Evaluation of a new binary system of grading oral epithelial dysplasia for prediction of malignant transformation

A head-to-head comparison of four grading systems for oral epithelial dysplasia

AIMS

Oral epithelial dysplasia (OED) carries a risk of malignant transformation to oral squamous cell carcinoma. Clinical risk stratification for these patients is challenging, and reliant upon histological grading. The World Health Organisation (WHO) grading system is the current gold standard, although the binary system, two- and six-point prognostic models have also been proposed. This study assesses the interobserver agreement and malignant transformation outcomes for these four grading systems.

METHODS AND RESULTS

Up to 5 years of outcome data were collected for this retrospective cohort of 137 patients. Archived slides were reviewed by three pathologists, and grades for the WHO, binary, two- and six-point systems were assigned. Interobserver agreement was assessed with Light's kappa coefficient. Kaplan-Meier and Cox regression survival analyses were used to assess the correlation of each grading system with malignant transformation. The WHO, binary, two- and six-point systems had kappa coefficients of 0.42, 0.31, 0.17 and 0.41, respectively. All grading systems stratified lesions by malignant transformation risk, except the two-point model. Moderate OED (WHO) did not show an increased risk of malignant transformation, while severe OED had a hazard ratio (HR) of 13.7 (P = 0.02). The high-risk category for the binary and six-point systems had HRs of 4.67 (P = 0.03) and 5.28 (P = 0.03), respectively.

CONCLUSIONS

The interobserver agreement of the WHO, binary and six-point systems is comparable. The six-point and binary systems provided the most useful risk stratification. This study highlights the potential value of the six-point prognostic model for OED grading, which has comparable performance with the current gold standard.

Salivary EGF: EGFR ratio as potential early diagnostic biomarker for oral cancer detection in tobacco chewers: a preliminary cross-sectional study

BACKGROUND

Tobacco chewing and smoking are major risk factors for oral cancer, with Oral Squamous Cell Carcinoma (OSCC), comprising approximately 90% of cases, especially in South-Central Asia. This study examines the early diagnostic value of salivary Epidermal Growth Factor (EGF) and Epidermal Growth Factor Receptor (EGFR) for OSCC in long-term chewers of tobacco.

METHODS

This study assessed salivary EGF and EGFR concentrations by Enzyme-Linked Immunosorbent Assay (ELISA), in three groups: Healthy Controls (HC, n = 41), Tobacco Chewers with a 10-years history of tobacco use (TC, n = 41), and newly diagnosed OSCC patients (with tobacco chewing history of more than 10 years) with no prior history of neoplasms or anticancer treatment (OSCC, n = 19). All participants were over the age of 35.

RESULTS

Salivary EGF levels were significantly reduced, while EGFR levels were elevated in tobacco chewers (TC) and newly diagnosed OSCC patients compared to healthy controls (HC), with no significant difference observed between TC and OSCC groups. Notably, the EGF: EGFR ratio demonstrated better diagnostic performance for OSCC in TC compared to EGF or EGFR alone. ROC analysis highlighted the potential of these biomarkers as diagnostic tools for OSCC in TC.

CONCLUSION

Salivary EGF: EGFR ratio may serve as an early diagnostic biomarker for OSCC in TC. Reduced EGF and elevated EGFR levels suggest their role in disease progression, warranting further large-scale studies for clinical validation.

S100A7 as a predictive biomarker in malignant transformation of oral epithelial dysplastic lesions

BACKGROUND

S100A7 expression is increased in oral potentially malignant disorders (OPMD) at risk of transformation to oral squamous cell carcinoma (OSCC). The objective of this study was to evaluate S100A7 expression in OPMD which transformed and to correlate these results with the 3-tier and 2-tier dysplasia grading systems, and an S100A7 immunohistochemistry-based signature algorithm (S100A7 ARS).

METHODS

Formalin fixed paraffin embedded specimens from 48 patients with OPMD that had transformed into OSCC were selected. Thirty-five patients with multiple biopsies of dysplasia which had not transformed, and 25 cases with normal appearing and/or hyperkeratotic oral mucosa were included as control groups. Specimens were stained for S100A7 protein by immunohistochemical methods. Expression of S100A7 was assessed semi-quantitatively and by image analysis for the S100A7 ARS.

RESULTS

The semi-quantitative score had strong correlation with the S100A7 ARS and allowed differentiation of OPMD from the Control groups. The S100A7ARS was also useful in differentiation of OPMD that transformed to carcinoma from non-transforming cases (p < 0.05).

CONCLUSION

S100A7 immunohistochemical staining and the S100A7 ARS has potential for identifying oral potentially malignant lesions that have an increased risk of malignant transformation.

Binary- and Three-Tiered Oral Epithelial Dysplasia Grading System and Malignant Transformation

OBJECTIVES

Oral epithelial dysplasia (OED) can be graded histopathologically by using a binary- or three-tiered grading system. This study aimed to analyze and compare the prognostic value of the two systems in a large single-institute material.

MATERIALS AND METHODS

The study was a retrospective histopathological re-evaluation analysis of 612 OEDs over 29 years at the Institute of Dentistry, University of Turku, Turku, Finland. OED patients who later developed squamous cell carcinoma (OSCC) were identified from the Finnish Cancer Registry database.

RESULTS

Altogether, the mean age of 612 OEDs patients was 59.9 years. The male:female ratio was 0.67. According to the original three-tiered diagnosis, 67.7% of the samples were mild dysplasia, 28.7% moderate dysplasia, and 3.6% severe dysplasia cases. With binary-tiered diagnosis, low-grade dysplasia 84.1% was more common than high-grade dysplasia 15.9%. The malignant transformation rate was 7.8%. Regarding oral SCC development, no difference was found between the grading systems in predicting the malignant progression (p = 0.060).

CONCLUSIONS

Both binary- and three-tiered grading systems of dysplasia classification had similar predictive value for malignant transformation.

Identification of high-risk oral leukoplakia (OLK) using combined Raman spectroscopic analysis of brush biopsy and saliva samples: A proof of concept study

The gold standard method of diagnosis of oral leukoplakia (OLK) is a tissue biopsy followed by histological examination. Raman spectroscopic studies of cytological brush biopsy and saliva samples have previously been shown to differentiate low (no and mild dysplasia) and high risk (moderate and severe dysplasia) OLKs, discriminant models of cellular samples achieving higher specificity, whereas those based on saliva samples achieved higher sensitivity. The current study combines the spectral data sets of cell and saliva samples in an attempt to improve the overall efficiency of the discriminating models. Raman spectral data from cellular (nucleus and cytoplasm) and saliva samples, collected from patients with OLK (n = 12), was analysed as a concatenated or fused dataset and as data blocks in a multiblock analysis. The concatenated data was subjected to partial least squares-discriminant analysis (PLS-DA) to discriminate high and low grade dysplasia. Finally, multi-block analysis was performed using sequential orthogonalised PLS-DA, by which each set of data blocks was combined sequentially to provide maximum discrimination. For the concatenated dataset of cells and saliva, 87 % sensitivity and 76 % specificity were achieved, while in the case of the multi-block analysis, 97 % sensitivity and 100 % specificity were achieved. It is concluded that multiblock analysis provides maximum sensitivity and specificity using both cell and saliva datasets, compared to fused datasets. This study demonstrates that Raman spectroscopy of minimally invasive brush biopsy and saliva samples could have a role in differentiating high and low-risk OLKs.

United Kingdom and Ireland oral medicine and oral and maxillofacial surgery multidisciplinary clinics for the management of oral epithelial dysplasia

Oral epithelial dysplastic (OED) lesions have an increased risk of malignant change compared to normal mucosa. Multidisciplinary teams (MDTs) are widely used in medicine including for the management of patients with OED. There is little consensus in treatment, but a management algorithm from a joint oral medicine-oral and maxillofacial surgery (OM-OMFS) dysplasia management clinic was proposed in 2015 (the Liverpool Algorithm). We wished to determine the use of OM-OMFS MDTs for managing patients with OED in dental hospitals in the UK and Ireland using an online survey with results anonymised for analysis. We surveyed oral medicine units in the UK and Ireland reporting their use of joint clinics and management algorithms. All nineteen units responded with eight having OM-OMFS MDTs. Three used a published algorithm (Liverpool algorithm) and five used the algorithm with adaptations. 50% of units always excised lesions with moderate or severe dysplasia, with varying review intervals for different degrees of dysplasia. Seven of eight units kept patients with mild dysplasia under review for five years before discharge; for severe dysplasia some units never discharged. A total of 42% of oral medicine units in the UK and Ireland have MDTs for patients with OED. Most MDTs use the Liverpool Algorithm, or a slight variation of it, to help manage their patients. Wider adoption of MDTs and use of published algorithms may improve patient care by promoting consistent monitoring and management criteria.

