p53 Abnormal Oral Epithelial Dysplasias are Associated With High Risks of Progression and Local Recurrence-A Retrospective Study in a Longitudinal Cohort.

Grading of oral epithelial dysplasia (OED) can be challenging with considerable intraobserver and interobserver variability. Abnormal immunohistochemical staining patterns of the tumor suppressor protein, p53, have been recently shown to be potentially associated with progression in OED. We retrospectively identified 214 oral biopsies from 203 patients recruited in a longitudinal study between 2001 and 2008 with a diagnosis of reactive, nondysplastic lesions, low-grade lesions (mild OED and moderate OED) and high-grade lesions (HGLs; severe OED/carcinoma in situ). Tissue microarrays were constructed from the most representative area of the pathology. Three consecutive sections were sectioned and stained for hematoxylin and eosin, p53 immunohistochemistry, and p16 immunohistochemistry. The staining results were reviewed by 2 pathologists (Y.C.K.K., C.F.P.) blinded to clinical outcome. Samples were categorized into p53 abnormal OED (n = 46), p53 conventional OED (n = 118), and p53 human papillomavirus (HPV) OED (HPV associated) (n = 12) using a previously published pattern-based approach. All cases of p53 HPV OED (HPV associated) were identified in HGLs. In contrast, cases of p53 abnormal OED were observed in mild OED (9.5%), moderate OED (23%), and severe OED/carcinoma in situ (51%). None of the 27 reactive or nondysplastic lesions showed abnormal p53 staining patterns. Among the 135 low-grade lesions, 23 cases (17.0%; 2 mild OEDs and 21 moderate OEDs) progressed to HGL or squamous cell carcinoma, with 11 cases showing progression within the first 3 years. Remarkably, 82% (9/11) of these faster progressors showed abnormal p53 patterns. Survival analysis revealed that p53 abnormal OED had significantly poorer progression-free probability (P < .0001) with hazard ratio of 11.24 (95% CI, 4.26-29.66) compared with p53 conventional OED. Furthermore, p53 abnormal OED had poorer local recurrence-free survival compared with p53 wild-type OED (P = .03). The study supports that OED with p53 abnormal pattern is at high risk for progression and recurrence independent of the dysplasia grade.

Dental pulp stem cells promote malignant transformation of oral epithelial cells through mitochondrial transfer.

Oral epithelial dysplasia includes a range of clinical oral mucosal diseases with potentially malignant traits. Dental pulp stem cells (DPSCs) are potential candidates for cell-based therapies targeting various diseases. However, the effect of DPSCs on the progression of oral mucosal precancerous lesions remains unclear. Animal experiments were conducted to assess the effect of human DPSCs (hDPSCs). We measured the proliferation, motility and mitochondrial respiratory function of the human dysplastic oral keratinocyte (DOK) cells cocultured with hDPSCs. Mitochondrial transfer experiments were performed to determine the role mitochondria from hDPSCs in the malignant transformation of DOK cells. hDPSCs injection accelerated carcinogenesis in 4NQO-induced oral epithelial dysplasia in mice. Coculture with hDPSCs increased the proliferation, migration, invasion and mitochondrial respiratory function of DOK cells. Mitochondria from hDPSCs could be transferred to DOK cells, and activated mTOR signaling pathway in DOK cells. Our study demonstrates that hDPSCs activate the mTOR signaling pathway through mitochondrial transfer, promoting the malignant transformation of oral precancerous epithelial lesions.

Understanding interobserver variability of pathologists to improve oral epithelial dysplasia grading.

OBJECTIVE: This study aimed to understand reasons for interobserver variability in the grading of oral epithelial dysplasia (OED) through a survey of pathologists to provide insight for improvements in the reliability and reproducibility of OED diagnoses. METHODS: The study design included quantitative and qualitative methodology. A pre-validated 31-item questionnaire was distributed to general, head and neck, and oral and maxillofacial histopathology specialists worldwide. RESULTS: A total of 132 pathologists participated and completed the questionnaire. Over two-thirds used the three-tier grading system for OED, while about a third used both binary and three-tier systems. Regular reporters of OED preferred the three-tier system and grading architectural features. Continuing education significantly aided recognition of architectural and cytological changes. Irregular epithelial stratification and drop-shaped rete ridges had the lowest prognostic value and recognition scores, while loss of epithelial cell cohesion had the highest. Most participants used clinical information and often sought a second opinion when grading OED. CONCLUSION: Our study has found that frequency of OED reporting and attendance of CME/CPD can play an important role in grading OED. Variations in the prognostic value of individual histological features and the use of clinical information may further contribute to interobserver variability.

