Oral potentially malignant disorders: is malignant transformation predictable and preventable?

Oral Lichen Planus: A Narrative Review Navigating Etiologies, Clinical Manifestations, Diagnostics, and Therapeutic Approaches

Background/Objectives: Oral Lichen Planus (OLP) is a common immune-mediated inflammatory disorder affecting the oral mucosa, impacting 0.5% to 2% of the global population, primarily middle-aged women. Immunological dysregulation is a key factor in OLP's pathogenesis, involving CD4+ T helper and CD8+ T cytotoxic cells. The World Health Organization (WHO) classifies OLP as a potentially malignant disorder, with a risk of oral squamous cell carcinoma (OSCC) developing in up to 2% of lesions. This narrative review aims to provide a comprehensive overview of the etiopathogenesis, clinical manifestations, diagnostic criteria, and therapeutic strategies for OLP, informing clinical practice and guiding future research. Methods: A review of the literature from the PubMed and Google Scholar databases was conducted up to December 2023, focusing on studies addressing the etiopathogenesis, diagnosis, clinical manifestations, and treatment of OLP. Results: OLP's pathogenesis is driven by immune dysregulation, with CD4+ and CD8+ cells playing crucial roles. Clinically, OLP presents as reticular, erosive, bullous, and plaque-like lesions. Diagnosis relies on clinical examination, histopathology, and direct immunofluorescence. Recent advancements in diagnostic markers and imaging techniques have improved detection and monitoring. Treatment primarily involves corticosteroids, but novel therapies such as curcumin, retinoids, and laser therapy are increasingly used for their effectiveness and reduced side effects. These treatments show promise in symptom reduction and recurrence prevention, although long-term data are needed. Conclusions: Regular screenings and biopsies are essential due to OLP's likelihood of malignant transformation. This study urges further investigation into long-term results, improved diagnostic techniques, and evidence-based treatment regimens.

A Cross-Sectional Study on Oral Potentially Malignant Disorders: Diagnostic Challenges in Early Detection of Dysplasia and the Role of Velscope

BACKGROUND

The oral cancer burden has become a global challenge in the present scenario. Early diagnosis of oral potentially malignant disorders (OPMDs) with dysplasia is crucial to increasing the overall survival rate of the patients. Efficient chairside techniques are much needed to enhance diagnostic efficacy at early stages. This study evaluates the effectiveness of Velscope in detecting dysplastic lesions and analyzes the impact of lifestyle factors on the prevalence and progression of oral potentially malignant disorders among 40 participants.

METHODS

A cross-sectional study was conducted with 40 participants diagnosed with OPMDs. Participants underwent a Velscope examination followed by incisional biopsy and histopathological evaluation. Data on lifestyle factors such as tobacco, alcohol, pan, and gutka use were collected through self-reported questionnaires. Data were analyzed to assess Velscope efficacy and correlations between lifestyle risk factors and lesion sites. Statistical analysis was performed using SPSS statistics for Windows (version 26.0, IBM Corp., Armonk, NY). The significance level was fixed at 5% (α=0.05).

RESULTS

The data analysis of the study revealed that Velscope showed a sensitivity of 88.89% and a specificity of 46.15% (p = 0.013). The positive predictive value (PPV) of the Velscope was 77.42%, and the negative predictive value (NPV) was 66.67%. Overall, the diagnostic accuracy of the Velscope in this study was 75.0%. Cohen's kappa of 0.381 indicated moderate agreement with biopsy results. Biopsy results showed no statistically significant correlation was found between dysplasia and lesion site, gender, smoking, alcohol, or pan use except for gutka users, who had a significantly higher rate of dysplasia (p = 0.027).

CONCLUSION

Velscope demonstrated high sensitivity but moderate specificity in detecting dysplasia, emphasizing its role as an adjunctive tool in early detection and delineation of oral lesions in conjunction with biopsies for accurate diagnosis. The higher rate of positive results for dysplasia among gutka users suggests that focused public health interventions are needed to address significant lifestyle risk factors, which in turn could reduce malignant transformations in OPMDs.

Surgical protocols for oral leukoplakia and precancerous lesions across three different anatomic sites

OBJECTIVE

This systematic review and meta-analysis aimed to compare the risk of recurrence and cancer progression after surgical treatment for oral potentially malignant disorders (OPMD) and precancerous lesions in different anatomical sites.

MATERIALS AND METHODS

A comprehensive search was conducted in nine databases and grey literature. We included randomized controlled trials assessing surgical treatment efficacy for OPMD and precancerous lesions of cervical, vaginal, anal, and penile sites. Excision or ablation surgical treatments were considered.

RESULTS

Overall, 12 studies met the eligibility criteria for oral leukoplakia (OL), proliferative verrucous leukoplakia, cervical intraepithelial neoplasia (CIN), vaginal intraepithelial neoplasia, and anal intraepithelial neoplasia (AIN). In qualitative analysis of surgical protocols, the lack of margin description impacts the clinical outcomes of OL and AIN, and the ablative protocols were heterogeneous in both OPMD and precancerous lesions. No significant difference in OL (risk ratio 0.82 [95% CI: 0.59-1.15]) and CIN (risk ratio 0.31 [95% CI: 0.09-1.09]) for recurrence was observed when cold-knife was compared with ablative protocols. OL exhibited higher recurrence and cancer progression rates compared to CIN and AIN.

CONCLUSION

There is no difference in recurrence risk post-surgical treatment for OL and CIN. Surgical protocols for oral leukoplakia and CIN/AIN lack standardized approaches.

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.

Expression of FAP in Oral Leukoplakia and Oral Squamous Cell Carcinoma

OBJECTIVE

This study aimed to investigate the potential of fibroblast activation protein (FAP) as a biomarker in the progression of oral leukoplakia (OLK) carcinogenesis. This was achieved by evaluating FAP expression at different levels of the organisation, namely oral normal mucosa (NM), OLK, and oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Altogether, 88 paraffin-embedded tissue samples were examined, including 55 cases of OLK, 13 cases of OSCC, and 20 cases of NM (control group). An exhaustive investigation was performed to examine FAP expression in NM, OLK, and OSCC tissues via immunohistochemistry (IHC). The relationship between FAP expression and clinical pathologic characteristics was analysed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB) also proved the expression of FAP in NM, OLK, and OSCC cells. Aberrant FAP expression in OLK and OSCC was explored using in vitro experiments.

RESULTS

Immunohistochemical results showed that high FAP expression was significantly correlated with histopathologic grade (P = .038) but not correlated with age, sex, or region (P = .953, .622, and .108, respectively). The expression level of FAP in NM tissues (0.15 ± 0.01) was minimal, whereas it was observed in OLK (0.28 ± 0.04) and OSCC (0.39 ± 0.02) tissues with a noticeable increase in expression levels (P < .001). The expression level of FAP in OLK with severe abnormal hyperplasia (S-OLK) tissues (0.33 ± 0.04) was significantly higher than in OLK with mild abnormal hyperplasia (MI-OLK, 0.26 ± 0.02) and OLK with moderate abnormal hyperplasia (MO-OLK, 0.28 ± 0.03) tissues (P < .001 and P = .039, respectively). The results of RT-PCR illustrated that the relative expression of FAP mRNA in OLK cells (2.63 ± 0.62) was higher than in NM cells (0.87 ± 0.14), but lower than in OSCC cells (5.63 ± 1.06; P = .027 and .012, respectively). FAP expression was minimal in NM cells (0.78 ± 0.06), modest in OLK cells (1.04 ± 0.06), and significantly elevated in OSCC cells (1.61 ± 0.09) based on the results of WB (P < .001).

CONCLUSIONS

Significant variations in FAP expression were observed in NM, OLK, and OSCC tissues and cells. These findings revealed that FAP may be a reliable biomarker for the early diagnosis and evaluation of OLK carcinogenesis.

Clinicopathological evaluation of oral leukoplakia: a single-center study of 676 cases in Japan

OBJECTIVES

To analyze the clinical and histopathological characteristics of oral leukoplakia (OL) in the Japanese population and investigate the prevalence and risk factors for epithelial dysplasia (ED) and carcinoma within lesions.

STUDY DESIGN

Data, including age, sex, lesion site, and histopathological features, of 676 cases diagnosed with OL over the previous 10 years were analyzed. Dysplasia and carcinoma prevalence were determined.

