Malignant transformation risk of oral lichen planus: A systematic review and comprehensive meta-analysis

Low Incidence of Oral Squamous Cell Carcinoma in Patients With Oral Lichen Planus on Sustained Anti-Inflammatory Therapy: A Single-Centre Retrospective Study of 273 Patients

BACKGROUND

Oral lichen planus (OLP), a chronic inflammatory disease, can progress to oral squamous cell carcinoma (OSCC). The malignant transformation rate may be lower in OLP patients receiving anti-inflammatory therapy.

OBJECTIVE

To describe cases of malignant transformation among OLP patients on topical/systemic anti-inflammatory therapy.

METHODS

The medical records of 273 patients with OLP at an academic institution were retrospectively reviewed. Patients with epithelial dysplasia at OLP diagnosis were excluded. Biopsy-confirmed OSCC cases diagnosed ≥6 months after the initial visit were included. Chi-square and t-tests compared categorical and numerical variables, respectively.

RESULTS

The mean age at OLP diagnosis was 63 years (standard deviation [SD]: 12.2, range: 19-92); 79.9% were women and 89.4% were White. Most patients had erosive OLP (EOLP) (61.9%). 16.5% had concurrent genital LP and 10.6% had cutaneous LP. Tacrolimus swish-and-spit was the most frequently prescribed treatment (100%), followed by 10 mg clotrimazole troches (89.4%) and topical corticosteroids (85%). The median duration of clinical follow-up was 2.9 years (interquartile range: 1-5.5). Three (1.1%) patients developed OSCC on average 6.3 years post-OLP diagnosis, all with EOLP. OSCC most frequently affected the tongue (66.7%), followed by the gingiva (33.3%). Out of 3 tumours, one was stage II, one was stage III, and one was stage IV. OLP patients with vs. without OSCC were more often male (P = .04) and more frequently experienced dysphagia (P < .001).

CONCLUSION

OSCC incidence was low in OLP patients on sustained anti-inflammatory therapy, occurring exclusively in those with EOLP. Males and patients with dysphagia more often developed OSCC.

Thyroid Dysfunction and Oral Lichen Planus: Evidence From Two-Sample Mendelian Randomization Analysis

INTRODUCTION AND AIMS

Epidemiological studies have shown that the association between thyroid dysfunction (TD) and oral lichen planus (OLP) is controversial, and the causal relationship remains ill-defined. This study aims to investigate their probable mutual causality using bidirectional Mendelian randomization (MR) analyses.

METHODS

We extracted genetic instruments for OLP and 10 phenotypes of TD from the genome-wide association studies database. The inverse variance weighted method was primarily used to evaluate the bidirectional causal relationship between TD and OLP. The results' robustness was verified by sensitivity analysis (Cochran's Q test, MR-Egger intercept, and leave-one-out test). Bonferroni correction threshold (0.05/10) was applied to determine significant differences.

RESULTS

Forward MR analysis indicated that Hashimoto's thyroiditis (HT) was suggestively linked to a higher likelihood of developing OLP (P = .0077), while hypothyroidism significantly increased the risk of OLP occurrence (P = .0002). The reverse MR study found that OLP was suggestively related to the occurrence of hyperthyroidism (P = .0126) and thyroid cancer (P = .0244). Furthermore, OLP was found to significantly increase the risk of HT (P = 3.47 × 10-⁸), Graves' disease (P = 1.03 × 10-⁵), hypothyroidism (P = 1.08 × 10-⁸), and elevated thyroid-stimulating hormone levels (P = 1.99 × 10-⁶). No major pleiotropy or heterogeneity was detected (P > .05).

CONCLUSION

These findings suggest that hypothyroidism significantly increases the risk of OLP, while OLP may contribute to the development of autoimmune thyroid disorders, particularly HT, Graves' disease, hypothyroidism, and thyroid-stimulating hormone. These findings highlight the complex interaction between endocrine and immune systems, emphasizing the need for further research into shared molecular pathways and potential clinical implications.

CLINICAL RELEVANCE

This study provides a genetic foundation for understanding the relationship between TD and OLP, which aids early screening and diagnosis and informs therapy development.

Effect of high-intensity laser therapy and photobiomodulation therapy on oral lichen planus-a systematic review and meta-analysis

This study evaluates the efficacy and safety of High-Intensity Laser Therapy (HILT) and Photobiomodulation (PBM) in treating Oral Lichen Planus (OLP), and explores optimal PBM parameter settings. A search of PubMed, Embase, Cochrane Library, Web of Science, CNKI, and SinoMed was conducted for randomized controlled trials (RCTs) on laser therapy for OLP up to October 30, 2024. Study quality was assessed using the Cochrane risk of bias tool and the Jadad score. Eighteen studies were identified, with 16 involving 742 participants included in the meta-analysis. Eleven studies compared PBM with topical corticosteroids (TCS), and five compared HILT with TCS. HILT provided superior pain relief compared to TCS (SMD = -0.51, 95% CI [-0.79,-0.23]), while PBM showed comparable outcomes (SMD = -0.41, 95% CI [-0.87, 0.04]). PBM was more effective at pain relief with total energy density below 120 J/cm2. Both HILT and PBM reduced recurrence rates (RR = 0.33,95%CI [0.15,0.73]; RR = 0.43, 95% CI [0.25, 0.74]) and improved cure rates (RR = 1.44, 95% CI [1.01, 2.06]; RR = 1.47, 95% CI [1.05, 2.05]). PBM had no adverse reactions, while HILT and TCS had associated adverse events. HILT and PBM may be considered effective alternatives to TCS. For PBM treatment of OLP, a total energy density below 120 J/cm2 is advisable. Further large-scale studies are required to confirm these findings and refine laser parameters.

Distinct Immunological Features Compared to Lichen Planus and Oral Lichen Planus

Purpose

Lichen planus (LP) and oral lichen planus (OLP) share clinical and histological similarities, yet their distinct immunopathological mechanisms make differentiation and management challenging. Clarifying these differences is essential for accurate diagnosis and treatment. This study aimed to investigate the systemic immune profile of OLP using single-cell transcriptomics, identifying distinct immune cell subsets and signaling pathways contributing to its chronic inflammatory state. Additionally, it sought to compare the inflammatory lesion microenvironments of OLP and LP by analyzing key immune pathways and cellular interactions.

Methods

Peripheral blood mononuclear cells (PBMCs) were obtained from 16 OLP patients and 5 healthy controls. Single-cell transcriptomic data from PBMCs and lesion tissues of OLP and LP were analyzed to profile immune and inflammatory signatures. Key molecular findings were validated using independent datasets and enzyme-linked immunosorbent assays (ELISA).

