Oral Dysplasia Research Articles

Proceedings of the North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Oral Cavity Dysplasia: Why Does Histologic Grading Continue to be Contentious?

Head and neck squamous cell carcinoma (HNSCC) is the world's 6th most common malignancy. Oral cavity SCC (OCSCC) represents approximately one third of the HNSCC cases diagnosed annually in the United States. Despite therapeutic advances, OCSCC is frequently lethal, with a modest 5-year survival. Because OCSCC is often preceded by premalignant lesions, it is an ideal disease for screening initiatives. The conventional visual and tactile exam (CVTE), coupled with a tissue biopsy, remains the gold standard. However, CVTE alone cannot reliably differentiate between reactive/inflammatory and dysplastic lesions. Further, the histologic diagnosis of dysplasia is subjective in nature and a highly imperfect predictor of malignant transformation. This prognostic uncertainty creates a significant clinical management dilemma-watchful waiting with increased patient psychological and economic burdens versus unnecessary aggressive treatment. As such, the development and validation of novel diagnostic platforms such as Artificial Intelligence (AI) and prognostic molecular biomarkers may help address these critical unmet clinical needs.

Ki-67 Expression as a Prognostic Marker: A Comparative Immunohistochemical Analysis of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma.

Introduction Oral dysplasia is a frequent precancerous condition that may lead to oral cancer. The histopathologic abnormalities exhibited in a chronic, progressive, and premalignant condition of the oral mucosa are referred to as oral epithelial dysplasia (OED). It might show up as erythroplakia, leukoplakia, or leukoerythroplakia. OED is a premalignancy histologic marker that predicts a higher likelihood of squamous cell carcinoma development. Aims and objectives The aim of this study is to identify an association between Ki-67 protein expression and histological grading of OED and oral squamous cell carcinoma (OSCC) and to compare the expression of Ki-67 in different grades of OED and OSCC with the prognosis. Materials and methods The current retrospective research is focused on evaluating epithelial dysplasia and analyzing the function of Ki-67 as a prognostic marker after receiving institutional ethical approval. Group I - normal oral mucosa (NOM), Group II - OED, and Group III - OSCC were included in the study. For statistical analysis, SPSS Statistics version 21.0 (IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 28.0. Armonk, NY: IBM Corp) was utilized. The Cox regression model was employed to look at interactions between various prognostic variables. At p<0.05, differences were deemed statistically significant. Results Ki-67 expression was confined to the basal layers in the normal oral epithelium and in the basal, suprabasal, and spinous layers in OED.Ki-67 positive cells were mostly found on the perimeter of well, moderate, and poorly differentiated OSCC tumor nests with Ki-67 positive cells scattered throughout OSCC.According to statistical analysis, there is a substantial difference in expression between OEDand NOM, OSCC and NOM, and OED and OSCC. Conclusion Our study showed that there is a progressive increase in Ki-67 expression across various grades of OED, and the highest expression was noted in OSCC. Early identification and prompt treatment will help in improving the quality of life of such patients.

Angiopoietin-like 4 induces head and neck squamous cell carcinoma cell migration through the NRP1/ABL1/PXN pathway

ObjectivesThe molecular mechanisms whereby angiopoietin-like 4 (ANGPTL4), a pluripotent protein implicated in cancer development, contributes to head and neck squamous cell carcinoma (HNSCC) growth and dissemination are unclear. Materials and MethodsWe investigated ANGPTL4 expression in human normal oral keratinocytes (NOKs), dysplastic oral keratinocytes (DOKs), oral leukoplakia cells (LEUK1), and HNSCC cell lines, as well as in tissue biopsies from patients with oral dysplasia, and primary and metastatic HNSCC. We further examined the contribution of ANGPTL4 cancer progression in an HNSCC orthotopic floor-of mouth tumor model and the signaling pathways linking ANGPTL4 to cancer cell migration. ResultsANGPTL4 expression was upregulated in premalignant DOKs and HNSCC cell lines compared to NOKs and was increased in tissue biopsies from patients with oral dysplasia, as well as in primary and metastatic HNSCC. We also observed that downregulation of ANGPTL4 expression inhibited primary and metastatic cancer growth in an HNSCC orthotopic tumor model. Interestingly, ANGPTL4 binding to the neuropilin1 (NRP1) receptor led to phosphorylation of the focal adhesion protein, paxillin (PXN), and tumor cell migration; this was dependent on the tyrosine kinase ABL1. Treatment with the ABL1 inhibitor, dasatinib and small interfering RNA silencing of NRP1 or ABL1 expression blocked PXN phosphorylation and tumor cell migration. ConclusionOur findings suggest an early, sustained, and angiogenesis-independent autocrine role for ANGPTL4 in HNSCC progression and expose ANGPTL4/NRP1/ABL1/PXN as an early molecular marker and vulnerable target for the prevention of HNSCC growth and metastasis.