Is Dysplasia the Sole Determinant of the Prognosis in Oral Potentially Malignant Disorders?

BACKGROUND

The dynamic nature of oral epithelial dysplasia, involving both progression and regression over time, complicates prognostic predictions for the lesion.

OBJECTIVE

This paper addresses the intricacies of this challenge and advocates for a nuanced strategy. It proposes a comprehensive assessment, tailored to individual patients, incorporating genetic, behavioral, and medical factors to enhance the precision of lesion evaluation.

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.

Oral epithelial dysplasia with lichenoid features shares proteomic overlap with oral epithelial dysplasia without lymphocytic immune response

OBJECTIVE

This study investigates the proteomic profiles of oral epithelial dysplasia with lichenoid features (OEDwithLF) and evaluates its relevance as a histopathological feature for lichenoid mucositis (LM) through differential proteomic characterization.

STUDY DESIGN

SWATH-MS proteomic profiling was conducted on FFPE samples from 6 OEDwithLF, 5 OED cases without associated lymphocytic infiltration, and 5 LM cases. Protein expression levels were quantified and compared. In silico analysis examined the biological and molecular functions of dysregulated proteins.

RESULTS

A total of 460 proteins were identified. Unsupervised clustering revealed significant differences between LM and OEDwithLF, with fewer differences observed between OEDwithLF and OED. Bioinformatic analysis indicated dysregulated proteins are involved in nucleic acid binding, ribosome function, and developmental biology. Key potential biomarkers include KRT17, LYSC, CAL5, and CRNN.

CONCLUSIONS

The proteomic profile of OEDwithLF is similar to OED without associated lymphocytic infiltration, but significantly different from LM. OED is relevant in lichenoid tissues, and its proteomic changes can be detected. Although OED may coexist with interface mucositis, it is not a defining feature of LM. This challenges the exclusion of epithelial dysplasia from lichenoid diagnoses. Based on this hypothesis-generating study, further investigation is warranted.

Photobiomodulation Exerts Anti-Inflammatory and Antioxidant Effects Reducing the Development of Tumors Elicited by 4-NQO in the Mice Tongue

OBJECTIVE

Evaluate the influence of photobiomodulation in a model of oral carcinogenesis induced by 4-nitroquinoline-n-oxide (4-NQO).

SUBJECTIVE

Ninety-six Swiss mice received topical application of 1% 4-NQO on tongue dorsum, for 20 weeks. The tongue was subjected to photobiomodulation with red (71.4 J/cm2) and infrared laser (142.8 J/cm2) starting at week 0, 12, and 16. After 20 weeks, tongues were removed for the following analyzes: histological assessment, immunohistochemical reactions (cyclin D1/Ki-67/TGF-β1), quantification of MPO, n-AG, MDA, GSH, total proteins, TNF-α, IL-1β, and IL-6 levels.

RESULTS

4-NQO showed significant increase in the frequency of carcinoma (p < 0.001), and in the immunostaining for cyclin D1/Ki-67/TGF-β1 (p < 0.005), along with increased levels of TNF- α, IL-1β, IL-6, MPO, n-AG, MDA, and total proteins (p < 0.001), that were reduced by photobiomodulation with red and infrared lasers (p < 0.005).

CONCLUSION

Photobiomodulation reduces tumor development, accompanied by reduced inflammatory cells and content of cytokines and oxidative markers associated with carcinogenesis.

Diagnostic Criteria for Oral Epithelial Dysplasia: Predicting Malignant Transformation

PURPOSE

In 2022, the World Health Organization (WHO) proposed new criteria for the diagnosis of oral epithelial dysplasia (OED), however their association with patient's outcome is still unknown. This study compared the different classification systems of OED and evaluate their efficacy in predicting malignant transformation.

METHODS

A total of 195 slides of leukoplakia and erythroplakia were graded according to the WHO 2017, 2022, and the Binary System classification, and were correlated with the lesion's evolution.

RESULTS

A progressive increase in malignant transformation according to the severity of OED, with both the WHO and the Binary classification systems was detected. Among individual criteria, changes in cell morphology were independently associated with an increased risk of malignant transformation (HR = 2.8, 95%CI 1.1-7.5, p = 0.032). Considering the new set of OED criteria published in 2022, it was detected that a new cutoff of 4 architectural alterations and 6 cytological alterations predicts better malignant transformation.

CONCLUSION

Malignant transformation was equally predicted by the OED classification systems. Due to the increased number of architectural and cytological features in WHO 2022, a new cutoff for classifying OED from low to high-grade considering 4 architectural and 6 cytological alterations is proposed. The findings allow a more accurate assessment of malignant transformation risk in OED.

Oral Leukoplakia Microbiome Predicts the Degree of Dysplasia and is Shaped by Smoking and Tooth Loss

OBJECTIVE

This study aimed to determine if the oral potentially malignant disorder, oral leukoplakia (OLK), exhibited microbiome changes that predict the degree of dysplasia and the risk of malignant progression.

RESULTS

We examined the microbiome in 216 swabs of OLK from 177 patients. Compared to healthy controls (n = 120 swabs from 61 patients), who were less likely to smoke and had better oral health, OLK patients exhibited an increased abundance of Rothia mucilaginosa, Streptococcus parasanguinis and S. salivarius, resembling acetaldehyde generating communities described previously. Compared to the patients' healthy contralateral normal (CLN) mucosa (n = 202), which acts as a matched control for oral health parameters, OLK exhibited increased S. infantis, Leptotrichia spp., Bergeyella spp., Porphyromonas spp. and F. nucleatum. Machine learning with clinical and microbiome data could discriminate high-risk dysplasia (moderate to severe) from low-risk dysplasia (none or mild) (sensitivity 87.4%; specificity 76.5%). Follow-up swabs were recovered from 58 patients, eight of whom progressed to a higher grade of dysplasia or OSCC and these eight patients exhibited a higher abundance of Fusobacterium species at their initial presentation.

CONCLUSIONS

Our study suggests that the OLK microbiome has potential to be an aid to the prediction of dysplasia grade and the risk of malignant transformation.

A novel AI-based score for assessing the prognostic value of intra-epithelial lymphocytes in oral epithelial dysplasia

BACKGROUND

Oral epithelial dysplasia (OED) poses a significant clinical challenge due to its potential for malignant transformation and the lack of reliable prognostic markers. Current OED grading systems do not reliably predict transformation and suffer from considerable observer variability. Recent studies have highlighted that peri-epithelial lymphocytes may play an important role in OED malignant transformation, with indication that intra-epithelial lymphocytes (IELs) may also be important.

METHODS

We propose a novel artificial intelligence (AI) based IEL score from Haematoxylin and Eosin (H&E) stained Whole Slide Images (WSIs) of OED tissue slides. We determine the prognostic value of our IEL score on a digital dataset of 219 OED WSIs (acquired using three different scanners), compared to pathologist-led clinical grading.

RESULTS

Our IEL scores demonstrated significant prognostic value (C-index = 0.67, p < 0.001) and were shown to improve both the binary/WHO grading systems in multivariate analyses (p < 0.001). Nuclear analyses confirmed the positive association between higher IEL scores, more severe OED and malignant transformation (p < 0.05).

CONCLUSIONS

This underscores the potential importance of IELs, and by extension our IEL score, as prognostic indicators in OED. Further validation through prospective multi-centric studies is warranted to confirm the clinical utility of IELs.

Convolutional neural networks for accurate real-time diagnosis of oral epithelial dysplasia and oral squamous cell carcinoma using high-resolution in vivo confocal microscopy

Oral cancer detection is based on biopsy histopathology, however with digital microscopy imaging technology there is real potential for rapid multi-site imaging and simultaneous diagnostic analysis. Fifty-nine patients with oral mucosal abnormalities were imaged in vivo with a confocal laser endomicroscope using the contrast agents acriflavine and fluorescein for the detection of oral epithelial dysplasia and oral cancer. To analyse the 9168 images frames obtained, three tandem applied pre-trained Inception-V3 convolutional neural network (CNN) models were developed using transfer learning in the PyTorch framework. The first CNN was used to filter for image quality, followed by image specific diagnostic triage models for fluorescein and acriflavine, respectively. Images were categorised based on a histopathological diagnosis into 4 categories: no dysplasia, lichenoid lesions, low-grade dysplasia and high-grade dysplasia/oral squamous cell carcinoma (OSCC). The quality filtering model had an accuracy of 89.5%. The acriflavine diagnostic model performed well for identifying lichenoid (AUC = 0.94) and low-grade dysplasia (AUC = 0.91) but poorly for identifying no dysplasia (AUC = 0.44) or high-grade dysplasia/OSCC (AUC = 0.28). In contrast, the fluorescein diagnostic model had high classification performance for all diagnostic classes (AUC range = 0.90-0.96). These models had a rapid classification speed of less than 1/10th of a second per image. Our study suggests that tandem CNNs can provide highly accurate and rapid real-time diagnostic triage for in vivo assessment of high-risk oral mucosal disease.

