The clinical determinants of malignant transformation in oral epithelial dysplasia

Cancer Precursor Syndromes and Their Detection in the Head and Neck

This article explores the multifaceted landscape of oral cancer precursor syndromes. Hereditary disorders like dyskeratosis congenita and Fanconi anemia increase the risk of malignancy. Oral potentially malignant disorders, notably leukoplakia, are discussed as precursors influenced by genetic and immunologic facets. Molecular insights delve into genetic mutations, allelic imbalances, and immune modulation as key players in precancerous progression, suggesting potential therapeutic targets. The article navigates the controversial terrain of management strategies of leukoplakia, encompassing surgical resection, chemoprevention, and immune modulation, while emphasizing the ongoing challenges in developing effective, evidence-based preventive approaches.

A Review of the Repair of DNA Double Strand Breaks in the Development of Oral Cancer

We explore the possibility that defects in genes associated with the response and repair of DNA double strand breaks predispose oral potentially malignant disorders (OPMD) to undergo malignant transformation to oral squamous cell carcinoma (OSCC). Defects in the homologous recombination/Fanconi anemia (HR/FA), but not in the non-homologous end joining, causes the DNA repair pathway to appear to be consistent with features of familial conditions that are predisposed to OSCC (FA, Bloom's syndrome, Ataxia Telangiectasia); this is true for OSCC that occurs in young patients, sometimes with little/no exposure to classical risk factors. Even in Dyskeratosis Congenita, a disorder of the telomerase complex that is also predisposed to OSCC, attempts at maintaining telomere length involve a pathway with shared HR genes. Defects in the HR/FA pathway therefore appear to be pivotal in conditions that are predisposed to OSCC. There is also some evidence that abnormalities in the HR/FA pathway are associated with malignant transformation of sporadic cases OPMD and OSCC. We provide data showing overexpression of HR/FA genes in a cell-cycle-dependent manner in a series of OPMD-derived immortal keratinocyte cell lines compared to their mortal counterparts. The observations in this study argue strongly for an important role of the HA/FA DNA repair pathway in the development of OSCC.

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

BACKGROUND

Oral lichen planus (OLP) and oral epithelial dysplasia (OED) present diagnostic challenges due to clinical and histologic overlap. This study explores the immune microenvironment in OED, hypothesizing that immune signatures could aid in diagnostic differentiation and predict malignant transformation.

METHODS

Tissue samples from OED and OLP cases were analyzed using immunofluorescence/immunohistochemistry (IF/IHC) for CD4, CD8, CD163/STAT1, and PD-1/PDL-1 expression. RNA-sequencing was performed on the samples, and data was subjected to CIBERSORTx analysis for immune cell composition. Gene Ontology analysis on the immune differentially expressed genes was also conducted.

RESULTS

In OED, CD8 + T-cells infiltrated dysplastic epithelium, correlating with dysplasia severity. CD4 + lymphocytes increased in the basal layer. STAT1/CD163 + macrophages correlated with CD4 + intraepithelial distribution. PD-1/PDL-1 expression varied. IF/IHC analysis revealed differential immune cell composition between OED and OLP. RNA-sequencing identified upregulated genes associated with cytotoxic response and immunosurveillance in OED. Downregulated genes were linked to signaling, immune cell recruitment, and tumor suppression.

CONCLUSIONS

The immune microenvironment distinguishes OED and OLP, suggesting diagnostic potential. Upregulated genes indicate cytotoxic immune response in OED. Downregulation of TRADD, CX3CL1, and ILI24 implies dysregulation in TNFR1 signaling, immune recruitment, and tumor suppression. This study contributes to the foundation for understanding immune interactions in OED and OLP, offering insights into future objective diagnostic avenues.

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.

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.

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.

Oral Epithelial Dysplasia in Tobacco Non-habitués: A Case Report and Review of Literature

Oral potentially malignant disorders (OPMDs) encompass a diverse group of clinical lesions, which, on histopathological evaluation, may reveal features of hyperplasia, oral epithelial dysplasia (OED), or even early invasive squamous cell carcinoma. OEDs are often perceived to be associated with a deleterious habit such as tobacco chewing. It has emerged that OEDs may occur even in the absence of a tobacco habit and could be attributed to factors such as trauma, chronic inflammation, and inherent genetic aberrations. Authors have reported a preponderance of such lesions in young females, particularly at sites distinct from those noted in habitués. Additionally, the probability of malignant transformation of OED has been reported to be higher in non-habitués as compared to habitués when lesions are left unaddressed. There remains a paucity of data regarding the exact molecular basis, behavior, and response to treatment of OED among tobacco non-habitués. In view of the increasing number of oral lesions demonstrating epithelial dysplasia in the absence of exposure to significant risk factors, we highlight the scenario with a case. A 39-year-old female, non-habitué, presented with a non-scrapable, white lesion on the maxillary buccal gingiva. Incisional biopsy revealed features of moderate epithelial dysplasia that, on further evaluation of the excisional specimen, confirmed features of severe epithelial dysplasia. Genotyping for human papillomavirus (HPV) was carried out to assess the presence of high-risk HPV strains (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68), which are usually associated with OED and/or oral squamous cell carcinomas (OSCCs) in non-habitués. A comprehensive review of various tissue and molecular factors, which play a key role in the pathophysiology of non-habit-associated OED has been illustrated in this report. While the etiological focus of OPMDs is often directed toward deleterious habits and exposure to carcinogens, it is essential to be vigilant for this entity even among non-habitués. A meticulous screening of the oral cavity, for all patients, shall facilitate the prevention and early diagnosis of OED, particularly in individuals not exposed to habit-forming risk factors.

Associations between clinical and histopathological characteristics in oral leukoplakia

OBJECTIVES

To identify possible associations between patients' demographics and habits and the clinical aspects and histopathological characteristics of oral leukoplakia (OL) at patients' first visit.

METHOD

A total of 140 consecutive patients with OL at a single institute between 1997 and 2019. All biopsies were microscopically examined for classic dysplasia (CD) (WHO definition oral epithelial dysplasia) and differentiated dysplasia (DD) known from differentiated vulvar intraepithelial neoplasia. Clinical characteristics were correlated to histopathological diagnosis and odds ratios (OR) were calculated.

RESULTS

A total of 96 females and 44 males, mean age 58 years, were presented. OLs were found mainly on the tongue (41%) and floor of mouth (FOM) (18%). Homogeneous OLs (58%) were associated with smoking, FOM and size <2cm and non-homogeneous OLs (42%) with non-smokers. No dysplasia was present in 40% and any dysplasia (AD) in 60%. Tongue OLs were correlated with AD (OR:6.0) and CD (OR:5.7). FOM OLs were correlated with CD (OR:4.5). DD was correlated with non-homogeneous OLs (OR:2.6).