Biomarkers of epithelial-mesenchymal transition: E-cadherin and beta-catenin in malignant transformation of oral lesions.

Objective: Detecting oral lesions at high risk of becoming cancer may enable early interventions to prevent oral cancer. The diagnosis of dysplasia in an oral lesion is used to predict this risk but is subject to interobserver and intraobserver variability. Studying biomarkers or molecular markers that reflect underlying molecular alterations can serve as an additional and objective method of risk assessment. E-cadherin and beta-catenin, molecular markers of epithelial-mesenchymal transition (EMT), potentially contribute to early malignant progression in oral tissue. This narrative review provides an overview of EMT, its relation to oral cancer, and the interaction among E-cadherin, beta-catenin, and the Wnt pathway in malignant progression of oral tissue. Methods: Full-text literature on EMT, E-cadherin, beta-catenin, oral epithelial dysplasia, and oral cancer was retrieved from PubMed and Google Scholar. Results: Sixty original research articles, reviews, and consensus statements were selected for review. Discussion: EMT, a biological mechanism characterized by epithelial and mesenchymal changes, can contribute to cancer development. Molecular markers of EMT including TWIST, vimentin, and N-cadherin may serve as prognostic markers of oral cancer. Dependent on Wnt pathway activity and the loss of membranous E-cadherin, E-cadherin and beta-catenin can play various roles along the spectrum of malignant progression, including tumour inhibition, early tumour progression, and late-stage tumour progression. Cross-sectional immunohistochemical research has found changes in expression patterns of E-cadherin and beta-catenin from normal oral tissue, oral epithelial dysplasia, to oral squamous cell carcinoma. Conclusion: Future research should explore the longitudinal role of EMT markers in predicting malignant progression in oral tissue.

Objectif: La détection de lésions buccales présentant un risque élevé d'évoluer en cancer peut permettre des interventions précoces pour prévenir le cancer de la bouche. Le diagnostic de dysplasie dans le cas de lésions buccales sert à prédire ce risque, mais il est soumis à une variabilité d'un observateur à l'autre et avec le même observateur. L'étude de marqueurs biologiques ou de marqueurs moléculaires correspondant à des altérations moléculaires sous-jacentes peut constituer une méthode objective supplémentaire d'évaluation des risques. L'E-cadhérine et la bêta-caténine, des marqueurs moléculaires de la transition épithélio-mésenchymateuse (TEM), pourraient contribuer aux premières étapes de l'évolution maligne du tissu buccal. Cette revue narrative donne un aperçu de la TEM, de ses liens avec le cancer de la bouche et de l'interaction entre l'E-cadhérine, la bêta-caténine et la voie de signalisation Wnt dans l'évolution maligne du tissu buccal. Méthodes: On a obtenu le texte intégral d'études portant sur la TEM, l'E-cadhérine, la bêta-caténine, la dysplasie épithéliale buccale et le cancer de la bouche sur PubMed et Google Scholar. Résultats: Soixante articles sur des études originales, des revues et des déclarations de consensus ont été sélectionnés aux fins d'examen. Discussion: La TEM, un mécanisme biologique caractérisé par des changements épithéliaux et mésenchymateux, peut contribuer à l'apparition d'un cancer. Les marqueurs moléculaires de la TEM, notamment TWIST, la vimentine et la N-cadhérine, peuvent servir de marqueurs pronostiques du cancer de la bouche. En fonction de l'activité de la voie de signalisation Wnt et de la perte de l'E-cadhérine membraneuse, l'E-cadhérine et la bêta-caténine peuvent jouer divers rôles dans le spectre de l'évolution maligne, notamment l'inhibition tumorale, la progression tumorale précoce et l'évolution tumorale avancée. Des études transversales d'immunohistochimie ont révélé des changements dans les modèles d'expression de l'E-cadhérine et de la bêta-caténine avec le passage du tissu buccal normal, de la dysplasie épithéliale buccale au carcinome squameux de la bouche. Conclusion: À l'avenir, des études devraient explorer le rôle longitudinal des marqueurs de la TEM dans la prévision de l'évolution maligne dans les tissus buccaux.

Artificial Intelligence Applications in Oral Cancer and Oral Dysplasia.