The role of OCT4 and CD44 in lower lip carcinogenesis

PURPOSE

Carcinogenesis is characterized by the transformation of normal cells into malignant cells. Concerning the lower lip, exposure to UV radiation is the main etiological factor associated with the development of epidermoid carcinomas and actinic cheilitis. According to the hierarchical model theory, cancer development is driven by populations of cancer stem cells. In this context, this study aimed to compare the expression of octamer-binding transcription factor 4 (OCT4) and CD44 in 40 lower lip epidermoid carcinoma (LLEC) and 40 actinic cheilitis (AC) cases.

METHODS

OCT4 and CD44 expressions were assessed semi-quantitatively according to the percentage of positive epithelial cells (PP) and intensity of expression (IE), resulting in a total immunolabeling score (PIT).

RESULTS

No statistically significant differences were detected between OCT4 and CD44 immunoexpression and clinicopathological parameters, except for lymph node metastasis, in which a decrease in CD44 expression in the core tumor of cases with lymph node metastasis was observed. Furthermore, decreased CD44 expression was observed in LLEC cases when compared to AC cases.

CONCLUSIONS

The findings reported herein suggest a higher participation of CD44 in early carcinogenesis stages. In addition, the imbalance between OCT4 and CD44 immunoexpressions suggests the presence of different neoplastic cell subpopulations.

Four decades of treatment for actinic cheilitis: Outcomes, challenges, and the introduction of a new clinical index

OBJECTIVE

To evaluate the clinical outcomes of surgical and non-surgical treatments for actinic cheilitis (AC) over a four-decade period and to introduce a novel Clinical Index for the Treatment and Control of Actinic Cheilitis (CITC-AC) for improved patient stratification and management.

MATERIALS AND METHODS

A retrospective cohort study analyzed 151 patients diagnosed with AC treated at a university clinic between 1980 and 2020. Sociodemographic, clinical, and histopathological data were collected. Treatments were categorized as sun protection (SP), topical corticosteroids (TC), surgical removal (SR), and vermilionectomy. Therapeutic outcomes, recurrence rates, and malignant transformation were assessed. The CITC-AC was developed to guide clinical decision-making based on stratified risk.

RESULTS

A total of 87% of patients achieved therapeutic resolution. Recurrence was observed in 13%, and malignant transformation occurred in 7% of cases. Surgical treatments, particularly vermilionectomy, demonstrated superior outcomes with no recurrence or malignancy. Non-surgical treatments, including the novel use of Omcion-A Orabase, achieved favorable outcomes but exhibited higher recurrence rates. The CITC-AC provided a structured framework for stratifying patients by severity and risk, aiding in the selection of appropriate interventions and follow-up schedules.

CONCLUSIONS

This study highlights the importance of individualized treatment strategies and consistent follow-up in AC management. While surgical interventions remain the gold standard for advanced cases, non-surgical treatments are effective for early-stage lesions. The CITC-AC offers a practical tool for optimizing patient care and reducing progression to squamous cell carcinoma (SCC). Prospective studies are needed to validate its applicability across diverse clinical settings.

Is Binary Grading Better Than WHO System for Grading Epithelial Dysplasia? A Systematic Review and Meta-Analysis

BACKGROUND

This meta-analysis summarizes the current evidence on the intra- and inter-observer agreement between WHO and the binary grading systems used to assess epithelial dysplasia (ED).

METHODS

A systematic search for observational studies that compared the level of agreement among pathologists between WHO and binary grading systems for ED was conducted using three databases: Medline, Scopus, and EBSCOhost. For the meta-analysis, summary estimations of kappa value (κ) and standard error (SE) were utilized.

RESULTS

The pooled analysis of observations by 46 pathologists from a total of eight studies showed better interobserver agreement in the interpretation of ED for the binary system (κ = 0.31; 95% confidence interval [CI], 0.23-0.40) in comparison with the WHO (κ = 0.14; 95% CI, 0.10-0.19). The intra-observer agreement was reported only by five studies and was also found to be higher for the binary system (κ = 0.44; 95% CI, 0.31-0.57) compared to the WHO (κ = 0.25; 95% CI, 0.11-0.39).

CONCLUSIONS

Our results validate that the binary system has better overall intra-observer and interobserver agreement than the WHO system. Further studies with larger cohorts are mandatory before clinically relevant conclusions are drawn, as evidence remains inadequate.

Epidemiological landscape of tongue cancer in younger patients in a National Cancer Center in Brazil

This study investigates the changing epidemiological profile of tongue squamous cell carcinoma (SCC) to young patients, highlighting its rising incidence among non-traditional risk groups. A retrospective descriptive study was conducted, covering data from medical records between 2000 and 2012. Patients were categorised into two age groups (≤ 40 years; 41-50 years). Sociodemographic and clinicopathological characteristics were evaluated. A total of 108 patients participated, mostly aged 41-50. Alcohol consumption (43.3%) surpassed smoking. Majority (56.7%) aged ≤ 40 never smoked. Lateral tongue border was most affected, with stages III and IV prevalent. Patients aged ≤ 40 were mostly eligible for surgery (44%). Survival tied to staging and surgery; age had no significant impact. Young squamous cell carcinoma patients often lacked traditional risk factors like smoking, underwent surgery, and typically had disease-free margins. The study underscores the importance of broad external policies for early diagnosis, beyond just traditional risk groups.

Mast cells and factor XIIIa+ dendrocytes in actinic cheilitis and lip squamous cell carcinoma

There is an interaction between dendrocytes and mast cells in the skin. However, in elastosis-related diseases such as actinic cheilitis (AC) and lower lip squamous cell carcinoma (LLSCC), this interaction remains unknown. We investigated the presence of intact and degranulated mast cells in AC and LLSCC. Associations of mast cells with factor XIIIa+ dendrocytes and inflammatory infiltrate were assessed. Forty cases of AC (20 with low-grade and 20 with high-grade epithelial dysplasia), 50 cases of LLSCC, and 10 cases of normal oral mucosa were evaluated. Toluidine blue staining was performed to identify mast cells, and mast cell densities were calculated in the inflammatory infiltrate. Factor XIIIa+ dendrocytes were immunohistochemically quantified. The highest ratio of intact/degranulated mast cells density was detected in LLSCC (5.9 cells/mm2), followed by AC with high-grade epithelial dysplasia (4.8 cells/mm2). Statistically significant differences were found in the density of intact mast cells compared to degranulated mast cells in AC with low-grade epithelial dysplasia (p<0.001), AC with high-grade epithelial dysplasia (p=0.005), and LLSCC (p<0.001). A positive correlation between degranulated mast cells and total inflammatory infiltrate (p=0.03) was observed in the LLSCC group. The expression of factor XIIIa+ dendrocytes was highest in AC with low-grade epithelial dysplasia (16.5 cells/mm2). The link between mast cell density, factor XIIIa+ dendrocytes, and inflammatory infiltrate indicates a potential crosstalk in lip carcinogenesis.

Anti-VEGFR2 neutralising antibody slows the progression of multistep oral carcinogenesis

Angiogenesis plays an important role in cancer growth and metastasis, and it is considered a therapeutic target to control tumour growth following anti-angiogenic therapy. However, it is still unclear when tissues initiate angiogenesis during malignant transformation from premalignant condition and whether this premalignant condition could be a therapeutic target of anti-angiogenic therapy. In this study, we aimed to analyse the onset of angiogenesis by evaluating morphological and functional alterations of microvessels during oral multistep carcinogenesis using a 4-nitroquinoline 1-oxide (4NQO)-induced oral carcinogenesis mouse model. In the study, we initially confirmed that with the use of 4NQO, oral lesions develop in a stepwise manner from normal mucosa through oral epithelial dysplasia (OED) to oral squamous cell carcinoma (OSCC). Evaluation of CD31-immunostained specimens revealed that microvessel density (MVD) increases in a stepwise manner from OEDs. Histological and functional analyses revealed the structural abnormalities and leakage of blood vessels had already taken place in OED. Then we evaluated the expression profiles of Hif1a and Vegfa along with hypoxic status and found that OED exhibited increased Vegfa expression under hypoxic conditions. Finally, we tested the possibility of OEDs as a target of anti-angiogenic therapy and found that anti-VEGFR2 neutralising antibody in OED slowed the disease progression from OED to OSCC. These data indicate that an angiogenic switch occurs at the premalignant stage and morphological, and functional alterations of microvessels already exist in OED. These findings also elucidate the tumour microenvironment, which gradually develops along with carcinogenic processes, and highlight usefulness of the 4NQO-induced carcinogenesis model in the study of epithelial and stromal components, which will support epithelial carcinogenesis. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Histopathological risk assessment in multisite epithelial dysplasia: A meta-analysis

OBJECTIVE

Histopathological grading of oral epithelial dysplasia (OED) is the current standard for stratifying cancer progression risk but is associated with subjectivity and variability. This problem is not commonly seen regarding the grading of epithelial dysplasia in other sites. This systematic review aims to compare grading systems for oral, anal, penile, and cervical epithelial dysplasia to determine their predictive accuracy for recurrence and malignant transformation (MT) outcomes.

