.37 ± 2.95 years; fifteen patients were aged bellow 30 years and 15 patients were equal or above 30 years. The mean lesions size was significantly higher among patients with radicular cysts than preapical granuloma (5.07 ± 1.35 vs. 0.94 ± 0.21; p=0.048. granulomas lesions were slightly higher among females in age group 30-39 years ( 25% vs. 10%), and the radicular cysts lesions were higher among females in all age group as compare to male patients Conclusions: Lesions size was significantly higher among patients with radicular cysts than that of preapical granuloma. A peak incidence between the third and fourth decades of life and predominance among female

Spectrum of Ductal Carcinoma In Situ (DCIS) Lesions of the Breast: From Morphology to Molecular Characteristics.

Background Specific molecular characteristics of invasive breast cancer have been linked to an increased risk of early relapse. Similarly, ductal carcinoma in situ (DCIS) displays a comparable molecular profile, although their prevalence and implications are not yet fully understood. Aims and objectives The study design defined a multivariable statistical approach aimed at describing the interplay between the histopathological features of ductal carcinoma in situ (DCIS) and their molecular profile. The objective was to explore the correlations between the histopathological features of DCIS (tumor location, DCIS grade, DCIS type, and presence or absence of comedo necrosis) and various biomarkers like estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER2/neu), androgen receptor (AR), and epidermal growth factor receptor (EGFR), in addition to the Ki-67 labeling index. Methods In this retrospective study, we selected and analyzed 100 diagnosed cases of ductal carcinoma in situ (DCIS) to represent various subtypes, grades, and morphological characteristics. A detailed histopathological review and immunohistopathological staining for ER, PR, HER2/neu, AR, EGFR, and Ki-67 were performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue blocks. Molecular subtyping was done based on the biomarker analysis into luminal A, luminal B, luminal HER2/neu, HER2/neu enriched, and triple-negative subtypes. Statistical analysis was done to examine the correlation between tumor location, histopathological features of ductal carcinoma in situ (DCIS), and the expression of the immunohistochemical markers and the molecular subtypes. Results The majority of cases exhibited positivity for estrogen receptor (ER) and progesterone receptor (PR). A strong association was observed between histopathological features (DCIS grade, type, and comedo necrosis) of DCIS and ER/PR status. Additionally, a significant correlation was found between ductal carcinoma in situ (DCIS) grade and HER2/neu status. However, no association was identified between histopathological features and AR or EGFR status. Contrary to expectations, triple-negative DCIS did not show the most aggressive behavior, whereas HER2/neu-positive tumors, particularly high-grade ones, exhibited more aggressive features. No low-grade cases of luminal HER2/neu and HER2/neu-enriched tumors were found. A higher Ki-67 labeling index was found in cases with grade 3 and solid and comedo architectural types of DCIS, while low-grade tumors had a lower Ki-67 labeling index. Conclusion These findings suggest that hormone pathways play a crucial role in ductal carcinoma in situ (DCIS) progression, but the molecular interactions are complex and extend beyond simple binary associations. The complex relationship between the histopathological features of ductal carcinoma in situ (DCIS) and its hormone receptor status warrants further investigation with a larger sample size to fully understand the underlying mechanisms. The results challenge the expectation that triple-negative DCIS is the most aggressive subtype, highlighting the need for further research into the prognostic significance of different DCIS subtypes.

Immunohistochemical Expression of Vitamin D receptor in Breast Cancer in Erbil city

Background & objectives: Vitamin D receptor is a nuclear receptor that modulates the activity of genes. The purpose of this study was to evaluate the frequency of vitamin D receptor expression in breast carcinoma by immunohistochemistry and to investigate the association between vitamin D receptor expression with some clinicopathologic factors, like tumor grading, staging, histologic type (ductal and non-ductal) and the hormonal status. Methods: One hundred formalin-fixed paraffin embedded tissue blocks of mastectomy and core biopsy specimens diagnosed as carcinoma, were obtained from a private laboratory in Erbil city/Iraq from October 2020-October 2022. In this study, vitamin D antibody (a mouse monoclonal antibody) was applied to a breast cancer tissue samples and its expression was assessed. Results: Nuclear vitamin D receptor was expressed in 32% of the cases, and a strong relation was noted between vitamin D receptor expression and low-grade tumor (p = 0.034), estrogen receptor (p-value =0.007), and progesterone receptor (p = 0.045) positivity, while no significant association was noted between vitamin D receptor expression and other clinicopathologic parameters like age, lymph node status, tumor stage, the type of the cancer and human epidermal growth factor receptor 2 status. Conclusion: increased Vitamin D receptor expression in breast tumors appears to be associated with a better prognosis. Vitamin D receptor expressed in one third of cases in which there was significant association with tumor grade and hormonal receptors.