Oral squamous cell carcinoma (OSCC) is a highly unpredictable disease with devastating mortality rates that have not changed over the past decades, in the face of advancements in treatments and biomarkers, which have improved survival for other cancers. Delays in diagnosis are frequent, leading to more disfiguring treatments and poor outcomes for patients. The clinical challenge lies in identifying those patients at the highest risk of developing OSCC. Oral epithelial dysplasia (OED) is a precursor of OSCC with highly variable behavior across patients. There is no reliable clinical, pathological, histological, or molecular biomarker to determine individual risk in OED patients. Similarly, there are no robust biomarkers to predict treatment outcomes or mortality in OSCC patients. This review aims to highlight advancements in artificial intelligence (AI)-based methods to develop predictive biomarkers of OED transformation to OSCC or predictive biomarkers of OSCC mortality and treatment response. Biomarkers such as S100A7 demonstrate promising appraisal for the risk of malignant transformation of OED. Machine learning-enhanced multiplex immunohistochemistry workflows examine immune cell patterns and organization within the tumor immune microenvironment to generate outcome predictions in immunotherapy. Deep learning (DL) is an AI-based method using an extended neural network or related architecture with multiple "hidden" layers of simulated neurons to combine simple visual features into complex patterns. DL-based digital pathology is currently being developed to assess OED and OSCC outcomes. The integration of machine learning in epigenomics aims to examine the epigenetic modification of diseases and improve our ability to detect, classify, and predict outcomes associated with epigenetic marks. Collectively, these tools showcase promising advancements in discovery and technology, which may provide a potential solution to addressing the current limitations in predicting OED transformation and OSCC behavior, both of which are clinical challenges that must be addressed in order to improve OSCC survival.

Controversies regarding oral lichen planus and lichenoid-dysplastic lesions.

Objective: Oral lichen planus (OLP) is an immune-mediated condition featuring chronic inflammation. The World Health Organization classifies OLP as potentially malignant, but it is believed that the malignant transformation of OLP occurs in lesions with both lichenoid and dysplastic features (LD). This review discusses the issues surrounding OLP and LD, including their malignancy, classification, and categorization, and whether lichenoid inflammation causes dysplastic changes in LD or vice versa. Methods: English full-text literature on OLP, LD and/or dysplasia was retrieved from PubMed, CINAHL, and Google Scholar. Results: Thirty-six publications including original research articles, reviews, meta-analyses, books, reports, letters, and editorials were selected for review. Discussion: Research suggests that OLP has malignant potential, although small, and that LD should not be disregarded, as dysplasia presenting with or without lichenoid features may develop into cancer. There is also disagreement over the classification and categorization of LD. Different terms have been used to classify these lesions, including lichenoid dysplasia, OLP with dysplasia, and dysplasia with lichenoid features. Moreover, in LD, it is not clear if dysplasia or lichenoid infiltration appears first, and if inflammation is a response to dysplasia or if dysplasia is a response to the persistent inflammation. The main limitation in the literature is the inconsistency and subjective nature of histological diagnoses, which can lead to interobserver and intraobserver variation, ultimately resulting in the inaccurate diagnosis of OLP and LD. Conclusion: Although further research is required to understand OLP and LD, both lesions should be considered potentially malignant and should not be disregarded.

Objectif: Le lichen plan buccal (LPB) est une pathologie auto-immune qui se présente sous la forme d'une inflammation chronique. Selon la classification de l'Organisation mondiale de la santé, le LPB est une pathologie potentiellement maligne. Toutefois, on soupçonne que la transformation maligne du LPB se produit dans des lésions présentant à la fois des caractéristiques lichénoïdes et dysplasiques (LD). Cet examen porte sur les questions relatives au LPB et aux LD, notamment leur malignité, leur classification et leur catégorisation, et pour savoir si l'inflammation du lichénoïde entraîne des changements dysplasiques des LD ou vice versa. Méthodes: On a utilisé le texte intégral de documents rédigés en anglais sur le LPB, les LD et la dysplasie issus de PubMed, de CINAHL et de Google Scholar. Résultats: Trente-six publications, notamment des articles sur des études originales, des revues, des méta-analyses, des livres, des rapports, des lettres et des éditoriaux, ont été sélectionnées aux fins d'examen. Discussion: Des études suggèrent que le LPB est potentiellement malin, bien que ce potentiel soit faible, et que les LD ne doivent pas être ignorés : en effet, une dysplasie peut évoluer en cancer, qu'elle présente des caractéristiques lichénoïdes ou non. On constate également un désaccord quant à la classification et à la catégorisation des LD. Différents termes ont été utilisés pour la classification de ces lésions, notamment « dysplasie lichénoïde ¼, « LPB dysplasique ¼ et « dysplasie à caractéristiques lichénoïdes ¼. De plus, dans le cas des LD, on ne sait pas avec certitude si la dysplasie ou l'infiltration lichénoïde apparaît en premier, ni si l'inflammation découle de la dysplasie ou si la dysplasie est une conséquence de l'inflammation persistante. La principale limite de la littérature est due aux incohérences et à la nature subjective des diagnostics histologiques, qui peut entraîner des variations d'un observateur à l'autre ou même avec un même observateur, ce qui entraîne à terme des diagnostics erronés de LPB et de LD. Conclusion: Bien que d'autres études soient nécessaires pour comprendre le LPB et les LD, les lésions de ces 2 catégories doivent être considérées comme potentiellement malignes et ne doivent pas être ignorées.