METHODS

The review protocol was registered in PROSPERO (CRD42023403035) and was reported according to the PRISMA checklist. A comprehensive search was performed in the main databases and gray literature. The risk of bias in individual studies was analyzed using the Joanna Briggs Institute checklist for each study design.

RESULTS

Forty-six studies were deemed eligible and included in this systematic review, of which 45 were included in the quantitative analysis. Meta-analysis revealed that the binary system demonstrated a higher predictive ability for MT/recurrence of OED compared to multilevel systems. Higher predictive accuracy of MT was also observed for binary grading systems in anal intraepithelial neoplasia.

CONCLUSIONS

No significant difference was found between the current grading systems of epithelial dysplasia in different body parts. However, binary grading systems have shown better clinical outcomes.

Decreased Nuclear Immunoexpression of ING3 is a Frequent Event in Lip Carcinogenesis

PURPOSE

Evaluate the immunohistochemical expression of the ING3 in actinic cheilitis and squamous cell carcinoma of the lower lip.

METHODS

Forty-five specimens of actinic cheilitis and 48 specimens of squamous cell carcinoma of the lower lip were submitted to immunohistochemical detection of ING3. The protein expression in different cellular sublocations was compared between the two groups, and associations with the clinicopathological variables were analyzed. A significance level of 5% was adopted for all tests.

RESULTS

Deaths were significantly more frequent in tumors with a high histopathological risk score (p < 0.05). In actinic cheilitis, significant differences were found in the nucleus-cytoplasmic expression of ING3 and expression restricted to the cytoplasm with binary histopathological grading (p < 0.05). In squamous cell carcinoma of the lower lip, there was no statistically significant difference when comparing ING3 expressions with clinical and morphological parameters (p > 0.05). Nucleo-cytoplasmic ING3 expression was significantly lower in squamous cell carcinoma of the lower lip when compared to actinic cheilitis (p < 0.05) and the expression restricted to the cytoplasm was significantly higher in squamous cell carcinoma of the lower lip (p < 0.05).

CONCLUSION

The results of this study suggest that there is a marked decrease in the nuclear expression of ING3 as malignant progression occurs, indicating an impaired tumor suppressor function of this protein in actinic cheilitis and squamous cell carcinoma of the lower lip.

Human Papilloma Virus-Related Oral Mucosal Lesions in Turkey: A Retrospective Cohort Study

INTRODUCTION

The human papillomavirus (HPV) is the etiological agent of a variety of oral mucosal benign and pre/malignant lesions, which demonstrate a wide range of prevalence according to geographic regions.

MATERIAL AND METHODS

This study specifically examined the typing of HPV-associated oral mucosal lesions in Turkish patients. The DNA from FFPE blocks of 228 lesions was utilized for this purpose. A total of 87 oral mucosal lesions were classified as benign, 68 as premalignant, and 73 as malignant. DNA from these lesions was amplified using polymerase chain reaction, and genotypes were identified using restriction fragment length polymorphisms (RFLP).

RESULTS

HPV-DNA was identified in 17 out of 228 patients, indicating a prevalence incidence of 7.4%. In benign oral lesions, the prevalence of HPV-DNA was 9.2% (8/87 cases), whereas in premalignant, oral epithelial dysplasia, and oral squamous cell carcinoma lesions, it was 6.9% (9/141 cases). A significant statistical difference was found between patients who tested positive for HPV and those who tested negative in terms of the location of the lesion and the age of the patients (p = 0.0097, p = 0.02, respectively).

CONCLUSIONS

This study underscores the considerable prevalence of HPV infection in oral mucosal lesions among individuals in Central Anatolia, Turkey.

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.

Treatment outcomes of oral leukoplakia on the irradiated or nonirradiated mucosa among survivors of head and neck cancer in the papulation where practice of betel nut chewing and cigarette smoking are widespread

BACKGROUND

Radiotherapy (RT) has numerous effects on the oral mucosa, primarily genetic alterations and changes in the microenvironment. The characteristics of oral leukoplakia (OL) may differ between patients who have received previous head and neck cancer (HNC) treatment with radiation therapy and those who have not. Due to a lack of data on this scenario, we aimed to investigate the surgical outcomes of OL by comparing these two patient groups.

METHODS

This retrospective cohort study enrolled a total of 224 OL lesions in 124 patients who underwent carbon dioxide laser (CO2 laser) surgery from July 2002 to Aug 2021. All patients had received previous treatments for HNC, with 59 patients undergoing only surgical approach, 65 patients undergoing RT, and 46 patients undergoing concurrent chemotherapy during RT. The analysis was performed on a per-lesion basis, not a per-capita basis. We investigated the associations of clinicopathological characteristics and treatment outcomes of OL lesions that developed from irradiated or nonirradiated oral mucosa.

RESULTS

The median follow-up time was 5.87 years. Postoperative recurrence of OL occurred in 30 patients. Malignant transformation occurred in 17 patients with the incidence rate 4.19% annually and 13.7% cumulatively. The average time for OL transforming into squamous cell carcinoma was 3.27 ± 3.26 years (median 1.82, range 0.11 - 11.90). In univariate analysis, non-homogeneous morphology (P = 0.042), moderate to high-grade dysplasia (P = 0.041), and nonirradiated oral mucosa (P = 0.0047) were predictors for malignant transformation. However, in the Cox proportional hazard model, only nonirradiated oral mucosa remained an independent prognostic factor related to postoperative malignant transformation of OL (P = 0.031, HR 5.08, CI95 1.16 - 22.25).

CONCLUSION

In the population whose OL is strongly aetiologically linked to environmental carcinogens such as betel nut and tobacco, OL lesions that develop on previously irradiated oral mucosa have a lower risk for postoperative malignant transformation compared to those that develop on nonirradiated mucosa. This finding highlights the potential impacts of radiation on OL. Further research is needed to confirm this observation and elucidate the underlying mechanism.

Validity of nomograms for predicting cancer risk in oral leukoplakia and oral lichen planus

OBJECTIVES

This study assessed the validity of nomograms for predicting malignant transformation (MT) among patients with oral leukoplakia (OL) and oral lichen planus (OLP).

MATERIALS AND METHODS

Two nomograms were identified following a systematic search. Variables to interrogate both nomograms were obtained for a retrospective OL/OLP cohort. Then, the nomograms were applied to estimate MT probabilities twice and their average was used to calculate the discriminatory performance, calibration, and potential net benefit of the models. Subgroup analyses were performed for patients with OL, OLP, and oral epithelial dysplasia.

RESULTS

Predicted probabilities were mostly significantly higher among OL/OLP patients who developed MT compared to those who did not (p = <0.001-0.034). AUC values and Brier scores of the nomograms were 0.644-0.844 and 0.040-0.088 among OL patients and 0.580-0.743 and 0.008-0.072 among OLP patients. Decision curve analysis suggested that the nomograms had some net benefit for risk stratification. However, the models did not best binary dysplasia grading in discriminatory validity and net benefit among patients with OL and oral epithelial dysplasia.

CONCLUSION

Nomograms for predicting MT may have satisfactory validity among patients with OL than OLP, but they do not outperform binary dysplasia grading in risk stratification of OL.

Machine learning methods in predicting the risk of malignant transformation of oral potentially malignant disorders: A systematic review

BACKGROUND

Oral Potentially Malignant Disorders (OPMDs) refer to a heterogenous group of clinical presentations with heightened rate of malignant transformation. Identification of risk levels in OPMDs is crucial to determine the need for active intervention in high-risk patients and routine follow-up in low-risk ones. Machine learning models has shown tremendous potential in several areas of dentistry that strongly suggest its application to estimate rate of malignant transformation of precancerous lesions.