RESULTS

In male patients, the most affected site was the gingiva (42.7%), whereas in females, it was the tongue (47.6%). Moreover, ED was more prevalent in males (41.9%), whereas epithelial hyperplasia was more common in females (44.7%). A significant difference was observed between affected sites with regard to the presence of dysplasia. The ED rates by site were 64.6% and 33.7% for the tongue and gingiva, respectively (P < 0.05). The squamous cell carcinoma rates by site were 23.4%, 5.4%, and 3.4% for the tongue, buccal mucosa, and gingiva, respectively (P < 0.05). Logistic regression analysis revealed a higher prevalence of dysplasia in males than it did in females and that the risk for both dysplasia and carcinoma was highest in the tongue.

CONCLUSIONS

Dysplasia is common in OL cases, often showing carcinoma. Early biopsy and interventions are key in OL management.

Calcitriol Treatment Decreases Cell Migration, Viability and β-Catenin Signaling in Oral Dysplasia

Nearly 90% of oral cancers are characterized as oral squamous cell carcinoma (OSCC), representing the sixth most common type of cancer. OSCC usually evolves from oral potentially malignant disorders that, in some cases, are histologically consistent with a oral dysplasia. The levels of 1α,25 dihydroxyvitamin D3 (1,25-(OH)2D3; calcitriol), the active form of vitamin D3, have been shown to be decreased in patients with oral dysplasia and OSCC. Moreover, treatment with 1,25-(OH)2D3 has been proven beneficial in OSCC by inhibiting the Wnt/β-catenin pathway, a signaling route that promotes cell migration, proliferation, and viability. However, whether this inhibition mechanism occurs in oral dysplasia is unknown. To approach this question, we used dysplastic oral keratinocyte cultures and oral explants (ex vivo model of oral dysplasia) treated with 1,25-(OH)2D3 for 48 h. Following treatment with 1,25-(OH)2D3, both in vitro and ex vivo models of oral dysplasia showed decreased levels of nuclear β-catenin by immunofluorescence (IF) and immunohistochemistry (IHC). Consistently, reduced protein and mRNA levels of the Wnt/β-catenin target gene survivin were observed after treatment with 1,25-(OH)2D3. Moreover, 1,25-(OH)2D3 promoted membranous localization of E-cadherin and nuclear localization of vitamin D receptor (VDR). Functionally, DOK cells treated with 1,25-(OH)2D3 displayed diminished cell migration and viability in vitro.

Inhibition of PORCN Blocks Wnt Signaling to Attenuate Progression of Oral Carcinogenesis

PURPOSE

Oral squamous cell carcinoma (OSCC) is commonly preceded by potentially malignant lesions, referred to as oral dysplasia. We recently reported that oral dysplasia is associated with aberrant activation of the Wnt/β-catenin pathway, due to overexpression of Wnt ligands in a Porcupine (PORCN)-dependent manner. Pharmacologic inhibition of PORCN precludes Wnt secretion and has been proposed as a potential therapeutic approach to treat established cancers. Nevertheless, there are no studies that explore the effects of PORCN inhibition at the different stages of oral carcinogenesis.

EXPERIMENTAL DESIGN

We performed a model of tobacco-induced oral cancer in vitro, where dysplastic oral keratinocytes (DOK) were transformed into oral carcinoma cells (DOK-TC), and assessed the effects of inhibiting PORCN with the C59 inhibitor. Similarly, an in vivo model of oral carcinogenesis and ex vivo samples derived from patients diagnosed with oral dysplasia and OSCC were treated with C59.

RESULTS

Both in vitro and ex vivo oral carcinogenesis approaches revealed decreased levels of nuclear β-catenin and Wnt3a, as observed by immunofluorescence and IHC analyses. Consistently, reduced protein and mRNA levels of survivin were observed after treatment with C59. Functionally, treatment with C59 in vitro resulted in diminished cell migration, viability, and invasion. Finally, by using an in vivo model of oral carcinogenesis, we found that treatment with C59 prevented the development of OSCC by reducing the size and number of oral tumor lesions.

CONCLUSIONS

The inhibition of Wnt ligand secretion with C59 represents a feasible treatment to prevent the progression of early oral lesions toward OSCC.

Prevalence and Malignant Transformation Rate of Oral Erythroplakia Worldwide - A Systematic Review

Background

To determine the characteristics of oral erythroplakia (OE) on a global scale, it is important to analyse and evaluate findings from various studies conducted across multiple geographical locations.

Objectives

This review was conducted to determine the prevalence and malignant transformation rate (MTR) of OE.

Data Sources

A systematic search was performed to identify studies reporting the prevalence and MTR of OE across various databases - PubMed, Web of Science, Google Scholar, Elsevier and ScienceDirect without any restriction for the time of publication.

Study Eligibility Criteria

This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines, and the protocol was registered in the PROSPERO database (ID: CD42023395215).

Results

The prevalence rate of OE reported across the studies ranged from 0.04% to 1.14% with a mean of 0.25 + 0.002%. The MTRs reported across the studies included ranged from 2.6% to 65% with a mean of 30 ± 0.2%.

Limitations and Conclusions

Based on the findings from the present review, it can be concluded that while the range of MTRs of OE varies widely across different geographical locations, the average rate can be considered 30%. The review also identified a need for conducting more studies on the prevalence rates as well as longitudinal studies assessing the MTR across different regions.

Analysis of drug factors in 5-aminolevulinic acid photodynamic therapy for oral potentially malignant disorder

OBJECTIVES

This study aimed to analyze the influence of drug factors on the efficacy of 5-aminolevulinic acid (ALA) photodynamic therapy for oral potentially malignant disorder to improve clinical efficacy and promote clinical rational drug use.

METHODS

Literature on the treatment of oral potentially malignant disorder by using ALA photodynamic therapy was collected and analyzed from PubMed, ISI Web of Knowledge database, CNKI, VIP, and Wanfang database.

RESULTS

A total of 690 cases were collected, with an average complete response rate of 65.94%. The groups treated with 16.8% methyl aminolevulinate cream, local topical, once a week, and pre-activation time of 2-4 hours were better than the other subgroups, with average complete response rates of 100%, 66.91%, 78.28%, and 77.54%, respectively.

CONCLUSIONS

Drug factors have direct influence on the curative effect. The development of novel oral ALA formulations from the perspective of drug improvement is an important strategy to improve efficacy.

Oral Leukoplakia. A Five-Year Follow-Up Study

Background: Oral leukoplakia (OLK) is the most studied oral potentially malignant disorders in the scientific literature. Its malignant transformation (MT) rate varies between 1.1% and 40.8%, depending on the type of study and population group studied. There is no universal agreement to treat or manage these lesions, so it is up to each clinician's experience and expertise in how he/she manages these patients. Objective:The aim of this retrospective study was to assess the clinical aspects and pattern of evolution of OLK in 30 patients five years or more after the initial diagnosis. Material and methods:We selected 30 OLK patients from our database. Demographic, clinical and evolutive data was retrieved from the medical files. The following variables were analysed: age and sex, smoking habits, clinical features (form, dimension, site of the lesion), result of mycological examination, treatment and outcomes of the lesions over a follow-up of more than five years. Results:For a follow-up of 119.63 months, we detected a value of 0.2% MT rate per year. Outcomes varied from the complete disappearance of the lesion to recurrence and malignant transformation with a variety of treatment methods applied. Conclusion:Despite the low MT rate for a long follow-up, it is hard to say which treatment method is the best, due to the heterogeneity of the clinical aspects of the lesions and because there is no standardised test method, either genetic testing or immunohistochemical testing. We recommend a varied approach, suitable for each patient's needs and medical context, always when possible histopathological confirmation for grading epithelial dysplasia, which remains the most reliable method of checking the process of malignant transformation.

Expression of the Embryonic Cancer Stem Cells' Biomarkers SOX2 and OCT3/4 in Oral Leukoplakias and Squamous Cell Carcinomas: A Preliminary Study

INTRODUCTION

Cancer stem cells (CSCs) are incriminated for initiating the process of carcinogenesis either de novo or through the transformation of oral potentially malignant disorders (OPMDs) to oral squamous cell carcinoma (OSCC). The aim of this study was to detect the expression of embryonic-type CSC markers OCT3/4 and SOX2 in OSCCs and oral leukoplakias (OLs), the most common of OPMDs.