Association of podoplanin expression to histopathological grades of oral epithelial dysplasia and oral squamous cell carcinoma.

Objective: To determine the expression of podoplanin, and to correlate it with histopathological grades in oral epithelial dysplasia and oral squamous cell carcinoma cases. METHODS: The retrospective, analytical, cross-sectional study was conducted at the City Laboratory, Peshawar, Pakistan, and comprised specimen block data of histologically diagnosed cases of oral benign lesions, dysplastic lesions and oral squamous cell carcinoma from January 2017 to August 2021. Two sections (4um) were cut from each specimen block for Haematoxylin and Eosin staining and immunohistochemistry. The slides were re-evaluated by two pathologists for confirmation of the diagnosis, and podoplanin marker was applied to cases selected using immunohistochemistry. Data was analysed using SPSS 22. RESULTS: Of the 80 cases identified, 68(85%) were analysed. There were 20(29.4%) benign cases; 11(55%) females and 9(45%) males with mean age 39.90±16.23 years, 20(29.4%) oral dysplastic cases; 14(70%) males and 6(30%) females with mean age 57.75±12.02 years, and 28(41.2%) oral squamous cell carcinoma cases; 17(61%) males and 11(39%) females with mean age 50.55±14.80 years. Podoplanin expression in oral epithelial dysplasia cases was significant (p=0.028), while it was not significant in the other 2 groups (p>0.05). CONCLUSIONS: Podoplanin when used along with histopathological evaluation could aid as an adjuvant technique in the diagnosis and grading of oral epithelial dysplasia.

Clinical, histopathological characteristics and malignant transformation of proliferative verrucous leukoplakia with 36 patients: a retrospective longitudinal study.

BACKGROUND: Proliferative verrucous leukoplakia (PVL), distinguished by its malignant transformation rate of 43.87% to 65.8%, stands as the oral potentially malignant disorder with the highest propensity for malignancy. PVL is marked by distinctive heterogeneity regarding the clinical or histopathological characteristics as well as prognostic factors pertinent to this condition. The purpose of this study is to compile and assess the clinicopathological features, malignant transformation, and associated risk factors in patients diagnosed with PVL. METHODS: This study is a hospital-based retrospective longitudinal study of 36 patients diagnosed with PVL from 2013 to 2023. We conducted complete clinical and histopathological evaluations of the patients. RESULTS: The cohort comprised 16 males and 20 females, yielding a male-to-female ratio of 1:1.25. The follow-up period ranged from 8 to 125 months, with an average of 47.50 months. The most common clinical type of lesion was the verrucous form (58.33%), and the gingiva was the most common site (44.44%). Each patient had between 2 to 7 lesions, averaging 3.36 per patient. During the follow-up period, twelve patients (33.3%) developed oral cancer, with an average time to malignant transformation of 35.75 months. Kaplan-Meier survival analysis indicated that patients with complaints of pain, roughness, or a rough sensation, with diabetes, and the presence of cytologic atypia histologically showed a higher risk of malignant transformation (p < 0.05). In this study, the rate of malignant transformation in the treatment group (5/23) was lower than that in the untreated group (7/13), however, no statistically significant difference (p = 0.05). CONCLUSION: The main complaints of pain, roughness, or foreign body sensation, coupled with cytologic atypia histologically are indicative of an increased risk of malignant transformation in PVL. Further research is needed to elucidate the influence of these clinicopathological parameters on the malignant progression of PVL.

Oral epithelial dysplasia detection and grading in oral leukoplakia using deep learning.