CONCLUSIONS

CD was most frequently observed in tongue and FOM OLs, while DD was associated with non-homogeneous OLs. In this series of patients, there was no consistent reliable association between the clinical and histopathological features and clinical characteristics can therefore not substitute microscopic examination of biopsies.

Influence of site and smoking on malignant transformation in the oral cavity: Is the microbiome the missing link?

The tongue and floor of the mouth are high-risk sites for oral squamous cell carcinoma (OSCC), while smoking is its most significant risk factor. Recently, questions have been raised as to the role of the oral microbiome in OSCC because of a wealth of evidence demonstrating that the microbiome of OSCC differs from that of healthy mucosa. However, oral site and smoking also have a significant impact on oral microbial communities, and to date, the role these factors play in influencing the dysbiotic microbial communities of OSCC and precursor lesions has not been considered. This review aims to examine the influence of site and smoking on the oral microbiome and, in turn, whether these microbiome changes could be involved in oral carcinogenesis.

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.

Automated detection of premalignant oral lesions on whole slide images using convolutional neural networks

INTRODUCTION

Oral epithelial dysplasia (OED) is a precursor lesion to oral squamous cell carcinoma, a disease with a reported overall survival rate of 56 percent across all stages. Accurate detection of OED is critical as progression to oral cancer can be impeded with complete excision of premalignant lesions. However, previous research has demonstrated that the task of grading of OED, even when performed by highly trained experts, is subject to high rates of reader variability and misdiagnosis. Thus, our study aims to develop a convolutional neural network (CNN) model that can identify regions suspicious for OED whole-slide pathology images.

METHODS

During model development, we optimized key training hyperparameters including loss function on 112 pathologist annotated cases between the training and validation sets. Then, we compared OED segmentation and classification metrics between two well-established CNN architectures for medical imaging, DeepLabv3+ and UNet++. To further assess generalizability, we assessed case-level performance of a held-out test set of 44 whole-slide images.

RESULTS

DeepLabv3+ outperformed UNet++ in overall accuracy, precision, and segmentation metrics in a 4-fold cross validation study. When applied to the held-out test set, our best performing DeepLabv3+ model achieved an overall accuracy and F1-Score of 93.3 percent and 90.9 percent, respectively.

CONCLUSION

The present study trained and implemented a CNN-based deep learning model for identification and segmentation of oral epithelial dysplasia (OED) with reasonable success. Computer assisted detection was shown to be feasible in detecting premalignant/precancerous oral lesions, laying groundwork for eventual clinical implementation.

Transcriptional analysis highlights three distinct immune profiles of high-risk oral epithelial dysplasia

Oral potentially malignant disorders (OPMD) are precursors of oral squamous cell carcinoma (OSCC), and the presence of oral epithelial dysplasia (OED) in OPMD confers an increased risk of malignant transformation. Emerging evidence has indicated a role for the immune system in OPMD disease progression; however, the underlying immune mechanisms remain elusive. In this study, we used immune signatures established from cancer to delineate the immune profiles of moderate and severe OED, which are considered high-risk OPMD. We demonstrated that moderate and severe OEDs exhibit high lymphocyte infiltration and upregulation of genes involved in both immune surveillance (major histocompatibility complex-I, T cells, B cells and cytolytic activity) and immune suppression (immune checkpoints, T regulatory cells, and tumor-associated macrophages). Notably, we identified three distinct subtypes of moderate and severe OED: immune cytotoxic, non-cytotoxic and non-immune reactive. Active immune surveillance is present in the immune cytotoxic subtype, whereas the non-cytotoxic subtype lacks CD8 immune cytotoxic response. The non-immune reactive subtype showed upregulation of genes involved in the stromal microenvironment and cell cycle. The lack of T cell infiltration and activation in the non-immune reactive subtype is due to the dysregulation of CTNNB1, PTEN and JAK2. This work suggests that moderate and severe OED that harbor the non-cytotoxic or non-immune reactive subtype are likely to progress to cancer. Overall, we showed that distinct immune responses are present in high-risk OPMD, and revealed targetable pathways that could lead to potential new approaches for non-surgical management of OED.

Predicting Progression of Oral Lesions to Malignancy Using Machine Learning

OBJECTIVE

To use large-scale electronic health record (EHR) data to develop machine learning models predicting malignant transformation of oral lesions.

METHODS

A multi-institutional health system database was used to identify a retrospective cohort of patients with biopsied oral lesions. The primary outcome was malignant transformation. Chart review and automated system database queries were used to identify a range of demographic, clinical, and pathologic variables. Machine learning was used to develop predictive models for progression to malignancy.

RESULTS

There were 2192 patients with a biopsied oral lesion, of whom 1232 had biopsy proven oral dysplasia. There was malignant transformation in 34% of patients in the oral lesions dataset, and in 54% of patients in the dysplasia subset. Multiple machine learning-based models were trained on the data in two experiments, (a) including all patients with biopsied oral lesions and (b) including only patients with biopsy-proven dysplasia. In the first experiment, the best machine learning models predicted malignant transformation among the biopsied oral lesions with an area under the curve (AUC) of 86%. In the second experiment, the random forest model predicted malignant transformation among lesions with dysplasia with an AUC of 0.75. The most influential features were dysplasia grade and the presence of multiple lesions, with smaller influences from other features including anemia, histopathologic description of atypia, and other prior cancer history.

CONCLUSION

With diverse features from EHR data, machine learning approaches are feasible and allow for generation of models that predict which oral lesions are likely to progress to malignancy.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Prediction of malignant transformation in oral epithelial dysplasia using infrared absorbance spectra

Oral epithelial dysplasia (OED) is a histopathologically-defined, potentially premalignant condition of the oral cavity. The rate of transformation to frank carcinoma is relatively low (12% within 2 years) and prediction based on histopathological grade is unreliable, leading to both over- and under-treatment. Alternative approaches include infrared (IR) spectroscopy, which is able to classify cancerous and non-cancerous tissue in a number of cancers, including oral. The aim of this study was to explore the capability of FTIR (Fourier-transform IR) microscopy and machine learning as a means of predicting malignant transformation of OED. Supervised, retrospective analysis of longitudinally-collected OED biopsy samples from 17 patients with high risk OED lesions: 10 lesions transformed and 7 did not over a follow-up period of more than 3 years. FTIR spectra were collected from routine, unstained histopathological sections and machine learning used to predict malignant transformation, irrespective of OED classification. PCA-LDA (principal component analysis followed by linear discriminant analysis) provided evidence that the subsequent transforming status of these 17 lesions could be predicted from FTIR data with a sensitivity of 79 ± 5% and a specificity of 76 ± 5%. Six key wavenumbers were identified as most important in this classification. Although this pilot study used a small cohort, the strict inclusion criteria and classification based on known outcome, rather than OED grade, make this a novel study in the field of FTIR in oral cancer and support the clinical potential of this technology in the surveillance of OED.

