Malignant transformation to oral cancer by subtype of oral potentially malignant disorder: A prospective cohort study of Taiwanese nationwide oral cancer screening program

Osthole mitigates the myofibroblast properties in oral submucous fibrosis by suppressing the TGF-β/smad2 signaling pathway and NCK-AS1 expression

Background/purpose

Natural products are gaining increasing recognition as an alternative source for alleviating fibrosis as they can regulate various mediators or pathways against fibrosis by targeting non-coding RNAs. In the current study, we aimed to investigate the therapeutic effects of osthole in oral submucous fibrosis (OSF), a precancerous condition of the oral cavity.

Materials and methods

The cytotoxicity of osthole to normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues was assessed using MTT assay. Collagen gel contraction and transwell migration assays were conducted to examine the myofibroblast activities. Besides, the expression of TGF-β/Smad2 signaling as well as α-SMA and type I collagen were measured. Additionally, RNA sequencing was used to identify a potential target involved in the anti-fibrotic effect of osthole.

Results

Osthole exhibited a higher cytotoxic effect on fBMFs compared to normal BMFs and dose-dependently reduced several myofibroblast activities, including collagen gel contractility and transwell migration ability. In addition, the expression of the TGF-β/Smad2 pathway was inhibited along with a lower expression of α-SMA and type I collagen in osthole-receiving cells. Moreover, the administration of osthole downregulated the expression of NCK1-AS1 in fBMFs, which was proven to mediate the anti-fibrosis property of osthole.

Conclusion

Our results indicate that osthole may be a promising compound to inhibit the progression of OSF.

Enhancing malignant transformation predictions in oral potentially malignant disorders: A novel machine learning framework using real-world data

This study addresses the challenge of accurately predicting malignant transformation risk in patients with oral potentially malignant disorders (OPMDs). Using data from 1,094 patients across three institutions (2004-2023), the researchers compared traditional statistical methods, including a Cox proportional hazards (Cox-PH) nomogram, with machine learning (ML) algorithms. A novel Self Attention Artificial Neural Network (SANN) model was developed, trained, and validated alongside other ML models including ANN, RF, and DeepSurv. The SANN model outperformed all other approaches, achieving an AUC of 0.9877, with sensitivity, specificity, accuracy, and precision exceeding 0.96. In comparison, the Cox-PH nomogram achieved AUCs of 0.880-0.902. Comprehensive evaluations using Receiver Operating Characteristic, calibration curves, and decision curve analysis demonstrated SANN's superior predictive efficacy, robustness, and generalizability. These findings highlight the potential of customized ML models, particularly SANN, to enhance early identification and management of high-risk OPMD patients, outperforming conventional statistical methods.

Feasibility study of single-image super-resolution scanning system based on deep learning for pathological diagnosis of oral epithelial dysplasia

This study aimed to evaluate the feasibility of applying deep learning combined with a super-resolution scanner for the digital scanning and diagnosis of oral epithelial dysplasia (OED) slides. A model of a super-resolution digital slide scanning system based on deep learning was built and trained using 40 pathological slides of oral epithelial tissue. Two hundred slides with definite OED diagnoses were scanned into digital slides by the DS30R and Nikon scanners, and the scanner parameters were obtained for comparison. Considering that diagnosis under a microscope is the gold standard, the sensitivity and specificity of OED pathological feature recognition by the same pathologist when reading different scanner images were evaluated. Furthermore, the consistency of whole-slide diagnosis results obtained by pathologists using various digital scanning imaging systems was assessed. This was done to evaluate the feasibility of the super-resolution digital slide-scanning system, which is based on deep learning, for the pathological diagnosis of OED. The DS30R scanner processes an entire slide in a single layer within 0.25 min, occupying 0.35GB of storage. In contrast, the Nikon scanner requires 15 min for scanning, utilizing 0.5GB of storage. Following model training, the system enhanced the clarity of imaging pathological sections of oral epithelial tissue. Both the DS30R and Nikon scanners demonstrate high sensitivity and specificity for detecting structural features in OED pathological images; however, DS30R excels at identifying certain cellular features. The agreement in full-section diagnostic conclusions by the same pathologist using different imaging systems was exceptionally high, with kappa values of 0.969 for DS30R-optical microscope and 0.979 for DS30R-Nikon-optical microscope. The performance of the super-resolution microscopic imaging system based on deep learning has improved. It preserves the diagnostic information of the OED and addresses the shortcomings of existing digital scanners, such as slow imaging speed, large data volumes, and challenges in rapid transmission and sharing. This high-quality super-resolution image lays a solid foundation for the future popularization of artificial intelligence (AI) technology and will aid AI in the accurate diagnosis of oral potential malignant diseases.

Multistate oral carcinogenesis-A prospective cohort study and a parallel case-control study in Taiwan

BACKGROUND

To characterize multistate oral carcinogenesis, we conducted a cohort study of patients with oral precancer and a parallel case-control study of oral cancers and controls in Taiwan.

METHODS

During 2013-2019, we recruited patients with oral precancer (n = 1998) or invasive oral cancer (n = 768) and hospital-based controls (n = 717). Precancer patients were followed up biannually for up to five years; questionnaire data and biospecimens were collected at multiple timepoints. Precancer natural history (regression/persistence, incidence, progression) was evaluated through follow-up visits and linkages with Taiwan's Cancer Registry.

COHORT UPDATES

Cross-sectionally, 71 % of oral precancers and 62 % of cancers were attributable to betel-quid chewing, smoking, and alcohol. Precancer patients had substantially elevated risk of oral cancer (standardized-incidence-ratio vs. Taiwan general population = 14.1; 95 %CI = 12.0-16.6). Among precancer patients, 156 incident invasive oral cancers occurred (median follow-up = 6.4 years; incidence rate = 1,221/100,000 person-years; annual incidence = 1.2 %; 1-year cumulative-incidence = 1.8 %; 5-year cumulative-incidence = 6.9 %; 10-year cumulative-incidence = 9.5 %). Baseline precancer histopathology strongly predicted risk of progression to oral cancer (5-year cumulative-incidence: no-dysplasia = 5.2 %, mild-dysplasia = 7.1 %, moderate-dysplasia = 32.8 %, severe-dysplasia = 45.9 %). Most oral cancers (88.5 %) were preceded by precancers identified during the study. The study has established a resource of >63,500 biospecimens, including biopsies (n = 6,012), oral cytology (n = 18,422), oral rinses (n = 15,054), saliva (n = 15,066), and blood (n = 8,990). Ongoing investigations are characterizing oral carcinogenesis at the epidemiologic, macroscopic, microscopic, microbiomic, and genomic levels.