BACKGROUND: The grading of oral epithelial dysplasia is often time-consuming for oral pathologists and the results are poorly reproducible between observers. In this study, we aimed to establish an objective, accurate and useful detection and grading system for oral epithelial dysplasia in the whole-slides of oral leukoplakia. METHODS: Four convolutional neural networks were compared using the image patches from 56 whole-slide of oral leukoplakia labeled by pathologists as the gold standard. Sequentially, feature detection models were trained, validated and tested with 1,000 image patches using the optimal network. Lastly, a comprehensive system named E-MOD-plus was established by combining feature detection models and a multiclass logistic model. RESULTS: EfficientNet-B0 was selected as the optimal network to build feature detection models. In the internal dataset of whole-slide images, the prediction accuracy of E-MOD-plus was 81.3% (95% confidence interval: 71.4-90.5%) and the area under the receiver operating characteristic curve was 0.793 (95% confidence interval: 0.650 to 0.925); in the external dataset of 229 tissue microarray images, the prediction accuracy was 86.5% (95% confidence interval: 82.4-90.0%) and the area under the receiver operating characteristic curve was 0.669 (95% confidence interval: 0.496 to 0.843). CONCLUSIONS: E-MOD-plus was objective and accurate in the detection of pathological features as well as the grading of oral epithelial dysplasia, and had potential to assist pathologists in clinical practice.

Expression of CLLD7 and CHC1L Proteins in Oral Epithelial Dysplasia in a Group of Thai Patients.

OBJECTIVES: Previous study showed aberrant CLLD7 and CHC1L protein expression in oral squamous cell carcinoma (OSCC) compared to normal oral mucosa (NOM). This study aimed to evaluate the expression of these proteins in oral epithelial dysplasia (OED). MATERIALS AND METHODS: Forty specimens of OED and 11 NOM were used. The expression of CLLD7 and CHC1L was determined by immunohistochemistry. In each case, at least 1000 cells were counted. Presence of nuclear, cytoplasmic, and/or membrane staining of CLLD7 and CHC1L were considered positive. Percentages of total positive cells and positive cells at different locations were recorded. SPSS version 18 was used to compare variation between groups with statistical significance at p<0.05. RESULTS: No significant differences in the percentages of total positive cells of CLLD7 and CHC1L were found between NOM and all grades of OED. Nevertheless, there were significant differences in subcellular staining of these two proteins. In CLLD7, the nuclear staining of the moderate and the severe OED groups was significantly lower than that of the NOM group (p<0.05). The percentages of membrane staining of CHC1L in moderate and severe OED were significantly higher than that of NOM (p<0.001). In addition, the nuclear staining of CHC1L in each grade of OED was significantly lower than that of NOM (p<0.05). CONCLUSION: The subcellular mislocalization of CLLD7 and CHC1L in OED suggests that the expression of these potential tumor suppressor proteins might be dysregulated during the dysplastic process. The distinct membrane staining of CHC1L observed in OED but not in NOM is a useful characteristic that can be used to separate OED from NOM. Thus, CHC1L may be a good marker to assist in the diagnosis of OED.

Prognostic biomarkers for malignant progression of oral epithelial dysplasia: an updated systematic review and meta-analysis.

Oral epithelial dysplasia (OED) is a premalignant condition that carries an appreciable risk of malignant progression. The current grading system for severity, as defined by the World Health Organization, is a valuable clinical tool, but further work is required to improve the accuracy of predicting OED malignant progression. This systematic review aimed to assess progress in prognostic biomarker discovery in OED over the past 16 years. The primary objective was to update the latest evidence on prognostic biomarkers that may predict malignant progression of OED, with strict inclusion criteria of studies with a longitudinal design and long-term follow-up data to enhance the robustness and translational clinical potential of the findings. Of 2829 studies identified through the searching of five databases, 20 met our inclusion criteria. These studies investigated a total of 32 biomarkers, 20 of which demonstrated significant potential to predict malignant progression of OED. Meta-analysis demonstrated the significant prognostic value of four biomarkers: podoplanin, EGFR expression, p16 methylation, and DNA aneuploidy. Our review has identified 20 reported biomarkers with prognostic potential to predict malignant progression in OED, but their translation into clinical practice remains elusive. Further research is required, and this should focus on validating the promising biomarkers identified in large cohort studies, with adherence to standardised reporting guidelines.

Evaluation of Cytotoxic T Lymphocytes and Natural Killer Cell Distribution in Oral Squamous Cell Carcinoma and Oral Epithelial Dysplasia: An Immunohistochemical Study.