Preliminary Study of the Cancer Stem Cells' Biomarker CD147 in Leukoplakia: Dysplasia and Squamous Cell Carcinoma of Oral Epithelial Origin.

Objectives Cancer stem cells (CSCs) are responsible for initiating the process of carcinogenesis de novo, as well as through the transformation of oral potential malignant disorders (OPMDs) to oral squamous cell carcinoma (OSCC). The aim of our study was to detect the expression of stemness-type CSC marker CD147 in oral leukoplakias (OLs), the most common OPMD, and OSCCs as well. Materials and methods This study focuses on the semiquantitative immunohistochemical pattern of the expression of the CSCprotein biomarker CD147 in paraffin-embedded samples of 20 OSCCs of different grades of differentiation and 30 cases of OLs without or with different grades of dysplasia, compared to the normal oral epithelium in terms of cells' stain positivity. Statistical analysis wasperformed through Statistical Package for Social Sciences (SPSS) version 25.0(IBM SPSS Statistics, Armonk, NY) with Pearson chi-square test, and the significance level was set at 0.05 (p=0.05). In addition, the study clarified the expression of the respective gene of CD147 through quantitative polymerase chain (qPCR), in paraffin-embedded samples of the two extreme graduations: OLs of mildly dysplastic or non-dysplastic cases (n=10 cases) andOSCCs of moderately/poorly differentiated cases(n=17). Statistical analysis wasthen performed through SPSS version 25.0 with an independent paired t-test, and the significance level was set at 0.05 (p=0.05). Results The gene CD147 was expressed in all cases, although no statistically significant correlations were established. Regarding its protein products, the characteristic membranous staining of CD147 was noticed in the majority of the samples, mostly in the basal and parabasal layers of the epithelium. CD147 was upregulated significantly in the moderately and severely dysplastic OLs than in the mildlydysplastic and non-dysplastic OLs (p=0.008). Also, CD147 was upregulated significantly in the mildly dysplastic and non-dysplastic OLs than in the normal oral epithelium (p=0.012). Discussion The characteristic expression of CD147 in OLs and OSCCs' lesions suggests the presence of stemlike cancer cells, illustrating an underlying effect on the early stages of oral dysplasia, in the OL stage. The clinical application of CD147 as prognostic factor requires the experimental evaluation in larger number of samples. Conclusion Stem cells play an important role in the process of carcinogenesis. A major goal in cancer researchis the identification of specific biomarkers for the detection of cancer stem cells. CD147 is considered as an innovative stem cell marker. Our findings in oral mucosal potentially malignant disorders showed that CD147 is expressed more intenselyin parallel with the progression of the grade of dysplasia in OL.On the other hand, in oral squamous cell carcinoma, CD147 expression remains stable regardless of the degree of differentiation.