CONCLUSIONS

A majority of oral precancers/cancers in Taiwan are caused by betel-quid chewing, smoking, and alcohol. Patients with oral precancer have substantially elevated risk of site-concordant oral cancer. We highlight our study as a resource to collaboratively address questions regarding oral precancer/cancer natural history and clinical management.

Behavior Changes for Smokers and Betel Quid Chewers Participating in the Organized Oral Mucosal Screening Between 2010 and 2021 in Taiwan

OBJECTIVE

To investigate the likelihood of smoking and betel quid chewing behavior changes, as well as the associated factors, among subjects in a nationwide oral cancer screening program in Taiwan, where oral cancer is the fourth leading malignancy in men.

METHODS

The Taiwanese Oral Cancer Screening Program targets smokers and betel quid chewers over the age of 30. Between 2010 and 2021, 2,578,245 individuals participated in the program at least twice. During each visit, the central data monitoring center collected information on gender, age, education level, smoking and betel quid chewing habits, the quantities consumed, and diagnoses of oral potentially malignant disorders (OPMDs) and oral cancer. A three-state Markov chain exponential regression model was employed to assess the probabilities of behavior change-deterioration, maintenance, or improvement-and the factors influencing these changes.

RESULTS

The largest proportion of both smokers and betel quid chewers remained unchanged in the repeated attendees. The smoking cessation transition result was less than 10%, whereas the reduction in dosage exceeded 20%. However, the discontinuation of betel quid chewing was observed in more than 20% of individuals in the low-dose group, and there was also a reduction in dosage of more than 20%. The positive OPMDs caused the progression of the Net Force Progression (NFP) from an initial stage of none, as well as the NFP between low and high doses of both smoking and betel quid chewing. Higher levels of education, residing in urban areas, and receiving screenings in large hospitals help to avoid the progressive NFP between low and high doses of smoking. Additionally, these factors also help to prevent the development of the NFP from an initial stage of none, as well as the progressive NFP between low and high doses of betel quid chewing.

CONCLUSIONS

Participation in an oral cancer screening program can effectively enhance hazardous oral behaviors, including smoking and betel quid chewing. Although it may not have a substantial effect on smoking cessation, it can decrease the daily consumption of cigarettes. This approach demonstrates encouraging outcomes in encouraging individuals to quit betel quid chewing and decrease their daily consumption. Higher levels of education, urban residency, and receiving screenings at large hospitals all have a good impact on reducing dangerous oral cancer behaviors.

Diseases with oral malignant potential: Need for change to inform research, policy, and practice

This manuscript critically examines the current classification of oral potentially malignant disorders, questioning the practicality and implications of labeling such a large population as precancerous, given that the actual progression to oral cancer is significantly low for most disorders. The paper advocates for a revised classification system that accurately reflects the varying malignancy risks associated with different disorders. It suggests a reassessment of the diagnostic and management approaches to mitigate overdiagnosis and alleviate patient burdens. We propose categorizing diseases with oral malignant potential as follows: Oral Precancerous Diseases, encompassing high-risk lesions and conditions like erythroplakia, non-homogeneous leukoplakia, proliferative leukoplakia, and actinic keratosis; Oral Potentially Premalignant Diseases, covering lesions, conditions, and systemic diseases with distinct oral manifestations harboring a limited or undefined risk of transformation, such as homogeneous leukoplakia, oral submucous fibrosis, oral lichenoid diseases, chronic hyperplastic candidosis, keratosis of known aetiology (smokeless tobacco, khat), palatal lesions in reverse smokers, and dyskeratosis congenita; and Systemic Conditions with Oral Malignant Potential including Fanconi's anemia, xeroderma pigmentosum, and chronic immunosuppression (including patients post-bone marrow transplantation), which are associated with an increased risk of oral cancer without preceding precursor lesions. We provide illustrative examples to demonstrate how this framework offers practical guidance for research, policy-making, and clinical practice.

Advancements in diagnosing oral potentially malignant disorders: leveraging Vision transformers for multi-class detection

OBJECTIVES

Diagnosing oral potentially malignant disorders (OPMD) is critical to prevent oral cancer. This study aims to automatically detect and classify the most common pre-malignant oral lesions, such as leukoplakia and oral lichen planus (OLP), and distinguish them from oral squamous cell carcinomas (OSCC) and healthy oral mucosa on clinical photographs using vision transformers.

METHODS

4,161 photographs of healthy mucosa, leukoplakia, OLP, and OSCC were included. Findings were annotated pixel-wise and reviewed by three clinicians. The photographs were divided into 3,337 for training and validation and 824 for testing. The training and validation images were further divided into five folds with stratification. A Mask R-CNN with a Swin Transformer was trained five times with cross-validation, and the held-out test split was used to evaluate the model performance. The precision, F1-score, sensitivity, specificity, and accuracy were calculated. The area under the receiver operating characteristics curve (AUC) and the confusion matrix of the most effective model were presented.

RESULTS

The detection of OSCC with the employed model yielded an F1 of 0.852 and AUC of 0.974. The detection of OLP had an F1 of 0.825 and AUC of 0.948. For leukoplakia the F1 was 0.796 and the AUC was 0.938.

CONCLUSIONS

OSCC were effectively detected with the employed model, whereas the detection of OLP and leukoplakia was moderately effective.

CLINICAL RELEVANCE

Oral cancer is often detected in advanced stages. The demonstrated technology may support the detection and observation of OPMD to lower the disease burden and identify malignant oral cavity lesions earlier.

Precursor Lesions, Overdiagnosis, and Oral Cancer: A Critical Review

Despite the profession placing great emphasis on oral potentially malignant disorders (OPMDs) as a gateway for early recognition and consequently better outcomes for oral cancer, the death rates for lip and oral cavity cancer have remained stagnant for three decades. Evidence shows that only a small fraction of oral cancers are in fact preceded by OPMDs, and that most OPMDs have an annual transformation rate of less than 1%. As OPMDs encompass a very heterogeneous group of oral conditions, it could be argued that only patients with oral mucosal diseases bearing a substantial risk of malignant transformation warrant close surveillance and treatment, these include proliferative leukoplakia, erythroplakia, non-homogeneous leukoplakia, as well as diseases presenting with severe dysplasia at biopsy. In this narrative review, I discuss the intricate epidemiology of the malignancies that we colloquially refer to as oral cancer, explore the limitations of focusing on OPMDs to reduce the incidence and mortality of oral cavity cancer, and argue that a may-be cancer label represents overdiagnosis for most OPMDs.