Oral Epithelial Dysplasia Grading Systems: A Systematic Review & Meta-Analysis

This systematic review and meta-analysis aims to provide a robust qualitative and quantitative analysis of the different systems used to assess the grade of oral epithelial dysplasia (OED). This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyzes (PRISMA) statement. Six electronic databases were searched for primary research published over the past four decades. Overall quality and level of evidence were based on the Johns Hopkins Research Evidence Appraisal Tool, while evidence of heterogeneity was determined by the Q-statistic and I^{^2} statistic. Evidence of publication bias was determined using Egger's regression and the Rank correlation tests. A total of 170 records were identified. Only 9 primary research articles were included in the qualitative systematic review. Four studies (4/9) were included in the final quantitative meta-analysis. The grading systems analyzed included the WHO, binary, Ljubljana, Smith and Pindborg, Brothwell, and the oral intraepithelial neoplasia. The results demonstrate the binary system to be superior to the WHO system in grading OED, by providing better inter-observer agreement, however, the substantial error among the inter-observer κ values analyzed indicates the significance of this finding to be of minimal impact. Lack of reliable reproducibility of the grading systems and lack of common effect size (heterogeneity analysis) were noted.

The clinical utility of contemporary oral epithelial dysplasia grading systems

INTRODUCTION

Clinical management of oral potentially malignant disorders relies on accurate histopathological assessment of the presence and grade of oral epithelial dysplasia. Whilst adjunctive laboratory tests have provided useful prognostic information, none are in widespread clinical use. This study was performed to assess the clinical utility of two contemporary oral epithelial dysplasia grading systems.

METHODS

Patients were identified from a clinical database. Oral epithelial dysplasia grading was performed by three oral and maxillofacial pathologists blinded to clinical outcome using the WHO 2017 system and a binary classification. The primary outcome measure was the development of oral squamous cell carcinoma, termed 'malignant transformation'.

RESULTS

131 cases satisfied the inclusion criteria, of which 23 underwent malignant transformation. There was substantial inter-rater agreement between the study pathologists for both grading systems, measured using kappa statistics (κ = 0.753-0.784). However, there was only moderate agreement between the consensus WHO 2017 dysplasia grade for the study against the original grade assigned by a pool of six pathologists in the context of the clinical service (κ = 0.491). Higher grade categories correlated with an increased risk of developing cancer using both grading systems.

CONCLUSION

This study demonstrates that the WHO 2017 and binary grading systems are reproducible between calibrated pathologists and that consensus reporting is likely to improve the consistency of grading. The WHO and binary systems were prognostically comparable. We recommend that institutions implement consensus oral epithelial dysplasia grading and prospectively audit the effectiveness of risk stratifying their patients with oral potentially malignant disorders. (249 words).

Identification of specific clinical risk factors associated with the malignant transformation of oral epithelial dysplasia

BACKGROUND

Factors that increase the risk of malignant transformation of oral epithelial dysplasia (OED) are not completely elucidated.

METHODS

A retrospective chart review was performed assessing risk factors for transformation of OED, and cancer staging for transformed cases at Sunnybrook Health Sciences Centre.

RESULTS

Two-hundred four patients were diagnosed with OED, and 16.7% (34) underwent malignant transformation. Risk factors associated with transformation included: heavy tobacco smoking, excessive EtOH consumption, non-homogenous leukoplakia, size >200 mm² , moderate dysplasia or greater than moderate, progression of dysplasia grades, and immunosuppression. Transformed cases followed for a dysplastic lesion were associated with a stage-I cancer diagnosis, and cancer cases with no prior biopsy were associated with a stage-IV diagnosis.

CONCLUSIONS

In addition to commonly cited risk factors, immunosuppression was associated with malignant transformation, including the use of topical steroids. Analyzing risk factors can help clinicians define risk of progression in patients with OED.

Premalignant and malignant lesions of oral cavity in eastern India: a hospital-based study

BACKGROUND

Oral carcinoma and precancers are major public health challenges in India and other developing countries.

OBJECTIVES

Aim of the study was to assess the associations of demographic characteristics, addictions, chief complaints of mouth/oral and clinical diagnosis by cytology smear and punch biopsy in early detection of oral premalignant and malignant lesions. Methods Study was designed on retrospective data of case files of CDC, CNCI, Kolkata, from patients attended from January 1996 to September 2016. History was taken, histopathology and Pap smear were performed. Descriptive statistical analysis, cross-tabulation and Pearson's Chi-square test were done.

RESULTS

Total participants (n = 692); 110 (15.9%) having history of swallowing betel leaf, nut lime, dokta, jarda, catecheu with an average of 11 years. Three hundred twenty-five (46.9%) had multiple addiction (cigarette/bidi/tobacco/all). Ninety-eight (12.1%), 99 (12.2%) and 68 (8.4%) were addicted to cigarette, bidi and chewing tobacco, respectively. Twenty-nine participants were addicted to alcohol; 18 (2.6%) and 11 (1.5%) took country and foreign alcohol correspondingly. Clinicians thoroughly examined lips (4.1%), buccal mucosa (27.3%), gingival (2.8%), tongue (23.1%), hard and soft palate (4.9%), mouth loor (5.2%) and other parts (32.3%); diagnosed participants as normal (22.8%)/benign (23.1%)/premalignant (39.1%)/malignant (14.8%). Smears confirmed 60, 131, 42, 9 and 8 cases as carcinoma, mild, moderate, severe dysplasia and inflammation, respectively. The punch biopsy identified 11 carcinomas, two severe, two moderate and seveeen mild dysplasia's. Chi-square test showed significant association between smear and examination (P = 0.022), diagnosis and examinations of the oral cancer patients (P = 0.0001).