Abstract 3930: MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma

Abstract Introduction: Most oral squamous cell carcinomas (OSCC) progress through clinically identifiable stages, starting from premalignant epithelial dysplasia to early invasive OSCC. How cells transform from premalignant dysplasia to early invasive OSCC is unknown. High monocarboxylate transporter 1 (MCT1; SLC16A1) expression is correlated with poor outcomes in OSCC patients, where it is thought to promote tumor growth by supporting metabolic coupling between cancer cells and tumor stroma. Because expression of MCT1 is markedly increased in OSCC patients, we sought to determine if MCT1 played a role in the progression of oral dysplasia in early invasive OSCC. Methods: Immunohistochemistry (IHC) was used to evaluate changes in the levels of MCT1 expression across adjacent normal, dysplasia, and OSCC tissues to identify expression patterns during cancer progression. Genetic knockout (KO) of SLC16A1 via CRISPR/Cas9 and pharmacological blockade by the MCT1 inhibitor AZD3965 were used on OSCC (TR146) and dysplastic (DOK) cell lines. KO was confirmed by qRT-PCR and immunoblotting. MCT1-KO and AZD3965-treated cells were assayed for changes in cell invasion using Matrigel-coated transwell assays. Correlative changes in gene expression based on MCT1 staining and disease progression were also observed in adjacent normal, dysplasia, and OSCC regions in each tissue section using Nanostring GeoMx Digital Spatial Profiler. Results: Expression of MCT1 was directly correlated to the progression of disease from dysplasia to early superficially invasive OSCC relative to normal adjacent epithelium. KO of MCT1 significantly decreased the invasion of dysplastic and OSCC cell lines compared to the wild-type (parental) controls. AZD3965 also decreased invasion in the parental dysplastic and OSCC lines. To identify progressive changes in gene expression across normal, dysplasia, and early invasive OSCC, transcripts for cancer-related genes were quantified in the epithelial and stromal compartments from patient samples. Compared to the normal epithelium, upregulation in gene expression, including SLC16A1, was observed in the cell cycle and metabolic pathways in OSCC tissues. Conclusions: Our data suggest that MCT1 plays a key role in breaching of the basement membrane and facilitating tumor cell migration and invasion. Targeting MCT1 in oral dysplasia may prevent progression to OSCC in oral cancer patients. Citation Format: Ethan J. Wong, Ali Khammanivong, Ravi Maisuria, Erin B. Dickerson, Raj Gopalakrishnan. MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3930.

Point-of-care Analysis for Non-invasive Diagnosis of Oral cancer (PANDORA): A technology-development proof of concept diagnostic accuracy study of dielectrophoresis in patients with oral squamous cell carcinoma and dysplasia.

Delays in the identification and referral of oral cancer remain frequent. An accurate and non-invasive diagnostic test to be performed in primary care may help identifying oral cancer at an early stage and reduce mortality. Point-of-care Analysis for Non-invasive Diagnosis of Oral cancer (PANDORA) was a proof-of-concept prospective diagnostic accuracy study aimed at advancing the development of a dielectrophoresis-based diagnostic platform for oral squamous cell carcinoma (OSCC) and epithelial dysplasia (OED) using a novel automated DEPtech 3DEP analyser. The aim of PANDORA was to identify the set-up of the DEPtech 3DEP analyser associated with the highest diagnostic accuracy in identifying OSCC and OED from non-invasive brush biopsy samples, as compared to the gold standard test (histopathology). Measures of accuracy included sensitivity, specificity, positive and negative predictive value. Brush biopsies were collected from individuals with histologically proven OSCC and OED, histologically proven benign mucosal disease, and healthy mucosa (standard test), and analysed via dielectrophoresis (index test). 40 individuals with OSCC/OED and 79 with benign oral mucosal disease/healthy mucosa were recruited. Sensitivity and specificity of the index test was 86.8% (95% confidence interval [CI], 71.9%-95.6%) and 83.6% (95% CI, 73.0%-91.2%). Analysing OSCC samples separately led to higher diagnostic accuracy, with 92.0% (95% CI, 74.0%-99.0%) sensitivity and 94.5% (95% CI, 86.6%-98.5%) specificity. The DEPtech 3DEP analyser has the potential to identify OSCC and OED with notable diagnostic accuracy and warrants further investigation as a potential triage test in the primary care setting for patients who may need to progress along the diagnostic pathway and be offered a surgical biopsy.