Changes in the tumour microenvironment mark the transition from serous borderline tumour to low-grade serous carcinoma.

Low-grade serous ovarian carcinoma (LGSC) is a rare and lethal subtype of ovarian cancer. LGSC is pathologically, biologically, and clinically distinct from the more common high-grade serous ovarian carcinoma (HGSC). LGSC arises from serous borderline ovarian tumours (SBTs). The mechanism of transformation for SBTs to LGSC remains poorly understood. To better understand the biology of LGSC, we performed whole proteome profiling of formalin-fixed, paraffin-embedded tissue blocks of LGSC (n = 11), HGSC (n = 19), and SBTs (n = 26). We identified that the whole proteome is able to distinguish between histotypes of the ovarian epithelial tumours. Proteins associated with the tumour microenvironment were differentially expressed between LGSC and SBTs. Fibroblast activation protein (FAP), a protein expressed in cancer-associated fibroblasts, is the most differentially abundant protein in LGSC compared with SBT. Multiplex immunohistochemistry (IHC) for immune markers (CD20, CD79a, CD3, CD8, and CD68) was performed to determine the presence of B cells, T cells, and macrophages. The LGSC FAP+ stroma was associated with greater abundance of Tregs and M2 macrophages, features not present in SBTs. Our proteomics cohort reveals that there are changes in the tumour microenvironment in LGSC compared with its putative precursor lesion, SBT. These changes suggest that the tumour microenvironment provides a supportive environment for LGSC tumourigenesis and progression. Thus, targeting the tumour microenvironment of LGSC may be a viable therapeutic strategy. © 2024 The Pathological Society of Great Britain and Ireland.

Genomic analysis of BAX and Bcl-2 gene mutations in human papilloma virus-associated squamous cell carcinoma of the cervix

PurposeThe aim of the current study was to molecularly determine Bcl-2 and BAX gene mutations in HPV-associated squamous cell carcinoma of the cervix.MethodsFormalin-fixed, paraffin-embedded tissue blocks, all consisting of squamous cell carcinoma of the cervix, were used for this study. The nucleic acid amplification technique and various steps for DNA sequencing, including DNA extraction and polymerase chain reaction, were used.ResultsMutations were detected in the Bcl-2 gene of patients with squamous cell carcinoma of the cervix in the 10–860 bp region, while BAX gene mutations were detected in the 10–320 bp region. The nucleotide mutations in the Bcl-2 gene were A > G (50%), C > T (33.33%), and G > A > T (16.67%), while the BAX gene mutations were A > (16.67%), T > (16.67%), G > (16.67%), A > C (16.67%), T > G (16.67%), and T > C (16.67%). The mutations in the BAX gene were Indel (50%), Transversion (33.4%), and Transition (16.6%), while only the Transition mutation (100%) was detected in the Bcl-2 gene. The functional mutations in the BAX gene were only missense mutations (100%), but in the Bcl-2 gene, the functional mutations were missense (50%) and silent (50%) mutations.ConclusionOur findings revealed genomic mutations of different types and frequencies in the BAX and Bcl-2 genes in squamous cell carcinoma of the cervix, which should encourage further research to better understand these mutations and exploit them for clinical use.