CONCLUSION

The study provided strong evidence that betel leaf, chewing tobacco, smoking and alcohol are independent risk factors for oral cancer. Cytological smear and biopsy are cost-effective approaches for early detection.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Early-Phase Interventional Trials in Oral Cancer Prevention

Simple Summary

Oral cancer is a devastating disease with increasing incidence worldwide. Oral epithelial dysplasia (OED) is a potentially malignant disorder and patients with OED are at increased risk of developing oral cancer. Current strategies for management of OED include surgery or close observation and both fail to address the underlying pathogenesis of the disease. There is an urgent need for evidence-based medical treatments for OED to prevent oral cancer development in this cohort. Chemoprevention trials to date have not delivered therapeutic agents for routine clinical practice. Historically, there has been significant heterogeneity in the design of oral cancer chemoprevention trials, with most failing to selectively recruit patients with biopsy-proven OED, which limits the usefulness of the findings in the OED population. The present paper aims to review the current evidence and the methodology of early-phase trials in oral cancer chemoprevention. Novel strategies in oral cancer chemoprevention will also be discussed.

Abstract

The increasing breadth of molecular targets, promise of immune-targeted therapies and repurposed agents have heightened interest in cancer prevention. While, to date, testing of oral cancer chemoprevention strategies has failed to deliver therapeutic agents for routine clinical practice, there remains an urgent need for further clinical research to overcome this hurdle. Patients at the greatest risk of disease stand to benefit the most from inclusion in clinical trials; therefore, there is a need to carefully define this population using validated clinical and molecular markers. Safety, tolerability and the efficacy of interventions is assessed through carefully selected endpoints. These endpoints may include pharmacodynamic, clinical, histological and on-target molecular modifications as an individual or as a composite endpoint. Early-phase trials provide an area of opportunity to explore novel and repurposed agents in the setting of oral cancer chemoprevention, eventually leading to phase III trials with clinical endpoints such as transformation and clinical outcome; these studies are large, lengthy and expensive and should be reserved for the most promising of agents. This paper will explore current evidence in oral cancer chemoprevention, drug repurposing, selection of appropriate endpoints for early-phase trials and novel therapeutic angles in oral cancer chemoprevention.

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.

Loss of FANCD2 and related proteins may predict malignant transformation in oral epithelial dysplasia

OBJECTIVE

Predicting malignant transformation (MT) in oral epithelial dysplasia (OED) is challenging. The higher rate of MT reported in nonsmokers suggests an endogenous etiology in oncogenesis. We hypothesize that loss of FANCD2 and associated proteins could influence genomic instability and MT in the absence of environmental carcinogens.

STUDY DESIGN

Longitudinal archival samples were obtained from 40 individuals with OED: from diagnosis to the most recent review in 23 patients with stable OED or until excision of the squamous cell carcinoma in 17 patients with unstable OED undergoing MT. Histopathological reassessment, immunohistochemistry for FANCD2, and Western blotting for phosphorylation/monoubiquitylation status of ATR, CHK1, FANCD2, and FANCG were undertaken on each tissue sample.

RESULTS

Decreased expression of FANCD2 was observed in the diagnostic biopsies of OED lesions that later underwent MT. Combining the FANCD2 expression scores with histologic grading more accurately predicted MT (P = .005) than histology alone, and it correctly predicted MT in 10 of 17 initial biopsies. Significantly reduced expression of total FANCD2, pFANCD2, pATR, pCHK-1, and pFANCG was observed in unstable OED.

CONCLUSIONS

There is preliminary evidence that defects in the DNA damage sensing/signaling/repair cascade are associated with MT in OED. Loss of expression of FANCD2 protein in association with a higher histologic grade of dysplasia offered better prediction of MT than clinicopathologic parameters alone.

Oral tongue leukoplakia: analysis of clinicopathological characteristics, treatment outcomes, and factors related to recurrence and malignant transformation

OBJECTIVES

The tongue is identified as a high-risk site for oral leukoplakia and malignant transformation. The purpose of this study is to investigate the clinicopathological characteristics and treatment outcomes of tongue leukoplakia and assess the factors related to recurrence and malignant transformation.

MATERIALS AND METHODS

One hundred and forty-four patients who received carbon dioxide laser surgery for tongue leukoplakia from 2002 to 2019 were analyzed statistically.

RESULTS

The follow-up period was 54.90 ± 54.41 months. Thirty patients showed postoperative recurrence (20.83%), and 12 patients developed malignant transformation (8.33%). The annual transformation rate was 2.28%. Univariate analysis showed that a history of head and neck cancer, size of lesion area, clinical appearance, and pathology were significant factors for both recurrence and malignant transformation. In the multivariate logistic regression, a history of head and neck cancer and size of lesion area were independent prognostic factors for recurrence, and a history of head and neck cancer was the only independent factor for postoperative malignant change.

CONCLUSIONS

Clinicians should adopt more aggressive strategies for tongue leukoplakia patients with a history of head and neck cancer.

CLINICAL RELEVANCE

These results may help clinicians gain a better understanding of oral tongue leukoplakia.

Management of oral leukoplakia: a position paper of the Society of Oral Medicine, Chinese Stomatological Association

OBJECTIVE

The objective of this study was to develop the first edition of a Chinese evidence-based position paper on the management of oral leukoplakia (OLK).

STUDY DESIGN

The consultant group for drafting the position paper consisted of 31 oral medicine specialists and 2 evidence-based medicine specialists. English studies (searched in PubMed, EMBASE, and the Cochrane Library) and Chinese studies (searched in China National Knowledge Infrastructure and WanFang) published before January 2018 were used. The quality of the study was assessed using the Grading of Recommendations Assessment, Development, and Evaluation grid, and the strength of the recommendations was determined based on the results of 3 rounds of voting among the consultant group members using the Delphi method.

RESULTS

Twenty-two evidence-based guidelines for clinical management and monitoring of OLK were established in this position paper. A clinical path diagram for oral health practitioners was constructed based on the recommendations.

CONCLUSION

Current evidence suggests that management and monitoring of patients with OLK should be performed by experienced clinicians to control the lesion and for early detection of malignant transformation. However, all recommendations are based on evidence of low or extremely low quality and may require further modification as new evidence is produced.

Malignant transformation in a cohort of patients with oral epithelial dysplasia

Oral epithelial dysplasia (OED) is often diagnosed in oral potentially malignant disorders (OPMD) and carries an increased risk of malignant transformation. Currently, the reported risk of malignant transformation for OED varies. Here we present the risk in a cohort of 150 patients with OED at a specialist centre. In this cohort 2.6%, 4.1%, and 29.2% cases of mild, moderate, and severe OED, respectively, progressed to oral squamous cell carcinoma at the dysplastic site, while a small number developed a malignant lesion elsewhere. Moreover, 17 patients experienced an increase in grade of dysplasia and two showed histological resolution of their lesions.