MATERIALS AND METHODS

The study type is experimental, and the study design is characterized as semiquantitative research, which belongs to the branch of experimental research. The experiment was conducted in the Department of Oral Medicine/Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece. This study focuses on the semiquantitative immunohistochemical (IHC) pattern of expression of CSCs protein-biomarkers SOX2 and OCT3/4, in paraffin embedded samples of 21 OSCCs of different grades of differentiation and 30 cases of OLs with different grades of dysplasia, compared to five cases of normal oral mucosa in both terms of cells' stain positivity and intensity. Statistical analysis was performed through SPSS 2017 Pearson Chi-square and the significance level was set at 0.05 (p=0.05). The expression of the respective genes of SOX2 and OCT3/4 was studied through quantitative polymerase chain reaction (qPCR), in paraffin-embedded samples of 12 cases of OLs with mild/non dysplasia and 19 cases moderately/poorly differentiated OSCCs(n=19) and five normal mucosa using the Independent Paired T-test.

RESULTS

The genes SOX2 and Oct3/4 were expressed in all examined cases although no statistically significant correlations among normal, OL and OSCC, were established. A nuclear/membrane staining of OCT3/4 was noticed only in three out of 21 OSCCs but in none of OLs or normal cases (without statistical significance). A characteristic nuclear staining of SOX2 was noticed in the majority of the samples, mostly in the basal and parabasal layers of the epithelium. SOX2 was significantly detected in the OSCCs group (strong positivity in 17/21) than in the OL group (30 cases, mostly mildly stained) (p-value=0.007), and the normal oral epithelium (mild stained, p=0.065). Furthermore, SOX2 was overexpressed in well differentiated OSCCs group (5/OSCCs, strongly stained) rather than in mildly dysplastic and non-dysplastic OLs samples (14/OLs, mildly stained) (p-value =0.035).

CONCLUSION

The characteristic expression of SOX2 but not of OCT3/4 in OLs' and OSCCs' lesions suggests the presence of neoplastic cells with certain CSC characteristics whose implication in the early stages of oral tumorigenesis could be further evaluated. The clinical use of SOX2, as prognostic factor, requires further experimental evaluation in larger number of samples.

Cancer Stem Cells' Biomarker ALDH1&2 Increased Expression in Erosive Oral Lichen Planus Compared to Oral Leukoplakia

INTRODUCTION

ALDH1&2 has been considered an oral cancer stem cell (CSC) marker. Oral carcinogenesis is a process that usually passes through oral potentially malignant disorders (OPMD). Oral lichen planus (OLP) consists of immune-related chronic disorders that have been included in the OPMDs due to their possible transformation into oral cancer. The aim of this study was to investigate the early presence of ALDH1&2 in OLP compared to early oral leukoplakias (OL), especially mildly and non-dysplastic OL.

MATERIALS AND METHODS

The study type is experimental, and the study design is characterized as semiquantitative research which belongs to the branch of experimental research. The study sample consisted of paraffin-embedded OLP biopsy samples from the archives of the Department of Oral Medicine/Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece, during the period 2009-2019. The study sample contained 24 cases of OLP (14 erosive and 10 reticular) and 30 cases of OL (16 cases of moderately and severely dysplastic OL and 14 cases of mildly and non-dysplastic OL). The CSC-related biomarker ALDH1&2 was examined using semiquantitative immunohistochemistry (monoclonal antibody sc-166362, Santa Cruz Biotechnology, Dallas, Texas, USA, 1:100). ALDH1&2 expression was evaluated through a scale of 1 to 3 depending on the percentage of positive epithelial cells and was compared to normal epithelium as well as cases of OL (the most prominent OPMD). The statistical analysis was performed with the Pearson chi-square test and the significance level was set at p≤0.05.

RESULTS

The cytoplasmic staining of ALDH1&2 was observed mostly in the epithelial cells of the basal layer of the epithelium of OLP. Overall, this expression was significantly increased compared to normal epithelium. In addition, statistically significantly higher expression of ALDH1&2 was observed in the erosive form of OLP. Interestingly, this OLP positivity was higher compared to mild and non-dysplastic leukoplakias (p<0.001).

CONCLUSIONS

ALDH1&2 is a confirmed CSC marker that was found to be clearly increased in OLP and characteristically in erosive OLP epithelium for the first time. Noteworthy, it was more prominent in erosive OLP rather than in mildly and non-dysplastic OL. Whether this pattern of expression raises the red flag of an early epithelial "CSC" phenotype in OLP or that ALDH1&2 expression indicates a response to the OLP inflammatory process requires further investigation.

Aldehyde Dehydrogenase: An Off-Label Marker of Endothelial Activation in Oral Squamous Cell Carcinoma

The vascular endothelial (VE) expression of aldehyde dehydrogenase (ALDH) 1/2 family in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) cases has not been studied so far. The aim of this study was to illustrate the "off-label" endothelial expression of cancer stem cell (CSC) biomarker, ALDH1/2, adjacent to oral potentially malignant and malignant lesions in order to shed some light on the mechanisms leading to oral carcinogenesis.  Materials and methods: The expression of CSC protein-biomarker ALDH1/2 was detected through immunohistochemistry (IHC) in 30 paraffin-embedded samples of OL and 21 samples of OSCC compared to five samples of normal oral mucosa. Statistical analysis was done using SPSS, Pearson Chi-square, and Fischer's exact test. The significance level was set at 0.05 (p≤ 0.05).  Results: In oral mucosal vessels, ALDH1/2 was not expressed. It was expressed significantly more in the vessels of OSCCs compared to the OLs (Fisher's exact test, p-value= 0,001). However, when endothelial expression of ALDH1/2 in the vasculature of OLs was compared with that of the normal oral mucosa, no significant change was noticed (Fisher's exact test, p-value=1.000).  Discussion: The IHC VE expression of ALDH1/2 in OSCC vasculature but not in OL indicates a possible significantly stronger activation of endothelial cells during carcinogenesis, which could be an indicator of the role of inflammation in the development of field cancerization and of prognostic value for (vascular/lymphatic) metastasis.

HPV infection in oral cancer, our experience: prevalence, clinical implications, and current vaccination program in Spain

Background

Oral cancer is the 11th most common type of cancer in the world, with established major risk factors as tobacco and alcohol, and recently included high-risk human papillomavirus types 16 and 18. HPV types 16 and 18 are the etiologic agents of cervical cancers and a proportion of oropharyngeal cancers. However, the picture of HPV and the clinical implications of oral cancers are not clear with most reports combining oral cancer data with head and neck cancers. It has been confirmed as a favorable prognostic factor in oropharyngeal cancer. However, the prognostic value of HPV in oral squamous cell carcinoma is still unclear.

Material and Methods

The main objective of this article is to present the evidence encountered following a bibliographical review of recent publications specifically related to oral cancer and its differences from oropharyngeal cancer. The secondary goals are to present the findings of a five-year retrospective observational study of the prevalence of HPV infection in oral cancer patients treated by the Oral and Maxillofacial Surgery Department at La Paz University Hospital (Madrid, Spain), and finally, we to evaluate and compare our country's HPV prevention program in comparison to other European countries.

Results

According to the review of the literature, HPV positive oral squamous cell carcinoma is associated with significantly decreased overall survival and distant control. Bibliographic review suggest HPV infection can be used as a negative prognostic factor in oral squamous cell carcinoma.

Conclusions

As regards diagnostic testing for HPV, it should be extended to as many cases of oral cavity squamous cell carcinoma as possible, especially in those with risk factors. The current vaccination program in Spain does not have adequate coverage and is significantly under the level of other European Union countries; it should be expanded and catch-up strategies should be included. Key words:HPV, OSSC, Papillomavirus, oral carcinoma, prevention.

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.

Clinical predictors of malignant transformation and recurrence in oral potentially malignant disorders: A systematic review and meta-analysis

OBJECTIVE

We performed a systematic review dedicated to pooling evidence for the associations of clinical features with malignant transformation (MT) and recurrence of 3 oral potentially malignant disorders (OPMDs) (actinic cheilitis [AC], oral leukoplakia [OL], and proliferative verrucous leukoplakia [PVL]).

STUDY DESIGN

We selected studies that included clinical features and risk factors (age, sex, site, size, appearance, alcohol intake, tobacco use, and sun exposure) of OL, PVL, and AC associated with recurrence and/or MT.

