Malignant transformation of oral leukoplakia: a follow-up study

Malignant transformation rate of oral leukoplakia in the past 20 years: A systematic review and meta-analysis

BACKGROUND

This meta-analysis aimed to assess the rate of malignant transformation (MT) of oral leukoplakia (OL) and to study potential risk factors for the MT of OL into oral squamous cell carcinoma (OSCC).

METHOD

We performed a bibliographic search on nine electronic databases, including PubMed, MEDLINE, and Wanfang Data, for data on the MT rate of OL. Possible risk factors were calculated using Comprehensive Meta-Analysis and Open Meta [Analyst] software.

RESULTS

The pooled proportion of OL MT for the total population described in the 26 selected studies was 7.20% (95% confidence interval: 5.40-9.10%). Nonhomogeneous type lesions, higher grades of dysplasia, the location of the lesion (tongue and multifocal), and female sex had significant effects on the MT of OL.

CONCLUSION

OL tended to develop into OSCC (7.2%), and those with significant MT risk factors should be subjected to regular follow-up and observation. However, we require large-scale prospective studies to validate these results, together with unified clinicopathological diagnostic criteria, standardized risk factor recording/assessment methods, and long-term follow-up guidelines.

Follow-up study of veterans with white and red oral mucosal lesions at Veterans Affairs Dental Clinics

OBJECTIVES

This analysis examined the clinical and histopathological characteristics of white and red oral mucosal lesions and patient lifestyle behaviors to understand how the lesions changed over 19-23 years, including among patients who developed oral and pharyngeal cancer.

MATERIALS AND METHODS

Seventy-five individuals with red and/or white oral mucosal lesions with clinical diagnoses of smokeless tobacco lesions, leukoplakia, erythroplakia, lichen planus, ulcer, and virus-associated lesions were identified in six Veterans Affairs Medical Center Dental Clinics (VAMC) from 1996 to 2001. Biopsy results and patients' sociodemographic, medical, and tobacco/alcohol use characteristics were obtained. Study dentists used standardized forms to capture information about the lesions. Study participants were re-examined at intervals through January 2002. In 2020, a retrospective review of VAMC and public records ascertained whether participants developed oral cancer or died.

RESULTS

The most common red or white oral mucosal lesions among the 75 study participants were leukoplakia (36.0%), smokeless tobacco lesions (26.7%), virus-associated lesions (18.7%), and lichen planus (16.0%). Lesions in 11% of participants with leukoplakia and one-third of participants with lichen planus persisted for 5 years or more. Dysplasia was present in four participants with leukoplakia. Seventeen percent of participants developed a new white or red oral mucosal lesion. Five patients (6.1%) developed oral or pharyngeal cancer, four among participants with leukoplakia (one with prior dysplasia) and one among participants with lichen planus. Four of the cancers developed 6-20 years after enrollment, and only one was at the original lesion site.

CONCLUSIONS

The occurrence of oral and pharyngeal cancers in some study participants with white and red oral mucosal lesions many years after enrollment reinforces the need for patients, dentists, and health care systems to have better methods to identify and assess the malignant potential of oral lesions, monitor patients over time, and intercept high-risk oral lesions before they become cancerous.

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.

Occurrence of field cancerization in clinically normal oral mucosa: A systematic review and meta-analysis

OBJECTIVE

The purpose was to describe whether there are field cancerization (FC) indicators in clinically normal mucosa opposite to primary oral squamous cell carcinoma (OSCC).

METHODS

A search of the Cochrane Library, PubMed, Embase, Web of Science, Scopus, and Livivo databases was performed on June 12, 2022, which retrieved 152 records without duplicates. Studies that analyzed FC in biopsies in clinically normal tissue opposite to primary OSCC were included. The search was conducted under the PRISMA guideline and the protocol was registered in PROSPERO (CRD42017077125).

RESULTS

Eight articles with 302 patients were included, 192 men and 110 women, mean age 57.1 years. Most patients had deleterious habits. All studies performed histopathological confirmation of OSCC and biopsies were obtained the clinically normal mirror mucosa. The meta-analysis carried out with eight studies. The studies showed 57.3 % of cases with histopathological changes of clinically normal mucosa opposite to primary OSCC (Confidence interval 95 %, 0.443-0.703; heterogeneity: Q value 18.715; I² 73.284 %; n = 205). p53 and Ki-67 immunohistochemical analysis may be predictive for detecting changes. There was p53 immunoexpression in 41.3 % of cases (p = 0.872) (n = 55), ki-67 immunoexpression (< 20 %) in 68 % (p = 0.001) (n = 97) and ki-67 immunoexpression (> 20 %) in 28.4 % of cases (p = 0.000) (n = 110).