An anatomical perspective on clinicopathological characteristics and treatment outcomes of dorsal and ventrolateral tongue leukoplakia after carbon dioxide laser surgery

Background

The tongue has been identified as a high-risk site for malignant transformation of oral leukoplakia. The purpose of this study was to investigate the clinicopathological characteristics and treatment outcomes of the dorsal and ventrolateral tongue leukoplakia.

Methods

Demographic data and pathological results of patients who underwent carbon dioxide laser surgery for tongue leukoplakia from 2002 to 2019 were retrospectively reviewed and analyzed statistically.

Results

Of the 111 patients enrolled, 80 were males and 31 females, with a mean age of 51.86 ± 11.84 years. The follow-up time was 3.74 ± 4.19 years. Fifteen patients had a postoperative recurrence (13.51%). Four (3.6%) patients developed malignant transformation. Annual transformation rate was 4.03%. There were no differences in the time to develop carcinoma (3.19 ± 1.94 vs. 3.51 ± 2.12 years, P = 0.83), overall cumulative malignant transformation rates (7.41% vs. 2.25%, P = 0.12), and annual transformation rates (2.32% vs. 0.64%, P = 0.099). The prevalence of the ventrolateral tongue leukoplakia was higher than that of the dorsal tongue leukoplakia (P < 0.001). The results of multivariate logistic regression analysis showed that the degree of pathology was the only independent prognostic factor related to postoperative malignant transformation (P = 0.045).

Conclusions

Dorsal tongue leukoplakia is not as frequently encountered clinically as ventrolateral tongue leukoplakia. The response of the dorsal tongue and ventrolateral tongue leukoplakia to laser therapy of are comparable in postoperative recurrence and postoperative malignant transformation. Clinicians should take a more aggressive attitude toward oral tongue leukoplakia with higher grade of dysplasia.

Readdressing dysplasia at surgical margins as predictive biomarker of malignant transformation

Clinical, histological and molecular alterations observed at surgical margins could be regarded as predictive markers of malignant transformation. However, there are contrasting views on usefulness of oral epithelial dysplasia (OED) in predicting malignant transformation. In this regard, investigation of OED status at surgical margins could give an interesting perspective to this notion. We searched the reputed databases to retrieve the original research articles wherein the OED status was investigated at the mucosal surgical margins of oral squamous cell carcinoma (OSCC). Intriguingly, in all the studies, number of cases in 'no dysplasia' category was higher than other grades of dysplasia. In our institutional experience of 92 cases of OSCC, 75 (82%) cases showed no evidence of dysplasia at surgical margins. Thus, we conclude that dysplasia status at surgical margins does not support the OED as potential marker of malignant transformation.

UK consensus recommendations on the management of oral epithelial dysplasia during COVID-19 pandemic outbreaks

OBJECTIVES

Oral Epithelial Dysplasia (OED) is associated with an increased risk of oral cancer development. The SARS-CoV-2 pandemic is necessitating the suspension or dramatic reduction of face-to-face non-urgent elective services, including OED clinics. Little is known regarding the potential impact of elective services suspension upon the risk of OED progression, and whether alternative strategies (e.g. remote consultations) may be introduced to ensure OED surveillance. The aim of this paper is to provide expert-opinion consensus recommendations for the management of OED during the current and future pandemic outbreaks.

MATERIALS AND METHODS

A working group of nine UK-based senior clinicians and academics in Oral and Maxillofacial Surgery and Oral Medicine was created and twelve consensus statements were developed using a modified-Delphi process. Greater than 80% agreement was considered a consensus.

RESULTS

Consensus was achieved for all twelve statements (89-100% agreement). The group agreed that, during the temporary suspension of elective services associated with COVID-19 pandemic outbreaks, patients with OED can be risk stratified to determine the length of accepted delay in face-to-face consultation. Remote consultations with patient-provided clinical photographs may be a useful way of maintaining a level of surveillance in this group of patients.

CONCLUSIONS

Using an expert working group methodology, we have developed consensus recommendations for the monitoring of individuals with OED during pandemic outbreaks associated with temporary suspension of elective services. This has identified areas of future research and highlighted the need for a stronger evidence base to inform the set-up and delivery of surveillance regimens for patients with OED.

Annual malignant transformation rate of oral leukoplakia remains consistent: A long-term follow-up study

OBJECTIVES

Numerous clinical and histopathological characteristics have been associated with malignant transformation (MT) of oral leukoplakia (OL), including classic and differentiated epithelial dysplasia, but MT predictions remain suboptimal. The objective of this study was to determine the annual MT rate of OL and to identify clinicopathological risk factors associated with MT.

PATIENTS AND METHODS

170 patients with OL were included in this retrospective cohort study, 117 females and 53 males. Follow-up ranged from 12 to 219 months (median 54). The analyzed variables included age, gender, smoking habits, clinical presentation, subsite, size and treatment. In a subgroup of 140 patients, histopathological diagnoses were reviewed with regard to the presence of dysplasia, discerning both classic dysplasia and differentiated dysplasia.

RESULTS

MT occurred in 23% of the patients, resulting in an annual MT rate of 4.9% (95% CI: 3.5 - 6.6) which remained consistent. High-risk subsite (tongue and floor of mouth) was the only clinical predictor for MT (Hazard Ratio = 2.7, 95% CI: 1.3 - 5.5, p = 0.007). In 140 patients, classic dysplasia (Hazard Ratio = 7.2, 95% CI: 1.6 - 33.1, p = 0.012) and differentiated dysplasia (Hazard Ratio = 6.6, 95% CI: 1.2 - 25.4, p = 0.026) were predictors for MT. Binary grading between dysplasia and no dysplasia was significant for predicting MT (Hazard Ratio = 6.4, 95% CI: 1.5 - 27.5, p = 0.013).

CONCLUSION

Since annual MT rate of OL remains stable during follow-up, regular long-term or even life-long follow-up is advocated. Specific oral subsites and epithelial dysplasia are predictors for MT of OL.