RESULTS

Based on the meta-analysis results, non-homogeneous OL appears to have a 4.53 times higher chance of recurrence after treatment. We also found 6.52 higher chances of MT of non-homogeneous OL. Another clinical feature related to higher MT chances is the location (floor of the mouth and tongue has 4.48 higher chances) and the size (OL with >200 mm2 in size has 4.10 higher chances of MT). Regarding habits, nonsmoking patients with OL have a 3.20 higher chance of MT. The only clinical feature related to higher chances of MT in patients with PVL was sex (females have a 2.50 higher chance of MT).

CONCLUSIONS

Our study showed that some clinical features may indicate greater chances of recurrence after treatment and MT of OPMD.

Prediction of the risk of cancer and the grade of dysplasia in leukoplakia lesions using deep learning

OBJECTIVES

To estimate the probability of malignancy of an oral leukoplakia lesion using Deep Learning, in terms of evolution to cancer and high-risk dysplasia.

MATERIALS AND METHODS

A total of 261 oral leukoplakia lesions with a mean of 5.5 years follow-up were analysed from standard digital photographs. A deep learning pipeline composed by a U-Net based segmentation of the lesion followed by a multi-task CNN classifier was used to predict the malignant transformation and the risk of dysplasia of the lesion. An explainability heatmap is constructed using LIME in order to interpret the decision of the model for each output.

RESULTS

A Dice coefficient of 0.561 was achieved on the segmentation task. For the prediction of a malignant transformation, the model provided a sensitivity of 1 with a specificity of 0.692. For the prediction of high-risk dysplasia, the model achieved a specificity of 0.740 and a sensitivity of 0.928.

CONCLUSION

The proposed model using deep learning can be a helpful tool for predicting the possible malignant evolution of oral leukoplakias. The generated heatmap provides a high confidence on the output of the model and enables its interpretability.

Can tissue biomarkers be used to determine the prognosis of oral leukoplakia lesions with regards to malignant transformation?

Design Systematic review looking at published studies which aimed to identify human tissue biomarkers which could predict malignant transformation of oral leukoplakia (OL) lesions.Case/control selection Articles were identified from PubMed, EBSCO and Cochrane library databases using combinations of keywords. Randomised clinical trials, case-control studies and prospective and retrospective cohort studies were included. All studies had to include follow-up data. There were no restrictions regarding gender, age groups, geographic origin, or year of publication. The selection process involved two of the researchers independently analysing titles and abstracts to identify articles for full-text reading. The same authors then read the articles identified for full-text reading, applying the eligibility criteria. If there was a disagreement with regards to the selection, a discussion was had until a consensus was reached.Data analysis Qualitative data was presented as reported from the primary studies. Quantitative analysis was not carried out due to the high heterogeneity across the studies.Results Forty-six studies were included within the systematic review. These studies identified a total of 3,783 patients with OL, of which 1,047 went on to develop oral cancer, giving an average malignant transformation incidence of 27.6%. Forty-nine different tissue biomarkers were evaluated among the included studies, with the p53 and podoplanin proteins and loss of heterozygosity the most frequently discussed.Conclusions Of the biomarkers studied, podoplanin and chromosomal loci abnormalities (such as loss of heterozygosity) would appear the most promising in being able to predict malignant transformation of OL lesions; however, further research is required.

The antinociceptive effect of garlic, garlic preparations, and derivative compounds

The antinociceptive effects of garlic have shown promise in treating different chronic diseases in humans, such as knee osteoarthritis, rheumatoid arthritis, and peripheral arterial occlusive disease stage II. The most common garlic products are garlic powder (dried garlic), steam distilled garlic oils, garlic oil macerate, and aged garlic extract. These commercial products contain organosulfur compounds (OSC) that have been extensively evaluated in preclinical models and some clinical assays to treat different diseases against pain. In this review, we describe the importance of some bioactive compounds found in garlic and its role in treating pain. A systematic search of the literature in Dimensions, PubMed, Scopus, Web of Science was performed. Terms and preselected keywords relating to garlic, its derivates and organusulfur compunds in pain, were used to perform a systematic literature search. Two independent reviewers screened papers for inclusion and assessed the methodological quality. The antinociceptive activity of garlic and its OSC is related to its antioxidant and anti-inflammatory properties, which may be explained by the ability to block the synthesis of PGs, pro-inflammatory cytokines and interferon-γ, by the reduction COX- 2 activity and by increases the levels of anti-inflammatory cytokines. Besides, garlic extract is an activator of TRPA1 and TRPV1, where the principal responsible for this activation are OSC. The relationship between these pathways allows a better understanding how garlic and its derivates could be carrying out its pharmacological action over the management of acute and chronic pain and provide a base by further investigations.

Oral leukoplakia: A clinicopathological study and malignant transformation

OBJECTIVES

To assess the clinicopathological characteristics of a cohort of patients with oral leukoplakia (OL) managed in a Romanian dental hospital and to evaluate the risk of malignant transformation (MT).

MATERIALS AND METHODS

We conducted a hospital-based retrospective study using the clinical charts of patients diagnosed with OL that had complete clinical and histopathological evaluation followed up for 1-16 years.

RESULTS

From 120 included patients, 68 (56.7%) were females, and 71 (59.2%) were current smokers. The homogeneous form was present in 60% of cases; the buccal mucosa was the most frequently involved site. MT was observed in 9 cases, which was more common in females and in those with dysplastic leukoplakia. A significant statistical association was found between MT and dysplasia grade (χ² test: p = 0.007). MT occurred during a mean interval of time 75 months in both treated and non-treated patients.

CONCLUSIONS

In this leukoplakia cohort, most of the lesions encountered were in smokers, clinically homogeneous and 62.5% proved histologically benign. But despite the clinically benign appearance of leukoplakia, tissue diagnosis of some cases was carcinoma. The results of the current study advocate the necessity for biopsy even in apparently homogeneous, clinically benign lesions. The malignization rate was 7.5%; two-thirds were nonhomogeneous lesions.

The RNA Methylation Modification 5-Methylcytosine Impacts Immunity Characteristics, Prognosis and Progression of Oral Squamous Cell Carcinoma by Bioinformatics Analysis

Disorders pertaining to 5-methylcytosine (m5C) modifications are involved in the pathological process of many diseases. However, the effect of m5C on the tumorigenesis and progression of oral squamous cell carcinoma (OSCC) remains unclear. In this study, we integrated the genomic and clinical data of 558 OSCC samples to comprehensively evaluate m5C modification patterns. Based on 16 m5C methylation regulators, two m5C modification clusters were identified with distinct tumor immune microenvironment (TIME) characteristics and prognosis in OSCC. We then performed weighted gene co-expression network analysis (WGCNA) to identify m5C modification cluster-related modules. Genes in the selected module were chosen to construct the m5Cscore scoring system for evaluating m5C modification pattern in individual OSCC patients. Patients with a high m5Cscore had higher immune, stromal, and ESTIMATE scores; lower tumor purity score; lower immune activity; and higher tumor mutational burden. The overall survival rate and progression-free survival rate were markedly worse and the tumor recurrence rate was higher in OSCC patients with a high m5Cscore. Furthermore, patients with oral leukoplakia who also had a high m5Cscore had a higher risk of deterioration to OSCC. This study demonstrated that m5C modification patterns might affect the TIME in OSCC. m5Cscore may provide a new approach for predicting the prognosis and progression of OSCC.

Deep Learning Predicts the Malignant-Transformation-Free Survival of Oral Potentially Malignant Disorders

Simple Summary

Mouth cancer is the most common malignancy in the head-and-neck region. Usually, these tumors develop from white lesions in the mouth that appear long before cancer diagnosis. However, platforms that can estimate the time-factored risk of cancer occurring from these diseases and guide treatment and monitoring approaches are elusive. To this end, our study presents time-to-event models that are based on machine learning for prediction of the risk of malignancy from oral white lesions following pathological diagnosis as a function of time. These models displayed very satisfactory discrimination and calibration after multiple tests. To facilitate their preliminary use in clinical practice and further validation, we created a website supporting the use of these models to aid decision making.