METHODS

A comprehensive literature search was performed on Pubmed/MEDLINE, Web of Science, Scopus, Embase, Cochrane Library database to identify articles including machine learning models and algorithms to predict malignant transformation in OPMDs. Relevant bibliographic data, study characteristics, and outcomes were extracted for eligible studies. Quality of the included studies was assessed through the IJMEDI checklist.

RESULTS

Fifteen articles were found suitable for the review as per the PECOS criteria. Amongst all studies, highest sensitivity (100%) was recorded for U-net architecture, Peaks Random forest model, and Partial least squares discriminant analysis (PLSDA). Highest specificity (100%) was noted for PLSDA. Range of overall accuracy in risk prediction was between 95.4% and 74%.

CONCLUSION

Machine learning proved to be a viable tool in risk prediction, demonstrating heightened sensitivity, automation, and improved accuracy for predicting transformation of OPMDs. It presents an effective approach for incorporating multiple variables to monitor the progression of OPMDs and predict their malignant potential. However, its sensitivity to dataset characteristics necessitates the optimization of input parameters to maximize the efficiency of the classifiers.

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.

Assessment of the association of myofibroblasts and structural components of the extracellular matrix with histopathological parameters of actinic cheilitis and lower lip squamous cell carcinoma

BACKGROUND

To evaluate the presence of myofibroblasts (MFs) in the development of lip carcinogenesis, through the correlation of clinical, histomorphometric and immunohistochemical parameters, in actinic cheilitis (ACs) and lower lip squamous cell carcinomas (LLSCCs).

METHODS

Samples of ACs, LLSCCs, and control group (CG) were prepared by tissue microarray (TMA) for immunohistochemical TGF-β, α-SMA, and Ki-67 and histochemical hematoxylin and eosin, picrosirius red, and verhoeff van gieson reactions. Clinical and microscopic data were associated using the Mann-Whitney, Kruskal-Wallis/Dunn, and Spearman correlation tests (SPSS, p < 0.05).

RESULTS

ACs showed higher number of α-SMA+ MFs when compared to CG (p = 0.034), and these cells were associated with the vertical expansion of solar elastosis (SE) itself (p = 0.027). Areas of SE had lower deposits of collagen (p < 0.001), immunostaining for TGF-β (p < 0.001), and higher density of elastic fibers (p < 0.05) when compared to areas without SE. A positive correlation was observed between high-risk epithelial dysplasia (ED) and the proximity of SE to the dysplastic epithelium (p = 0.027). LLSCCs showed a higher number of α-SMA+ MFs about CG (p = 0.034), as well as a reduction in the deposition of total collagen (p = 0.009) in relation to ACs and CG. There was also a negative correlation between the amount of α-SMA+ cells and the accumulation of total collagen (p = 0.041). Collagen and elastic density loss was higher in larger tumors (p = 0.045) with nodal invasion (p = 0.047).

CONCLUSIONS

Our findings show the possible role of MFs, collagen fibers, and elastosis areas in the lip carcinogenesis process.

Human Papillomavirus-Associated Oral Epithelial Dysplasia: A Practical Approach to Make the Diagnosis

Background

High-risk Human Papillomavirus (HPV) genotypes are found in malignant oral epithelial lesions, and HPV infection is proposed as a risk factor for initiating Squamous cell carcinoma (SCC) in the head and neck region. This study suggests a practical approach to detect HPV in HPV-associated oral epithelial dysplasia (HAOED).

Methods

Fifty-four oral epithelial dysplasia specimens were examined, comprising twenty-seven cases diagnosed with high-grade dysplasia and twenty-seven cases diagnosed with low-grade dysplasia using a binary grading system. To assess the cases for HPV, the specimens were examined for p16 protein using an immunohistochemical (IHC) study, and then, the Chromatin In Situ Hybridization (CISH) test was performed for all positive cases. Chromatin Immunoprecipitation-Polymerase Chain Reaction (ChIP-PCR) was performed on CISH-positive specimens to assess the outcome. This cross-sectional study was conducted in 2020 at Tehran University of Medical Science. SPSS software version 22.0 was used to perform the Chi square or Fisher's exact test to examine the relationship between variables (statistically significant level P<0.05).

Results

The expression of p16 protein was not associated with the severity of epithelial dysplasia (81.5% in low-grade and 59.2% in high-grade cases) (P=0.16). Moreover, according to the CISH test result, 9.25% of all specimens were positive (P>0.99), and in the nine cases, undergone the ChIP-PCR study, two cases (22.2%) showed positivity for HPV-16, while one case (11.1%) demonstrated positivity for HPV-51.

Conclusion

Regarding HAOED, here, we proposed a step-by-step combination approach using different diagnostic methods, including IHC for p16 protein, CISH, and ChIP-PCR based on a complementary algorithm.

Manganese suppresses the development of oral leukoplakia by activating the immune response

OBJECTIVE

Manganese ion (Mn2+ ) is reported to promote the antitumor immune response by activating the cGAS-STING pathway, but it is unknown whether Mn2+ can prevent the malignant transformation of precancerous lesions. The effects of Mn2+ in treating oral leukoplakia (OLK) were explored in this work.

METHODS

Peripheral blood Mn analysis of the patients was performed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). A coculture model of dendritic cells (DCs)/macrophages, CD8+ T cells, and dysplastic oral keratinocytes (DOKs) was employed to analyze the role and mechanism of Mn2+ in a simulated OLK immune microenvironment. Western blot, RT-PCR, flow cytometry, enzyme-linked immunosorbent assay (ELISA), and lactate dehydrogenase (LDH) assays were adopted to detect the mechanism of Mn2+ in this model. 4-nitroquinoline oxide (4NQO)-induced OLK mice were used to assess the role of Mn2+ in suppressing OLK progression, and a novel Mn2+ -loaded guanosine-tannic acid hydrogel (G-TA@Mn2+ hydrogel) was fabricated and evaluated for its advantages in OLK therapy.

RESULTS

The content of Mn in patients' peripheral blood was negatively related to the progression of OLK. Mn2+ promoted the maturation and antigen presentation of DCs and macrophages and enhanced the activation of CD8+ T cells in the coculture model, resulting in effective killing of DOKs. Mechanistic analysis found that Mn2+ enhanced the anti-OLK immune response by activating the cGAS-STING pathway. Moreover, Mn2+ suppressed the development of 4NQO-induced carcinogenesis in the mouse model. In addition, the G-TA@Mn2+ hydrogel had better anti-OLK effects.

CONCLUSIONS

Mn2+ enhanced the anti-OLK immune response by activating the cGAS-STING pathway, and the G-TA@Mn2+ hydrogel is a potential novel therapeutic approach for OLK treatment.

Leveraging artificial intelligence for perioperative cancer risk assessment of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are mucosal conditions with an inherent disposition to develop oral squamous cell carcinoma. Surgical management is the most preferred strategy to prevent malignant transformation in OPMDs, and surgical approaches to treatment include conventional scalpel excision, laser surgery, cryotherapy, and photodynamic therapy. However, in reality, since all patients with OPMDs will not develop oral squamous cell carcinoma in their lifetime, there is a need to stratify patients according to their risk of malignant transformation to streamline surgical intervention for patients with the highest risks. Artificial intelligence (AI) has the potential to integrate disparate factors influencing malignant transformation for robust, precise, and personalized cancer risk stratification of OPMD patients than current methods to determine the need for surgical resection, excision, or re-excision. Therefore, this article overviews existing AI models and tools, presents a clinical implementation pathway, and discusses necessary refinements to aid the clinical application of AI-based platforms for cancer risk stratification of OPMDs in surgical practice.

Demystifying oral epithelial dysplasia: a histological guide

Oral epithelial dysplasia is a histologically diagnosed potentially premalignant disorder of the oral mucosa, which carries a risk of malignant transformation to squamous cell carcinoma. The diagnosis and grading of oral epithelial dysplasia is challenging, with cases often referred to specialist oral and maxillofacial pathology centres for second opinion. Even still there is poor inter-examiner and intra-examiner agreement in a diagnosis. There are a total of 28 features of oral epithelial dysplasia listed in the 5th edition of World Health Organization classification of tumours of the head and neck. Each of these features is poorly defined and subjective in its interpretation. Moreover, how these features contribute to dysplasia grading and risk stratification is even less well defined. This article discusses each of the features of oral epithelial dysplasia with examples and provides an overview of the common mimics, including the normal histological features of the oral mucosa which may mimic atypia. This article also highlights the paucity of evidence defining these features while offering suggested definitions. Ideally, these definitions will be refined, and the most important features identified to simplify the diagnosis of oral epithelial dysplasia. Digital whole slide images of the figures in this paper can be found at: https://www.pathogenesis.co.uk/r/demystifying-dysplasia-histology-dataset.