Expression of invadopodia markers can identify oral lesions with a high risk of malignant transformation

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity and is usually preceded by a range of premalignant tissue abnormalities termed oral potentially malignant disorders. Identifying malignant transformation is critical for early treatment and consequently improved survival and decreased morbidity. Invadopodia (INV) are specialized subcellular structures required for cancer cell invasion. We developed a new method to visualize INV in keratinocytes using fluorescent immunohistochemistry (FIHC) and semi‐automated images analysis. The presence of INV was used to determine the risk of malignant transformation. We analyzed 145 formalin‐fixed, paraffin‐embedded (FFPE) oral biopsy samples from 95 patients diagnosed as nondysplastic, dysplastic, and OSCC including 49 patients whose lesions transformed to OSCC (progressing) and 46 cases that did not transform to OSCC (control). All samples were stained for Cortactin, tyrosine kinase substrate with five SH3 domains (Tks5) and matrix metallopeptidase 14 (MMP14) using FIHC, imaged using confocal microscopy and analyzed using a multichannel colocalization analysis. The areas of colocalization were used to generate an INV score. Using the INV score, we were able to identify progressing lesions with a sensitivity of 75–100% and specificity of 72–76%. A positive INV score was associated with increased risk of progression to OSCC. Our results suggest that INV markers can be used in conjunction with the current diagnostic standard for early detection of OSCC.

Molecular, genomic and mutational landscape of oral leukoplakia

Oral leukoplakia (OLK) and its more aggressive clinical variant proliferative verrucous leukoplakia (PVL) remain enigmatic disorders clinically and histopathologically. Despite decades of research into both, there has been only incremental advancement in our understanding of their aetiology and pathogenesis and only minimal improvement in effective management strategies. Currently, no specific prognostic genetic or molecular marker has been reported for leukoplakia. There is, however, an emerging body of evidence characterising the genomic and transcriptomic profile of OLK. Regardless of the significance of cellular and architectural features of OLK and PVL, it is clear from studies reported in this review that new emerging evidence points to the presence of premalignant molecular subtypes of leukoplakia which require further investigation. This up-to-date review explores the contemporary genomic, transcriptomic and mutational landscape of leukoplakia broadly, discusses concepts that may not be widely recognised or accepted and purposefully highlights studies with juxtaposed findings in an effort to challenge dogma. It also highlights the urgent need for a concerted international effort of original collaborative research which will only occur by pooling collective efforts, resources and intellect to define the molecular fingerprint of this enigmatic disorder, in the hope it will better inform diagnosis, stratification and treatment.

The relevance of surgical margins in clinically early oral squamous cell carcinoma

OBJECTIVES

There is controversy regarding surgical margins in the management of early oral squamous cell carcinoma (OSCC). The main objectives of this study were to assess the: relevance of the margin independent of tumour variables; threshold for a safe margin; relevance of dysplasia at the margin.

MATERIALS & METHODS

UK based retrospective multicenter cohort study of patients with previously untreated and clinically early OSCC between 1998 and 2016. All patients had surgery as the primary modality and had surgical staging of the neck. Minimum follow-up was 2 years. Margins were classified as: clear ≥5.0 mm; close 1.0-4.9 mm; involved not cut-through (INC-T) 0.1-0.9 mm; cut-through (C-T) 0 mm.

RESULTS

669 patients were included. After adjusting for tumour variables Cox multivariate regression analysis demonstrated that close margins had similar survival outcomes to clear margins (Hazard Ratio(HR) 0.99 (95%CI 0.50-1.95) for Local Recurrence Free Survival (LRFS); HR 1.08 (95%CI 0.7-1.66) for Disease Free Survival (DFS); HR 0.74 (95%CI 0.44-1.25) for Disease Specific Survival (DSS); HR 0.80 (95%CI 0.58-1.11) for Overall Survival (OS)). C-T margins had significantly worse LRFS (HR 5.01 (95%CI 2.02-12.39)) and DFS (HR 2.58 (95%CI 1.28-5.20)). INC-T margins had significantly worse DFS (HR 1.98 (95% CI 1.01-3.87)). Time dependent receiver operating characteristic curve analysis did not demonstrate a clear margin threshold for LRFS within 24 months (AUC = 0.53 (95%CI 0.41-0.64)). Dysplasia at the margin did not influence LRFS or DFS.

CONCLUSION

Only resection margins <1 mm independently affected survival outcomes. This should be considered when making decisions regarding adjuvant treatment.

Increased expression of PD-1 and PD-L1 in oral lesions progressing to oral squamous cell carcinoma: a pilot study

Oral cancer is a devastating disease and is commonly preceded by a range of oral premalignant disorders. We investigated the expression of PD-1 and PD-L1 in oral epithelial dysplasia (OED) that progressed to oral squamous cell carcinoma (OSCC) compared to non-progressing dysplasia. 49 oral biopsies were analyzed, including 19 progressing cases, 20 cases did not progress, and 10 OSCC. Samples were stained with monoclonal antibodies for PD-1 and PD-L1, followed by conventional peroxidase reaction immunohistochemistry (IHC) imaged under light microscopy or fluorescent immunohistochemistry (FIHC) imaged using a confocal microscope. Images were analyzed using a novel semi-automated analysis protocol. PD-1/PD-L1 expression was assessed at the epithelium/tumor cells (TC) and at inflammatory cells in lamina propria. Our results show a significant increase in PD-L1 expression in progressing compared to non-progressing dysplasia. Using FIHC, we showed increased PD-L1 expression, increased nuclear density in progressing dysplasia and a better interobserver agreement compared with IHC. We developed a new FIHC-based quantitative method to study PD-1/PD-L1 expression in FFPE samples and showed that PD-L1 is highly expressed in premalignant lesions progressing to cancer. Our results suggest that immunomodulation via PD-L1/PD-1 pathway occurs prior to malignant transformation.

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.

Malignant transformation of oral leukoplakia: a follow-up study

OBJECTIVE

The main objective of the study was to identify the determinants that contribute to the malignant transformation of oral leukoplakia in a group of patients managed in secondary care. A secondary objective was to compare two dysplasia grading systems to determine their utility in assessing the prognosis.

MATERIAL AND METHODS

The cohort consisted of 93 patients diagnosed during the period 2009-2013. The variables recorded and analysed included age and sex, clinical presentation (colour) and severity of oral epithelial dysplasia (OED) scored by the WHO (2005) and the binary grading systems. The planned management included excision of high-grade dysplasia and observation of low-grade dysplasia lesions based on the WHO grading system. Patient factors were transcribed from the pathology records and updated using a questionnaire sent out to the whole group of patients. Data were analysed using χ² test and Kaplan-Meier analysis (P < 0.05).

RESULTS

Complete follow-up data were available for 93 patients. Malignant transformation occurred in 7 patients (7.5%) during a mean follow-up period of 30 months. Among the surgically excised group (n = 51), a recurrence of oral leukoplakia was noted in 16 patients (31%). WHO OED grading (P = 0.02) and the presence of red areas (P = 0.012) were useful in predicting malignant transformation with severe epithelial dysplastic lesions and red and white mixed lesions showing higher rates.