Transcriptomic analysis predicts the risk of progression of premalignant lesions in human tongue

The 5-year survival rate for patients with oral squamous cell carcinomas (SCC), including tongue SCC, has not significantly improved over the last several decades. Oral potentially malignant disorders (OPMD), including oral dysplasias, are oral epithelial disorders that can develop into oral SCCs. To identify molecular characteristics that might predict conversion of OPMDs to SCCs and guide treatment plans, we performed global transcriptomic analysis of human tongue OPMD (n = 9) and tongue SCC (n = 11) samples with paired normal margin tissue from patients treated at Weill Cornell Medicine. Compared to margin tissue, SCCs showed more transcript changes than OPMDs. OPMDs and SCCs shared some altered transcripts, but these changes were generally greater in SCCs than OPMDs. Both OPMDs and SCCs showed altered signaling pathways related to cell migration, basement membrane disruption, and metastasis. We suggest that OPMDs are on the path toward malignant transformation. Based on patterns of gene expression, both OPMD and tongue SCC samples can be categorized into subclasses (mesenchymal, classical, basal, and atypical) similar to those seen in human head and neck SCC (HNSCC). These subclasses of OPMDs have the potential to be used to stratify patient prognoses and therapeutic options for tongue OPMDs. Lastly, we identified a gene set (ELF5; RPTN; IGSF10; CRMP1; HTR3A) whose transcript changes have the power to classify OPMDs and SCCs and developed a Firth logistic regression model using the changes in these transcripts relative to paired normal tissue to validate pathological diagnosis and potentially predict the likelihood of an OPMD developing into SCC, as data sets become available.

Clinical resolution in diagnosis of leukoplastic lesion associated with oral dysplasia: case report

The objective of the present study is to report a clinical case that emphasizes the diagnosis of mild epithelial dysplasia located in the unilateral region of the buccal mucosa. Patient, 49 years old, female, pheoderma, attended the dental clinic of the Nilton Lins University, referring a dental fracture as the main reason for the consultation. The intraoral clinical examination revealed a unilateral lesion in the buccal mucosa with plaque characteristics and whitish coloration. Initially, it was decided to perform an excisional biopsy of the lesion with a diagnostic hypothesis of lichen planus. The extracted pieces were sent to the Department of Pathology and Legal Medicine of the Federal University of Amazonas School of Medicine for confirmation of the diagnostic hypothesis, confirmed by the report as mild epithelial dysplasia. Subsequently, the patient was referred to perform the other dental procedures that were later scheduled and is under follow-up, with no complaints or adverse complications. Therefore, given the clinical resolution presented, the differential diagnosis was essential, enabling a satisfactory clinical conduct.

Somatic Variants and Exon-Level Copy Number Changes in Five Hyperplastic Oral Leukoplakias

Oral leukoplakia (OL), an oral potentially malignant disorder, begins with a hyperplastic/hyperkeratotic stage at which no genome-scale somatic single nucleotide variant profiles have been described so far. We performed exome sequencing of five cases at this stage with no evidence of dysplasia to identify genetic alterations (exon-level copy number alterations, indels, and single nucleotide variants), their association with transcript levels, and relationship with oral cancer susceptibility. Pathway enrichment analysis of genes associated with tobacco chewing and age-related mutation signatures, transcripts with variants predicted to be functionally damaging and those with significantly altered levels all indicated the involvement of focal adhesion, ECM-receptor interactions, regulation of cytoskeleton, and DNA repair. Two novel mutations identified in FAT1 tumor suppressor gene were associated with decreased transcript levels. In addition, 16 expressed cancer driver genes contained functionally damaging variants. Many of the affected genes were also reported in dysplastic OL lesions. The presence of variants in cancer driver genes and those shared with oral dysplasias possibly provides a basis for further progression and increased susceptibility to oral cancer.