Abstract

Machine-intelligence platforms for the prediction of the probability of malignant transformation of oral potentially malignant disorders are required as adjunctive decision-making platforms in contemporary clinical practice. This study utilized time-to-event learning models to predict malignant transformation in oral leukoplakia and oral lichenoid lesions. A total of 1098 patients with oral white lesions from two institutions were included in this study. In all, 26 features available from electronic health records were used to train four learning algorithms—Cox-Time, DeepHit, DeepSurv, random survival forest (RSF)—and one standard statistical method—Cox proportional hazards model. Discriminatory performance, calibration of survival estimates, and model stability were assessed using a concordance index (c-index), integrated Brier score (IBS), and standard deviation of the averaged c-index and IBS following training cross-validation. This study found that DeepSurv (c-index: 0.95, IBS: 0.04) and RSF (c-index: 0.91, IBS: 0.03) were the two outperforming models based on discrimination and calibration following internal validation. However, DeepSurv was more stable than RSF upon cross-validation. External validation confirmed the utility of DeepSurv for discrimination (c-index—0.82 vs. 0.73) and RSF for individual survival estimates (0.18 vs. 0.03). We deployed the DeepSurv model to encourage incipient application in clinical practice. Overall, time-to-event models are successful in predicting the malignant transformation of oral leukoplakia and oral lichenoid lesions.

Oral Cancer Discrimination and Novel Oral Epithelial Dysplasia Stratification Using FTIR Imaging and Machine Learning

The Fourier transform infrared (FTIR) imaging technique was used in a transmission model for the evaluation of twelve oral hyperkeratosis (HK), eleven oral epithelial dysplasia (OED), and eleven oral squamous cell carcinoma (OSCC) biopsy samples in the fingerprint region of 1800–950 cm⁻¹. A series of 100 µm × 100 µm FTIR imaging areas were defined in each sample section in reference to the hematoxylin and eosin staining image of an adjacent section of the same sample. After outlier removal, signal preprocessing, and cluster analysis, a representative spectrum was generated for only the epithelial tissue in each area. Two representative spectra were selected from each sample to reflect intra-sample heterogeneity, which resulted in a total of 68 representative spectra from 34 samples for further analysis. Exploratory analyses using Principal component analysis and hierarchical cluster analysis showed good separation between the HK and OSCC spectra and overlaps of OED spectra with either HK or OSCC spectra. Three machine learning discriminant models based on partial least squares discriminant analysis (PLSDA), support vector machines discriminant analysis (SVMDA), and extreme gradient boosting discriminant analysis (XGBDA) were trained using 46 representative spectra from 12 HK and 11 OSCC samples. The PLSDA model achieved 100% sensitivity and 100% specificity, while both SVM and XGBDA models generated 95% sensitivity and 96% specificity, respectively. The PLSDA discriminant model was further used to classify the 11 OED samples into HK-grade (6), OSCC-grade (4), or borderline case (1) based on their FTIR spectral similarity to either HK or OSCC cases, providing a potential risk stratification strategy for the precancerous OED samples. The results of the current study support the application of the FTIR-machine learning technique in early oral cancer detection.

Notch signaling in oral pre-cancer and oral cancer

Notch signaling involves cell to cell contact. It is an ancient signaling mechanism that is conserved throughout the animal kingdom. The basic function of Notch signaling is to decide cell fate and execute asymmetrical division. Notch signaling is indispensable for embryo growth. Aberrant Notch signaling involves in cancer progression by altering cell proliferation rate, tumor micro-environment, stem cell activities. The role of Notch signaling in cancer progression is context-dependent. In breast cancer and T cell lymphoma Notch signaling is highly active, whereas in squamous cell carcinoma (SCC) as oral and skin cancer, the signaling is suppressed. It is believed that in SCC, Notch-mediated tumor growth is due to the cell non-autonomous function. Oral cancer is the 6th most risky cancer worldwide. In many patients, oral cancer is preceded by pre-cancer conditions. In this review, we have summarized the research knowledge related to the role of Notch signaling in oral cancer and pre-cancer conditions and the therapeutic options available targeting different components of Notch pathways.

Elevated USP9X drives early-to-late-stage oral tumorigenesis via stabilisation of anti-apoptotic MCL-1 protein and impacts outcome in oral cancers

BACKGROUND

Overexpression of anti-apoptotic MCL-1 protein in oral squamous cell carcinoma (OSCC) is linked to disease progression, therapy resistance and poor outcome. Despite its characteristic short half-life owing to ubiquitin-proteasome-dependent degradation, oral tumours frequently show elevated MCL-1 protein expression. Hence, we investigated the role of deubiquitinase USP9X in stabilising MCL-1 protein and its contribution to oral tumorigenesis.

METHODS

Expression of MCL-1 and USP9X was assessed by immunoblotting and immunohistochemistry in oral cancer cell lines and tissues. The association between MCL-1 and USP9X was confirmed by coimmunoprecipitation and immunofluorescence. Cell death assessment was performed by MTT, flow cytometry and clonogenic assays.

RESULTS

Both USP9X and MCL-1 are significantly elevated in oral premalignant lesions and oral tumours versus normal mucosa. USP9X interacts with and deubiquitinates MCL-1, thereby stabilising it. Pharmacological inhibition of USP9X potently induced cell death in OSCC cells in vitro and in vivo. The elevated expression of USP9X and MCL-1 correlated with poor prognosis in OSCC patients.

CONCLUSION

We demonstrate the oncogenic role of USP9X in driving early-to-late stages of oral tumorigenesis via stabilisation of MCL-1, suggesting its potential as a prognostic biomarker and therapeutic target in oral cancers.

Recurrence and malignant transformation rates of high grade oral epithelial dysplasia over a 10 year follow up period and the influence of surgical intervention, size of excision biopsy and marginal clearance in a UK regional maxillofacial surgery unit

OBJECTIVES

To determine the overall recurrence rate (RR) and malignant transformation rate (MTR) of high grade oral mucosal epithelial dysplasias (HGOED).

MATERIALS & METHODS

A clinicopathological review of records of patients diagnosed with a unifocal HGOED between 2004 and 2016 on incisional biopsy who then underwent excision. The mean duration of follow-up was 47.7 months (±29.9 SD).

RESULTS

Full demographic, historical and histopathological data were available for 120 patients. Six were lost to follow-up after excisional biopsy. Invasive squamous cell carcinoma (SCC) was present in 19 (18.3%) excisions. HGOED affected the lateral and ventral tongue in 58% of patients. Fourteen (11.7%) were not treated surgically but kept under surveillance. The overall RR was 34.7% (33 patients) and MTR 17.8% (17 patients). Four of the 14 (28.6%) patients who had not had the HGOED excised developed SCC, by contrast to the 13 of the 106 (12.3%) who had been treated. RR was significantly associated with positive excision margins (p = 0.007; OR = 3.6) and a clinical presentation of erythroplakia (p = 0.023; OR = 1.5). MTR was significantly associated with age (p = 0.034), clinical appearance (p = 0.030), site (p = 0.007), treatment received (p = 0.012) and positive excision margins (p = 0.007). The mean time for recurrence to develop was 62 months (±31.5 SD) (range 22-144 months), that for malignant transformation was 50 months (±32.5 SD) (range 8-97 months).

CONCLUSION

Patients with HGOED require follow-up for at least 10 years after treatment. Younger age, homogeneous clinical appearance, complete excision, a larger excision specimen and clear margins all improve prognosis.

Patient-reported pain after surgical removal of leukoplakia - an observational 1-year follow-up study

OBJECTIVE

Oral leukoplakia (OL) presents as a white lesion of the oral mucosa and is not typically associated with the sensation of pain. OL should be surgically removed when possible because it is considered a potentially malignant oral disorder (PMOD). This study assessed the pain sensations experienced by patients in association with the occurrence and surgical treatment of OL.

METHODS

Inclusion criteria were: a clinical diagnosis of OL; biopsy excision; and observation for at least 12 months in the ORA-LEU-CAN study. At the first visit, all the patients were asked about the occurrence of symptoms within the lesion. Ninety-four subjects were assessed over a period of 1 year. All patients underwent complete removal of OL. The patient cohort was divided into three sub-groups: (i) no pain before excision and at the 1-year follow-up; (ii) pain before excision; and (iii) pain at the 1-year follow-up.