Results

Prostaglandin D2 synthase (PTGDS), a pivotal enzyme in prostaglandin metabolism, emerged as a diagnostic marker with elevated expression in NK cells from OLP patients. Additionally, a novel CXCR4 high-TSC22D3 high CD4 cytotoxic T cell subset with enhanced cytotoxicity was identified, potentially contributing to OLP pathogenesis. OLP blood samples also demonstrated significant upregulation of TNF and TLR signaling in NK cells, indicating a heightened chronic inflammatory state. Comparative tissue analysis revealed intensified TNF-driven inflammation and a disrupted HIF1A- vascular endothelial growth factor (VEGF) interactions in OLP, contrasting with LP's robust VEGF-mediated angiogenesis.

Discussion

These findings highlight distinct immunopathogenic mechanisms between OLP and LP. The upregulation of PTGDS in NK cells and CXCR4 high-TSC22D3 high CD4 cytotoxic T cells in PBMCs indicates systemic immune dysregulation in OLP, while tissue-level differences suggest impaired vascular remodeling and chronic inflammation. These insights underscore the need for targeted immunomodulatory therapies.

Conclusion

This study identifies distinct immune signatures that differentiate OLP from LP, highlighting potential therapeutic targets that require further validation for personalized treatment strategies.

Clinical Features of Oral Lichen Planus: A Pictorial and Systematic Review

Oral lichen planus (OLP) is an inflammatory mucocutaneous relapsing and remitting condition that includes a spectrum of oral clinical manifestations including mild painless white lesions to painful erosions and ulcers. The complexity of clinical presentation of OLP lesions often represents a challenge for both young and experienced otolaryngologists and dental practitioners. Therefore, the aim of the present article was to review the literature regarding the main clinical features of OLP. A literature search was conducted in four electronic databases (Medline / PubMed, Scopus, Embase, and Web of Science) using the combination of the terms "oral lichen planus" AND "symptoms" OR "signs" OR "clinical". The initial search resulted in 432 articles. After screening the duplicates and following the application of exclusion criteria, the full texts of 18 articles were included in the review. A thorough knowledge of clinical patterns and symptoms of OLP is crucial for any otolaryngologist and dental practitioner. An early diagnosis and a long term follow up seem to be the best clinical approach to manage such subtle and chronic condition.

Overexpression of inflammatory human caspase-4 in relation to clinical severity of oral lichen planus

OBJECTIVE

Involvement of non-canonical inflammasome, comprising inflammatory human caspase-4, caspase-5, and Gasdermin D, in the pathogenesis of oral lichen planus (OLP) has never been demonstrated. We aimed to determine human caspase-4, caspase-5, and Gasdermin D expressions in OLP, to correlate their expressions with OLP severity, and to measure salivary interleukin (IL)-1β levels.

STUDY DESIGN

OLP and normal oral mucosal specimens (n = 42 each) were processed for immunohistochemistry or immunoblotting. The clinical score for OLP severity was assessed at the most severe site. The immunohistochemical (IHC) score was a summation of intensity and positive cell scores. Salivary IL-1β levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Median IHC scores of caspase-4 and Gasdermin D in OLP group were significantly greater than those in normal mucosal group (P < .01), consistent with significantly upregulated expressions by immunoblotting (P < .05). The IHC scores of caspase-4 and Gasdermin D were positively correlated with the clinical scores (P < .05). Salivary IL-1β levels in the OLP group were significantly greater than those in the normal mucosal group (P < .001).

CONCLUSIONS

Our study demonstrates enhanced human caspase-4 and Gasdermin D expressions in relation to increased OLP severity with elevated salivary IL-1β levels, proposing clinical applications of these biomolecules as potential prognostic markers and/or new therapeutic intervention for OLP.

Risk of Malignant Transformation of Oral Lichen Planus and Oral Lichenoid Lesions: A Single Centre, 10-Year Review

BACKGROUND

Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are common chronic inflammatory diseases associated with malignant transformation. Risk factors associated with malignant transformation of OLP and OLL are not well defined.

METHODS

A retrospective chart review assessed risk factors for progression of OLP and OLL to oral epithelial dysplasia (OED) or oral squamous cell carcinoma (OSCC) at a tertiary care centre in Toronto, Canada.

RESULTS

Five-hundred-fifty-five patients identified with biopsy proven OLP or OLL met the inclusion criteria. In total, 3.2% (n = 18) progressed to OED (1.8%, n = 10) or OSCC (1.4%, n = 8). Risk factors associated with transformation included the plaque-like subtype (OR = 40.33, p < 0.001) and lesions located on the tongue (OR = 6.81, p = 0.008).

CONCLUSIONS

Clinical examination to identify lesion subtype and location provides useful indicators for risk of progression in patients with OLL and OLP.

Clinical characteristics, management, and malignancy rate of oral lichen planus: A European multicenter study

INTRODUCTION

Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous condition that includes a spectrum of oral clinical manifestations ranging from mild painless white lesions to painful erosions and ulcers. The purpose of this European multicenter study is to describe the general characteristics of OLP lesions, the clinical and histopathological diagnosis, and the management of OLP at different European Oral Medicine and Maxillofacial Surgery centers, in order to minimize selections biases and provide information about the current trends in the treatment of OLP across Europe.

MATERIALS AND METHODS

Data and histopathological records of patients with OLP were retrospectively revised and only those patients that fulfilled the diagnostic criteria from the 2016 position paper by American Academy of Oral and Maxillofacial Pathology were included. The following data were recorded for each patient: gender, age, voluptuary habits, risk factors for OLP (psychological stress, medications, systemic diseases), location of OLP lesions, clinical presentation, patterns of clinical expression, symptoms, treatment, possible clinical improvement, and malignant transformation.

RESULTS

A total of 565 OLP patients (422 females, 143 males) fulfilled the inclusion criteria. The mean age of the study population at diagnosis was 60.11 years. In 262 patients (46.4 %), just a site of OLP was identified: in 186 of these "one-site" patients, OLP was diagnosed just in buccal mucosa. The most frequently observed clinical pattern was reticular. When evaluating the treatment received, 294 patients were kept in follow up with a Wait-and-see approach. The most frequent treatment regimen was the use of topical corticosteroids (123 patients). A significant statistical association was found between the prescription of topical corticosteroids (P < .0005) or retinoids (P < .000005) and symptoms improvement. Squamous cell carcinoma associated with OLP lesions was observed during the follow-up in 9 OLP patients out of 565 (1.6 %).

CONCLUSIONS

Reticular and mixed clinical patterns are the most frequent subtypes of OLP. The use of topical corticosteroids and retinoids for the management of OLP seems to allow good improvement results of symptoms and signs. A clinical long-term follow-up is fundamental due to the chronic nature of OLP and possible malignant transformation.