GPR68 limits the severity of chemical-induced oral epithelial dysplasia

Head and neck cancer is the sixth most common malignancy, and there is an urgent need to identify physiological processes contributing to tumorigenesis. Extracellular acidification caused by aerobic glycolysis within tumor microenvironments can stimulate proton-sensing receptors. GPR68, or ovarian cancer G protein-coupled receptor 1, responds to extracellular acidity and is highly expressed in head and neck squamous cell carcinoma (HNSCC) as well as normal esophageal tissue. To study the role of GPR68 in oral dysplasia, wild-type and GPR68−/− mice were treated with 4-Nitroquinoline N-oxide (4NQO) in drinking water for 11–13 weeks, followed by normal water for 11–12 weeks. 4NQO treatment resulted in 45 percent of GPR68−/− mice developing severe dysplasia or squamous cell carcinoma compared to only 10.5 percent of GPR68+/+ mice. This correlated with increased frequencies of regulatory T cells in the spleens of male GPR68−/− mice. Dysplastic regions of the tongue had increased CD31 staining compared to normal regions in both GPR68−/− and GPR68+/+ mice, suggesting that angiogenesis was GPR68-independent. RNA knockdown studies using HNSCC cell lines demonstrated no direct effect of GPR68 on survival or growth. Overall, we demonstrate that GPR68-deficiency worsens the severity of chemical-induced oral dysplasia, suggesting a protective role for this gene in tumorigenesis.

Spatial PD-L1, immune-cell microenvironment, and genomic copy-number alteration patterns and drivers of invasive-disease transition in prospective oral precancer cohort.

Studies of the immune landscape led to breakthrough trials of programmed death-1 (PD-1) inhibitors for recurrent/metastatic head and neck squamous cell carcinoma therapy. This study investigated the timing, influence of somatic copy-number alterations (SCNAs), and clinical implications of PD-L1 and immune-cell patterns in oral precancer (OPC). The authors evaluated spatial CD3, CD3/8, and CD68 density (cells/mm2 ) and PD-L1 (membranous expression in cytokeratin-positive intraepithelial neoplastic cells and CD68) patterns by multiplex immunofluorescence in a 188-patient prospective OPC cohort, characterized by clinical, histologic, and SCNA risk factors and protocol-specified primary end point of invasive cancer. The authors used Wilcoxon rank-sum and Fisher exact tests, linear mixed effect models, mediation, and Cox regression and recursive-partitioning analyses. Epithelial, but not CD68 immune-cell, PD-L1 expression was detected in 28% of OPCs, correlated with immune-cell infiltration, 9p21.3 loss of heterozygosity (LOH), and inferior oral cancer-free survival (OCFS), notably in OPCs with low CD3/8 cell density, dysplasia, and/or 9p21.3 LOH. High CD3/8 cell density in dysplastic lesions predicted better OCFS and eliminated the excess risk associated with prior oral cancer and dysplasia. PD-L1 and CD3/8 patterns revealed inferior OCFS in PD-L1 high intrinsic induction and dysplastic immune-cold subgroups. This report provides spatial insight into the immune landscape and drivers of OPCs, and a publicly available immunogenomic data set for future precancer interrogation. The data suggest that 9p21.3 LOH triggers an immune-hot inflammatory phenotype; whereas increased 9p deletion size encompassing CD274 at 9p24.1 may contribute to CD3/8 and PD-L1 depletion during invasive transition. The inferior OCFS in PD-L1-high, immune-cold OPCs support the development of T-cell recruitment strategies.

CD44 Expression in Oral Lichen Planus and Related Lesions-An Immunohistochemical Study.