RESULTS

Overall, pain was reported by 21.3% of the patients at the study start whereas 13.8% of the patients reported pain 1 year after surgical treatment. Patient-reported pain from the lesion at study inclusion was significantly associated with lesions found on the lateral side of the tongue (p=.002). Pain reported by patients one year after surgery was significantly related to female gender (p=.038) and the presence of epithelial cell dysplasia (p=.022).

CONCLUSION

We conclude that surgical removal of OL results in a low risk of long-term post-surgical pain. However, OL located on the lateral side of the tongue and in OL with dysplasia are more likely to be associated with pain.

The Role of Human Papilloma Virus in Dictating Outcomes in Head and Neck Squamous Cell Carcinoma

The Human Papilloma Virus (HPV) is an oncogenic virus which is associated with the development of head and neck squamous cell carcinoma (HNSCC), predominantly within the oropharynx. Approximately 25% of oropharyngeal squamous cell carcinoma (OPSCC) cases worldwide are attributable to HPV infection, with an estimated 65% in the United States. Transmission is via exposure during sexual contact, with distinctive anatomical features of the tonsils providing this organ with a predilection for infection by HPV. No premalignant lesion is identifiable on clinical examination, thus no comparative histological features to denote the stages of carcinogenesis for HPV driven HNSCC are identifiable. This is in contrast to HPV-driven cervical carcinoma, making screening a challenge for the head and neck region. However, HPV proffers a favorable prognosis in the head and neck region, with better overall survival rates in contrast to its HPV negative counterparts. This has resulted in extensive research into de-intensifying therapies aiming to minimize the morbidity induced by standard concurrent chemo-radiotherapy without compromising efficacy. Despite the favorable prognosis, cases of recurrence and/or metastasis of HPV positive HNSCC do occur, and are linked with poor outcomes. HPV 16 is the most frequent genotype identified in HNSCC, yet there is limited research to date studying the impact of other HPV genotype with respect to overall survival. A similar situation pertains to genetic aberrations associated in those with HPV positive HNSCC who recur, with only four published studies to date. Somatic mutations in TSC2, BRIP1, NBN, TACC3, NFE2l2, STK11, HRAS, PIK3R1, TP63, and FAT1 have been identified in recurrent HPV positive OPSCC. Finding alternative therapeutic strategies for this young cohort may depend on upfront identification of HPV genotypes and mutations which are linked with worse outcomes, thus ensuring appropriate stratification of treatment regimens.

Assembling a consensus on actinic cheilitis: A Delphi study

AIMS

To discuss the terminology to define and classify actinic cheilitis (AC) and to build a consensus on the diagnostic and therapeutic approaches to AC.

METHODS

Two-round Delphi study using a questionnaire including 34 closed sentences (9 on terminology and taxonomy, 5 on potential for malignant transformation, 12 on diagnostic aspects, 8 on treatment) and 8 open questions. Experts' agreement was rated using a Likert scale (1-7).

RESULTS

A consensus was reached on 24 out 34 statements (73.5%) and on 5 out of 8 (62.5%) close-ended questions. The response rate was identical in both rounds (attrition of 0%). AC is the term with the highest agreement (median of 7 (strongly agree; IQR: 6-7)) and the lowest dispersion (VC = 21.33). 'Potentially malignant disorder' was the preferred classification group for AC (median of 7) and 85.6% of participants showing some level of agreement (CV < 50). Experts (66.75%) consider AC a clinical term (median: 7; IQR: 4-7) and believe definitive diagnosis can be made clinically (median: 6; IQR: 5-7), particularly by inspection and palpation (median: 5; IQR: 4-6). Histopathological confirmation is mandatory for the management of AC (median: 5; IQR: 2.5-7), even for homogeneous lesions (median: 5; IQR: 3.5-6). Consensus was reached on all treatment statements (VC < 50).

CONCLUSIONS

AC is a potentially malignant disorder with a significant lack of agreement on diagnostic criteria, procedures, biopsy indications and the importance of techniques to assist in biopsy. A consensus was reached on nomenclature and management of this disorder.

Recurrence in Oral Premalignancy: Clinicopathologic and Immunohistochemical Analysis

Oral leukoplakia (OL) has a propensity for recurrence and malignant transformation (MT). Herein, we evaluate sociodemographic, clinical, microscopic and immunohistochemical parameters as predictive factors for OL recurrence, also comparing primary lesions (PLs) with recurrences. Thirty-three patients with OL, completely removed either by excisional biopsy or by laser ablation following incisional biopsy, were studied. Selected molecules associated with the STAT3 oncogenic pathway, including pSTAT3, Bcl-xL, survivin, cyclin D1 and Ki-67, were further analyzed. A total of 135 OL lesions, including 97 PLs and 38 recurrences, were included. Out of 97 PLs, 31 recurred at least once and none of them underwent MT, during a mean follow-up time of 48.3 months. There was no statistically significant difference among the various parameters in recurrent vs. non-recurrent PLs, although recurrence was most frequent in non-homogeneous lesions (p = 0.087) and dysplastic lesions recurred at a higher percentage compared to hyperplastic lesions (34.5% vs. 15.4%). Lower levels of Bcl-xL and survivin were identified as significant risk factors for OL recurrence. Recurrences, although smaller and more frequently homogeneous and non-dysplastic compared to their corresponding PLs, exhibited increased immunohistochemical expression of oncogenic molecules, especially pSTAT3 and Bcl-xL. Our results suggest that parameters associated with recurrence may differ from those that affect the risk of progression to malignancy and support OL management protocols favoring excision and close monitoring of all lesions.

Retraction: Oral leukoplakia, a clinical-histopathological study in 412 patients

The authors detected some minor errors in the published manuscript (Rubert A, Bagán L, Bagán JV. Oral leukoplakia, a clinical-histopathological study in 412 patients. J Clin Exp Dent. 2020 Jun 1;12(6):e540-e546. doi: 10.4317/jced.57091. PMID: 32665812; PMCID: PMC7335600.) and have requested that the entire article be republished with these errors already rectified.

Background

A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal.

Material and Methods

A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions.

Results

Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.5%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00).

Conclusions

In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia. Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

Small Dysplastic Oral Leucoplakia in a Smoking Woman: a Case Report

Background

Oral leucoplakia is clinical term used to describe white plaques, and that is part of the group of oral potentially malignant disorders. Leucoplakia may show epithelial dysplasia, mainly in harder smoking patient. This case report discusses a small leucoplakia with dysplasia on the tongue's lateral border in a woman, diagnosed early after a routine clinical consultation.

Methods

A 57-year-old female patient consulted to the Oral Diagnosis and Surgery Service of the State University of Ponta Grossa, Brazil. First, the patient was referred for the extraction of her lower incisors due to periodontal disease. During clinical examination, was identified a sessile white plaque, of small size, and located on the tongue's left lateral border. Thus, the lesion's diagnostic hypothesis was oral leucoplakia due to patient be chronic smoker for 40 years. The incisional biopsy was performed, with the epithelial tissue and part of the connective tissue removed.

Results

The histopathological examination revealed a stratified and keratinized pavement epithelium, with cellular atypia, and presence of hyperchromatism and nuclear pleomorphism. However, the alterations were restricted to the epithelium's basal, characterizing a mild dysplasia. The proposed treatment was surgical removal of the lesion, and the patient was also instructed to quit smoking, as well as she continues to follow-up.

Conclusions

The presented case emphasizes the importance of early diagnosis and the orientation of risk factors to smoking patients, even in small lesions that can clinically appear harmless.

Malignant transformation of oral potentially malignant disorders in Taiwan: An observational nationwide population database study

Oral cancer is one of the leading causes of cancer death, which are mostly preceded by oral potentially malignant disorders (OPMDs). Taiwanese government launched a free oral cancer screening program. The aim of this study was to analyze the malignant transformation rate of OPMDs.This study was based on national-wide oral screening databases. 3,362,232 people were enrolled. Patients clinically diagnosed with leukoplakia, erythroplakia, oral submucosal fibrosis (OSF), oral verrucous hyperplasia (OVH), and oral lichen planus (OLP), from 2010 to 2013, were identified. We followed up OPMD patients in cancer registry databases to analyze the malignant transformation rate.The malignant transformation rates from the highest to the lowest were: OVH > OSF > erythroplakia > OLP > leukoplakia. The malignant transformation rate was 24.55, 12.76, 9.75, 4.23, and 0.60 per 1000 person-years in the OVH, OSF, erythroplakia, leukoplakia, and comparison cohort. The hazard ratio was 8.19 times higher in the OPMD group compared with comparison cohort group, after age and habit adjustment. Female patients with OPMDs had a high risk of malignant transformation.Nationwide screening is very important for early diagnosis. OVH had the highest malignant transformation possibility. Female OPMD patients are a rare but have a relatively high malignant transformation rate.