Evaluating cell type deconvolution in FFPE breast tissue: application to benign breast disease

Abstract Transcriptome profiling using RNA sequencing (RNA-seq) of bulk formalin-fixed paraffin-embedded (FFPE) tissue blocks is a standard method in biomedical research. However, when used on tissues with diverse cell type compositions, it yields averaged gene expression profiles, complicating biomarker identification due to variations in cell proportions. To address the need for optimized strategies for defining individual cell type compositions from bulk FFPE samples, we constructed single-cell RNA-seq reference data for breast tissue and tested cell type deconvolution methods. Initial simulation experiments showed similar performances across multiple commonly used deconvolution methods. However, the introduction of FFPE artifacts significantly impacted their performances, with a root mean squared error (RMSE) ranging between 0.04 and 0.17. Scaden, a deep learning-based method, consistently outperformed the others, demonstrating robustness against FFPE artifacts. Testing these methods on our 62-sample RNA-seq benign breast disease cohort in which cell type composition was estimated using digital pathology approaches, we found that pre-filtering of the reference data enhanced the accuracy of most methods, realizing up to a 32% reduction in RMSE. To support further research efforts in this domain, we introduce SCdeconR, an R package designed for streamlined cell type deconvolution assessments and downstream analyses.

Novel role of CD34+ stromal cells/telocytes in oral submucous fibrosis development and its malignant transformation

BackgroundTelocytes are interstitial cells widely distributed in the extracellular matrix of numerous tissues distinguished by their long, thin, and moniliform projections. Telocytes have a role in the stimulation of angiogenesis and contribute to the development and progression of fibrosis. AimThe current study aimed to assess and compare the telocyte distribution in normal mucosa, oral submucous fibrosis (OSF), and OSCC associated with OSF (OSCCOSF). Materials and MethodsFormalin-fixed and paraffin-embedded tissue blocks of 30 OSF cases, 15 OSCCOSF cases, and 15 normal oral mucosae were obtained. Immunohistochemical staining was done with antibodies to CD34 to assess the vasculature and telocytes. The mean vascular density (MVD) and mean telocyte density were compared between the groups using the Kruskal-Walli test. ResultsA statistically significant high MVD (3.4 ± 1.22) and mean telocyte density (3.8 ± 1.35) was observed in OSCCOSF cases while it was lowest in advanced OSF cases. MVD was higher in early OSF cases than in normal mucosa. ConclusionThis study showed a decrease in CD34-positive telocytes in OSF, indicating that telocyte loss promotes the development of fibrosis.Increased angiogenesis coexisted with an increase in telocytes in OSCCOSF.

3D Virtual Histopathology by Phase-Contrast X-Ray Micro-CT for Follicular Thyroid Neoplasms.

Histological analysis is the core of follicular thyroid carcinoma (FTC) classification. The histopathological criteria of capsular and vascular invasion define malignancy and aggressiveness of FTC. Analysis of multiple sections is cumbersome and as only a minute tissue fraction is analyzed during histopathology, under-sampling remains a problem. Application of an efficient tool for complete tissue imaging in 3D would speed-up diagnosis and increase accuracy. We show that X-ray propagation-based imaging (XPBI) of paraffin-embedded tissue blocks is a valuable complementary method for follicular thyroid carcinoma diagnosis and assessment. It enables a fast, non-destructive and accurate 3D virtual histology of the FTC resection specimen. We demonstrate that XPBI virtual slices can reliably evaluate capsular invasions. Then we discuss the accessible morphological information from XPBI and their significance for vascular invasion diagnosis. We show 3D morphological information that allow to discern vascular invasions. The results are validated by comparing XPBI images with clinically accepted histology slides revised by and under supervision of two experienced endocrine pathologists.

Molecular Spectrum of K-RAS Mutations in Colorectal Cancer Patients in Peshawar, Pakistan

Background: The global incidence of colorectal cancer (CRC) has surged, presenting a significant health challenge with an annual occurrence of 1.7 million cases. The American Cancer Society reports that KRAS and BRAF mutations contribute to 20-50% of CRC cases. This study addresses the gap in data on KRAS mutations in CRC patients in Peshawar, Pakistan. Objective: To determine the prevalence and types of KRAS mutations in colorectal cancer patients in Peshawar, Pakistan. Methods: This retrospective, cross-sectional study was conducted at the Nuclear Medicine, Oncology, and Radiotherapy Institute (NORI) Hospital in Islamabad from April to November 2022. DNA was extracted from formalin-fixed, paraffin-embedded tissue blocks of 58 CRC patients, regardless of age and gender, following informed verbal consent. KRAS mutation testing was performed using the Cobas Z480 Real-time thermal cycler. Results: Among the 58 CRC patients, 34 (58.6%) were females, and 24 (41.4%) were males. The highest CRC incidence (36.2%) was observed in the 11-25 years age group. KRAS mutations at codons 12 and 13 were found in 18% of cases, with all isolates carrying the G12D mutation. Kaplan-Meier analysis revealed a lower survival probability for patients with codon 12 mutations compared to those with codon 13 mutations. Conclusion: The study highlights the need for broader research on KRAS mutations across diverse ethnicities and geographical regions in Pakistan to better understand CRC prevalence and improve patient outcomes.