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.

Controversies in verruco papillary lesions of the oral cavity-A systematic review

INTRODUCTION

Verruco papillary lesions (VPL) in the oral cavity encompass a spectrum of lesions starting from benign, potentially malignant to entirely malignant tumors. Much of the controversies in these entities occur due to lack of consensus on the disease characteristics and the management. This systematic review was conducted to identify and describe different lesions categorized as VPL in the oral cavity and their association with malignancy.

METHODS

An electronic literature search was conducted in MEDLINE (via PubMed), Scopus, LILAC, IMSEAR, and CENTRAL databases, which retrieved a total of 1020 abstracts. These abstracts were managed through Rayyan and Mendeley software, and only 28 studies with high quality were included in the systematic review.

RESULTS

Studies were published from 1992 to 2021. From the extracted data, nine different entities under the umbrella term VPL were identified associated with malignancy. We describe the clinical and histopathological characteristics of these and propose a uniform framework for nomenclature.

CONCLUSIONS

Lack of well-planned research with adequate follow-up duration and inadequate quality standards are major barriers for the lack of evidence. The use of uniform nomenclature, as proposed in this study, and research at the molecular level will greatly reduce the controversies in understanding oral VPL associated with malignancy.

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

The Way to Malignant Transformation: Can Epigenetic Alterations Be Used to Diagnose Early-Stage Head and Neck Cancer?

Identifying and treating tumors early is the key to secondary prevention in cancer control. At present, prevention of oral cancer is still challenging because the molecular drivers responsible for malignant transformation of the 11 clinically defined oral potentially malignant disorders are still unknown. In this review, we focused on studies that elucidate the epigenetic alterations demarcating malignant and nonmalignant epigenomes and prioritized findings from clinical samples. Head and neck included, the genomes of many cancer types are largely hypomethylated and accompanied by focal hypermethylation on certain specific regions. We revisited prior studies that demonstrated that sufficient uptake of folate, the primary dietary methyl donor, is associated with oral cancer reduction. As epigenetically driven phenotypic plasticity, a newly recognized hallmark of cancer, has been linked to tumor initiation, cell fate determination, and drug resistance, we discussed prior findings that might be associated with this hallmark, including gene clusters (11q13.3, 19q13.43, 20q11.2, 22q11-13) with great potential for oral cancer biomarkers, and successful examples in screening early-stage nasopharyngeal carcinoma. Although one-size-fits-all approaches have been shown to be ineffective in most cancer therapies, the rapid development of epigenome sequencing methods raises the possibility that this nonmutagenic approach may be an exception. Only time will tell.

Oral Submucous Fibrosis: Etiological Mechanism, Malignant Transformation, Therapeutic Approaches and Targets

Oral submucosal fibrosis (OSF) is a chronic, progressive and potentially malignant oral disorder with a high regional incidence and malignant rate. With the development of the disease, the normal oral function and social life of patients are seriously affected. This review mainly introduces the various pathogenic factors and mechanisms of OSF, the mechanism of malignant transformation into oral squamous cell carcinoma (OSCC), and the existing treatment methods and new therapeutic targets and drugs. This paper summarizes the key molecules in the pathogenic and malignant mechanism of OSF, the miRNAs and lncRNAs with abnormal changes, and the natural compounds with therapeutic effects, which provides new molecular targets and further research directions for the prevention and treatment of OSF.

IMPACT OF E-CIGARETTES ON THE ORAL HEALTH - LITERATURE REVIEW

E-cigarettes are electronic devices used to inhale aerosols generated from the vaporization of flavored liquids. Nowadays, the use of e-cigarettes has become one of the most popular alternatives to traditional smoking. The wide variety of devices and liquids makes it challenging to assess the health effects of using e-cigarettes. During the vaporization of e-liquids, toxins, carcinogens, and various other chemicals can be released and inhaled by the user. Limited data exist regarding the potential health impact of exposure to e-vapors, primarily derived from animal studies and in vitro research. The oral tissues are the first site of direct interaction with the components of the inhaled vapor. While e-cigarettes are commonly portrayed as safer alternatives to tobacco cigarettes, little is known about the short- or long-term health effects of their use. The aim of this review is to briefly present the available data regarding the impact of chemical ingredients and toxins present in e-cigarette vapors on oral cavity cells.

Evaluation of Nationwide Oral Mucosal Screening Program for Oral Cancer Mortality among Men in Taiwan

The nationwide oral cancer screening program was launched for high-risk people (tobacco smokers or betel-nut chewers) in 1999 in Taiwan, but no study has taken the prevalence of tobacco smoking and betel-nut chewing into account for evaluating the impact of the screening program on oral cancer mortality. This study incorporated the risk fraction method with interrupted time-series analysis to evaluate the impact of the nationwide oral mucosal screening program among men in Taiwan. This study estimated the expected oral cancer mortality trend if the screening program had not launched in 1999, which revealed that the increasing oral cancer mortality trend would level off after 2009 due to the declining prevalence of tobacco smoking and betel-nut chewing. In 2000-2007, the percentage changes between the observed (implementation of the screening program) and expected (if the screening program had not launched) oral cancer mortality rate was not statistically significant for each age group. In 2008-2020, the significant percentage changes were -178% (99% CIs: -140.8 to -215.2), -75.4% (-59.4 to -91.4), -33.7% (-24.7 to -42.7), -18.8% (-12.0 to -25.6), and -15.3% (-9.5 to -21.2) for age groups of 30-34, 35-39, 40-44, 45-49, and 50-54, respectively. In addition to its influence on tobacco smoking and betel-nut chewing, the oral mucosal screening program was associated with the reduction of oral cancer mortality among men in Taiwan.

Chronic mechanical irritation enhances the effect of tobacco and alcohol on the risk of oral squamous cell carcinoma: a case-control study in Argentina

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a multifactorial disease. The individual effect of each risk factor for OSCC may be conditioned by the frequency of other factors. The objective of this study was to identify the association between chronic mechanical irritation (CMI) and OSCC and to analyse the influence of CMI on other important risk factors for OSCC.