CONCLUSION

Leukoplakias (7.5%) transformed over a mean follow-up period of 30 months. Dysplasia grading and the clinical appearance by colour (mixed white and red) were significant predictors of malignant transformation CLINICAL SIGNIFICANCE: Patients with erythroleukoplakia and those diagnosed with moderate or severe epithelial dysplasia require more intensive interventions as such lesions have a higher risk of developing a malignancy.

Malignant transformation rate of oral leukoplakia-systematic review

OBJECTIVE

The aim of this study was to perform a systematic review of prevalence studies to determine the rate of malignant transformation of oral leukoplakia and assess the influence of demographic factors (age, gender, and geographic region) on the overall transformation rate.

STUDY DESIGN

A search was conducted for publications until July 2019 in 4 electronic databases and peer-reviewed journals. A manual search was performed on the bibliographies of the collected articles, and the authors were contacted for additional information. This study was previously registered with the trial number CRD42019126909 and study quality assessed through established methods. The results were expressed by means of proportions or odds ratios with a 95% confidence interval. Meta-regression was undertaken to evaluate possible sources of heterogeneity, and funnel plot visual analysis was performed to assess publication bias.

RESULTS

The 34 observational epidemiologic studies included reported data on 26,209 patients with oral leukoplakia from 18 different countries. Meta-analysis of 32 studies (23,489 patients) presented an estimated overall mean proportion of malignant transformation rate of 9.70% (7.80-11.70) (I² = 98.66%; τ² < 0.001; χ² = 23.18; degrees of freedom [df] = 31). When comparing genders, the odds ratio favored males with 0.622 (0.468-0.826) (I² = 29.77%; τ² = 0.089; χ² = 22.78; df = 16).

CONCLUSIONS

Within the limitations of the included studies in this systematic review, the results suggest that the malignant transformation rate was dependent on demographic factors and follow-up time. Future studies should include the development of guidelines to standardize the methodology for long-term follow-up assessment, thus reducing the risk of bias.

Oral Potentially Malignant Disorders

Oral potentially malignant disorders (OPMDs) are precursor lesions that may undergo malignant transformation to oral cancer. These lesions most commonly present clinically as white patches (leukoplakia). However, they may also be red (erythroplakia), or red and white (erythroleukoplakia). There are many risk factors associated with the development of an OPMD, and with the risk of malignant transformation of the lesion. A biopsy with subsequent microscopic examination from the lesional tissue is necessary in identification of OPMD. This article reviews the clinical appearance of OPMDs, associated risk factors, diagnosis and histologic appearance, and treatment.

Potentially malignant disorders of the oral cavity and oral dysplasia: A systematic review and meta-analysis of malignant transformation rate by subtype

IMPORTANCE

Potentially malignant disorders of the oral cavity (OPMD) are a heterogeneous group of lesions associated with a variable risk of malignant transformation (MT) to invasive cancer. Leukoplakia (LE), lichen planus (LP), oral lichenoid lesions (OLL), oral erythroplakia (OE), oral submucous fibrosis (OSF), and proliferative verrucous leukoplakia (PVL) are among the most common of these lesions. Oral dysplasia is a mucosal area characterized by cellular and architectural derangement, which may be associated with OPMDs or not.

OBJECTIVE

To define the MT rate of OPMDs and the risk of development into cancer of mild vs moderate/severe oral dysplasia. This in order to implement adequate follow-up strategies and treatment decisions.

STUDY DESIGN

We performed a systematic review and meta-analysis on studies reporting the MT rates of OPMDs and oral dysplasia. Ninety-two studies were included for the analysis. Cumulative rates were reported for OPMDs overall and as a subgroup, a comparison was made of mild vs moderate/severe dysplasia. Meta-regression on OPMD and year of publication was also performed.

MAIN OUTCOME AND MEASURES

Overall MT rates of OPMDs and odds ratio of MT of mild vs moderate/severe dysplasia.

RESULTS

Overall MT rate across all OPMD groups was 7.9% (99% confidence interval [CI] 4.9%-11.5%). MT rates of the specific OPMD subgroups were as follows: LP 1.4% (99% CI 0.9%-1.9%), LE 9.5 (5.9%-14.00%), OLL 3.8% (99% CI 1.6%-7.00%), OSF 5.2% (99% CI 2.9%-8.00%), OE 33.1% (99% CI 13.6%-56.1%), and PVL 49.5% (99% CI 26.7%-72.4%). Regarding the dysplasia grades comparison, the meta-analysis showed that moderate/severe dysplasia is meaningfully associated to a much greater risk of MT compared to mild dysplasia with an odds ratio of 2.4 (95% CI 1.5-3.8) [Correction added on 27 December 2019, after first online publication: CI updated from 99% to 95%.]. Heterogeneity was not significant. Annual MT rates were approximated based on the average follow-up as reported in the various subgroups. Lichen planus had an annual MT of 0.28%, OLL of 0.57%, leukoplakia of 1.56%, PVL of 9.3%, and OSF of 0.98%. Mild dysplasia had an annual MT of 1.7%, while severe dysplasia of 3.57%. Meta-regression showed a significant negative correlation of PVL MT rate and year of the study (P value <.001).

CONCLUSIONS AND RELEVANCE

OPMDs and oral dysplasia are relatively common conditions that general practitioners, head and neck, and oral medicine specialists, face in their everyday practice. Our analysis confirms the significant risk of MT of these lesions, although variable among the subgroups. Moderate/severe dysplasia bears a much higher risk of cancer evolution than mild dysplasia. It is important to raise public health awareness on the MT rates of these conditions, at the same time efficacious communication with the patient is of utmost importance. This, coupled with strict follow-up measures and optimal treatment strategies, would help in reducing the transformation of these oral conditions into invasive cancer.