Comparative Study of OLP and OLL: Demographic and Clinical Profile in a Reference Center in Brazil

OBJECTIVE

To compare the demographic and clinical profiles of oral lichen planus (OLP) and oral lichenoid lesions (OLL) diagnosed at a reference center in Southern Brazil from 2010 to 2019.

METHODS

This retrospective study included 117 cases of suspected OLP submitted for biopsy. Investigated variables comprised sociodemographic profiles, medical history, harmful habits, clinical characteristics, and histopathological features. Categorical and numerical variables were analyzed using chi-square and Mann-Whitney tests (p < 0.01), respectively.

RESULTS

Applying strict diagnostic criteria, 29% (n = 34) of cases were classified as OLP and 71% (n = 83) as OLL. OLP cases had mainly multifocal manifestations (82.4%), exhibiting a reticular pattern (100%) and primarily occurring on the buccal mucosa (94.1%). Conversely, OLL cases presented both unilateral (48.2%) and multifocal (51.8%) distributions, with a predominantly atrophic-erosive pattern (77.1%) and higher occurrence on the buccal mucosa (69.9%) and tongue (48.2%). OLL patients reported a higher frequency of systemic disorders and medication use (p < 0.01). Hypertension was the most prevalent condition, leading to the frequent use of cardiovascular medications. Two OLL cases without initial dysplasia underwent malignant transformation.

CONCLUSION

Patient profiles and clinical manifestations of the entities were similar, highlighting the utility of a differential diagnosis, particularly given the apparent association between malignant transformation and OLL cases.

Oncological Outcomes of Patients With Oral Potentially Malignant Disorders

Importance

Understanding the clinical course and malignant transformation rate of oral potentially malignant disorders (OPMDs)-including oral leukoplakia, oral erythroplakia, oral submucous fibrosis, and oral lichen planus-is crucial for early detection and improved survival rates in patients with oral cancer.

Objective

To evaluate the progression of oral cancer from OPMDs using a large US electronic medical database.

Design, Setting, and Participants

This retrospective cohort study used data from the University of California, San Francisco's PatientExploreR database between January 1973 and March 2024. Patients with oral leukoplakia, oral erythroplakia, oral submucous fibrosis, and oral lichen planus were identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes and keywords. Demographics, tobacco and alcohol use, HIV status, and other known risk factors for oral cancer were recorded to identify factors associated with malignant transformation. Logistic regression and descriptive analyses were used.

Exposure

Diagnosis of oral leukoplakia, oral erythroplakia, oral submucous fibrosis, or oral lichen planus.

Main Outcomes and Measures

Incidence of oral cancer, malignant transformation rate, median time to progression, and associations between demographics and risk factors and the development of oral cancer.

Results

Among 4 225 251 individuals in the database, 4371 were diagnosed with oral cancer (median [IQR] age, 63 [53-71] years; 2610 [59.9%] male; 0.1% of the cohort), and 110 (2.5%) had a preceding OPMD. Oral leukoplakia was found in 1124 patients, with 94 (8.4%) undergoing malignant transformation (median [IQR] time to progression, 25 [7-129] months). HIV-positive patients with oral leukoplakia were more likely to develop oral cancer (odds ratio, 3.80; 95% CI, 1.35-10.70). Of 22 patients with oral erythroplakia, 11 (50.0%) developed oral cancer (median [IQR] time to progression, 3.7 [0.2-334] months). Those who smoked tobacco with oral erythroplakia showed a higher malignant transformation rate (odds ratio, 3.75; 95% CI, 0.54-26.05). Of the 78 patients with oral submucous fibrosis, 4 (5.1%) underwent malignant transformation (median [IQR] time to progression, 36 [36-48] months). Only 1 patient with oral lichen planus developed oral cancer after 5 years.

Conclusions and Relevance

This cohort study showed that OPMDs have notable but varying propensities to progress to oral cancer. Early detection and monitoring of OPMDs are crucial for improving patient outcomes. However, the risk, etiopathogenesis, and clinical presentation vary for each OPMD and should, therefore, be considered distinct diseases.

Glycyrrhizin alleviates the toxicity of hydroxychloroquine in treating oral lichen planus by occupying heat shock protein 90 alpha

BACKGROUND

Oral lichen planus (OLP) is a common chronic inflammatory disease with the potential of malignant transformation. Hydroxychloroquine (HCQ), derived from quinine originating from Cinchona spp. bark, is a commonly prescribed off-label for OLP. However, it lacks robust evidence-based medicine practice, as well as theoretical guidance for its pharmacodynamic targets and for mitigating adverse reactions.

PURPOSE

To compare the efficacy of HCQ with first-line treatment prednisone for treating severe erosive OLP and to identify compatible phytomedicine that is reasonably available based on elucidating the molecular targets related to clinical benefits and adverse reactions.

METHODS

We performed a single-center, randomized, investigator-blinded, positive-controlled, non-inferiority trial. Patients who met the enrollment criteria were randomly allocated (1:1) to receive either HCQ or prednisone therapy for 4 weeks and follow-up for 3 months. The primary outcome measures included reductions in the erosion area and pain level. Potential targets of HCQ and associated toxic effects in treating OLP were identified through in silico analysis and validated through histological evaluation. Common hepatoprotective agents, including glycyrrhizin and total glucosides of peony, were analyzed for their potential targets. Then tri-molecular docking study was performed to screen available phytomedicine agent for alleviating adverse reaction of HCQ. Finally, in vitro experiments were performed to validate these targeted effects.

RESULTS

A total of 62 patients were enrolled from January 2021 to August 2023. After a 4-week treatment, there's no significant difference between patients receiving HCQ and PDN in the reduction of erosion area (median, 44 vs 58.5; HCQ - PDN difference: -11; 95 % CI, -39 to 13; p = 0.438) or pain level (median, 3 vs 3; HCQ - PDN difference: 0; 95 % CI, -1 to 1; p = 0.925). Heat shock protein 90 (HSP90) alpha and beta were identified as potential therapeutic targets of HCQ for treating OLP, while HSP90α is also associated with the adverse reactions of HCQ. The expressions of HSP90α and HSP90β in OLP tissue were significantly reduced compared to normal tissue. The phytomedicine glycyrrhizin was selected due to its specific interaction with the GLY-181 site of HSP90α, same as HCQ's toxic targets. HCQ exerted pro-proliferative and anti-inflammatory effects in vitro. And both HCQ and glycyrrhizin treatment restore the expression of HSP90β, while HCQ treatment also restored the expression of HSP90α.

CONCLUSIONS

HCQ was not inferior to prednisone for treating severe erosive OLP, suggesting it as an alternative to first-line treatment. Integrating phytopreparation glycyrrhizin into conventional HCQ treatment in OLP can help detoxify by occupying the HSP90α binding site.