MATERIALS AND METHODS

A prospective and age/sex-matched case-control study was performed in two institutions from Argentina between 2009 and 2019, with consecutive and newly diagnosed OSCC. The frequencies of tobacco, alcohol, and CMI were analysed using conditional logistic regression. Cumulative tobacco consumption and the presence of CMI were analysed using the Mann-Whitney test.

RESULTS

CMI and OSCC were associated with an OR of 7.02 (95% CI 3.57-13.78, p < 0.001). The combination of CMI and alcohol demonstrated the highest risk of OSCC (OR 53.83, CI 95% 8.04-360, p < 0.0001), followed by the combination of CMI, tobacco, and alcohol (OR 48.06, CI 95% 8.47-272, p < 0.0001). The combination of CMI and tobacco was also significant (OR 5.61, CI 95% 1.07-29.54, p = 0.042). Patients with CMI developed OSCC with less cumulative tobacco use compared with those without CMI.

CONCLUSION

CMI is an independent risk factor for OSCC, and it could act as a risk modifier among tobacco and alcohol users having an enhancing effect.

CLINICAL RELEVANCE

Elimination of CMI could decrease the risk of OSCC.

Oral potentially malignant disorder research in Taiwan and mainland China: A scientometric analysis

Scientometric analysis of a disease is often conducted to recognize research trends and study hotspots. In this report, we analyze the scientometric characteristics of oral potentially malignant disorder (OPMD) research in Taiwan and mainland China. There are 324 and 718 articles on OPMD research originating from Taiwan and Mainland between 2006 and 2021, respectively. The most common subtype of OPMD research in Taiwan and Mainland is oral submucous fibrosis and lichen planus, respectively. Based on the list of main keywords extracted from the included articles, areca/betel quid chewing and alcohol use are the distinctive risk factors in Taiwan. Research on cancer screening, fibroblast/myofibroblast, and smooth muscle actin α are distinctive keywords in Taiwan; whereas the research on apoptosis, cytokine, and inflammation are distinctive keywords in Mainland. The distinctive characteristics of OPMD research are analyzed between Taiwan and mainland China, which may reflect the importance and concerned topics of research.

Relationship Between Dietary Fiber and Vitamin C Intake and Oral Cancer

BACKGROUND

Dietary fiber and vitamin C has been reported to play a possible role in tumorigenesis. However, few studies have estimated their association with oral cancer risk. In this project, we investigated the relationship between dietary fiber and vitamin C and oral cancer risk in adults in Southern China.

METHODS

382 patients newly diagnosed with oral cancer were matched to 382 hospital derived controls by frequency matching in age and sex. Pre-diagnostic consumption of dietary fiber and vitamin C intake were measured through food frequency questionnaire. Association between nutrients intake and oral cancer risk were evaluated by logistic regression. OR value and 95% confidence interval was calculated.

RESULTS

Intake of dietary fiber and vitamin C was significantly lower in oral cancer patients (8.15 g/day) than in control participants (8.88 g/day). Increased dietary fiber or vitamin C intake was linked to a decreased incidence of OC after adjustment of age, marital status, residence, BMI, occupation, education, tobacco smoking, alcohol consumption and family history of cancer Ptrend < 0.001). Compared with the lowest tertile, the adjusted OR of the top tertile of dietary fiber was 0.47 (95 % CI 0.32, 0.68). While the adjusted OR of the highest tertile was 0.60 (95 % CI 0.42, 0.87) compared with the lowest tertile of vitamin C.

CONCLUSIONS

Dietary intake of fiber and vitamin C were lower in oral cancer patients than in control participants. Dietary fiber and vitamin C were inversely related to risk of oral cancer risk.

Are There Betel Quid Mixtures Less Harmful than Others? A Scoping Review of the Association between Different Betel Quid Ingredients and the Risk of Oral Submucous Fibrosis

Oral submucous fibrosis (OSF) is a potentially malignant condition of the oral cavity characterized by progressive fibrosis of the submucosal tissues. OSF is typically associated with the use of betel quid (BQ), a chewing package made of natural products (e.g., areca nut, betel leaves), with or without smokeless tobacco. BQ ingredients contain pro-carcinogenic bioactive compounds, but also potentially protective biomolecules, and we have shown recently that the chemical properties of different BQ recipes vary, which may explain the unequal prevalence of OSF and oral cancer in BQ users in different geographical regions. Hence, this scoping review was aimed at evaluating the existing literature regarding different BQ compounds and their association with OSF. The repository of the National Library of Medicine (MEDLINE/PubMed), medRxiv databases, Google scholar, Baidu scholar, CNKI, and EBSCO were used to search for publications that investigated the association between BQ chewing and OSF up to November 2021. The search terminology was constructed using the keywords "betel quid" and "oral submucous fibrosis", and their associated terms, with the use of Boolean operators. The search was conducted under Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, together with clear inclusion and exclusion criteria. The review showed that the risk of developing OSF varied between different BQ recipes, and that chewing BQ mixtures containing betel inflorescence (BI) significantly increased the risk of OSF, as did the addition of tobacco. Conversely, the use of betel leaf in the mixture was likely to be protective, which may be due to the presence of polyphenols. Although further research is needed to determine the effect of individual BQ ingredients in the development of OSF, our pilot results provide the scope and rationale for informing future chemopreventive strategies for OSF and oral cancer in BQ chewers.

Critical update, systematic review, and meta-analysis of oral erythroplakia as an oral potentially malignant disorder

Background

Oral erythroplakia has been classically considered as the potentially malignant disorder with the highest rate of malignant development into squamous cell carcinoma. This critical systematic review and meta‐analysis aim to estimate the malignant development rate of oral erythroplakia and identify the associated risk factors.

Methods

We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and LILACS, with keywords “erythroplakia,” “erythroplasia,” “malignant transformation,” “malignant development,” “malignization,” “carcinogenesis,” “oral cancer,” “oral squamous cell carcinoma,” “mouth neoplasm,” and “prognosis.” Meta‐analysis was conducted using a random‐effects model.

Results

Ten observational studies with 441 patients met the inclusion criteria, whose mean malignant development rate was 12.7% and with a mean follow‐up period of patients of 6.66 years. In the initial biopsy, 42.8% of oral erythroplakia were already squamous cell carcinoma. The buccal mucosa was the most frequent location of oral erythroplakia, but the floor of the mouth was the most common site of malignant development. All patients who underwent malignant development showed epithelial dysplasia on the initial diagnostic biopsy.