Oral epithelial dysplasia: Causes, quantification, prognosis, and management challenges

Oral epithelial dysplasia is a spectrum of architectural and cytological epithelial changes caused by accumulation of genetic changes, and is associated with an increased risk of progression to squamous cell carcinoma. It is a microscopic diagnosis of immense clinical importance. The initial reports of oral potentially malignant disorders with oral epithelial dysplasia transforming to oral cancer helped in understanding the nature of oral malignancies. Since then, clinical studies on oral potentially malignant disorders have combined microscopic findings of oral epithelial dysplasia to assess the malignant transformation potential of different grades of epithelial dysplasia. A significant amount of scientific literature has amassed on oral epithelial dysplasia relating to aspects of its diagnosis and management. However, the evidence base is weak as a result of the significant variability of published research. Poorly described study methods, variability in different oral epithelial dysplasia grading systems, inter- and intra-examiner variability causing issues of reliability, inadequate sample size, and inconsistent durations of follow-up are some of the methodological issues contributing to the failure to provide dependable information. Randomized clinical trials on the malignant transformation potential of oral epithelial dysplasia and its treatment outcomes are limited. This comprehensive literature review on oral epithelial dysplasia summarizes the scientific knowledge published in the scientific literature in English since its first description. The historical development, etiological factors, grading systems, diagnostic criteria, assessment of risk factors and prevention of malignant transformation, management principles of different grades of oral epithelial dysplasia (surgical and nonsurgical), recommendations on follow-up, and prognostic indicators are discussed in detail.

Comparison of the Efficacy of Sediment Cytology over Oral Brush Cytology in Oral Leukoplakia

INTRODUCTION

A method called sediment cytology includes the investigation of smears arranged from the sediment of the biopsy specimen fixatives. The sediment from this fixative is used to prepare smears and provides a potentially rich source for cytological material. Investigation of the fixative sediment and understanding of the cytological picture with pertinent clinical and radiological information permits diagnosis in a few hours.

AIM

To evaluate the diagnostic efficacy of sediment cytology and oral brush cytology compared with histopathological findings in oral leukoplakia (OL) cases.

METHODS

Cytological smears were obtained from 30 clinically diagnosed OL lesions using 2 techniques: oral cytobrush and 10% formalin fixative sedimentation. Both smears were stained with Papanicolaou. Cytological smear evaluation was conducted with respect to cellularity, cell distribution, cellular clumping, and the presence of blood, debris, inflammatory cells, and microbial colonies. The cytopathological scores for all cases were compared between sediment and brush cytology and correlated with the histopathological diagnosis. For statistical analysis, the κ test and the Wilcoxon matched-pair test were used.

RESULTS

The cytobrush technique had a sensitivity of 83.3% for OL cases histopathologically diagnosed as severe dysplasia, while the sediment cytology technique had a sensitivity of 16.6%. For moderate/mild dysplasia cases, the cytobrush technique had a sensitivity of 7.7%, whereas the sediment technique showed no diagnostic sensitivity.

CONCLUSION

Based on the results from the present study, sediment cytology, unlike oral brush cytology, is not a useful screening tool for the preliminary diagnosis of potentially malignant oral lesions.

Risk Factors Associated With Malignant Transformation in Patients With Oral Leukoplakia in a Chinese Population: A Retrospective Study

PURPOSE

The study aim was to investigate the risk factors for the progression of oral leukoplakia (OLK) to malignancy.

PATIENTS AND METHODS

The data from 2,628 patients with OLK were retrospectively reviewed. Of these 2,628 patients, 192 had undergone sequential biopsies and were separated into 4 groups according to their final diagnosis. The risk factors were analyzed using Kaplan-Meier univariate survival analysis and Cox multivariate analysis.

RESULTS

In 41 of the 2,628 patients (1.7%), the OLK had progressed to cancer, with a mean interval to malignancy of 26.7 months. Of the 192 patients with sequential biopsies, OLK was maintained or had progressed to mild, moderate, or severe dysplasia or carcinoma in 50, 66, 35, and 41 patients, respectively. The 3- and 5-year oral cancer-free survival (OCFS) was 78.9 and 72.5%, respectively. The factors associated with worse overall survival were lesions located in the ventral tongue (P = .04), alcohol use (P = .025), nonhomogeneous lesions (P < .01), and high-risk dysplasia (P < .01). Cox regression analyses indicated that nonhomogeneous lesions (P = .03) and high-risk dysplasia (P < .01) were independent prognostic factors for the progression of OLK to malignancy.

CONCLUSIONS

High-risk dysplasia and nonhomogeneous lesions were shown to be important factors for progression to malignancy in patients with OLK. Thus, such patients should receive close follow-up and undergo sequential biopsies in the first 2 to 3 years for early screening of OLK evolving into a malignancy.

Quality of life in patients with oral leukoplakia

BACKGROUND

Oral leukoplakia (OL) is the most common oral potentially malignant disorder, yet despite its chronic and potentially disabling nature, the literature concerning impacts of OL on quality of life (QoL) is limited. This study aimed to evaluate QoL in subjects with OL compared to controls using QoL questionnaires.

METHODS

Fifty individuals with OL and 50 controls matched for age, gender, smoking, and alcohol use were administered the Short Generic Health Questionnaire (SF-12) and the discipline-specific Oral Potentially Malignant Disorder Questionnaire (OPMDQ). Responses were compared between the two groups.

RESULTS

Subjects with OL reported poorer QoL scores compared to controls in two domains "Role limitations due to physical problems" and "Pain" of the SF-12 questionnaire, and in two domains "Difficulty with diagnosis" and "Effect of treatment on daily life" and in the overall scores of the OPMDQ. Females reported poorer QoL in the overall OPMD QoL score and in the domains of "Physical and function limitation" and "Psychological and social well-being," while older individuals in the domains of "Physical and function limitation" and "Effect of treatment on daily life." Non-alcohol drinkers and subjects with dysplastic or non-homogeneous OLs also reported poorer QoL scores.

CONCLUSIONS

Quality of life assessments provide useful insight into the impact of OL on an individual's life and opportunity to improve clinical care.

Oral Epithelial Dysplasia and Premalignancy

Leukoplakia and erythroplakia are two entities under the moniker of "oral potentially malignant disorders" that are highly associated with the presence of oral epithelial dysplasia (OED) at first biopsy, while lesions of submucous fibrosis develop OED after being present for years. Importantly, traumatic/frictional keratoses are often mistaken clinically for leukoplakia and it is important for the pathologist to recognize and report them as such. The features of OED have been well-described and other architectural features will be discussed here, in particular verrucous and papillary architecture, bulky epithelial proliferation and epithelial atrophy. Proliferative leukoplakia, verrucous or otherwise, often show only hyperkeratosis in early lesions, with development of OED occurring over time, and squamous cell carcinoma developing in the majority of cases over time. The concept of hyperkeratosis without features of OED and that is not reactive, is likely a precursor to the dysplastic phenotype. Many cases of leukoplakia exhibiting OED are associated with a band of lymphocytes at the interface and these should not be mistaken for oral lichen planus.