Tongue Squamous Cell Carcinoma and Oral Lichen Planus: A Rare Case Report of a Pregnant Woman

Squamous cell carcinoma (SCC) of oral mucosa is increasingly affecting younger individuals, particularly in the tongue. SCC can develop from disorders like oral lichen planus (OLP). This case highlights the first known instance of OLP and SCC in a pregnant woman, suggesting hormonal changes and HPV as possible risk factors.

Antinuclear Positivity and Malignant Transformation Potential of Oral Potentially Malignant Disorder

OBJECTIVE

This multicenter cohort study aimed to investigate the impact of antinuclear antibody (ANA) positivity on the malignant transformation potential of oral potentially malignant disorders (OPMDs) using the Observational Health Sciences and Informatics network tools for the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM).

MATERIALS AND METHODS

Retrospective cohort data from five medical centers were analyzed. Cox regression and 1:4 propensity score matching followed by aggregated meta-analysis were used to evaluate association between ANA positivity and the risk of oral squamous cell carcinoma (OSCC). The index date was defined as the first day of diagnosis of OPMD. The target and comparator cohorts comprised patients who tested positive and negative for ANA within 180 days before or after the index date, respectively.

RESULTS

Among 27,984 OPMD patients, 1302 patients (4.65%) confirmed malignant transformation. Among these, 3035 patients had ANA laboratory data. After 1:4 PS matching, 523 and 1598 patients with positive and negative for ANA were analyzed. Meta-analysis of the hazard ratios demonstrated that ANA positivity significantly increased the risk of malignant transformation compared to ANA negativity.

CONCLUSIONS

ANA positivity is a significant prognostic marker for predicting malignant transformation in patients with OPMD.

Is autoimmunity associated with the development of premalignant oral conditions and the progression to oral squamous cell carcinoma?: A literature review

OBJECTIVE

Oral potentially malignant disorders (OPMDs) are oral mucosal conditions that may progress to oral squamous cell carcinoma (OSCC). Although autoimmunity has linked to the malignant transformation potential of various precancerous conditions, its role in OPMD remains unclear. This review aimed to identify the role of systemic autoimmunity on OPMD development and their progression to OSCC.

METHODS

A comprehensive literature search was conducted using PubMed, Cochrane CENTRAL, and SCOPUS database for articles published up to January 2024. The key questions addressed by this review were "Is autoimmunity associated with the development of OPMD" and "How does systemic autoimmunity influence the potential for malignant transformation of OPMD?". This review followed the PRISMA guidelines for scoping reviews (PRISMA-ScR).

RESULTS

Of the 1265 articles initially identified, 21 fulfilled the search criteria. Three themes were emerged; 1) the prevalence and prognosis of oral cancers in patients with systemic autoimmune diseases, 2) circulating autoantibodies in OPMD patients, and 3) autoimmune-related markers linked to malignant transformation in OPMD patients. This review indicated that systemic autoimmunity may contribute to chronic inflammatory conditions, disruption of oral mucosal integrity, and interference with the DNA damage repair process, thus influencing malignant transformation in the oral epithelium of patients with OPMD.

CONCLUSION

The co-occurrence of OPMD with circulating autoantibodies or systemic autoimmune diseases underscores the importance of understanding these interactions for improved management of OPMD and early detection of OSCC.

HSP90 Complex From OLP Lesion Induces T-Cell Polarization via Activation of Dendritic Cells

OBJECTIVES

To investigate the effects of the heat shock protein 90 (HSP90) complex from oral lichen planus (OLP) lesion tissues on dendritic cell (DC) activation and the polarization of naïve T cells.

METHODS

Expression of HSP90 in OLP lesions and healthy control (HC) mucosa was evaluated by single-cell RNA sequence, IHC, qRT-PCR, and immunoblotting. HSP90 complex was extracted by immunoprecipitation from oral mucosa as the agonist of DCs. Expression of IFN-α and MHC was detected by flow cytometry. After cocultured with pre-stimulated DCs, polarization of naïve T cells was investigated by cytokine analysis.

RESULTS

HSP90 was significantly higher in the lamina propria of OLP lesion and closely related to lymphocyte infiltration. HSP90 complex of OLP lesion activated DCs via TLR9 and increased their IFN-α secretion and MHC II expression. Pre-stimulated DCs increased the proportion of Th17 cells.

CONCLUSIONS

HSP90 complex isolated from OLP lesion activated TLR9/IFN-α of DCs and further promoted the polarization of naïve T cells toward Th17 immunity.

Malignant transformation rate of erosive oral lichen planus: a retrospective study

Oral lichen planus (OLP) is a chronic inflammatory oral condition previously known to have a rate of malignant transformation of around 1%. Additionally, erosive lichen planus, a subtype of lichen planus, which is a known risk factor for malignant transformation, has previously been unquantified in a large cohort of patients. In a single unit observation between 2005 and 2021 we retrospectively assessed 1,920 patients who underwent histological analysis for suspected oral lichen planus, and followed the progression of their disease to assess the rate of malignant transformation. In total, 1.39% of OLP transformed to oral squamous cell carcinoma over an average of 5.8 years. However, we found that the transformation rate of erosive OLP into malignancy was 5.98% with an aggressive clinical pathway. To our knowledge the incidence of erosive OLP has not previously been quantified in a large cohort of patients. This retrospective study sheds light on, and raises warning signs about, the seriousness of this condition.

Erosive lichen planus: an unmet disease burden

Objectives

To explore the demographic and clinical profile of erosive lichen planus (ELP) across multiple ethnicities within a single cohort, deepening our understanding of disease severity, progression and outcomes.

Methods

A longitudinal retrospective cohort study of ELP patients in the ethnically diverse population of East London was carried out, profiling ELP (n = 57) against the milder reticular lichen planus (RLP) (n = 35).

Results

A higher prevalence of ELP was observed in white populations compared to other ethnicities. Affected females were no more likely than males to develop ELP. There was an increased time to diagnosis for ELP patients (median ELP: 452 days, RLP: 312 days), spending longer in primary care before onward referral, in particular when referred by their general medical practitioner (GP) (median dentist 313 days, GP: 606 days). Depression was more likely to occur alongside ELP. Being an ex-smoker is a risk factor for ELP while being a current smoker is associated with RLP. A higher proportion of patients with ELP were missing teeth and had periodontal disease. Multisite involvement was more common in ELP, (ELP: 68% RLP: 11.43%). 55% of ELP cases developed scarring and were less likely to respond to first line medications, requiring systemic immunosuppression. The duration of follow up was increased in the ELP who were reviewed for almost twice as long as RLP patients (ELP 71 months, RLP 35 months).