Prevalence of HER-2 expression and correlation with clinicopathological features in gynecological cancer: A single-center retrospective study in China.

e17500 Background: Targeted therapy for human epidermal growth factor receptor 2 (HER2) has become a standard of care in several HER2-expressing solid tumors. Nonetheless, there remains an unmet need for effective treatment, for instance, anti-HER2 antibody-drug conjugates (ADCs), in advanced stage gynecological cancer. In this context, we presented a retrospective study on the incidence of HER2 expression in primary gynecological cancer based on a single-center data from southwestern China. Methods: Paraffin-embedded tumor tissue blocks, clinicopathological, and survival data of gynecological cancer patients were collected from Chongqing University Cancer Hospital. HER2 IHC scoring was carried out according to the updated ASCO/CAP guidelines for breast and gastroesophageal adenocarcinoma by two pathologists independently. Data analysis was performed using SPSS v.24. Results: A total of 104 cases of cervical cancer, 102 cases of endometrial cancer and 103 cases of ovarian cancer were included between 2019 and 2023. HER2 expression was detected in 31.7% samples, with scores of 1+, 2+, and 3+ in 23.9% (74/309: 36/104, 16/102, 22/103), 5.8% (18/309: 7/104, 7/102, 4/103), and 1.9% (6/309: 2/104, 1/102, 3/103) of patients, respectively. Notably, ultra-low HER2 expression with incomplete and faint staining in ≤10% of tumor cells was observed in 41.1% (127/309: 37/104, 53/102, 37/103) of patients. Metastasis and lymphovascular invasion were associated with elevated HER2 expression in endometrial cancer (p=0.037, 0.040, respectively), while a larger tumor size was associated with elevated HER2 expression in cervical cancer (p=0.004). However, no positive association between HER2 status and overall survival (OS) was found in cervical, endometrial or ovarian cancer. In our cohort, metastasis was the only risk factor related to reduced OS of gynecological cancer patients by COX regression analysis (HR=14.00, 95%CI=1.32-148.21, p=0.028). Conclusions: Our data revealed a considerable number of patients with HER2-low and ultra-low gynecological cancer. It might represent a significant portion in real-world scenarios and warrant more consideration in selecting candidates for HER2-targeted ADCs, especially for those with relapsed or refractory conditions. Given the inherent challenge in interpretation, the study highlights the necessity for a consensus on evaluating HER2 immuno-staining results in gynecological cancer. Clinical trial information: MR-50-23-019676 . [Table: see text]

Extracellular (EC) Mucin5AC (MUC5AC) detection after neoadjuvant therapy (NAT) and the risk of recurrence in resected pancreatic ductal adenocarcinoma (R-PDA).