CONCLUSIONS

The findings suggest that FC can occur, and there are histopathological changes in clinically normal tissue opposite to primary OSCC. Nevertheless, the review showed that more longitudinal studies on FC are needed to draw a conclusive indication of the occurrence of FC in oral tissues opposite to OSCC.

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.

Azoxystrobin induces apoptosis via PI3K/AKT and MAPK signal pathways in oral leukoplakia progression

Background: Oral leukoplakia (OLK) is one of the oral potentially malignant disorders (OPMDs) with an increased risk of developing oral squamous cell carcinoma (OSCC). There is no ideal therapeutic drug yet. Our previous study showed azoxystrobin (AZOX) inhibited the viability of OLK cells and the incidence of mouse tongue cancer. However, its specific mechanism has not been clarified. Here, we used network pharmacology with experimental validation to investigate the roles and mechanisms of AZOX in OLK.

Methods: The targets of AZOX and OLK were obtained from online databases. The overlapping genes were identified by the Jvenn database. STRING and Cytoscape software were used to construct the PPI network. GO and KEGG enrichment analyses were used to analyze the biological function. Molecular docking and CETSA were used to verify the direct binding between AZOX and its key targets. 4NQO induced mouse tongue carcinogenesis model was constructed to clarify the treatment response of AZOX in vivo. TUNEL staining was performed to detect the effect of AZOX on apoptosis in mouse OLK tissues. CCK8 assay, flow cytometry, and western blot were used to detect the effect of AZOX on cell proliferation and apoptosis in DOK cells. The expression of PI3K/AKT and MAPK markers were analyzed by immunohistochemistry in vivo or by western blot in vitro.

Results: Venn diagram showed 457 overlapping targets, which were involved in the PI3K/AKT, MAPK, and apoptosis pathways, and the top 5 hub modules were TP53, STAT3, AKT1, MAPK1, and PIK3R1. AZOX was bound with the highest force to AKT and PI3K by AutoDock Vina. PyMOL software visualized that AZOX could fit in the binding pocket of the AKT and PI3K. The carcinogenesis rate of the mouse OLK in the high-dose AZOX group was significantly reduced. AZOX induced apoptosis in the OLK tissues and DOK cells, and the expression of PI3K, AKT, p-ERK was decreased, and the expression of p-p38 and p-JNK was increased. CETSA indicated that AZOX might have a direct binding with AKT and PI3K.

Conclusion: AZOX may induce apoptosis via PI3K/AKT and MAPK pathways in OLK. This study reveals the potential therapeutic targets of AZOX in OLK.

Analysis of Oral Leukoplakia and Tobacco-Related Habits in Population of Chengalpattu District- An Institution-Based Retrospective Study

Objective

The study aimed to evaluate the prevalence of oral leukoplakia and to assess the risk of developing oral leukoplakia in patients with tobacco-related habits among the populations of Chengalpattu district, Tamil Nadu, India. 

Materials and Methods

Incidence and prevalence of oral leukoplakia differ among different populations in India due to cultural and demographic diversities. The results obtained from this study can be used as a reference in future research and policy-making for tobacco control. Data for this study were manually ascertained from the Department of Oral Pathology and Microbiology, SRM Kattankulathur Dental College and Hospital, SRM Institute of Science and Technology, Potheri, Chengalpet district, Tamil Nadu, India. The medical records of the patients diagnosed with the abnormalities and diseases of the oral mucosa, especially the white lesions of the oral cavity, between January 2011- March 2021 (10 years). The basic inclusion criteria for this study were to include the histopathology reports of the white lesions with no malignant changes during clinical diagnosis. The data was analyzed based on age, gender, tobacco-related habits, and histopathological diagnosis. The exclusion criteria for the study were the cases reported as carcinoma, patients associated with syndromes, biopsies outside the mentioned period, and those patients with incomplete clinical or histopathological details.