Background The tumor microenvironment comprises stromal cells, a few immune cells, vascular channels, and an extracellular matrix. The immune cells play a pivotal role in arresting the development of various tumors by identifying and killing the abnormal tumor cells. These immune cells with cytotoxic function include the natural killer (NK) cells and CD8+ T lymphocytes. Human NK cells express the cell surface marker CD57 and can be identified by using monoclonal antibodies. CD8+ cytotoxic T cells are a critical subpopulation of T cells and are important mediators of adaptive immunity. The anti-tumor immunity is important to assess the prognosis of tumors and develop new therapies. This study aimed to evaluate the immunohistochemical expression of CD8 and CD57 immune cells in oral squamous cell carcinoma (OSCC), oral epithelial dysplasia (OED), and normal oral mucosa. Methodology Clinically diagnosed and histopathologically confirmed cases of OSCC (n = 22), oral leukoplakia with OED (n = 22), and normal oral mucosa (n = 22) comprised the study groups. The tissue sections were subjected to immunohistochemical analysis for CD8 and CD57 expression by calculation of the mean labeling index. The results were statistically analyzed using a one-way analysis of variance, Bonferroni multiple comparison test, and Student's t-test. SPSS software version 20.0 (IBM Corp., Armonk, NY, USA) was used for the statistical analysis, and the significance level was set at 0.05. Results An overall statistically significant difference was obtained in the number of CD8+ T lymphocyte cells and CD57+ NK cells when compared between OSCC, OED, and normal oral mucosa (p = 0.01). Variations in the number of CD8+ T lymphocyte cells and CD57+ NK cells were observed when a comparison was made between OED and OSCC and between OSCC and normal mucosal samples (p = 0.01). The study results showed that the mean labeling index of CD8 and CD57 increased in OSCC when compared to OED and normal mucosa (p = 0.01). Conclusions Samples of OED with moderate or severe dysplasia and samples of OSCC were accompanied by a higher level of infiltrating immune cells such as T cells, B cells, NK cells, and macrophages when compared to normal mucosa. The results suggested that the expression of CD8 and CD57 cells increased from normal mucosa to OED and the highest expression was found in OSCC. CD8 and CD57 could be used as surrogate markers to assess the malignant potential of the lesion and to determine the prognosis of patients with oral cancer.

Oral epithelial dysplasia with lymphocytic immune response: clinicopathological characterisation of 44 cases.

AIMS: Oral epithelial dysplasia (OED) often exhibits a lymphocytic/lichenoid immune response (LIR), imparting histological resemblance to lichenoid mucositis and rendering diagnosis challenging. The clinical appearances of OED and lichenoid inflammatory processes are generally divergent, presenting as well-demarcated hyperkeratotic plaques and diffuse white and/or red mucosal change with variably prominent Wickham striae, respectively. To date, clinicopathological characterisation of OED with LIR, including clinical/gross appearance, has not been depicted. METHODS AND RESULTS: Cases of solitary OED with LIR for which a clinical photograph was available were identified in the authors' institutional files. Clinical and histological features were documented. In 44 identified cases, dysplasia was mild (19 of 44, 43.2%), moderate (19 of 44, 43.2%) and severe (six of 44, 13.6%). Clinically/grossly, all 44 cases (100.0%), presented as well-demarcated hyperkeratotic plaques lacking diffuse white-and-red mucosal change or Wickham striae. Histologically, OED with LIR exhibited numerous 'lichenoid' features beyond the lymphocytic band in the superficial lamina propria, including: leucocyte transmigration (38 of 44, 86.4%), spongiosis (37 of 44, 84.1%), Civatte/colloid bodies (36 of 44, 81.8%), basal cell degeneration (29 of 45, 65.9%), sawtooth rete ridges (11 of 44, 25.0%) and subepithelial clefting (7 of 44, 15.9%). CONCLUSIONS: Virtually any lichenoid histological feature may be seen in OED with LIR, representing a significant diagnostic pitfall. The typical clinical appearance of OED with LIR is of a well-demarcated hyperkeratotic plaque, characteristic of keratinising dysplasia and devoid of lichenoid features. This suggests that pathologist access to clinical photographs during diagnostic interpretation of biopsied white lesions, which represents opportunity to perform gross examination of the disease process, may reduce interobserver variability and improve diagnostic accuracy in this challenging differential diagnosis.

Immunophenotypic and Gene Expression Analyses of the Inflammatory Microenvironment in High-Grade Oral Epithelial Dysplasia and Oral Lichen Planus.