Conclusion

Overall malignant development rate of OE in the meta‐analysis was 19.9%. We could not associate any specific clinicopathological feature with the malignant development. The presence of epithelial dysplasia in the initial biopsy remains the worst prognostic factor. Further observational studies on OE are needed, with well‐established diagnostic criteria and good clinical follow‐up, in order to identify the true risk of malignant development of oral erythroplakia and the related risk factors.

Malignant Transformation Rate of Oral Submucous Fibrosis: A Systematic Review and Meta-Analysis

Oral submucous fibrosis (OSF) is a chronic progressive condition affecting the oral cavity, oropharynx and upper third of the oesophagus. It is a potentially malignant disorder. The authors collated and analysed the existing literature to establish the overall malignant transformation rate (MTR). A retrospective analysis of medical and dental scientific literature using online indexed databases was conducted for the period 1956 to 2021. The quality of the enrolled studies was assessed by the Newcastle-Ottawa Scale (NOS). A meta-analysis using a random effects model of a single proportion was performed along with statistical tests for heterogeneity. The overall proportion of malignancy across all studies was 0.06 (95% CI, 0.02–0.10), indicating an overall 6% risk of malignant transformation across all studies and cohorts. Sub-group analyses revealed strong differences in proportion of malignancy according to ethnicity/cohort; Chinese = 0.02 (95% CI 0.01–0.02), Taiwanese = 0.06 (95% CI, 0.03–0.10), Indian = 0.08 (95% CI, 0.03–0.14) and Pakistani = 0.27 (95% CI 0.25–0.29). Overall, the MTR was 6%; however, wide heterogeneity of the included studies was noted. Geographic variations in MTR were noted but were not statistically significant. Further studies are required to analyse the difference between cohort groups.

Management of oral leukoplakia by ablative fractional laser‐assisted photodynamic therapy: A 3‐year retrospective study of 48 patients

Objectives

This study aimed to review the results of oral leucoplakia (OL) using ablative fractional laser‐assisted photodynamic therapy (AFL‐PDT) and to further evaluate the risk factors for recurrence and malignant transformation.

Materials and Methods

Forty‐eight patients diagnosed with OL using histopathology were enrolled in this study. All patients received one session of AFL‐PDT. Therapeutic efficacy was evaluated 1 month posttreatment. Follow‐up was scheduled every 3 months in the first year and every 6 months thereafter.

Results

An overall positive response rate of 87.5% (42/48) was achieved, including 62.5% (30/48) complete responses and 25.0% (12/48) partial responses. During the 3‐year follow‐up period, the recurrence and malignant transformation rates were 37.5% (18/48) and 8.3% (4/48), respectively. Lesions on gingiva/palate seemed to be associated with recurrence (p < 0.001; odds ratio [OR]: 1.64, 95% confidence interval [CI]: 1.13–2.37). The severity of epithelial dysplasia (p = 0.02; OR: 2.93, 95% CI: 1.96–4.42) and recurrence (p = 0.016; OR: 3.14, 95% CI: 2.04–4.84) were associated with a predisposition to malignant transformation.

Conclusions

AFL‐PDT is an effective management of OL, but requires close follow‐up. OL lesions on the gingiva/palate are predisposed to recurrence. OLs that recur with moderate/severe epithelial dysplasia have a higher risk of transforming into oral squamous cell carcinoma.

Molecular Mechanisms of Malignant Transformation of Oral Submucous Fibrosis by Different Betel Quid Constituents-Does Fibroblast Senescence Play a Role?

Betel quid (BQ) is a package of mixed constituents that is chewed by more than 600 million people worldwide, particularly in Asia. The formulation of BQ depends on a variety of factors but typically includes areca nut, betel leaf, and slaked lime and may or may not contain tobacco. BQ chewing is strongly associated with the development of potentially malignant and malignant diseases of the mouth such as oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC), respectively. We have shown recently that the constituents of BQ vary geographically and that the capacity to induce disease reflects the distinct chemical composition of the BQ. In this review, we examined the diverse chemical constituents of BQ and their putative role in oral carcinogenesis. Four major areca alkaloids—arecoline, arecaidine, guvacoline and guvacine—together with the polyphenols, were identified as being potentially involved in oral carcinogenesis. Further, we propose that fibroblast senescence, which is induced by certain BQ components, may be a key driver of tumour progression in OSMF and OSCC. Our study emphasizes that the characterization of the detrimental or protective effects of specific BQ ingredients may facilitate the development of targeted BQ formulations to prevent and/or treat potentially malignant oral disorders and oral cancer in BQ users.

Clinical and Histologic Features Associated With Malignant Transformation of Oral Cavity Dysplasia Managed at a Single North American Institution

Importance

Reports characterizing clinical and histologic features associated with a higher risk for development of malignant lesions in the background of an oral potentially malignant disorder have largely reflected East Asian populations. Long-term studies among the North American population are rare.

Objective

To evaluate risk of malignant transformation (MT) of oral dysplastic lesions by investigating the demographic, social, clinical, and histologic factors that may be associated with an increased rate as well as a decreased time to MT.

Design, Setting, and Participants

This was a retrospective cohort study with medical record review at a single institution from January 1, 2000, to December 31, 2019, with follow-up for 20 years. Patients were excluded if they were younger than 18 years, the first biopsy diagnosis showed cancer, biopsies were never performed, biopsies were taken from sites outside of the oral cavity, there was no additional follow-up after the first visit, or the biopsy specimen was not characterized on the spectrum of dysplasia.

Exposures

Diagnosis of leukoplakia of oral mucosa, unspecified lesions of oral mucosa, or other disturbances of oral epithelium.

Main Outcomes and Measures

Main outcome measures included MT rate and time to MT as well as demographic, social, clinical, physical, and histologic features associated with MT.

Results

Thirty-eight of 264 lesions (14%) in 241 patients (132 men and 109 women; mean [SD] age, 64 [13] years) underwent MT. Of the 38 lesions that underwent MT, 19 (50%) underwent transformation by 424 days, 28 (75%) by 870 days, and 34 (90%) by 1600 days. Nodularity, friability, and mass effect were more commonly observed in malignant lesions (nodularity: 42.9% vs 10.0%; difference, 32.9%; OR, 6.72; 95% CI, 3.03-14.89; friability: 42.9% vs 12.8%; difference, 30.1%; OR, 5.11; 95% CI, 1.66-15.69; mass effect: 54.2% vs 10.4%; difference, 43.8%; OR, 10.16; 95% CI, 4.12-25.09). Men were less likely than women to have multiple lesions in the oral cavity (OR, 0.40; 95% CI, 0.22-0.74). Having multiple abnormal sites was associated with higher percentage of MT (OR, 3.38; 95% CI, 1.63-7.01).