Results

Among 141 white lesions, about 85 cases [60.2%] were confirmed as oral leukoplakia, of which the study population had 55 (64.7%) males and 30 (35.3%) females. The age group which was commonly seen was 41-60 years. About 80% of the population with oral leukoplakia had the habit of tobacco consumption. The use of tobacco products was seen more commonly in the male population than the female, and consumption of tobacco and alcohol was seen in 6% of the population. In our study, we found the study population had the habit of using smokeless tobacco rather than smoking cigarettes and bidis. About 20% of the population diagnosed with leukoplakia did not have any habits. The most commonly affected site was buccal mucosa (67%), followed by the tongue (12%).

Conclusion

Our study shows a statistical association between oral leukoplakia and tobacco product consumption among the population of Chengalpattu district. The oral health care providers must take utmost care and vigilance to diagnose the lesion at its earliest stage and give appropriate treatment modalities and effective tobacco interventions. 

Malignant transformation of oral epithelial dysplasia in Southwest Finland

Oral epithelial dysplasia (OED) is considered a risk for oral squamous cell carcinoma (OSCC). A meta-analysis estimated a mean malignant transformation rate of 12.1% (95% CI 8.1-17.9). The main target of this study was to define how many OED patients develop OSCC in the hospital district of Southwest Finland. A total of 571 patients diagnosed with OED were identified. Their potential subsequent diagnosis of OSCC was derived from the Finnish Cancer Registry. The risk of OSCC development in OED patients was compared with that of the general population without OED. During a mean follow-up of 5.5 (range 0.1-29.0) years 10.9% of OED patients developed OSCC. OED patients had a 44.7-fold higher risk (95% CI 34.4-56.7) of developing OSCC than the general population. The risk was at its highest within two years of OED diagnosis. OED patients in Southwest Finland have a significantly increased risk of developing OSCC relative to the general population, especially within the first two years of dysplasia diagnosis.

Betel quid chewing and oral potential malignant disorders and the impact of smoking and drinking: A meta-analysis

BACKGROUND

Oral potential malignant disorders (OPMDs) are a precancerous condition of oral disease. Several studies have found that betel quid chewing, smoking and alcohol drinking might be the risk factors of OPMDs. But the relationships of them, especially their interaction are still inconclusive.

AIM

To evaluate the relationship between betel quid chewing and OPMDs and to explore the interaction of smoking and alcohol drinking on the relationship.

METHODS

We searched PubMed, Web of Science, Embase and the Cochrane Library databases with items complete until January 2021 for relevant studies. The research data were extracted according to the inclusion criteria. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the effect size. Subgroup analysis was performed to assess interactions between exposures and OPMDs. Relative excess risk of interaction (RERI) was used to estimate the size of interaction.

RESULTS

Nine articles were selected in the final meta-analysis. The results showed that betel quid chewing (pooled OR: 8.70, 95%CI: 5.18-14.61), alcohol consumption (pooled OR: 1.95, 95%CI: 1.5-2.55), and smoking (pooled OR:4.35, 95%CI: 3.06-6.2) could significantly increase the risk of OPMDs compared to individuals without these behaviors. Smoking and alcohol drinking synergistically increased the association between betel quid chewing and OPMDs (pooled OR_(BQ+SM):14.38, 95%CI: 7.14-28.95; pooled OR_(BQ+DK): 11.12, 95%CI: 8.00-15.45, respectively). The RERI_(BQ+SM) and RERI_(BQ+DK) were 2.33 and 1.47, respectively.

CONCLUSION

The synergistic effects between smoking/drinking and betel quid highlights the importance of focusing on individuals with multiple exposures. Further study should be conducted to confirm these interactions.

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.

Patients with oral preneoplastic lesions and integration of dental pathology referrals

PURPOSE

Oral cancers lack standardized monitoring systems. Our institution has developed an active surveillance system which provides detailed monitoring and follow up of patients with oral preneoplastic lesions (OPL). We examined a historic cohort of patients with OPL seen by regional dental professionals and a current cohort of clinic patients. The major aim was to examine follow up practices for biopsy proven dysplasia to gauge appropriateness of an active monitoring system for oral carcinoma.

MATERIALS AND METHODS

Questionnaires regarding patients with OPL were sent to 285 dentists who had requested oral pathology services from our institution. The follow up practices of 141 dentists were evaluated for patients with OPL. We then examined our current clinic referral patterns for the number of dental referrals after the creation of an oral carcinoma active surveillance clinic.