Malignant transformation of oral leukoplakia: Systematic review and meta-analysis of the last 5 years

OBJECTIVE

Oral leukoplakia (OL) is the most frequently encountered oral potentially malignant disorder. The aims of this systematic review are to estimate the overall malignant transformation of OL and to assess the risk factors associated with malignant transformation of OL published in the last 5 years (2015-2020).

MATERIALS AND METHODS

We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and Cochrane databases with keywords "oral leukoplakia", "oral cancer", "oral carcinoma" and "oral squamous cell carcinoma". Meta-analysis was conducted using a random-effects model.

RESULTS

Twenty-four studies were selected, that reported a total of 16,604 patients. Malignant transformation proportion varied between 1.1% and 40.8%. Female gender, non-homogeneous clinical type, and presence of epithelial dysplasia were significantly related to MT. Other risk factors previously suggested did not show significant results.

CONCLUSIONS

The pooled proportion of malignant transformation MT was 9.8% (95% CI: 7.9-11.7). It is necessary to continue to conduct well-designed prospective clinicopathological studies on OL, using a uniform definition for OL to reduce the risk of bias for evaluating various factors associated with the MT.

Oral Cancer and Precancer: A Narrative Review on the Relevance of Early Diagnosis

Oral cancer (OC) is an uncommon malignancy in Western countries, being one of the most common cancers in some high-risk areas of the world. It is a largely preventable cancer, since most of the different risk factors identified, such as tobacco use, alcohol consumption, and betel nut chewing, are behaviors that increase the likelihood of the disease. Given its high mortality, early diagnosis is of utmost importance. Prevention and the anticipation of diagnosis begin with identification of potentially malignant lesions of the oral mucosa and with local conditions promoting chronic inflammation. Therefore, every lesion must be recognized promptly and treated adequately. The clinical recognition and evaluation of oral mucosal lesions can detect up to 99% of oral cancers/premalignancies. As stated by the World Health Organization, any suspicious lesion that does not subside within two weeks from detection and removal of local causes of irritation must be biopsied. Surgical biopsy remains the gold standard for diagnosis of oral cancer. Adjunctive tools have been developed and studied to help clinicians in the diagnostic pathway, such as toluidine blue vital staining and autofluorescence imaging. In the near future other methods, i.e., identification of salivary markers of progression may help in reducing mortality due to oral cancer.

Quality of life among Oral Potentially Malignant Disorder (OPMD) patients: A prospective study

Objective

The purpose of this study was to evaluate the quality of life among the Oral Potentially Malignant Disorder (OPMD) patients during diagnosis, at one month and 3 months after intervention (surgical or conservative).

Methods

The University of Washington Quality of Life version (4UWQOL v4) and World Health Organization (WHO-BREF) were repeatedly administered on 54 OPMD patients.

Results

The results of Friedman's ANOVA showed a statistically significant change in the mean scores for pain, activity, speech, shoulder, taste, saliva, mood, and anxiety domains of UWQOL with time, (p-value <0.05); while physical health, social relationships, environment domains of WHO- BREF have shown significant changes in their respective mean scores.

Conclusion

The assessment of Quality of Life (QOL) should routinely be done by the clinicians. If the clinicians start considering the QOL as the primary outcome of a treatment protocol, it will enhance patients' identity, well-being, and personality.

Information needs and oral epithelial dysplasia: Development and psychometric evaluation of a novel instrument

OBJECTIVES

Oral epithelial dysplasia (OED) can lead to significant information needs (IN) related to the risk of cancer development, the need for long-term monitoring and potential intervention. The present study aimed to develop and perform preliminary psychometric testing for a novel IN instrument specific to OED.

SUBJECTS AND METHODS

Patients diagnosed with OED were invited to complete the Oral Epithelial Dysplasia Informational Needs Questionnaire (ODIN-Q), which was developed based on a known theoretical framework and with items generated via expert input and the literature. Face validity and content validity were initially assessed prior to finalisation of the tool. ODIN-Q was tested for internal consistency and test-retest reliability along with construct validity.

RESULTS

ODIN-Q consists of 35 items, categorised under six domains, and rated by dual 4-point Likert scales (amount of information received and degree of importance). Internal consistency (Cronbach's alpha) was rated "excellent" for the scale (0.93) and both subscales (0.92/0.94). For test-retest reliability, moderate agreement was found (κ = 0.49-0.53). Regarding construct validity, a significant but limited relationship was found between ODIN-Q and the Krantz Health Opinion Survey.

CONCLUSION

ODIN-Q showed adequate psychometric properties of reliability and validity. Further validation is, however, needed to assess its structural validity and responsiveness.

Identification of HPV16-p16INK4a mediated methylation in oral potentially malignant disorder

To evaluate the possible involvement of epigenetic modulation by HPV16-p16^INK4a in oral potentially malignant disorder (OPMD). We generated DNA-methylation profiles, according to p16^INK4a expression and HPV16 genotype (positive or negative), of OPMD samples and p16^INK4a-HPV16 negative samples (used as control), using reduced-representation bisulphite sequencing (RRBS-Seq- Illumina) technology. Twelve samples, four for each group, as follows: 1) p16^INK4a+ HPV16+; 2) p16^INK4a+ HPV16-; 3) p16^INK4a- HPV16-, were analysed in triplicate for DNA-methylation profiles. Fifty-four per cent of DMRs were hypermethylated and 46% were hypomethylated. An increase in methylation of loci in OPMD was independent of the presence of HPV. The hypermethylated genes in HPV+ samples were associated with signalling pathways such as NICD traffics to nucleus, signalling by NOTCH1 (p = 0.008), Interferon-gamma (p = 0.008) and Interleukin-6 signalling (p = 0.027). The hypomethylated genes in HPV infection were associated with TRAF3-dependent IRF activation pathway (p = 0.002), RIG-I/MDA5 mediated induction of IFN-alpha/beta pathways (p = 0.005), TRAF6 mediated IRF7 activation (p = 0.009), TRIF-mediated TLR3/TLR4 signalling (p = 0.011) and MyD88-independent cascade release of apoptotic factors (p = 0.011). Protein association analysis of DMRs in OPMD revealed 19 genes involved in the cell cycle regulation, immune system, and focal adhesion. Aberrantly methylated loci in OPMD were observed in p16^INK4a positive samples which suggests that a shift in global methylation status may be important for cancer progression. The results suggest that HPV infection in OPMD induces modulation of genes related to the immune system and regulation of the cellular cycle.

Expression of transmembrane protein aquaporin-3 in oral epithelial dysplasia and oral squamous cell carcinoma

OBJECTIVES

The objective of this study was to evaluate aquaporin-3 (AQP3) expression in patient samples of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), thereby assessing the potential of AQP3 as a molecular marker for tumor progression.

STUDY DESIGN

An in vitro comparative study was done to determine the AQP3 expression on 20 surgical biopsy specimens each of OED and OSCC using immunohistochemistry. Twenty specimens of normal oral mucosa were kept as controls. The results were statistically analyzed using one-way analysis of variance and post hoc analysis.

RESULTS

The expression of AQP3 was analyzed and further semiquantified using H-scores. The mean H-score showed a statistically significant difference between OSCC, OED, and normal oral mucosa (P < .05). There was a significant increase in the expression of AQP3 in OSCC and OED compared to normal oral mucosa. The highest expression was observed in OSCC (P < .01).

CONCLUSION

The observations of the study indicate that staining intensity of AQP3 increased from dysplastic noninvasive lesion to invasive OSCC, suggesting a possible role of AQP3 as a biomarker for tumor progression.

Analysis of octamer-binding transcription factor-4 expression in oral leukoplakia

Background:

Oral potentially malignant disorders have a risk for malignant transformation but are difficult to reliably identify and predict which patients are at the risk for malignant transformation. OCT4 has been hypothesized to play a key oncogenic driver in a variety of solid tumors. A deeper understanding of the aberrant molecular pathways which lead to carcinogenesis needs to be identified by the potential markers.