BACKGROUND: Oral lichen planus (OLP) and oral epithelial dysplasia (OED) present diagnostic challenges due to clinical and histologic overlap. This study explores the immune microenvironment in OED, hypothesizing that immune signatures could aid in diagnostic differentiation and predict malignant transformation. METHODS: Tissue samples from OED and OLP cases were analyzed using immunofluorescence/immunohistochemistry (IF/IHC) for CD4, CD8, CD163/STAT1, and PD-1/PDL-1 expression. RNA-sequencing was performed on the samples, and data was subjected to CIBERSORTx analysis for immune cell composition. Gene Ontology analysis on the immune differentially expressed genes was also conducted. RESULTS: In OED, CD8 + T-cells infiltrated dysplastic epithelium, correlating with dysplasia severity. CD4 + lymphocytes increased in the basal layer. STAT1/CD163 + macrophages correlated with CD4 + intraepithelial distribution. PD-1/PDL-1 expression varied. IF/IHC analysis revealed differential immune cell composition between OED and OLP. RNA-sequencing identified upregulated genes associated with cytotoxic response and immunosurveillance in OED. Downregulated genes were linked to signaling, immune cell recruitment, and tumor suppression. CONCLUSIONS: The immune microenvironment distinguishes OED and OLP, suggesting diagnostic potential. Upregulated genes indicate cytotoxic immune response in OED. Downregulation of TRADD, CX3CL1, and ILI24 implies dysregulation in TNFR1 signaling, immune recruitment, and tumor suppression. This study contributes to the foundation for understanding immune interactions in OED and OLP, offering insights into future objective diagnostic avenues.

Potential Immunohistochemical Biomarkers for Grading Oral Dysplasia: A Literature Review.

Oral cancer is a prevalent global health issue, with significant morbidity and mortality rates. Despite available preventive measures, it remains one of the most common cancers, emphasising the need for improved diagnostic and prognostic tools. This review focuses on oral potentially malignant disorders (OPMDs), precursors to oral cancer, specifically emphasising oral epithelial dysplasia (OED). The World Health Organisation (WHO) provides a three-tier grading system for OED, and recent updates have expanded the criteria to enhance diagnostic precision. In the prognostic evaluation of OED, histological grading is presently regarded as the gold standard; however, its subjectivity and unreliability in anticipating malignant transformation or recurrence pose notable limitations. The primary objective is to investigate whether specific immunohistochemical biomarkers can enhance OED grading assessment according to the WHO classification. Biomarkers exhibit significant potential for comprehensive cancer risk evaluation, early detection, diagnosis, prognosis, and treatment optimisation. Technological advancements, including sequencing and nanotechnology, have expanded detection capabilities. Some analysed biomarkers are most frequently chosen, such as p53, Ki-67, cadherins/catenins, and other proteins used to differentiate OED grades. However, further research is needed to confirm these findings and discover new potential biomarkers for precise dysplasia grading and minimally invasive assessment of the risk of malignant transformation.

The Significance of Modified Histone H3 in Epithelial Dysplasia and Oral Cancer.

BACKGROUND: Oral carcinogenesis is complex and influenced by both genetic and epigenetic changes. Altered histone modification is the epigenetic event that plays a role in cancer development and progression. Distinct modification patterns of histones have been shown to affect patient prognosis in selected cancers. This study aimed to evaluate the profiles of histone H3 modification in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC) in association with the clinical-pathologic characteristics. METHODS: One hundred patients were divided into 4 groups: low-grade OED, high-grade OED, OSCC, and normal oral mucosa (NOM). The levels of 3 types of histone modification-the H3K18ac, H3K9me3, and H3K9ac-were analysed immunohistochemically. Their expression profiles were compared and correlated with prognostically relevant clinical and pathologic features. RESULTS: The H3K18ac and H3K9me3 were upregulated in OSCC, compared with OED and NOM. In contrast, the H3K9ac was downregulated in low-grade OED but increased in high-grade OED and OSCC. The hyperacetylations of H3K18 and H3K9 significantly correlated with advanced cancer depth of invasion and high T stage, respectively. CONCLUSIONS: Histone H3 acetylation and methylation at lysine residues are differentially involved in the multistep oral carcinogenesis and impact aggressive cancer phenotypes. The effect of H3K9ac appears early in OED development, whilst the increased H3K18ac and H3K9me3 may be vital in the emergence of OSCC.

OralEpitheliumDB: A Dataset for Oral Epithelial Dysplasia Image Segmentation and Classification.