Conclusion

ELP takes longer to diagnose, requires prolonged tertiary care and is more resistant to treatment, when compared across multiple ethnicities. These patients have increased medical and oral health needs and are at greater risk of scarring than the reticular form. A greater education amongst primary carers on its presentation, as well as a greater understanding of the cellular and molecular mechanisms driving ELP are required to improve diagnostics and identify novel therapeutic approaches.

Impact of Topical Fluocinonide on Oral Lichen Planus Evolution: Randomized Controlled Clinical Trial

Objective

To examine the impact of fluocinonide 0.05% gel formulation for the topical treatment of oral lichen planus (OLP).

Methods

Through an RCT design, 47 patients with OLP were randomly allocated for topical OLP treatment with fluocinonide 0.05% (n = 23) or placebo (n = 24). Patients were examined for OLP symptoms, signs, disease severity, and extension score changes over 6‐month follow‐up.

Results

After 6 months, in comparison with placebo, patients treated with fluocinonide experienced a significant reduction of OLP symptoms (p = 0.024), signs (p = 0.014), and OLP extension score (p = 0.028). The two‐way ANOVA estimation models revealed that treatment with fluocinonide determined, at 6 months, a positive significant effect on the reduced OLP signs (p = 0.017), OLP symptoms (p = 0.026), and OLP extension score (p = 0.028). The multivariate regression analysis highlighted that anxiety, stress, and depression were significant predictors of every analyzed OLP outcome (p < 0.05 for each parameter) and that patients who had baseline anxiety, depression, and stress gained more benefits from fluocinonide at 6‐month follow‐up.

Conclusions

Topical fluocinonide 0.05% was more efficacious compared to placebo in reducing OLP outcomes at 6‐month follow‐up. Anxiety, depression, and stress were significant predictors of OLP outcomes and positively impacted the treatment with fluocinonide at 6 months.

DAPK-1 as a Potential Early Marker for Malignant Transformation Risk of Oral Lichen Planus

Introduction Oral lichen planus (OLP) comprises a chronic inflammatory autoimmune disease observed in the oral cavity. It most commonly manifests as white papules arranged confluently, drawing a picture of white lines in the form of a network (reticular form). It may emerge in other forms as well. In our study, the erosive form presents the most clinical interest. Among the biomarkers that participate in the tumorigenesis process, DAPK-1 seems promising, rendering its study necessary. This study focuses on the investigation of the presence of the DAPK-1 using immunohistochemistry in OLP compared to oral squamous cell carcinoma (OSCC), oral leukoplakia (OL), a well-established oral potentially malignant disorder, and normal oral epithelium to evaluate its possible role as an early predictor of the possibility of malignant transformation risk of OLP lesions. Methods To monitor the expression profile of the tumor suppressor protein DAPK-1, an immunohistochemical detection took place in 18 samples of OLP (reticular and erosive type), in 22 OSCC samples of all degrees of differentiation, in 30 OL samples of all degrees of dysplasia, and five normal tissue samples used as the control group. To complete the above procedure, immunohistochemistry was used in a semiquantative manner. The paraffin-embedded tissue samples were selected from the archives of the Department of Oral Medicine/Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece, from biopsies performed in this department as well as from St. Lukas Hospital of Thessaloniki, Greece, between 2014 and 2019. The study was conducted per the Research and Ethics Committee guidelines of Aristotle University, School of Dentistry, and the Helsinki II declaration (protocol number 29/21.11.2018).  Results The statistical analysis showed that there was no statistically significant difference in DAPK-1 staining between normal tissues and OLP (p=0.588, independent-samples Kruskal-Wallis test). On the other hand, there was a statistically significant difference between OSCCs and OLPs (p<0,001, independent-samples Kruskal-Wallis test), with the extent of expression of DAPK-1 being greater in OLP than in OSCC. In addition, there was a statistical difference in DAPK-1 expression between OLPs and OLs (p=0,001, independent-samples Kruskal-Wallis test), with DAPK-1 being expressed more in OLP than in OL. Conclusion The DAPK-1, as a pro-inflammatory with its role as a tumor suppressor factor, was highly expressed in OLP, both reticular and erosive. The relatively milder expression of DAPK-1 in OL means that, between the two disorders, OLP is less likely to progress to oral cancer. On the other hand, OLP could also offer the background for further investigation of a possible correlation between methylation (immunohistochemical expression of proteins, deriving from potentially DNA-methylated genes) and the development of inflammation. It appears that DNA methylation is important in the regulation of inflammatory genes. Conversely, inflammation may regulate the DNA methylation of many genes involved in carcinogenesis and thus should be taken into account when studying the methylation behavior of genes such as DAPK-1 in pathologies characterized by a sparse inflammatory infiltrate.

Pyroptosis of oral keratinocyte contributes to energy metabolic reprogramming of T cells in oral lichen planus via OPA1-mediated mitochondrial fusion

Oral lichen planus (OLP) is a chronic inflammatory disease that is associated with an increased risk of carcinogenesis. The typical pathological features of OLP include submucosal T-cell banding, infiltration, and liquefactive degeneration of basal epithelial cells. However, the histological appearance of basal cell death cannot be explained by apoptosis of keratinocytes alone. The aim of this study was to explore a novel mechanism of epithelial cell death, pyroptosis, and its role in the development of OLP. The immunohistochemical results initially revealed pyroptosis in the epithelial cells of OLP. There was significant upregulation of pyroptosis-related inflammatory cytokines, specifically IL-1β. The expression of IL-1β is closely related to the severity of the patient's condition. In vitro, the culture supernatant from epithelial cells and exogenous IL-1β significantly promote the proliferation and activation of T cells. This effect can be inhibited by neutralizing antibody or receptor inhibitor of IL-1β. Stimulation with exogenous IL-1β enhances both glycolysis and oxidative phosphorylation in T cells, with a more pronounced increase in glycolysis. This is due to the regulation of NAD+ availability and mitochondrial dynamics by IL-1β. IL-1β specifically stimulates the expression of optic atrophy 1 (OPA1), particularly L-OPA1, which promotes mitochondrial fusion and increases NAD+ availability. This process upregulated glycolysis in T cells. The knockdown of OPA1 reverses these changes by reducing the proliferation and activation of T cells. In this study, IL-1β promoted OPA1 transcription by activating the NF-κB pathway. The expression of OPA1 is inhibited by the inhibitor of NF-κB pathway. These results suggest that OLP keratinocytes undergo pyroptosis, which then secrete inflammatory factors that activate the NF-κB signaling pathway of T cells. This pathway regulates OPA1-mediated mitochondrial fusion and energy metabolism reprogramming in T cells, contributing to the development of OLP. These findings provide new insights into the mechanisms and therapeutic strategies for OLP.