Aims:

To assess the OCT4 stemness factor in oral leukoplakia for its potential risk to malignant transformation.

Settings and Design:

20 cases of oral leukoplakia were obtained from archives at Oral Cancer Research & Coordinating center (OCRCC) Malaysia Subjects and Methods: 20 cases of oral leukoplakia were assessed by OCT4 immunohistochemically. Oral squamous cell carcinoma was used as a control.

Result:

no expression of OCT 4 was observed in any cases of oral leukoplakia.

Conclusion:

The molecular mechanisms of Oct4 regulation and in particular of its switch on and off in tissues depends upon its microenvironment, which makes it challenging in fundamental and applied research fields of regenerative medicine and cancer therapy. It's better that patients should undergo multiple biopsies for the early detection of malignant transformation with close follow-up during the first two to three years, a large amount of work remains to be done with multi-marker panel investigation, as cure rates have remained constant over three decades.

Morphometric analysis of basal cells of oral epithelium in predicting malignant transformation of oral potentially malignant disorders in patients with tobacco chewing habit

BACKGROUND

Oral potentially malignant disorders (OPMDs) are a heterogenous group of disorders which precede the development of oral cancer. These are characterized by increased risk of malignant transformation to Oral cancer.

AIMS & OBJECTIVES

In this study, an attempt has been made to assess the morphological alterations of the nuclei of the basal cells in OPMDs and oral squamous cell carcinoma (OSCC). Our objective was to compare the alterations and to assess the predictive factor of such alterations of basal cells in malignant transformation of OPMDs to OSCC.

MATERIALS AND METHODS

This was a retrospective study conducted on tissue sections of 150 formalin fixed, paraffin embedded blocks obtained from the archives. The specimens were grouped into OSCC group (n= 50) and OPMDs (n= 100). Nuclear features were evaluated using computer- assisted microscopic image analysis. One- way ANOVA analysis was done to verify the difference between the groups for all variables.

RESULTS

Our results showed statistically significant difference for all parameters between the groups. Among OPMDs, leukoplakia showed significant increase in nuclear area, nuclear perimeter, Nuclear/Cytoplasm (N/C) ratio, density and loss of polarity, while OSF showed significance with only perimeter, density and loss of polarity.

CONCLUSION

Based on findings of present study, it is concluded that measurements using computer- aided morphometric analysis may provide an objective means for predicting the malignant transformation OPMDs to OSCC. Among OPMDs, Leukoplakia has a higher chance of malignant transformation than OSF.

Oral Potentially Malignant Disorders and Oral Cavity Cancer

The Surveillance, Epidemiology, and End Results program from the National Cancer Institute reports that the aggregate number of oral cavity and pharyngeal cancer cases has been increasing over the past decade and, despite an overall decline in oral cavity cancers, this increase is largely related to a dramatic increase in cancers involving oropharyngeal subsites. Early detection of oral cavity cancers is commensurate with improved survival, and opportunistic screening by trained clinicians to detect oral cavity cancer and oral potentially malignant disorders is recommended by the American Dental Association and the American Academy of Oral Medicine.

Strategies to improve diagnosis and risk assessment for oral cancer patients

To realise the benefits of new diagnostic techniques for the prediction of oral cancer, further validation and multicentre analyses are needed to determine their clinical impact in contemporary practice.

Wnt/β-Catenin Signaling in Oral Carcinogenesis

Oral carcinogenesis is a complex and multifactorial process that involves cumulative genetic and molecular alterations, leading to uncontrolled cell proliferation, impaired DNA repair and defective cell death. At the early stages, the onset of potentially malignant lesions in the oral mucosa, or oral dysplasia, is associated with higher rates of malignant progression towards carcinoma in situ and invasive carcinoma. Efforts have been made to get insights about signaling pathways that are deregulated in oral dysplasia, as these could be translated into novel markers and might represent promising therapeutic targets. In this context, recent evidence underscored the relevance of the Wnt/β-catenin signaling pathway in oral dysplasia, as this pathway is progressively "switched on" through the different grades of dysplasia (mild, moderate and severe dysplasia), with the consequent nuclear translocation of β-catenin and expression of target genes associated with the maintenance of representative traits of oral dysplasia, namely cell proliferation and viability. Intriguingly, recent studies provide an unanticipated connection between active β-catenin signaling and deregulated endosome trafficking in oral dysplasia, highlighting the relevance of endocytic components in oral carcinogenesis. This review summarizes evidence about the role of the Wnt/β-catenin signaling pathway and the underlying mechanisms that account for its aberrant activation in oral carcinogenesis.

Association between hyperglycemia and the malignant transformation of oral leukoplakia in China

OBJECTIVES

This study aimed to examine the association between hyperglycemia and the malignant transformation of oral leukoplakia (OLK).

PATIENTS AND METHODS

This retrospective case-control study involved 133 patients with the malignant transformation of OLK into oral squamous cell carcinoma (case group) and 266 patients with untransformed OLK (control group). The clinical history and follow-up data included age, gender, lesion size and location, and fasting plasma glucose. Logistic regression analysis, Kaplan-Meier survival analysis, and univariate and multivariate Cox regression analyses were used to assess the effects of risk factors on the malignant transformation of OLK.

RESULTS

Hyperglycemia (adjusted hazard ratio [AHR] = 4.7, p = .001), non-homogenous OLK (AHR = 3.0, p < .001), location of the lesion on the ventral surface of the tongue or floor of the mouth (AHR = 3.6, p < .001), and epithelial dysplasia (AHR = 2.8, p = .005) had significant effects on the malignant transformation of OLK.

CONCLUSION

Hyperglycemia, non-homogenous OLK, location of the lesion on the ventral surface of the tongue or floor of the mouth, and epithelial dysplasia might be associated with malignant transformation of OLK.

Laser excision of oral leukoplakia: Does it affect recurrence and malignant transformation? A systematic review and meta-analysis

Oral leukoplakia (OL) is a white lesion with high potential of recurrence and malignant transformation. The variable clinical and histopathological features of OL may potentially impact both treatment and prognosis. Current literature shows that post treatment rates of recurrence and malignant transformation vary widely. The use of surgical lasers have been proposed with the objective of improving outcomes. We performed a systematic review and a comprehensive meta-analysis dedicated to pooling the rates of recurrence and malignant transformation of OL lesions treated using the main types of surgical lasers available. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 36 articles met the inclusion criteria. Selected studies included OL lesions that were treated by evaporation or excision using Nd:YAG laser, Er:YAG laser, CO2 laser, KTP laser, or diode laser. The results of this systematic review and meta-analysis suggest that surgical laser excision of OL may decrease recurrence rates but have no effect on the malignant transformation of OL when compared with conventional treatments.

Oral leukoplakia, a clinical-histopathological study in 412 patients

Background

A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal.

Material and Methods

A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions.

Results

Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.3%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00).

Conclusions

In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia.

Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

Cues used by dentists in the early detection of oral cancer and oral potentially malignant lesions: findings from the National Dental Practice-Based Research Network

OBJECTIVE

The aim of this study was to assess the influence of clinical cues on risk assessment of cancer-associated mucosal abnormalities.

STUDY DESIGN

We differentiated lesions with a low risk from those with a high risk for premalignancy or malignancy by using 4 cues: (1) color, (2) location, (3) induration, and (4) pain on exploration. Combinations of color and location were presented through 8 photographs, with induration and pain status variably presented in the standardized history and physical findings. This created 16 clinical scenarios (vignettes) that were permutations of the 4 cues. Three questions assessed the extent to which each cue was used in obtaining a clinical impression as to whether a lesion was benign, premalignant, or malignant.

RESULTS

Completed vignette questionnaires were obtained from 130 of 228 invited dentists, (two-thirds males; 79% white; mean age 52 years; average weekly hours of practice 33 hours). Only 40% of the responding dentists had statistically significant decision policies to assign a clinical diagnosis of a lesion as benign, premalignant, or malignant. Lesion location and color were the 2 dominant cues. As a cue, induration was used as a cue by more of the respondents in determining a clinical diagnosis of malignancy, and pain was infrequently used as a cue.

CONCLUSIONS

Many dentists do not to have a decision strategy for the clinical diagnosis and risk stratification of oral potentially malignant lesions.