Conclusions and Relevance

In this cohort study, nodularity and mass effect were associated with lesions that may push, displace, or invade surrounding tissue, and these were more likely to be present in oral dysplastic lesions that ultimately progressed to cancer. There may be less utility in continuing surveillance beyond 5 years.

The prevalence of oral squamous cell carcinoma with oral submucous fibrosis

Objective

The objective of the study was to find out the prevalence of oral squamous cell carcinoma (OSCC) with oral submucous fibrosis (OSF) in patients with OSF.

Materials and Methods

Of 48,757 patients, we found 300 OSF subjects. Three hundred patients of OSF were checked for OSCC. Both OSF and OSCC with OSF (OSCCwOSF) were diagnosed histopathologically. The prevalence of OSCCwOSF was calculated. Descriptive analysis was done. Chi-square test and t-test were calculated for proportions and mean, respectively, to check any difference among OSF and OSCCwOSF groups. Age-specific relative risk was calculated in OSF and OSCCwOSF groups. Multiple logistic regression analysis was done among odd ratios of the different variable between OSF and OSCCwOSF groups.

Results

The prevalence of OSCCwOSF among OSF was 13.7% over a period of 1 year. The mean age of OSCCwOSF group was 43.95 ± 10.22 years in comparison to the OSF group that was 35.51 ± 11.26 years (P < 0.00). The mean habit duration was significantly less in the OSF group when compared to OSCCwOSFgroup for mishri (P = 0.002). Age-specific adjusted relative risk of OSCC in OSF patient increases from 0.33 (18-34 years) to 3.86 (≥65 years).

Conclusion

It could be concluded that a 13.7% prevalence rate of OSCCwOSF in OSF patients should alert the clinician. Clinicians should, therefore, anticipate OSSC in OSF patients. This awareness could lead to the early diagnosis and management of such OSCC.

Development and validation of a nomogram prediction model for malignant transformation of oral potentially malignant disorders

OBJECTIVE

Oral potentially malignant disorders have increased the risk of oral squamous cell carcinoma. This study developed a nomogram model to assess the risks of malignant transformation of oral potentially malignant disorders.

MATERIALS AND METHODS

A retrospective analysis of patients diagnosed with oral potentially malignant disorders confirmed by pre-treatment biopsy was performed between 2010 and 2017 at the Peking University Hospital of Stomatology. The candidate risk factors for malignant transformation were screened from clinicopathological variables using Cox and stepwise regression analyses. The nomogram model was constructed based on the regression results and was validated through receiver operating characteristic curves and calibration curves. Decision curve analysis was used to estimate clinical usefulness.

RESULTS

A total of 6964 cases of oral potentially malignant disorders were assessed. The malignant transformation rate of oral potentially malignant disorders was 2.00%. Risk factors (age, site, kind of oral potentially malignant disorder, existence of dysplasia and its grade, and other cancers) derived from the regression analyses were entered into the nomogram model. Time-dependent receiver operating characteristic curve, calibration curve, and decision curve analyses showed high levels of predictive value and clinical relevance, although not for all oral potentially malignant disorders.

CONCLUSION

A specific dynamic nomogram could be adopted to predict the malignant transformation of oral potentially malignant disorders and implement interventions.

Ablative fractional laser-assisted photodynamic therapy vs. ablative fractional laser for oral leukoplakia treatment: A randomized, controlled pilot study

BACKGROUND

Ablative fractional laser-assisted photodynamic therapy (AFL-PDT) is explored as an effective method in some premalignant diseases, whereas the effect of AFL-PDT on oral leukoplakia (OL), the best-known precursor of oral squamous cell carcinoma, remains undetermined.

METHODS

Forty-eight patients, histologically diagnosed with OL, were randomized (1:1) to receive either AFL-PDT or ablative fractional laser (AFL) treatment. All patients were followed up at 1, 3, 6 and 12 months postoperatively. The primary endpoints of efficacy and clinical recurrence and the secondary endpoint of side effects were assessed.

RESULTS

Forty-four patients completed the study. The 100% effective cure rate in the AFL-PDT group was higher than that in AFL group (80.9%, P<0.05) with 19.1% difference (95%CI: 0.7-40.0%). Compared to AFL group, recurrence observed at 6 and 12 months post-treatment tended to occur in fewer patients in the AFL-PDT group (P<0.05). No severe adverse events or systemic side effects were observed in either group.

CONCLUSIONS

AFL-PDT may effectively reduce recurrence of OL with high clinical efficacy and good tolerability, suggesting it may be a promising treatment for OL.

LINC00084/miR-204/ZEB1 Axis Mediates Myofibroblastic Differentiation Activity in Fibrotic Buccal Mucosa Fibroblasts: Therapeutic Target for Oral Submucous Fibrosis

Oral submucosal fibrosis (OSF) is a precancerous condition in the oral cavity and areca nut consumption has been regarded as one of the etiologic factors implicated in the development of OSF via persistent activation of buccal mucosal fibroblasts (BMFs). It has been previously reported that an epithelial to mesenchymal transition (EMT) factor, ZEB1, mediated the areca nut-associated myofibroblast transdifferentiation. In the current study, we aimed to elucidate how areca nut affected non-coding RNAs and the subsequent myofibroblast activation via ZEB1. We found that long non-coding RNA LINC00084 was elicited in the BMFs treated with arecoline, a major alkaloid of areca nut, and silencing LINC00084 prevented the arecoline-induced activities (such as collagen gel contraction, migration, and wound healing capacities). The upregulation of LINC00084 was also observed in the OSF tissues and fibrotic BMFs (fBMFs), and positively correlated with several fibrosis factors. Moreover, we showed knockdown of LINC00084 markedly suppressed the myofibroblast features in fBMFs, including myofibroblast phenotypes and marker expression. The results from the luciferase reporter assay confirmed that LINC00084 acted as a sponge of miR-204 and miR-204 inhibited ZEB1 by directly interacting with it. Altogether, these findings suggested that the constant irritation of arecoline may result in upregulation of LINC00084 in BMFs, which increased the ZEB1 expression by sequestering miR-204 to induce myofibroblast transdifferentiation.