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Ocular Lichen Planus: A clinicopathologic review

Lichen planus is a chronic inflammatory dermatosis that can affect the skin, mucous membranes and nails. Cutaneous lichen planus lesions are best described by the "six Ps" - purple pruritic polygonal planar papules and plaques. Mucous membrane lesions are commonly associated with cutaneous lichen planus. Ocular involvement with lichen planus is rare and conjunctival involvement usually predominates, it can however be visually devastating. Ocular lichen planus often progresses to extensive conjunctival scarring which can be impossible to distinguish clinically from other cicatrising conjunctivitis, requiring histopathological confirmation. Here we review the ocular pathology of this condition.

Artificial intelligence-based predictive model for guidance on treatment strategy selection in oral and maxillofacial surgery

Application of deep learning (DL) and machine learning (ML) is rapidly increasing in the medical field. DL is gaining significance for medical image analysis, particularly, in oral and maxillofacial surgeries. Owing to the ability to accurately identify and categorize both diseased and normal soft- and hard-tissue structures, DL has high application potential in the diagnosis and treatment of tumors and in orthognathic surgeries. Moreover, DL and ML can be used to develop prediction models that can aid surgeons to assess prognosis by analyzing the patient's medical history, imaging data, and surgical records, develop more effective treatment strategies, select appropriate surgical modalities, and evaluate the risk of postoperative complications. Such prediction models can play a crucial role in the selection of treatment strategies for oral and maxillofacial surgeries. Their practical application can improve the utilization of medical staff, increase the treatment accuracy and efficiency, reduce surgical risks, and provide an enhanced treatment experience to patients. However, DL and ML face limitations, such as data drift, unstable model results, and vulnerable social trust. With the advancement of social concepts and technologies, the use of these models in oral and maxillofacial surgery is anticipated to become more comprehensive and extensive.

Development and validation of the Oral Lichen Planus-Disease Activity Scale: a novel tool for comprehensive clinical assessment

OBJECTIVE

To develop and validate the Oral Lichen Planus-Disease Activity Scale (OLP-DAS) for assessing overall disease activity of OLP.

METHODS

The OLP-DAS was created by refining the Thongprasom criteria, incorporating inputs from the literature and expert review, and integrating pain assessment. Content validity was evaluated in a virtual meeting with 8 Oral Medicine specialists. Reliability and validity of the final version were examined. Seventeen OLP subjects were assessed for disease activity by 10 investigators using the OLP-DAS, Oral Disease Severity Score (ODSS), OLP-Investigator Global Assessment (OLP-IGA), and Reticular-Erythema-Ulcerative (REU) scale. Convergent validity was assessed by rating 160 OLP subjects using the OLP-DAS, ODSS, and OLP-IGA. Inter-rater and intra-rater reliability, along with convergent validity, were analyzed using intraclass correlation coefficients (ICCs) and Spearman's rank correlation coefficients (rs).

RESULTS

The final OLP-DAS achieved excellent content validity indices. Inter-rater and intra-rater ICCs for total OLP-DAS scores were 0.93 and 0.96, respectively. Total OLP-DAS scores exhibited strong positive correlations with the ODSS and OLP-IGA (rs = 0.94 and rs = 0.76; P < 0.001, respectively). The OLP Severity Index (OLP-SI), a component of the OLP-DAS, showed very strong positive correlations with OLP disease activity parameters of the ODSS (rs = 0.90; P < 0.001).

CONCLUSIONS

The OLP-DAS is a valid and reliable clinician-reported outcome measure (CROM) for evaluating OLP disease activity.

CLINICAL RELEVANCE

The OLP-DAS, as a standardized CROM for OLP, is valuable for both routine clinical assessments and research applications.

A Molecular Hypothesis on Malignant Transformation of Oral Lichen Planus: A Systematic Review and Meta-Analysis of Cancer Hallmarks Expression in This Oral Potentially Malignant Disorder

We aimed to qualitatively and quantitatively analyze, through a systematic review and meta-analysis, the current evidence on the differential expression of the hallmarks of cancer in oral lichen planus (OLP) samples, in order to know the earliest molecular mechanisms that could be involved in the malignant transformation of this oral potentially malignant disorder. We searched MEDLINE/PubMed, Embase, Web of Science, and Scopus for studies published before November 2023. We evaluated the methodological quality of studies and carried out meta-analyses to fulfill our objectives. Inclusion criteria were met by 110 primary-level studies, with 7065 OLP samples, in which the expression of 104 biomarkers were analyzed through immunohistochemistry. Most OLP samples showed sustained cell proliferation signaling (65.48%, 95%CI = 51.87-78.02), anti-apoptotic pathways (55.93%, 95%CI = 35.99-75.0), genome instability (48.44%, 95%CI = 13.54-84.19), and tumor-promoting inflammation events (83.10%, 95%CI = 73.93-90.74). Concurrently, OLP samples also harbored tumor growth suppressor mechanisms (64.00%, 95%CI = 53.27-74.12). In conclusion, current evidence indicates that molecular mechanisms promoting hyperproliferative signaling, an antiapoptotic state with genomic instability, and an escape of epithelial cells from immune destruction, are developed in LP-affected oral mucosa. It is plausible that these events are due to the actions exerted by the chronic inflammatory infiltrate. Malignant transformation appears to be prevented by tumor suppressor genes, which showed consistent upregulation in OLP samples.

Dysbiosis and interactions of the mycobiome and bacteriome in mucosal lesions of erosive and non-erosive oral lichen planus patients

Background

Oral lichen planus (OLP) is a common oral mucosal disease, clinically categorized into erosive OLP (EOLP) and non-erosive OLP (NEOLP) based on symptoms, but its pathogenic mechanism remains unclear. This study aims to explore the relationship between OLP and the oral microbiome.

Methods

We collected oral mucosal samples from 49 patients and 10 healthy individuals and conducted 16S rRNA and ITS gene sequencing to explore the oral fungal and bacterial communities.

Results

We observed significantly lower α diversity of fungi in the EOLP group, with Candida being significantly enriched as the main dominant genus. In the NEOLP group, Aspergillaceae were significantly enriched. The EOLP group showed significant enrichment of Aggregatibacter and Lactobacillus, but the relative abundance of Streptococcus was notably lower than in the other two groups. In the NEOLP group, two species including Prevotella intermedia were significantly enriched. The microbial co-occurrence and co-exclusion networks display distinct characteristics across the three groups, with Lactobacillus assuming a significant bridging role in the ELOP group.

Conclusions

Our study indicates that EOLP and NEOLP experience varying degrees of dysbiosis at both the fungal and bacterial levels. Therefore, the pathogenic mechanisms and interactive relationships of these microbiota associated with OLP merit further in-depth investigation.