Prognostic importance of mitosis quantification and PHH3 expression in oral epithelial dysplasia

Oral epithelial dysplasia (OED) is diagnosed and graded using a range of histological features, making grading subjective and challenging. Mitotic counting and phosphohistone-H3 (PHH3) staining have been used for the prognostication of various malignancies; however, their importance in OED remains unexplored. This study conducts a quantitative analysis of mitotic activity in OED using both haematoxylin and eosin (H&E)-stained slides and immunohistochemical (IHC) staining for PHH3. Specifically, the diagnostic and prognostic importance of mitotic number, mitotic type and intra-epithelial location is evaluated. Whole slide images (WSI) of OED (n = 60) and non-dysplastic tissue (n = 8) were prepared for analysis. Five-year follow-up data was collected. The total number of mitosis (TNOM), mitosis type and intra-epithelial location was manually evaluated on H&E images and a digital mitotic count performed on PHH3-stained WSI. Statistical associations between these features and OED grade, malignant transformation and OED recurrence were determined. Mitosis count increased with grade severity (H&E: p < 0.005; IHC: p < 0.05), and grade-based differences were seen for mitosis type and location (p < 0.05). The ratio of normal-to-abnormal mitoses was higher in OED (1.61) than control (1.25) and reduced with grade severity. TNOM, type and location were better predictors when combined with histological grading, with the most prognostic models demonstrating an AUROC of 0.81 for transformation and 0.78 for recurrence, exceeding conventional grading. Mitosis quantification and PHH3 staining can be an adjunct to conventional H&E assessment and grading for the prediction of OED prognosis. Validation on larger multicentre cohorts is needed to establish these findings.

Calibration improves the agreement in grading oral epithelial dysplasia-Findings from a National Workshop in Malaysia

INTRODUCTION

A major pitfall of many of the established oral epithelial dysplasia (OED) grading criteria is their lack of reproducibility and accuracy to predict malignant transformation. The main objective of this study was to determine whether calibration of practicing oral pathologists on OED grading could improve the reproducibility of the WHO 2017 and the binary OED grading systems.

METHODS

A nationwide online exercise was carried out to determine the influence of calibration on the reproducibility of the WHO 2017 and the binary OED grading systems.

RESULTS

A significant improvement was observed in the inter-observer agreement for the WHO 2017 OED grading system (K 0.196 vs. 0.448; Kw 0.357 vs. 0.562) after the calibration exercise. The significant difference (p = 0.027) in the level of agreement between those with five or more years and less than 5 years of experience was no more observed (p = 0.426) after the calibration exercise. The percent agreement for binary grading was significantly higher (91.8%) for buccal mucosal lesions as compared to lesions on the tongue after the calibration exercise.

CONCLUSION

This study validates the significance of calibration in improving the reproducibility of OED grading. The nationwide exercise resulted in a statistically significant improvement in the inter-observer agreement for the WHO 2017 OED grading system among a large number of oral pathologists. It is highly recommended that similar exercises should be organized periodically by professional bodies responsible for continuing education among oral pathologists to improve the reliability of OED grading for optimal treatment of oral potentially malignant disorders.

Possible role of ALDH1 and CD44 in lip carcinogenesis

BACKGROUND

Lip squamous cell carcinoma (LSCC) accounts for 12% of all head and neck cancers. It is caused by chronic exposure to ultraviolet light solar radiation and related to previous actinic cheilitis (AC). This study aimed to investigate the immunostaining of the putative cancer stem cells (CSC) markers ALDH1 and CD44 in AC (n=30) and LSCC (n=20). ALDH1 positivity was found to be statistically higher in LSCC than in AC lesions (p=0.0045), whilst CD44 expression was statistically higher in AC than in LSCC lesions (p=0.0155). ALDH1+ cells in AC lesions were associated with specific clinical features: a younger age (<60 years old), the female gender, white skin, not smoking or consuming alcohol, and a fast evolution, and not associated with the chronic exposure to UV radiation (p<0.0001). CD44 positivity was associated with patients who were male, feoderm, smoked, consumed alcohol, underwent occupational exposure to UV-radiation, and demonstrated lesions with log-time evolution (p<0.0001). ALDH1 + cells were associated with mild dysplasia using a system from the World Health Organization (WHO), and with a low risk of malignant transformation, according to the binary system (p<0.0001). CD44+ cells were also associated with moderated dysplasia, according to the WHO system. In LSCC, ALDH1 + cells were positively associated with patients who were older (≥ 60 years old), smokers, and with those who consumed alcohol (p<0.0001). CD44 + cells in LSCC were associated with older (≥ 60 years old) patients as well, but also with female patients, white skin, non-smokers, and individuals who did not consume alcohol (p<0.0001), all of whom showed distinct patterns in pre- and malignant lesions of both markers. Additionally, in LSCC, both ALDH1 and CD44 staining were associated with smaller tumor sizes (T1/T2; p<0.0001). In summary, although both ALDH1 and CD44 were associated with the presence of dysplasia in AC lesions, the present findings suggest that ALDH1 and CD44 may be activated by different etiopathogenic pathways, predominantly in distinct steps of oral carcinogenesis. CD44 would thus be more significantly related to the potentially malignant lesion, while ALDH1 would be closely linked to malignancy.

Clinical outcomes of oral epithelial dysplasia managed by observation versus excision

IMPORTANCE

Oral potentially malignant disorders, including oral epithelial dysplasia (OED), are a group of conditions with an increased risk of progression to oral cancer. Clinical management of OED is challenging and usually involves monitoring with repeated incisional biopsies or complete surgical excision.

OBJECTIVE

To determine if complete surgical excision of OED impacts malignant transformation or improves survival outcomes in lesions that progress to malignancy.

DESIGN

A retrospective review of all patients diagnosed with OED between 2009 and 2016 was completed, and patients were followed until January 2022 for disease course and outcomes.

RESULTS

Hundred and fifty-five cases of OED met the inclusion criteria. Among the 61 lesions managed by observation, 15 progressed to cancer. Among the 94 lesions managed by surgical excision, 27 progressed to cancer. The overall malignant transformation rate was 27%, with an annual rate of 6.4%. Surgical excision with or without histologically negative margins did not decrease malignant transformation but was associated with lower oncologic staging at the time of diagnosis and improved survival.

CONCLUSIONS AND RELEVANCE

Surgical excision of OED with or without negative margins did not reduce the rate of transformation to oral cancer but resulted in lower oncologic staging at diagnosis, leading to improved patient outcomes. Our results support the implementation of more extensive tissue sampling to improve cancer diagnosis and patient outcomes.

Predictive modelling for the diagnosis of oral and laryngeal premalignant and malignant lesions using p53 and Ki-67 expression

Oral and laryngeal epithelial lesions are currently diagnosed using histological criteria based on the World Health Organization (WHO) classification, which can cause interobserver variability. An integrated diagnostic approach based on immunohistochemistry (IHC) would aid in the interpretation of ambiguous histological findings of epithelial lesions. In the present study, IHC was used to evaluate the expression of p53 and Ki-67 in 114 cases of oral and laryngeal epithelial lesions in 104 patients. Logistic regression analysis and decision tree algorithm were employed to develop a scoring system and predictive model for differentiating the epithelial lesions. Cohen's kappa coefficient was used to evaluate interobserver variability, and next-generation sequencing (NGS) and IHC were used to compare TP53 mutation and p53 expression patterns. Two expression patterns for p53, namely, diffuse expression type (pattern HI) and null type (pattern LS), and the pattern HI for Ki-67 were significantly associated with high-grade dysplasia (HGD) or squamous cell carcinoma (SqCC). With an accuracy and area under the receiver operating characteristic curve (AUC) of 84.6% and 0.85, respectively, the scoring system based on p53 and Ki-67 expression patterns classified epithelial lesions into two types: non-dysplasia (ND) or low-grade dysplasia (LGD) and SqCC or HGD. The decision tree model constructed using the p53 and Ki-67 expression patterns classified epithelial lesions into ND, LGD, and group 2, including HGD or SqCC, with an accuracy and AUC of 75% and 0.87, respectively. The integrated diagnosis had a better correlation with near perfect agreement (weighted kappa 0.92, unweighted kappa 0.88). The patterns HI and LS for p53 were confirmed to be correlated with missense mutations and nonsense/frameshift mutations, respectively. A predictive model for diagnosis was developed based on the correlation between TP53 mutation and p53 expression patterns. These results indicate that the scoring system based on p53 and Ki-67 expression patterns can differentiate epithelial lesions, especially in cases when the morphological features are ambiguous.