4171 Background: The clinical significance of MUC5AC glycoforms is unclear to date. Our earlier study showed the association of lower mature (MM) and immature (IM) MUC5AC in R-PDA with pathological treatment response and EC detection of MM (EC-MM). Here, we have the significance of EC-MM detection in the tissue of R-PDA post-NAT. Methods: Formalin-fixed paraffin-embedded tissue blocks of R-PDA from January 2010 to June 2021 were obtained from the Ohio State University biorepository. Using monoclonal antibodies for 45M1 (MM) and CLH2 (IM), immunohistochemistry was performed to study the cellular expression of MM and IM, and H-scores were calculated. Also, the presence or absence of EC expression of MM is noted. progression-free survival (PFS) and overall survival (OS) were the primary endpoints. Univariate and multivariate Cox regression models were used to model PFS and OS, and clinical and pathological variables were adjusted in the multivariate models. We performed univariate logistic regression analysis to examine the impact of MUC5AC expression on pathological features in resected specimens. Results: Among 100 R-PDA patients, 43 received NAT and 57 had upfront surgery (UpS)). In NAT-group (36-FOLFIRINOX, 2-FOLFOX, and 5-gemcitabine/nab-paclitaxel), EC-MM detection in the resected specimens was associated with worse PFS on multivariate analysis (MVA) (Hazard Ratio (HR) 0.2, 95 % CI: 0.059-0.766, p = 0.01). In the FOLFIRINOX-treated group, the EC-MM detection had a similar impact (HR 0.2, 95 % CI: 0.052-0.847, p = 0.02) on PFS. Cellular MM and IM expression were significant (p < 0.05) on MVA for OS in both groups, but the HRs were not clinically significant (NAT-group, MM - 0.9 & IM - 1.04, FOLFIRNIOX-group, MM - 0.8 & IM -1.02). Expression levels of cellular MM and IM in FOLFIRINOX group and MM alone in NAT-group significantly (p < 0.05) correlated with incomplete resection (R1/R2 vs R0) and perineural invasion. In the UpS group, MUC5AC glycoforms did not significantly correlate with survival or pathological features. Conclusions: Post NAT EC-MM detection and cellular MUC5AC (MM and IM) expression levels are associated with worse PFS and pathological features. Their role in the treatment of naïve patients is still unclear. MUC5AC can be a clinically useful predictive biomarker. Future research should focus examining its importance in advanced tumors and manipulating it for therapeutic purposes.

The diagnostic potentiality of the RNA aptamer against progesterone receptor isolated by crush and soak (CRUSOAK)-SELEX.

Aptamers are a class of molecular recognition elements that exhibit high binding affinity and specificity against their respective targets. In view of the many advantages aptamers harbor over their counterpart antibodies, we were impelled to isolate an RNA aptamer against progesterone receptor, particularly its DNA binding domain. A total of eight SELEX cycles were executed against the recombinant Progesterone Receptor DNA-binding domain (PR DBD). The RNA-protein complex in the gel shift assay was subjected to crush and soak method to elute the binders prior to conventional sequencing, the step of which was based upon to coin the term CRUSOAK-SELEX. The sequencing revealed three different classes of sequences, with one class termed, PRapt-3, showing the strongest binding against PR DBD. The dissociation constant of PRapt-3 RNA aptamer was estimated at 380nM ± 35nM. PRapt-3 was successfully used to develop aptamer-based diagnostic assays such as ELASA, aptamer-based dot blot, and aptamer-based western blot. The prominent highlight is the performance of the aptamer in aptacytostaining, which was unachievable with antibodies. Compared to its counterpart antibodies, PRapt-3 has a better penetration capacity in aptahistostaining using the formalin-fixed paraffin-embedded (FFPE) breast cancer cells and tissue blocks. This study represents the first ever demonstration of an aptamer against progesterone receptor and its diagnostic capacity.

Correlation of tumor-associated macrophage density and proportion of M2 subtypes with the pathological stage of colorectal cancer.

Colorectal cancer (CRC) is a prevalent global malignancy with complex prognostic factors. Tumor-associated macrophages (TAMs) have shown paradoxical associations with CRC survival, particularly concerning the M2 subset. We aimed to establish a simplified protocol for quantifying M2-like TAMs and explore their correlation with clinicopathological factors. A cross-sectional study included histopathological assessment of paraffin-embedded tissue blocks obtained from 43 CRC patients. Using CD68 and CD163 immunohistochemistry, we quantified TAMs in tumor stroma and front, focusing on M2 proportion. Demographic, histopathological, and clinical parameters were collected. TAM density was significantly higher at the tumor front, with the M2 proportion three times greater in both zones. The tumor front had a higher M2 proportion, which correlated significantly with advanced tumor stage (P = 0.04), pathological nodal involvement (P = 0.04), and lymphovascular invasion (LVI, P = 0.01). However, no significant association was found between the M2 proportion in the tumor stroma and clinicopathological factors. Our study introduces a simplified protocol for quantifying M2-like TAMs in CRC tissue samples. We demonstrated a significant correlation between an increased M2 proportion at the tumor front and advanced tumor stage, nodal involvement, and LVI. This suggests that M2-like TAMs might serve as potential indicators of disease progression in CRC, warranting further investigation and potential clinical application.