A multi-center cross-sectional study of 1495 Chinese oral lichen planus patients

OBJECTIVE

To explore the clinical epidemiological characteristics of oral lichen planus (OLP) and risk factors for erosive/ulcerative OLP.

MATERIALS AND METHODS

Patients diagnosed with OLP from 11 different hospitals were included in the study. Descriptive statistical methods were used to explore the clinical epidemiological characteristics and logistic regression, sensitivity analysis, and subgroup analysis were utilized to explore the risk factors for erosive/ulcerative OLP.

RESULTS

The average age of patients was 49.2 ± 13.3 years, and 61.4% of the patients were women. The ratios of patients with reticular, hyperemic/erythematous, and erosive/ulcerative lesions were 47.9%, 27.8%, and 24.2%, respectively. Analysis of risk factors for erosive/ulcerative OLP identified the following variables: age, course of disease of 12 months or more, II°-III° dental calculus, hypertension, diabetes, and heart disease, as well as regions of habitation. Subgroup analysis showed significant differences in risk factors for erosive/ulcerative OLP in patients with and without risk behaviors.

CONCLUSION

The clinical epidemiological characteristics of patients with OLP in the Chinese population in this study are basically consistent with existing reports in developed countries. And we identified clinical characteristics associated with erosive/ulcerative OLP through clinical epidemiological analysis.

Oral epithelial dysplasia with lymphocytic immune response: clinicopathological characterisation of 44 cases

AIMS

Oral epithelial dysplasia (OED) often exhibits a lymphocytic/lichenoid immune response (LIR), imparting histological resemblance to lichenoid mucositis and rendering diagnosis challenging. The clinical appearances of OED and lichenoid inflammatory processes are generally divergent, presenting as well-demarcated hyperkeratotic plaques and diffuse white and/or red mucosal change with variably prominent Wickham striae, respectively. To date, clinicopathological characterisation of OED with LIR, including clinical/gross appearance, has not been depicted.

METHODS AND RESULTS

Cases of solitary OED with LIR for which a clinical photograph was available were identified in the authors' institutional files. Clinical and histological features were documented. In 44 identified cases, dysplasia was mild (19 of 44, 43.2%), moderate (19 of 44, 43.2%) and severe (six of 44, 13.6%). Clinically/grossly, all 44 cases (100.0%), presented as well-demarcated hyperkeratotic plaques lacking diffuse white-and-red mucosal change or Wickham striae. Histologically, OED with LIR exhibited numerous 'lichenoid' features beyond the lymphocytic band in the superficial lamina propria, including: leucocyte transmigration (38 of 44, 86.4%), spongiosis (37 of 44, 84.1%), Civatte/colloid bodies (36 of 44, 81.8%), basal cell degeneration (29 of 45, 65.9%), sawtooth rete ridges (11 of 44, 25.0%) and subepithelial clefting (7 of 44, 15.9%).

CONCLUSIONS

Virtually any lichenoid histological feature may be seen in OED with LIR, representing a significant diagnostic pitfall. The typical clinical appearance of OED with LIR is of a well-demarcated hyperkeratotic plaque, characteristic of keratinising dysplasia and devoid of lichenoid features. This suggests that pathologist access to clinical photographs during diagnostic interpretation of biopsied white lesions, which represents opportunity to perform gross examination of the disease process, may reduce interobserver variability and improve diagnostic accuracy in this challenging differential diagnosis.

Analysis of oral lichen planus severity on micro-RNA linked with malignant transformation risks

OBJECTIVE

The present study evaluated the oral tissue expression of micro-RNA (miRNAs) linked to the potential malignant evolution of oral lichen planus (OLP). Furthermore, the correlation between OLP severity and miRNAs expression was assessed, and possible predictors of miRNAs in OLP patients were identified.

METHODS

The present study enrolled 41 patients with OLP (median age 58 years) and 42 healthy controls (median age 59 years). In each patient, miRNA levels (miR-7a-3p,-7a2-3p,-7a-5p,-21-3p,-21-5p,-100-3p,-100-5p,-125b-2-3p,-125b-5p,-200b-3p,-200b-5p) were assessed and analyzed through reverse transcription polymerase chain reaction. Clinical parameters and the eventual presence of OLP symptoms, signs, and disease severity scores in each patient were reported using an anamnestic questionnaire.

RESULTS

In comparison with healthy controls, OLP patients showed significantly higher miR-7a-3p,-7a-2-3p,-21-3p, miR-21-5p and miR-100-5p levels (p < 0.05) and significantly lower miR-125b-2-3p,-125b-5p,-200b-3p, and -200b-5p levels (p < 0.05). Furthermore, OLP symptoms and signs and disease severity scores were significantly correlated and were also predictors of all analyzed miRNAs (p < 0.05).

CONCLUSIONS

In comparison with healthy subjects, OLP patients exhibited unbalanced oral miRNAs expression linked to the risk of potential malignant evolution of OLP. Furthermore, some miRNAs were correlated with OLP extent and were significant predictors of OLP symptoms, signs, and disease severity scores.

Identification of the differentially expressed activated memory CD4+ T-cells-related genes and ceRNAs in oral lichen planus

Background

Oral lichen planus (OLP) is a common chronic oral mucosal disease with 1.4 % malignant transformation rate, and its etiology especially immune pathogenesis remains unclear. This study was aimed at investigating the immune cells related molecular underlying the pathophysiology of OLP through bioinformatics analysis.

Methods

The dataset GSE52130 obtained from the Gene Expression Omnibus (GEO) database was conducted a comprehensive analysis in this study. The CIBERSORTx was used for investigating immune cells infiltration. The gene set enrichment analysis (GSEA) and gene ontology (GO) enrichment were performed for exploring the biological functions and gene annotation. The protein-protein interactions (PPI) were constructed by STRING database and visualized by Cytoscape software. The cytohubba plugin was utilized for screening hub genes. The receiver operating characteristic (ROC) was performed for evaluating diagnostic value of hub genes. The miRNAs, lncRNAs and drugs were respectively predicted by NetworkAnalyst, miRTarbase, ENCORI, and DGIdb database.

Results

This study identified 595 differentially expressed genes (DEGs). The GSEA indicated keratinization, innate immune system and biological oxidation were involved in OLP. GO analysis showed extracellular matrix and keratinocyte were mainly enriched. And we found the activated memory CD4+ T cells were lowly infiltrated in OLP. We identified 101 activated memory CD4+ T-cells-related DEGs. Three hub genes (APP, IL1B, TF) were selected. APP and IL1B were significantly up-regulated, whereas TF was down-regulated in OLP. The three hub genes show high diagnostic value in OLP. Additionally, they were involved in MAPK signal, NF-kappaB signal and iron metabolism in OLP. What's more, NEAT1/XIST - miR - 15a - 5p/miR - 155-5p - APP/IL1B signal axis was focused in competing endogenous RNA (ceRNA) network. In addition, 35 drugs were predicted for OLP.