Development and validation of a multivariable model for prediction of malignant transformation and recurrence of oral epithelial dysplasia

BACKGROUND

Oral epithelial dysplasia (OED) is the precursor to oral squamous cell carcinoma which is amongst the top ten cancers worldwide. Prognostic significance of conventional histological features in OED is not well established. Many additional histological abnormalities are seen in OED, but are insufficiently investigated, and have not been correlated to clinical outcomes.

METHODS

A digital quantitative analysis of epithelial cellularity, nuclear geometry, cytoplasm staining intensity and epithelial architecture/thickness is conducted on 75 OED whole-slide images (252 regions of interest) with feature-specific comparisons between grades and against non-dysplastic/control cases. Multivariable models were developed to evaluate prediction of OED recurrence and malignant transformation. The best performing models were externally validated on unseen cases pooled from four different centres (n = 121), of which 32% progressed to cancer, with an average transformation time of 45 months.

RESULTS

Grade-based differences were seen for cytoplasmic eosin, nuclear eccentricity, and circularity in basal epithelial cells of OED (p < 0.05). Nucleus circularity was associated with OED recurrence (p = 0.018) and epithelial perimeter associated with malignant transformation (p = 0.03). The developed model demonstrated superior predictive potential for malignant transformation (AUROC 0.77) and OED recurrence (AUROC 0.74) as compared with conventional WHO grading (AUROC 0.68 and 0.71, respectively). External validation supported the prognostic strength of this model.

CONCLUSIONS

This study supports a novel prognostic model which outperforms existing grading systems. Further studies are warranted to evaluate its significance for OED prognostication.

The role of differentiated dysplasia in the prediction of malignant transformation of oral leukoplakia

OBJECTIVE

Oral leukoplakia is the most common oral potentially malignant disorder. Malignant transformation of oral leukoplakia occurs at an annual rate of 1%-7%. WHO-defined classic epithelial dysplasia is an important predictor of malignant transformation of oral leukoplakia, but we have previously shown in a proof of concept study that prediction improves by incorporation of an architectural pattern of dysplasia, also coined as differentiated dysplasia. We aimed to analyze this finding in a larger cohort of patients.

METHOD

For this retrospective study 176 oral leukoplakia patients were included. Biopsies for all patients were assessed for the presence of dysplasia and analyzed for cytokeratin 13 and 17 expression. Moreover, the inter-observer agreement for the diagnosis of differentiated dysplasia was determined.

RESULTS

In total, 33 of 176 patients developed oral squamous cell carcinoma during follow-up. Presence of classic epithelial dysplasia increased cancer risk two-fold (HR = 2.18, p = 0.026). Lesions without classic epithelial dysplasia could be further risk-stratified by the presence of differentiated dysplasia (HR = 7.36, p < 0.001). Combined classic epithelial and differentiated dysplasia imparted a seven-fold increased risk of malignant transformation (7.34, p = 0.001). Inter-observer agreement for the diagnosis of dysplasia, including differentiated dysplasia, was moderate (κ = 0.56, p < 0.001).

DISCUSSION

This study emphasizes the importance of the recognition of the architectural pattern of differentiated dysplasia as a separate entity for risk prediction of malignant transformation of oral leukoplakia. Presence of any pattern of dysplasia results in accurate prediction of malignant transformation risk of oral leukoplakia.

The use of deep learning state-of-the-art architectures for oral epithelial dysplasia grading: A comparative appraisal

BACKGROUND

Dysplasia grading systems for oral epithelial dysplasia are a source of disagreement among pathologists. Therefore, machine learning approaches are being developed to mitigate this issue.

METHODS

This cross-sectional study included a cohort of 82 patients with oral potentially malignant disorders and correspondent 98 hematoxylin and eosin-stained whole slide images with biopsied-proven dysplasia. All whole-slide images were manually annotated based on the binary system for oral epithelial dysplasia. The annotated regions of interest were segmented and fragmented into small patches and non-randomly sampled into training/validation and test subsets. The training/validation data were color augmented, resulting in a total of 81,786 patches for training. The held-out independent test set enrolled a total of 4,486 patches. Seven state-of-the-art convolutional neural networks were trained, validated, and tested with the same dataset.

RESULTS

The models presented a high learning rate, yet very low generalization potential. At the model development, VGG16 performed the best, but with massive overfitting. In the test set, VGG16 presented the best accuracy, sensitivity, specificity, and area under the curve (62%, 62%, 66%, and 65%, respectively), associated with the higher loss among all Convolutional Neural Networks (CNNs) tested. EfficientB0 has comparable metrics and the lowest loss among all convolutional neural networks, being a great candidate for further studies.

CONCLUSION

The models were not able to generalize enough to be applied in real-life datasets due to an overlapping of features between the two classes (i.e., high risk and low risk of malignization).

Oral leukoplakia classification and staging system with incorporation of differentiated dysplasia

OBJECTIVES

A classification and staging system for oral leukoplakia (OL) was introduced to promote uniform reporting. In this system, size and the histopathologic diagnosis are assessed and combined in a staging system. The various stages could be predictive for malignant transformation of OL. Differentiated dysplasia (DD) was recently recognized as an important architectural pattern of dysplasia and is highly associated with malignant transformation (MT) of OL. In the present study, DD was incorporated in the OL-system. The aim of the present study was to test the adapted system on a cohort of patients with OL.

PATIENT AND METHODS

The group consisted of 140 patients. The size, absence or presence and degree of classic dysplasia (CD) and DD were incorporated into the OL-system.

RESULTS

In 31/140 patients, MT occurred. Size was not statistically significant with MT (p = 0.422). The presence of dysplasia was predictive for MT (p = 0.003), whereby severe CD and DD were highly statistically significant for MT (p = 0.008). Stage IV was statistically significant for MT (p = 0.011).

CONCLUSIONS

The present study emphasizes the value of the slightly modified OL-system with incorporation of DD in uniform reporting of OL and the value in predicting MT.

Progression to malignancy in oral potentially malignant disorders: a retrospective study of 5,036 patients in Ontario, Canada

OBJECTIVES

Determine the rate of malignant transformation (MT) of oral potentially malignant disorders (OPMDs) and risk factors for transformation.

STUDY DESIGN

The OPMD database (2001-2015) from 2 biopsy services in Ontario, Canada, was linked to the Ontario Cancer Registry to determine the rate of progression to oral squamous cell carcinoma (OSCC). Clinical and histologic features of progressed and non-progressed cases were compared to determine risk factors for progression.

RESULTS

The MT rate was 6.4% (322/5,036 cases). The mean time for cancer development was 51.2 months. 33.6% of cases (107/322) progressed after over 60 months. The risk of cancer increased with age and was higher in non-smokers. The MT rate was highest in the tongue (11.4%), followed by the floor of mouth (7.1%) and gingiva (6.5%). Histologic grade was associated with progression to cancer (P < .0001). Atypical verrucous-papillary lesions with no or mild dysplasia predominantly affected older patients' gingiva, and the progression rate was significantly higher than conventional mild dysplasia (9.2% vs 3.2%, P = .0002).

CONCLUSIONS

Our population-based retrospective study showed that <10% of OPMDs progressed to cancer, which could take many years. Atypical papillary-verrucous proliferation without high-grade dysplasia is a subtype of OPMD requiring further study.

Identification of Proteomic Biomarkers in Proliferative Verrucous Leukoplakia through Liquid Chromatography With Tandem Mass Spectrometry

Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder associated with high risk of malignant transformation. Currently, there is no treatment available, and restrictive follow-up of patients is crucial for a better prognosis. Oral leukoplakia (OL) shares some clinical and microscopic features with PVL but exhibits different clinical manifestations and a lower rate of malignant transformation. This study aimed to investigate the proteomic profile of PVL in tissue and saliva samples to identify potential diagnostic biomarkers with therapeutic implications. Tissue and saliva samples obtained from patients with PVL were compared with those from patients with oral OL and controls. Label-free liquid chromatography with tandem mass spectrometry was employed, followed by qualitative and quantitative analyses, to identify differentially expressed proteins. Potential biomarkers were identified and further validated using immunohistochemistry. Staining intensity scan analyses were performed on tissue samples from patients with PVL, patients with OL, and controls from Brazil, Spain, and Finland. The study revealed differences in the immune system, cell cycle, DNA regulation, apoptosis pathways, and the whole proteome of PVL samples. In addition, liquid chromatography with tandem mass spectrometry analyses showed that calreticulin (CALR), receptor of activated protein C kinase 1 (RACK1), and 14-3-3 Tau-protein (YWHAQ) were highly expressed in PVL samples. Immunohistochemistry validation confirmed increased CARL expression in PVL compared with OL. Conversely, RACK1 and YWHA were highly expressed in oral potentially malignant disorder compared to the control group. Furthermore, significant differences in CALR and RACK1 expression were observed in the OL group when comparing samples with and without oral epithelial dysplasia, unlike the PVL. This research provides insights into the molecular mechanisms underlying these conditions and highlights potential targets for future diagnostic and therapeutic approaches.