Cluster of differentiation 44 (CD44) is a cell surface adhesion protein involved in the progression and metastasis of oral squamous cell carcinoma. The current study aims to evaluate the expression of CD44 in oral lichen planus and related lesions and thereby assess the relative risk of malignant transformation of these lesions. Formalin-fixed paraffin-embedded tissue blocks of 10 oral lichen planus (Group 1), 10 oral lichenoid lesions (Group 2), 8 with oral lichen planus with dysplasia (Group 3), and 5 with lichenoid dysplasia (Group 4) were included in the study. Immunostaining was done for the tissue sections using CD44 mouse monoclonal antibody. Staining density, staining intensity, and immunoreactive scores of CD44 were evaluated in all four groups. Statistical analysis was done by Statistical Package for the Social Sciences® software and the Kruskal-Wallis test was used. CD44 staining pattern of lichenoid dysplasia and lichen planus with dysplasia changed from membranous to cytoplasmic. The membranous CD44 immunoreactivity was mild with a score of 2.25 for Group 3 and 1.6 for Group 4 whereas moderate for other groups with a P-value of 0.009. The cytoplasmic immunoreactivity was significantly high in Group 3 (5.3 ± 2.6) followed by Group 4 (3.2 ± 1.2), Group 2 (1 ± 1.8), and Group 1 (0.7 ± 1.3) with a P-value of 0.001. The CD44 membranous immunoreactivity scores were low while the cytoplasmic immunoreactivity was high in oral lichen planus with dysplasia and oral lichenoid dysplasia when compared to oral lichen planus and oral lichenoid lesions. CD44 immunostaining pattern can help in assessing the malignant transformation of oral lichen planus or lichenoid lesions.

To evaluate eosinophilia (tissue eosinophilia, blood eosinophilia and tissue eosinophilia/blood eosinophilia ratio) in increasing grades/ severity of oral neoplastic lesions.

Oral squamous cell carcinoma (OSCC) is the most common cause of morbidity and mortality in India. Buccal mucosa is the most common site because of tobacco quid. Several parameters for the assessment of OSCC have been studied like lymph node metastasis, tumor stage, grade, and perineural invasion. Tumor-associated tissue eosinophilia is another parameter, on which several studies have been done because of its favorable and unfavorable prognosis. The aim of our study is to study quantitative and qualitative eosinophilia in premalignant and malignant lesions of squamous origin in oral cavity with respect to tumor-associated blood eosinophilia. A retrospective study was done at Tertiary care hospital between January 2016 and December 2016. A total of 150 cases of premalignant (oral leukoplakia and dysplasia) and malignant oral squamous cell carcinoma (of various grades) along with blood pictures were evaluated.

Salivary miRNAs Expression in Potentially Malignant Disorders of the Oral Mucosa and Oral Squamous Cell Carcinoma: A Pilot Study on miR-21, miR-27b, and miR-181b

(1) Background: Oral potentially malignant disorders (OPMD) represent a fundamental challenge for clinicians, considering the possibility of progression into oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Several studies have examined the expression of miRNAs in humans as diagnostic and prognostic biomarkers. Among these, miR-21, miR-27b, and miR-181b proved to be promising. This cohort study evaluated the different expressions of those miRNAs in the saliva of patients with OPMD and OSCC. (2) Methods: Patients with a clinical diagnosis of OPMD and/or OSCC were enrolled; saliva samples were collected; miRNAs were extracted and quantified via qRT-PCR was performed. Data were analyzed by subgroups based on the histopathological diagnosis (OSCC and the grade of OED) using the ΔΔCt method. Saliva from 10 healthy donors was used as the control. One-way ANOVA and Kruskal-Wallis tests were performed to assess the differences between groups. (3) Results: 23 patients for the OPMD group (6 with no dysplasia, 7 with low-grade, and 10 with high-grade dysplasia) and 10 with OSCC were analyzed. MiR-21 did not show any variation among groups; miR-27b was under-expressed in dysplastic lesions (p = 0.046); miR-181b was upregulated in high-grade dysplasia (p = 0.006), increasing with the degree of dysplasia, and decreasing in OSCCs. (4) Conclusions: Salivary miR-27b and miR-181b could be promising biomarkers for oral dysplasia. Further studies are needed to clarify their feasibility.

48. Evaluation of microbiotal changes in head and neck cancer

Traditional risk factors for head and neck cancer (SCCHN) remain tobacco and alcohol use but an increasing proportion of patients present without these risk factors. Non-smoking, non-drinking (NSND) patients are increasing, with reports of worse survival. Growing evidence links dysplastic oral and circulatory microbiome with an increased risk for oral carcinogenesis in NSND patients. We are analysing the oral, circulatory and faecal microbiota in patients with oral dysplasia and SCCHN.