Early diagnosis of potentially malignant disorders, such as oral epithelial dysplasia, is the most reliable way to prevent oral cancer. Computational algorithms have been used as an auxiliary tool to aid specialists in this process. Usually, experiments are performed on private data, making it difficult to reproduce the results. There are several public datasets of histological images, but studies focused on oral dysplasia images use inaccessible datasets. This prevents the improvement of algorithms aimed at this lesion. This study introduces an annotated public dataset of oral epithelial dysplasia tissue images. The dataset includes 456 images acquired from 30 mouse tongues. The images were categorized among the lesion grades, with nuclear structures manually marked by a trained specialist and validated by a pathologist. Also, experiments were carried out in order to illustrate the potential of the proposed dataset in classification and segmentation processes commonly explored in the literature. Convolutional neural network (CNN) models for semantic and instance segmentation were employed on the images, which were pre-processed with stain normalization methods. Then, the segmented and non-segmented images were classified with CNN architectures and machine learning algorithms. The data obtained through these processes is available in the dataset. The segmentation stage showed the F1-score value of 0.83, obtained with the U-Net model using the ResNet-50 as a backbone. At the classification stage, the most expressive result was achieved with the Random Forest method, with an accuracy value of 94.22%. The results show that the segmentation contributed to the classification results, but studies are needed for the improvement of these stages of automated diagnosis. The original, gold standard, normalized, and segmented images are publicly available and may be used for the improvement of clinical applications of CAD methods on oral epithelial dysplasia tissue images.

Expression of PD-L1 and p-RPS6 in epithelial dysplasia and squamous cell carcinoma of the oral cavity.

Introduction: Oral squamous cell carcinoma (OSCC) is often preceded by oral epithelial dysplasia (OED). The role of ribosomal protein S6 (RPS6) and programmed cell death ligand-1 (PD-L1) in the progression of OED to OSCC remains unclear. This study aimed to investigate the expression of phosphorylated RPS6 (p-RPS6) and PD-L1 in OSCC and OED and to examine its relationship with clinicopathological features. Methods: Fifty-two OSCC and 48 OED cases were recruited for immunohistochemical analysis of p-RPS6 and PD-L1 expression. The expression of markers was correlated with clinicopathological features of OSCC and OED. Results: We found p-RPS6 expression in all cases of OSCC and OED, whereas PD-L1 was expressed in 42/48 (87%) OED and in 28/52 (53%) OSCC. The patients with mild OED presented higher expression level of PD-L1 and p-RPS6 significantly, when compared to moderate-differentiated OSCC patients (p < 0.05). Moreover, we found a significant positive correlation between PD-L1 and p-RPS6 expression in OED and OSCC patients (p < 0.01). The PD-L1 expression was significantly related to more than 2 cm tumor size in OSCC patients (p = 0.007). Discussion: Our findings suggest the upregulation of PD-L1 may be related with activation of the mTOR pathway in the early events of tumor progression and the pathogenesis of OSCC.

Evaluation of CYP1B1, oxidative stress and phase II detoxification enzyme status in oral cancer progression model.

Background: Tobacco is one of the main etiological factors for oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD). CYP1B1 is an enzyme which plays a major role in the phase I detoxification of tobacco, the byproducts of which are subsequently detoxified by phase II enzymes Glutathione S Transferase (GST). We attempted to evaluate the L432V polymorphism and tissue expression of CYP1B1, along with the oxidant-antioxidant status in OSCC progression model. Method: ology: Tissue biopsies and blood samples were collected from the subjects; L432V polymorphism was evaluated by TaqMan RT-PCR, immunohistochemistry was performed on the tissue sample using CYP1B1 polyclonal primary antibody and Allred quick scoring system was used to evaluate the stained slides. Malonaldehyde (MDA) and GST activity were measured spectrophotometrically to assess oxidative-antioxidative status. Results: When the L432V polymorphism was analyzed, it was observed that in oral epithelial dysplasia (OED) and OSCC, CG was more common than GG genotype. Highest mean Allred score was observed in tobacco users (6.27), highest GST activity was seen in oral epithelial dysplasia (5.006 U/ml) and highest MDA activity was observed in OSCC (1553.94 nm/ml). Conclusion: Tobacco users with CG and GG genotypes are at equal risk of developing oral epithelial dysplasia or OSCC and L432V polymorphism does not appear to increase the risk of malignant transformation in oral epithelial dysplasia. Moreover, tobacco users with GG genotype and tissue expression of CYP1B1 may be at a greater risk of oxidative damage.