Expression of Epsin3 and its interaction with Notch signalling in oral epithelial dysplasia and oral squamous cell carcinoma

BACKGROUND

Most oral squamous cell carcinoma patients present with late-stage disease. Early detection of the disease is considered to be the most effective way of improving patient outcomes. Several biomarkers have been identified as indicators of oral cancer development and progression; however, none have been translated into clinical practice. In this study, we have investigated the role of Epsin3, an endocytic adaptor protein, and Notch1, a transmembrane signalling protein, in oral carcinogenesis with a view to explore their potential as biomarkers.

METHODS

Oral cancer cell lines and a normal oral keratinocyte cell line were used together with tissue samples of normal oral mucosa (n = 21), oral epithelial dysplasia (n = 74) and early stage (Stages I and II) oral squamous cell carcinoma (n = 31). Immunocytochemical staining, immunoblotting and real-time quantitative polymerase chain reaction (PCR) were performed to assess protein as well as gene expression levels.

RESULTS

The expression levels of Epsin3 and Notch1 mRNA and protein are variable across different oral squamous cell carcinoma derived cell lines. Epsin3 was upregulated in oral epithelial dysplasia and oral squamous cell carcinoma tissues compared with normal epithelium. Overexpression of Epsin3 resulted in a significant reduction of Notch1 expression in oral squamous cell carcinoma. Notch1 was generally downregulated in the dysplasia and oral squamous cell carcinoma samples.

CONCLUSION

Epsin3 is upregulated in oral epithelial dysplasia and oral squamous cell carcinoma and has the potential to be used as a biomarker for oral epithelial dysplasia. Notch signalling is downregulated in oral squamous cell carcinoma, possibly through an Epsin3-induced de-activation pathway.

Clinicopathological Analysis of Actinic Cheilitis: A Systematic Review with Meta-analyses

BACKGROUND

This systematic review aimed to conduct a complete investigation of the demographic aspects, clinicopathological features, degrees of epithelial dysplasia, and malignant transformation rate of actinic cheilitis.

METHODS

The study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered in the International Prospective Register of Systematic Reviews (CRD42020201254). A search without year and language restrictions was performed using PubMed/MEDLINE, Embase, Virtual Health Library, Scopus, Web of Science, and gray literature. Studies that provided information on patients with actinic cheilitis were included, excluding those with general information on other diseases or other types of cheilitis. Risk of bias was explored using the Joanna Briggs Institute tool. Narrative and quantitative data syntheses were performed using meta-analyses and subgroup analyses. Association tests were also performed.

RESULTS

Thirteen studies (728 patients) were included. The most prevalent clinical signs were dryness (99%), blurred demarcation between the lip vermilion and skin (82%), scaling (69%), and atrophy (69%). Regarding epithelial dysplasia, a prevalence of mild dysplasia (34.2%), followed by moderate (27.5%), and severe (14.9%). The malignant transformation rate was 14%. Crusts, ulcerations, and erythematous areas were associated with lip carcinoma (p < 0.001), and scaling was associated with actinic cheilitis (p < 0.001).

CONCLUSIONS

This study revealed several features of actinic cheilitis, providing an overview of the disease. It is suggested that new studies help develop policy guides for the standardization of clinical criteria, enabling more rigorous and homogeneous analysis of actinic cheilitis.

A digital score of peri-epithelial lymphocytic activity predicts malignant transformation in oral epithelial dysplasia

Oral squamous cell carcinoma (OSCC) is amongst the most common cancers, with more than 377,000 new cases worldwide each year. OSCC prognosis remains poor, related to cancer presentation at a late stage, indicating the need for early detection to improve patient prognosis. OSCC is often preceded by a premalignant state known as oral epithelial dysplasia (OED), which is diagnosed and graded using subjective histological criteria leading to variability and prognostic unreliability. In this work, we propose a deep learning approach for the development of prognostic models for malignant transformation and their association with clinical outcomes in histology whole slide images (WSIs) of OED tissue sections. We train a weakly supervised method on OED cases (n = 137) with malignant transformation (n = 50) and mean malignant transformation time of 6.51 years (±5.35 SD). Stratified five-fold cross-validation achieved an average area under the receiver-operator characteristic curve (AUROC) of 0.78 for predicting malignant transformation in OED. Hotspot analysis revealed various features of nuclei in the epithelium and peri-epithelial tissue to be significant prognostic factors for malignant transformation, including the count of peri-epithelial lymphocytes (PELs) (p < 0.05), epithelial layer nuclei count (NC) (p < 0.05), and basal layer NC (p < 0.05). Progression-free survival (PFS) using the epithelial layer NC (p < 0.05, C-index = 0.73), basal layer NC (p < 0.05, C-index = 0.70), and PELs count (p < 0.05, C-index = 0.73) all showed association of these features with a high risk of malignant transformation in our univariate analysis. Our work shows the application of deep learning for the prognostication and prediction of PFS of OED for the first time and offers potential to aid patient management. Further evaluation and testing on multi-centre data is required for validation and translation to clinical practice. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Genome sequencing reveals molecular subgroups in oral epithelial dysplasia

This study aimed to analyze the molecular characteristics of oral epithelial dysplasia (OED), highlighting the pathways and variants of genes that are frequently mutated in oral squamous cell carcinoma (OSCC) and other cancers. Ten archival OED cases were retrieved for retrospective clinicopathological analysis and exome sequencing. Comparative genomic analysis was performed between high-grade dysplasia (HGD) and low-grade dysplasia (LGD), focusing on 57 well-known cancer genes, of which 10 were previously described as the most mutated in OSCC. HGD cases had significantly more variants; however, a similar mutational landscape to OSCC was observed in both groups. CASP8+FAT1/HRAS, TP53, and miscellaneous molecular signatures were also present. FAT1 is the gene that is most affected by pathogenic variants. Hierarchical divisive clustering showed division between the two groups: "HGD-like cluster" with 4HGD and 2LGD and "LGD-like cluster" with 4 LGD. MLL4 pathogenic variants were exclusively in the "LGD-like cluster". TP53 was affected in one case of HGD; however, its pathway was usually altered. We describe new insights into the genetic basis of epithelial malignant transformation by genomic analysis, highlighting those associated with FAT1 and TP53. Some LGDs presented a similar mutational landscape to HGD after cluster analysis. Perhaps molecular alterations have not yet been reflected in histomorphology. The relative risk of malignant transformation in this molecular subgroup should be addressed in future studies.

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.

Altered Presence of Cancer Stem Cell ALDH1/2 in Oral Leukoplakias and Squamous Cell Carcinomas

INTRODUCTION

Cancer stem cells (CSCs) are responsible for initiating the process of carcinogenesis by enabling the self-renewal and self-proliferation of the cancer cells. This study aimed to investigate the presence of epithelial cells with cancer stem cells characteristics (ALDH+) in the early stages of oral precancerous lesions (Oral Leukoplakias) and the frequency of these cells in the different stages of oral squamous cell carcinomas (OSCCs).

MATERIALS & METHODS

The aim of this study was the detection of the immunohistochemical pattern of expression of CSC protein-biomarker ALDH1&2 (sc-166362, Santa Cruz Co, Dallas, Texas, USA) in paraffin-embedded samples of 30 cases of leukoplakia of all degrees of dysplasia and 21 cases of oral squamous cell carcinomas (OSCC) of all degrees of differentiation compared to the histologically normal oral epithelium. The samples were retrieved from 2009-2019 from the archives of the Department of Oral Medicine/Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece. The samples were evaluated through a three-tier scale (positive cells Ι: 6-35%, ΙΙ: 36-70%, ΙΙΙ: 71-100%). Statistical analysis was performed through SPSS Pearson Chi-square, and the significance level was set at 0.05 (p=0.05).  Results: The staining of ALDH1&2 was observed mildly in the cell membrane of cells in the stratum spinosum of the normal epithelium and the cell membrane of cells in the stratum basale of the normal epithelium, characteristically at the interface point with the basal membrane. ALDH1&2 were expressed significantly more in the OSCC than in the leukoplakia (p-value=0.0001) and the normal epithelium (p-value=0.0001). Mainly, ALDH1&2 were expressed significantly more in the severely and moderately dysplastic oral leukoplakia compared to the mildly dysplastic and non-dysplastic leukoplakia (p-value=0.001).

DISCUSSION

The characteristic expression of ALDH in potentially malignant oral and OSCC lesions suggests the presence of CSCs and their possible implication in the early stages of oral tumorigenesis, even at the stage of oral leukoplakia.