Salivary oxidative stress level among tobacco chewers and smokers: A comparative Study.

Tobacco contains various toxic contents which produce oxygen-free radicals that damage oral tissues. Since saliva encounters tobacco, it has antioxidant defense system and also can serve as a biomarker for oral diseases. Thus, the present study aims to evaluate salivary oxidative stress levels among smokers and chewers. Unstimulated saliva from 240 males who visited tobacco cessation clinic for the first time was collected. Standard protocol was followed to collect saliva and assess salivary antioxidant levels from 80 participants with the habit of smoking, smokeless, and both (smoking and smokeless) tobacco users. The collected data were statistically analyzed. The mean salivary superoxide dismutase and malonyldialdehyde levels were significantly high for participants with both habits (P < 0.000). There was a significant high reduction of glutathione peroxidase and catalase in participants with both habits (P < 0.000). Both smoking and smokeless tobacco modify salivary antioxidant activity. The estimation of salivary oxidative stress can serve as a diagnostic and prognostic biomarker for oral tissue damage and dysplasia. Furthermore, they can function as early biomarkers in preventing dysplastic changes in the oral cavity.

POTENTIAL BIOMARKERS FOR EARLY DETECTION OF ORAL CANCER: LEPTIN AND ADIPONECTIN

Aim: To determine adiponectin and leptin expression levels in samples from healthy, dysplastic and cancerous oral lesions and to investigate the potential role of these biomarkers in oral cancer development. &#x0D; Methods: Tissue samples from the archives which were histologically diagnosed as oral squamous cell carcinoma (OSCC) (n=24), oral dysplasia (n=12) and healthy tissue (n=16) were included. The concentration and purity of samples were determined after total RNA extraction. Thereafter, cDNA synthesis was performed. The differences between expression levels were evaluated with qPCR. Expression levels related to OSCC were performed according to normalizing gene ACTB. 2-ΔΔCT method was used for comparison of expression levels. Student t-test was used to compare the differences in gene expression levels between groups, using 2-ΔΔCT value for each gene. &#x0D; Results: Adiponectin and leptin expression levels were decreased by 1.09 (p = 0.49) and 10.3 (p = 0.22), respectively, in OSCC group, however differences were not statistically significant. The level of adiponectin expression decreased by 1.65 times (p = 0.62) and leptin expression increased by 3 times (p = 0.30) in the dysplasia group. When OSCC and dysplasia groups were compared, it was found that the level of adiponectin expression increased by 1.52 times (p = 0.99) and the level of leptin expression decreased by 30.94 times (p = 0.16) in the OSCC group. The samples were re-grouped as increased risk (OSCC+dysplasia) (n=36) and healthy (n=16) and a decrease by 16.5 (p= 0.3) in leptin expression and an increase by 1.14 (p= 0.6) in adiponectin expression was observed in the increased risk group compared to the healthy group.&#x0D; Conclusion: In tissue samples diagnosed as healthy, dysplastic and OSCC, expression levels for leptin and adiponectin have not been compared before. The results revealed a significant decrease in leptin expression and an increase in adiponectin expression in increased risk group.

Association of Stathmin (Op18) with TNM Staging and Grading of Oral Squamous Cell Carcinoma and Its Role in Tumor Progression