Depletion of miR-155 hinders the myofibroblast activities and reactive oxygen species generation in oral submucous fibrosis

BACKGROUND/PURPOSE

Emerging evidence suggests the significance of microRNA-155 (miR-155) in fibrogenesis and oxidative stress accumulation, but its function in oral submucous fibrosis (OSF) has not been investigated. In this study, we assessed the expression of miR-155 and its effects on the maintenance of myofibroblast activation.

METHODS

qRT-PCR was conducted to assess the expression of miR-155 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF samples. Collagen gel contraction, migration, and invasion capabilities were examined in fBMFs. DCFDA ROS assay was used to examine ROS generation. A luciferase reporter assay was carried out to verify the relationship between miR-155 and its potential target RPTOR.

RESULTS

We showed that the expression of miR-155 was aberrantly upregulated in OSF specimens and fBMFs. Inhibition of miR-155 ameliorated various myofibroblast activities, including collagen gel contraction, migration, and invasion abilities as well as ROS production. Results from the luciferase reporter assay demonstrated that miR-155 directly interacted with its target RPTOR.

CONCLUSION

Taken together, these findings indicate that miR-155 is implicated in the pathogenesis of oxidative stress-associated OSF, possibly through the regulation of RPTOR.

Gingival Leukoplakia: Hyperkeratosis with Epithelial Atrophy Is A Frequent Histopathologic Finding

White lesions on the gingiva and palatal mucosa may represent reactive keratoses, including specific diseases such as benign alveolar ridge keratosis, or nonreactive keratoses, such as true leukoplakia, the latter being associated with a high recurrence rate at this site. The aim of this study is to determine the histopathologic features of gingival keratoses. Hyperkeratotic lesions from the gingiva, palatal mucosa, and alveolar ridge mucosa were available for evaluation after excluding specific keratotic lesions such as candidiasis. There were 321 biopsies from 296 patients and approximately half of the cases (159/321, 49.5%) were reactive keratoses. The rest of the 162 biopsies from 149 patients (76 females; 51.0%) represented true leukoaplakias. The most common location was the gingiva (73.2%) followed by the palatal mucosa (17.0%). Hyperkeratosis/parakeratosis not reactive (HkNR) represented 43.8% of cases; 45.7% were dysplasia or carcinoma, and the rest were not readily classifiable as reactive or non-reactive keratoses. Histopathologic features commonly noted in the HkNR lesions include sharp demarcation (72.7%), corrugated surface (53.5%), and epithelial atrophy (48.1%). A lymphocytic band was noted in 8.5% of the cases, mostly associated with epithelial atrophy (5/6 cases). Seven patients with 17 biopsies from noncontiguous sites likely had proliferative leukoplakia; the most common location was the gingiva (88.2%) and the most common diagnosis was HkNR (52.9%). HkNR is a common histopathologic diagnosis for leukoplakias on the gingiva, and these lesions frequently exhibit thick hyperkeratosis, epithelial atrophy and a lymphocytic band at the interface.

Lichenoid dysplasia is not a distinct pathological entity

OBJECTIVES

Oral Lichenoid Dysplasia (OLD) is a controversial histological term applied to lesions that display features of oral lichen planus (OLP) and oral epithelial dysplasia (OED). In this study we investigated the molecular profiles of OLD, OLP and OED to determine whether OLD exists as a distinct pathological entity.

MATERIALS AND METHODS

Samples from patients presenting with lesions diagnosed histologically as OLP, OLD or OED underwent RNA sequencing followed by differential gene expression, functional enrichment and network analysis, sparse partial least squares discriminant analysis, and immune cell phenotypic estimation.

RESULTS

Unsupervised clustering demonstrated a group of genes with high expression in OLP and OLD, and low expression in OED, predominantly involved in inflammatory processes. Many genes were significantly differentially expressed between either OLD or OLP and OED, but few between OLD and OLP. Functional enrichment showed significant pathways and ontologies related to inflammatory signalling and immune response between OLD or OLP and OED. Broad commonality was found between OLP and OLD in upregulation of specific immune system pathways. Classifying models discriminated histologically diagnosed OLD from OED based upon molecular data alone. Bioinformatic profiling showed that immune cell populations in OLP and OLD were consistent, and distinct from OED.

CONCLUSION

Molecular data shows that OLD is not a distinct pathological entity. Its transcriptomic and immunophenotypic profile is similar to OLP and distinct from OED. We recommend that oral lichenoid dysplasia not be used as a distinct pathological entity. Our data further supports exclusion of dysplasia in diagnosis of OLP.

Architectural Alterations in Oral Epithelial Dysplasia are Similar in Unifocal and Proliferative Leukoplakia

The current WHO histopathologic criteria for oral epithelial dysplasia (ED) are based on architectural and cytologic alterations, and do not address other histopathologic features of ED. Here we propose new diagnostic criteria including architectural, organizational, and cytologic features for oral ED. Cases of unifocal leukoplakia (UL) and proliferative leukoplakia (PL) with clinical photographs and follow-up information were identified. Only cases that showed minimal cytologic atypia or mild ED were used to demonstrate critical architectural changes as defined in this study. Eight biopsies from eight UL patients and 34 biopsies from four PL patients were included. The biopsies showed (a) corrugated, verrucous or papillary architecture, (b) hyperkeratosis with epithelial atrophy, (c) bulky squamous epithelial proliferation, and (d) demarcated hyperkeratosis and "skip" segments. The architectural alterations defined here are as important as the currently used criteria for the diagnosis of ED. Clinicopathologic correlation when diagnosing oral ED is also of the utmost importance in accurate diagnosis.

Profiling risk factors of micro-invasive carcinoma within oral potentially malignant disorders: a cross-sectional study

OBJECTIVES

To investigate the clinicopathological profile and risk factors of micro-invasive carcinoma within oral potentially malignant disorders (OPMD).

METHODS

Micro-invasive carcinomas were identified in a large prospective series of OPMD patients (n = 810) from eastern China. Logistic regression was applied to evaluate odds ratios (OR) with 95% confidence interval (CI) for indicative of malignant risk in general OPMD.