RESULTS

There were 76.5% (108/141) of patients who received follow up after diagnosis of preneoplastic oral lesions with 14.1% who underwent repeat biopsy. There was a malignant transformation rate of 11.3% including transformation of 42.8% of severe dysplasias into carcinoma within 2 years. After establishment of a dental referral clinic, 21.8% of tumor visits in a six-week period were referred from the regional dental community.

CONCLUSIONS

A high rate of transformation of OPL to cancer in this cohort may support a role for joint dental and otolaryngology surveillance of dysplasia with longitudinal follow up.

Malignant development of proliferative verrucous/multifocal leukoplakia: A critical systematic review, meta-analysis and proposal of diagnostic criteria

BACKGROUND

Proliferative verrucous/multifocal leukoplakia (PVML) is an oral potentially malignant disorder (OPMD) that exhibits high rates of malignant development (MD). This study aimed to analyse the risk of MD of PVML, as well as to investigate the possible risk factors associated with its malignization.

METHODS

A bibliographical search of the PubMed, Embase, Web of Science, and Scopus databases was conducted. PVML MD rates were calculated as a pooled proportion, and the risk factors were calculated as risk ratios, using fixed and random models based on the presence of heterogeneity.

RESULTS

From a total of 417 records, 16 articles were retrieved for inclusion. The subgroup analysis revealed a higher MD rate in the studies that were conducted in America, and, likewise, said studies involved a longer follow-up time (>6 years). There was a non-significant lower risk of malignization among males. A negative correlation was observed between MD and the year in which the studies were published.

CONCLUSIONS

The pooled MD of PVML was 65.8% (95% CI: 55.3-76.2, p < 0.001). Prospective studies of PVML must be designed using simple and universal clinical diagnostic criteria to be able to make an early diagnosis of this important OPMD and acknowledge the frequency of MD.

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).

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.

Malignant Transformation Rate of Non-reactive Oral Hyperkeratoses Suggests an Early Dysplastic Phenotype

The presence of epithelial dysplasia (ED) in oral leukoplakia is the single most important predictor of malignant transformation (MT). The majority of leukoplakias, however, do not show evidence of ED and yet MT of these lesions is well-recognized. These lesions have been referred to as "hyperkeratosis/hyperplasia, no dysplasia," "keratosis of unknown significance" and "hyperkeratosis, not reactive (HkNR)." This study evaluates the MT rate of such leukoplakias. A literature review was performed to identify cohort studies on leukoplakias where (1) there was a recorded histopathologic diagnosis, (2) cases of "hyperkeratosis/hyperplasia, no dysplasia" comprised part of the cohort, and (3) follow-up information was available. There were 9,358 leukoplakias, of which 28.5% exhibited ED while 37.7% consisted of HkNR. Follow-up ranged from 15 to 73 months. The incidence of MT in leukoplakia exhibiting HkNR was 4.9%, compared to 15.3% for ED. Among oral squamous cell carcinomas (SCC) with previously biopsied, site-specific precursor lesions, 55.7% arose from ED/carcinoma in situ and 28.0% arose from HkNR. Leukoplakia exhibiting HkNR has a substantial MT rate, similar to that of mild ED, and must be recognized and managed appropriately to reduce oral SCC incidence.

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.

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.

Binary and WHO dysplasia grading systems for the prediction of malignant transformation of oral leukoplakia and erythroplakia: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to examine the evidence of the binary histologic grading system capacity for predicting malignant transformation and to compare it with that of the WHO systems.

MATERIAL AND METHODS

A systematic review was conducted, using PubMed, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO databases without any language or timeframe restrictions. Studies were included if they compared the binary and the WHO histologic grading systems in the prediction of malignant transformation of oral epithelial dysplasia (OED).

RESULTS

The capacity of the WHO and binary grading systems to predict malignant transformation ranged from 16 to 80% and from 5 to 80%, respectively. The pooled malignant transformation rate of lesions classified as severe dysplasia or carcinoma in situ by the WHO grading was 40% (95% confidence interval (CI), 0.02-0.87; I² = 92%; P = 0.00), while the corresponding value for lesions classified as high-risk by the binary grading system was 31% (95% CI, 0.00-0.84; I² = 97%; P = 0.00). Overall, there was no significant difference in prognostication accuracy between the WHO and the binary systems (odds ratio = 2.02; 95% CI, 0.88-4.64).