The purpose of the study was to evaluate the expression of stathmin in different histological grades and tumor, node, metastasis (TNM) staging of Oral carcinoma and various grades of oral dysplasia. The study also aims at observing the stathmin expression with respect to lymph node metastasis. A total of 90 histopathologically confirmed tissue sections were acquired, of which 30 sections of oral dysplasia, 30 oral squamous cell carcinoma (OSCC) and 30 normal tissue sections were stained immunohistochemically with stathmin. The tissue sections, were categorized into different grades of oral dysplasia and OSCC based on histopathological examination. For estimation of stathmin expression, manual examination of 300 cells was done in a minimum of five different areas of tissue section and a mean proportion of positive-stained cells were determined. The statistical analysis of the results was done using ANOVA test. A statistically significant increase in mean staining scores of stathmin in OSCC group compared to dysplasia and control groups. A statistically significant difference was observed in different grades of dysplasia and OSCC groups. Stage III and stage IV OSCC tissue sections showed high intensity staining scores of stathmin expression. An increased expression of stathmin was detected in various grades of OSCC and also with respect to staging of oral cancer. Half the cases of OSCC with lymph node metastasis showed high intensity scores of stathmin. Based on the above facts, stathmin expression was indicated as a potential tool for predicting the outcome of oral cancer patients with lymph node metastasis and its expression was increased in the group with poor prognosis. Any damage/mutation to stathmin can result in defects in cell division resulting in aneuploidy and in turn cancers. In this study, the results showed that there is a differential expression of stathmin in the early and the advanced grades and different TNM stages of OSCC. A high expression of stathmin was observed in all the cases with lymph node metastasis. These observations prove that stathmin has an important role in the progression, tumorigenicity, and prognosis of the oral cancer.

Recurrence of premalignant oral cavity and oropharynx lesions after pulsed diode laser treatment

PurposeLeukoplakia is common with a 1 % incidence in the population and may harbor preneoplastic changes. Diode lasers provide both precision and coagulation for excision of superficial lesions in clinical and operative settings with little damage to deeper tissue. We aim to determine the rate of oral and oropharyngeal hyperkeratosis and dysplasia recurrence after treatment with diode laser. Materials and methodsPatients with oral or oropharyngeal hyperkeratotic or mild dysplastic lesions treated with pulsed diode laser between 2013 and 2020 at a tertiary academic institution were analyzed. The main outcome measure was recurrence of hyperkeratosis and dysplasia after treatment. ResultsFourteen patients received diode laser treatment for hyperkeratotic or mild dysplastic lesions of the oral cavity or oropharynx. Demographic features included 9 (64.3 %) females and mean age of 66.6 years. In these 14 patients, 18 distinct lesions were identified. Eleven (61.1 %) lesions were located on the oral tongue, 4 (22.2 %) on the buccal mucosa, 2 (11.1 %) on the hard palate, and 1 (5.6 %) on the soft palate. Average time from lesion clinical diagnosis to the first diode laser treatment was 8.3 months with an average number of 1.4 treatments per lesion. Three (16.7 %) lesions experienced recurrence after the most recent treatment. None of the lesions underwent malignant transformation. None of the patients experienced bleeding, tethering, or dysarthria after treatment. One patient developed pyogenic granuloma and reported chronic tongue pain. ConclusionsPulsed diode laser treatment of leukoplakia was well tolerated with low complication rates and reasonable control of precancerous lesions.

Predicting Progression of Oral Lesions to Malignancy Using Machine Learning.

To use large-scale electronic health record (EHR) data to develop machine learning models predicting malignant transformation of oral lesions. A multi-institutional health system database was used to identify a retrospective cohort of patients with biopsied oral lesions. The primary outcome was malignant transformation. Chart review and automated system database queries were used to identify a range of demographic, clinical, and pathologic variables. Machine learning was used to develop predictive models for progression to malignancy. There were 2192 patients with a biopsied oral lesion, of whom 1232 had biopsy proven oral dysplasia. There was malignant transformation in 34% of patients in the oral lesions dataset, and in 54% of patients in the dysplasia subset. Multiple machine learning-based models were trained on the data in two experiments, (a) including all patients with biopsied oral lesions and (b) including only patients with biopsy-proven dysplasia. In the first experiment, the best machine learning models predicted malignant transformation among the biopsied oral lesions with an area under the curve (AUC) of 86%. In the second experiment, the random forest model predicted malignant transformation among lesions with dysplasia with an AUC of 0.75. The most influential features were dysplasia grade and the presence of multiple lesions, with smaller influences from other features including anemia, histopathologic description of atypia, and other prior cancer history. With diverse features from EHR data, machine learning approaches are feasible and allow for generation of models that predict which oral lesions are likely to progress to malignancy. 3 Laryngoscope, 133:1156-1162, 2023.