Abstract PS11-07: High prevalence of HER2-Low and AR expression in breast cancer brain metastases provide novel therapeutic options

Abstract Background: Although survival rates for patients with advanced breast cancer (BC) have improved overall, rates of BC brain metastases (BCBM) have increased over the past two decades, occurring in up to 15% to 30% of patients. BCBM greatly reduce quality of life and overall survival (OS) and are now the leading cause of BC patient mortality. Patients with primary HER2+ and triple negative BC (TNBC) are at highest risk for BM. Locoregional therapy with surgery and radiation are currently standard of care (SOC), but these treatments have significant morbidity and BCBM progressing despite these interventions are hard to treat. Systemic therapies to reduce cognitive impairment and increase survival are desperately needed, particularly in HER2-negative patients. Currently, immune checkpoint inhibitors (ICIs) and small molecules such as PARP inhibitors are among the limited systemic options that have BCBM activity in HER2-negative BC. However, the benefit of these therapies is limited to a select group of patients. For example, androgen receptor (AR) is expressed in 60-80% of all BC and, in our recently completed clinical trial (NCT03206203), patients with AR+ metastatic TNBC treated with carboplatin +/- atezolizumab received no clinical benefit from the addition of atezolizumab. Alternatives to ICIs are needed for patients with AR+ TNBC. HER2-low (H2L) BC is a newly defined subset of HER2-negative BC with a HER2 immunohistochemical (IHC) score of 1+ ( >10%) or 2+/in situ hybridization (ISH) negative phenotype. Recent clinical trials have demonstrated significant clinical benefit from novel HER2 antibody-drug conjugates (ADCs) in treating H2L BC. Trastuzumab-deruxtecan (T-Dxd), a HER2-directing ADC (topoisomerase I inhibitor conjugated to a humanized HER2-targeted antibody) was recently FDA approved as the first targeted therapy to treat H2L BC and can penetrate the blood–brain barrier. DESTINY-Breast04 demonstrated notable PFS and OS benefit of T-DXd compared to SOC in patients with H2L metastatic BC and included 61 patients with BCBM (results anticipated shortly). The overall rates of AR and H2L expression in patients with BCBM is unknown. The goal of this study is to investigate the prevalence of AR and HER2-low expression in a large cohort of BCBM treated at our institution. Methods: We retrospectively assessed rates of H2L and AR positivity (AR+) among patients with BCBM whose treatment included surgery at our institution between 2005-2023. Results were correlated with clinical receptor status (HR+/HER2-, HER2+/HR+, HER2+/HR- and TNBC) and clinical characteristics. Results of ER, PR, and HER2 testing performed for clinical purposes on the brain metastases and primary tumors were obtained from pathology reports. We retrieved formalin-fixed paraffin-embedded tissue blocks of the brain metastases and performed IHC for AR (SP107) and prognostic markers for cases with missing data. Results: We identified 101 cases of BCBM. Based on clinical prognostic markers, BCBM subtypes were HR+/HER2- (22%), HR+/HER2+ (14%), HER2+/HR- (21%) and TNBC (43%). Forty-five percent of the BCBM (n=45) were AR+ ( >10%) and 24% (n=24) demonstrated > 50% AR+. Among tumors with >50% AR+, 42% (n=10) are H2L (7 HR+[30%] and 3 TNBC [13%]). Forty-two percent of BCBM were H2L. Among the HER2-negative BCBM (n= 66), 64% (n=42) were H2L, including 23 of 44 TNBC (52%) and 19 of 22 HR+ (86)%. Fifteen percent of BMBC changed clinical subtype from the primary, including conversion to TNBC and H2L. Conclusion: AR+ positive (24% > 50% expression) and HER2-Low expressing (42%) tumors represent a significant proportion of our BCBM cohort providing exciting new options for treatment. Trials re-evaluating AR antagonists in combination with SOC utilizing high AR+ thresholds may benefit patients with BCBM. At least 10% of BCBM are both H2L and demonstrate >50% AR positivity providing the rationale for the combination of ADCs such as T-DXd and AR-targeted therapies for BCBM. Citation Format: Guadalupe Garcia, Paula Gonzalez-Ericsson, Brian Lehmann, Bret Mobley, Jennifer Pietenpol, Laura Kennedy, Ben Park, Melinda Sanders. High prevalence of HER2-Low and AR expression in breast cancer brain metastases provide novel therapeutic options [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS11-07.