CONCLUSIONS

Although some studies suggest that the binary system is associated with lower inter-rater variability when grading OED, the evidence remains inconclusive on whether this system is superior to that of the WHO at predicting malignant transformation.

CLINICAL RELEVANCE

The reproducibility of the binary system has the potential to be better for prognostic purposes. However, there is no high-quality evidence to confirm if this advantage may assist clinicians in decision-making.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Peroxiredoxin1 Knockdown Inhibits Oral Carcinogenesis via Inducing Cell Senescence Dependent on Mitophagy

Purpose

Cellular senescence is a physiological phenomenon by which cells irreversibly lose their proliferative potential. It is not clear whether senescent cells are related to malignant transformation in oral precancerous lesions. The role of peroxiredoxin1 (Prx1)-induced cell senescence in OLK malignant transformation has not been reported. The aim of this study is to investigate the role and mechanism of cell senescence in oral carcinogenesis.

Methods

In this study, 4-nitro-quinoline-1-oxide (4NQO) induced tongue carcinogenesis model in Prx1^+/+ and Prx1^+/- mice and dysplastic oral keratinocyte (DOK) were used. Prx1 knockdown DOK cells were harvested with shRNA injection, and cell senescence was detected via the senescence-associated β-galactosidase (SA β-gal) assay. The senescence and mitophagy-related proteins were observed by immunohistochemistry (IHC), Western blot and qRT-PCR. The binding of Prx1 with prohibitin 2 (PHB2) and light chain 3 (LC3) was predicted via ZDOCK and measured in mice by Duolink analysis.

Results

Histologically, 4NQO treatment induced epithelial hyperplasia, dysplasia (mild, moderate and severe), carcinomas in situ and oral squamous cell carcinoma (OSCC) in mouse tongue mucosa. The malignant transformation rate in Prx1^+/- mice (37.5%) was significantly lower compared with Prx1^+/+ mice (57.1%). In Prx1^+/+ mice, a higher number of senescent cells and greater expression of p53 and p21 were observed in hyperplastic and dysplastic tongue tissues when compared with those in OSCC tissues. Prx1 knockdown induced a greater number of senescent cells in hyperplastic tissues, and DOK cells accompanied cell cycle arrest at the G1 phase and PHB2/LC3II downregulation. Prx1 was predicted to dock with PHB2 and LC3 via ZDOCK, and the interactions were confirmed by in situ Duolink analysis.

Conclusion

Prx1 silencing inhibits the oral carcinogenesis by inducing cell senescence dependent on mitophagy.

The Analysis of the Frequency of Leukoplakia in Reference of Tobacco Smoking among Northern Polish Population

Objective: The aim of the study was an updated analysis of the frequency of leukoplakia in reference to tobacco smoking among the northern Polish population. Material and Methods: Medical records of 5720 patients who suffer from abnormalities and oral mucosa diseases between January 2015–December 2018 were analyzed. Among them, 416 medical charts of patients with leukoplakia were selected. The study group consisted of 196 women and 220 men aged between 21–86 years (average 45.6 years). The analysis was conducted in terms of age, gender, and smoking tobacco. The basic criterion for inclusion in the study was the presence of oral leukoplakia confirmed by histopathological examination, recorded in the chart. Information about the patient’s active smoking was obtained from documented medical interviews. An active smoker was defined as a patient who smoked 10 or more cigarettes a day for at least the previous six months. The study used parametric and non-parametric statistical methods. Results: The highest incidence of leukoplakia was found in the age group 41–60 (46.6%), where the vast majority were active smokers (85.1%), and mostly men (86.2%). However, among patients with leukoplakia, the highest prevalence of smoking was found in the age group 21–40 years (86.8%) in women, where out of 38 patients with leukoplakia, 33 were active smokers. More patients with leukoplakia were observed in groups of smokers and it was statistically significant. Homogeneous form was the most commonly diagnosed form of leukoplakia in our study; it was found in almost 95% of cases. Leukoplakia was mainly observed on the cheeks. Changes on the gums, the alveolar process or the bottom of the tongue and mouth were rarely found. Conclusion: Our studies revealed that there is a statistically significant correlation between tobacco smoking and the presence of oral leukoplakia among the northern Polish population. It should be noted that dentists, in particular, are capable of early diagnosis and implementation of appropriate treatment of leukoplakia and, most often, crucial elimination of the main risk factor, which is smoking, and the implementation of effective tobacco control interventions.

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.