RESULTS

Leukoplakia (41.4%), lichen planus (28.0%), and lichenoid lesion (23.7%) were the most 3 clinical subtypes of OPMD. A total of 62 (7.7%) micro-invasive carcinomas within OPMD were identified, and 96.8% of micro-invasive carcinoma was found within leukoplakia and erythroplakia. Multivariate regression analysis revealed that the risk of malignant change within OPMD located on lateral/ventral tongue (OR, 15.1; 95% CI, 1.85-122.8; P = 0.011) was higher than other sites. The risk of malignant change within non-homogenous type (OR, 103.3; 95% CI, 13.39-796.7; P < 0.001) was strikingly higher than other subtypes of OPMD, respectively. Intriguingly, the risk of micro-invasive carcinoma diagnosed in current smoker (OR, 3.96; 95% CI, 1.31-12.02; P = 0.015) was higher than non-smoker.

CONCLUSION

This large-scale cross-sectional study elucidated the clinical factors and risk assessment of micro-invasive carcinoma within OPMD.

CLINICAL RELEVANCE

Non-homogenous lesions located on lateral/ventral tongue might be monitored at closer intervals, and the need for rigorous management to detect malignant changes.

miR-10b regulated by Twist maintains myofibroblasts activities in oral submucous fibrosis

BACKGROUND/PURPOSE

Oral submucous fibrosis (OSF) is an oral precancerous disorder associated with the habit of areca nut chewing. MiR-10b has been shown to be upregulated in the oral cancer cells and induced by Twist. Our previous work has revealed that Twist participated in the pathogenesis of OSF and therefore we aimed to investigate whether Twist/miR-10b axis was involved in the activation of myofibroblast in the oral cavity.

METHODS

The expression levels of miR-10b in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) were examined. Besides, the expression of miR-10b was determined in fBMFs following knockdown of Twist or in BMFs after arecoline stimulation. Myofibroblast activities, including collagen gel contraction, migration and wound healing abilities, as well as the expression of α-SMA were measured in fBMFs treated with miR-10b inhibitor. Last, we investigated whether the effect of Twist overexpression could be reversed by suppression of miR-10b.

RESULTS

MiR-10b expression was overexpressed in both OSF tissues and fBMFs. The silence of Twist resulted in the downregulation of miR-10b in fBMFs and arecoline treatment led to an increase of miR-10b in a dose-dependent manner. Inhibition of miR-10b ameliorated the activation of myofibroblasts and the expression of α-SMA. Moreover, we demonstrated that suppression of miR-10b hindered the increased collagen gel contraction caused by Twist overexpression.

CONCLUSION

MiR-10b upregulation in OSF may be due to the stimulation of areca nut, leading to elevated myofibroblast activation. Our findings showed that the areca nut-induced expression of miR-10b was under the regulation of Twist and inhibition of miR-10b may provide a direction for treatment of OSF.

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.

Orabase-Formulated Benzalkonium Chloride Effectively Suppressed Oral Potentially Malignant Disorder In Vitro and In Vivo

Oral potentially malignant disorder (OPMD) is associated with an increased risk of progression to oral cancer. Patients with dysplastic changes of the precancerous lesions have a higher malignant transformation rate than those without dysplastic changes. Radiotherapy and surgery are the traditionally preferred choices for OPMD treatment. However, side effects caused by radiotherapy and surgery may reduce the willingness of patients to accept therapy. Therefore, developing an Orabase-formulated drug, which can be non-invasively administered, may provide an alternative treatment choice. To find, verify, and develop a new anti-cancer drug cost a lot of time and money, while drug repurposing can shorten both time and cost. In this study, we utilized high-throughput screening library to identify clinical drugs, which may have new bioactivities. Herein, we report that benzalkonium chloride (BAK), an antimicrobial preservative for pharmaceutical products, significantly induced reactive oxygen species production and cell death in oral precancerous cells. Additionally, our results showed that phosphorylation of STAT3 (Tyr705) and Akt (Ser473) were involved in cell death caused by BAK in DOK cells. According to animal studies, the development of DMBA-induced oral precancerous lesions was inhibited by 2% BAK. In conclusion, Orabase-formulated BAK may be a potential treatment for OPMD in the future.

Clincopathological characteristics and treatment outcomes of oral leukoplakia by carbon dioxide laser excision in the elderly patients

Background

Older age is one of the factors associated with malignant transformation of oral leukoplakia (OL). The purpose of this study is to analyze the clincopathological features and treatment outcomes of OL in the elderly patients.

Methods

The demographic data and histopathological results of the patients (age ≥ 65) who received carbon dioxide laser surgery for OL from 2002 to 2017 were analyzed statistically.

Results

There were 53 males and 16 females, with a mean age 71.2 ± 4.9. The follow‐up time was 42.5 ± 35.2 months. In the univariate analysis, morphology, pathology, and area were found to be factors associated with postoperative recurrence. Among these factors, pathology and area were the independent predictive factors for recurrence in the multivariate logistic regression model. Malignant transformation occurred in 8 of 69 patients (11.6%).

Conclusions

The pathological high‐risk dysplasia and area of OL were the two prognostic factors for postoperative recurrence.

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.

Orabase-formulated gentian violet effectively improved oral potentially malignant disorder in vitro and in vivo

Oral cancer is a prevalent cancer in male worldwide. Oral potentially malignant disorders (OMPDs) are the oral mucosa lesions that have high malignant transformation rate to oral cancer. The mainstay for OMPDs treatment includes carbon dioxide (CO₂) laser and surgery, which may lead to the side effects of scarring and impaired function of oral cavity in the patients and reduced their willingness to receive curative therapy. Therefore, developing a non-invasive and function-preserving therapy is clinically important. Since development of a novel chemotherapeutic drug requires a lot of time and cost, we applied the high-throughput screening (HTS) approach to identify new bioactivities for FDA-approved drugs, known as drug repurposing. Through this drug repurposing approach, we discovered that gentian violet (GV), which is well known for its antibacterial, antifungal, antihelminthic, antitrypanosomal and antiviral activities, was able to induce significant cell death in DOK oral precancerous cells through ROS production. Moreover, decreased phosphorylation of p53(Ser15) and NFκB(Ser536) was required for GV-induced cell death. In vivo, 3% GV orabase effectively suppressed the progression of DMBA-induced oral precancerous lesions. In conclusion, this new formulation of GV through drug repurposing has the potential to be further developed as a therapeutic drug for OPMD clinically.