Quantitative assessment Cyclooxygenase – 2 immunohistochemical expression in different grades of oral epithelial dysplasia

Oral leukoplakia (OLP) is one the most common potentially malignant disorders account 0.2 to 4.9% of malignant transformation and dysplastic lesions vary from 3-6% this rate of malignant conversion depends on the different grades of epithelial dysplasia. Recent literature suggests that increased levels of COX-2 in potentially malignant disorders and malignant tumors show prominent genetic evidence in tumorigenesis. Assessment of Cyclooxygenase-2 – 2 (COX-2) immunohistochemical expression in different grades of oral epithelial dysplasia. Materials and Methodology A total of forty formalin-fixed, paraffin-embedded tissue blocks were obtained from departmental archives which are histopathological diagnoses of different grades of oral epithelial dysplasia each grade ten samples was included. Stained with COX-2 and positive cells were counted and tabulated for statistical analysis. Results Comparison between genders in oral leukoplakia males was more when compared with females. The mean age in mild epithelial dysplasia was more when compared with moderate and severe epithelial dysplasia. Expression of COX-2 was increased from mild to severe epithelial dysplasia increases. The mean number of positive cells was increased. A comparison of all groups was not statistically significant (p≥0.05). Conclusion: Oral leukoplakia (OLP) is one the most common potentially malignant disorders which accounts for 0.2 to 4.9% of malignant transformation. COX-2 can be used for early detection and prognostic makers in different grades of oral epithelial dysplasia. Keywords: Cyclooxygenase, Expression, Oral leukoplakia, Potentially malignant transformation

Demographics and Pathomorphology of Ameloblastoma: A 9 Year Retrospective Review at a Tertiary Health Care Centre in North-Central Nigeria

Ameloblastoma is a benign but locally invasive neoplasm that arises from odontogenic epithelium of the dental lamina. It is classified into the conventional, unicystic, extraosseous/peripheral and metastasizing variants. It is the most common odontogenic tumour in Nigeria and other developing countries. It affects individuals of all ages, has a peak of occurrence in the fourth and fifth decades with no sex predilection. The Mandible is the most commonly affected site and the conventional variant is predominant. The aim of this study is to document the demographics and Pathomorphology of ameloblastoma diagnosed at the Jos University Teaching Hospital over the past nine years. There is no previous documentation of the pattern of this tumour in the North-central region of Nigeria making this study relevant. This is a retrospective observational review of all cases of ameloblastoma diagnosed histologically at the Jos University Teaching Hospital between January 1st 2015 to December 31st 2023. Materials utilized consisted of patient clinical case files, electronic histopathology result records, histopathology glass slides and formalin fixed paraffin embedded tissue blocks. The patient age, sex, anatomic location of tumour in the Jaw/face and pathomorphological features were recorded for all cases. The data obtained was analysed using Epi-info 7 (version 3.5.4) and Microsoft-Excel. Results were presented in tables and charts. Fifty one cases of ameloblastoma were diagnosed during the 9 years of review. Their ages ranged between 6 and 65 years with a mean age of 30.9±13.8 years and a peak of occurrence in the third decade. There were 29 males and 22 females with a male to female ratio (M:F) of 1.3:1. Ninety-two percent of cases occurred in the mandible and 8% in the maxilla. The conventional variant accounted for 72.5% of cases and the unicystic variant 27.5%. The follicular type accounted for 64.8% of cases of conventional ameloblastoma. Ameloblastoma occurred more commonly in males with a peak in the third decade. A vast majority of cases involved the mandible and the conventional type was predominant. This demographic pattern supports existing evidence that ameloblastoma occurs more commonly in males and in relatively younger patients in Africa.