Conclusion

Three activated memory CD4+ T-cells-related DEGs were identified by integrative analysis. It may provide novel insight into the pathogenesis of OLP and suggest potential therapeutic targets for OLP.

Oral and non-oral lichen planus show genetic heterogeneity and differential risk for autoimmune disease and oral cancer

Lichen planus (LP) is a T-cell-mediated inflammatory disease affecting squamous epithelia in many parts of the body, most often the skin and oral mucosa. Cutaneous LP is usually transient and oral LP (OLP) is most often chronic, so we performed a large-scale genetic and epidemiological study of LP to address whether the oral and non-oral subgroups have shared or distinct underlying pathologies and their overlap with autoimmune disease. Using lifelong records covering diagnoses, procedures, and clinic identity from 473,580 individuals in the FinnGen study, genome-wide association analyses were conducted on carefully constructed subcategories of OLP (n = 3,323) and non-oral LP (n = 4,356) and on the combined group. We identified 15 genome-wide significant associations in FinnGen and an additional 12 when meta-analyzed with UKBB (27 independent associations at 25 distinct genomic locations), most of which are shared between oral and non-oral LP. Many associations coincide with known autoimmune disease loci, consistent with the epidemiologic enrichment of LP with hypothyroidism and other autoimmune diseases. Notably, a third of the FinnGen associations demonstrate significant differences between OLP and non-OLP. We also observed a 13.6-fold risk for tongue cancer and an elevated risk for other oral cancers in OLP, in agreement with earlier reports that connect LP with higher cancer incidence. In addition to a large-scale dissection of LP genetics and comorbidities, our study demonstrates the use of comprehensive, multidimensional health registry data to address outstanding clinical questions and reveal underlying biological mechanisms in common but understudied diseases.

Efficacy and safety of topical clobetasol propionate in comparison with alternative treatments in oral lichen planus: an updated systematic review and meta-analysis

Background

Oral lichen planus (OLP) is a relatively common chronic T cell-mediated disease characterized by pain and inflammation. Clobetasol propionate (CLO) is the first-line drug in the treatment of OLP. The meta-analysis aimed to evaluate the efficacy and safety of CLO for treating patients with OLP.

Methods

PubMed, Embase and Web of Science were systematically searched from the database inception date up to August 2023. There were no restrictions on language or date of publication. The outcomes of our interest were as follows: improvement of clinical signs and/or symptoms, total lesion size, relapse and adverse events.

Results

A total of 17 RCTs evaluating the effects of CLO were included in this study. The results revealed no significant difference in the clinical score (WMD = 0.14, 95% CI: -0.39, 0.66; p = 0.609) and pain score (WMD = 0.17, 95% CI: -0.44, 0.79; p = 0.582) between CLO and other treatments. However, clinical resolution (RR = 1.61, 95% CI: 1.17, 2.22; p = 0.003) and symptoms improvement (RR = 1.80, 95% CI: 1.17, 2.77; p = 0.008) were significantly different between CLO and other treatments. Moreover, there was a significant reduction in the total lesion size with CLO treatment (WMD = -0.58, 95% CI: -1.03, -0.13; p = 0.011). In addition, CLO showed no statistical incidence of adverse events (RR = 1.46, 95% CI: 0.86, 2.50; p = 0.161) and relapse (RR = 1.56, 95% CI: 0.66, 3.71; p = 0.314) than other therapies.

Conclusion

This systematic review and meta-analysis of 17 randomized clinical trials supported the long-term application of CLO as an effective regimen in OLP patients.

Animal models to study the pathogenesis and novel therapeutics of oral lichen planus

Oral lichen planus (OLP) is a prevalent oral mucosal disease characterized by an unknown etiology and a complex pathogenesis. Patients with OLP endure a chronic course marked by alternating non-erosive and erosive lesions, with no definitive cure currently available. Particularly challenging is the treatment of recalcitrant erosive OLP, highlighting an urgent need for therapies targeting specific pathogenic pathways. In diseases like OLP, where the etiopathogenesis is intricate and elusive, animal models are indispensable for hypothesis testing and elucidating disease mechanisms. To date, only three animal models for oral lichenoid lesions have been reported in the literature. This Perspective paper evaluates these existing models, along with a novel OLP mouse model introduced at the 3rd International Conference on Oral Mucosal Immunity and Microbiome. The validity of these models is critically assessed, and their potential future applications in advancing our understanding of OLP are discussed.

Hypertension in oral lichen planus: A systematic review and meta-analysis

OBJECTIVES

To perform a systematic review and meta-analysis in order to qualitatively and quantitatively evaluate the prevalence and magnitude of the association of hypertension in patients with oral lichen planus (OLP).

METHODS

MEDLINE, Embase, Scopus, and Web of Science databases were searched for studies published before May 2022, not restricted by publication language or date. The methodological quality and risk of bias of primary-level studies were critically assessed. Meta-analyses were performed, as well as meta-regression, stratified, sensitivity and small-study effects analyses, a Galbraith (radial) plot, and trial sequential analysis. Quality of evidence was evaluated using GRADE system.

RESULTS

104 studies, including 16,587 patients, met the inclusion criteria. The results show that patients who suffer from OLP have a high prevalence of hypertension (PP = 24.17%, 95% CI = 21.45-27.00), with a low quality of evidence. A significant association between hypertension and oral lichen planus was also reported (OR = 1.28, 95% CI = 1.01-1.63, p = 0.04), showing a moderate quality of evidence.

CONCLUSIONS

Patients with OLP could be at an increased risk of suffering from hypertension which is probably due to multiple factors. Healthcare practitioners involved in OLP management should be aware of this comorbidity in order to apply suitable measures and make referrals if hypertension is suspected, although further research is needed.

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.

Histologic and Histomorphometric Comparative Study of Oral Lichen Planus Versus Oral Lichenoid Reaction

Aim

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory disease classified as an oral potentially malignant disorder (OPMD) and increased transformation risk to oral cancer. Oral lichenoid reactions (OLRs) share the clinical manifestations of OLP. This study aimed to determine histomorphometric changes in OLPs and OLRs in comparison to the healthy control, which helps to plan for the establishment of diagnostic criteria.

Materials and Methods

This cross-sectional prospective study was conducted on a total of 75 tissue-embedded paraffin-block samples, including OLPs (n = 25), OLR cases (n = 25), and healthy control individuals (n = 25). The study groups were compared by chi-squared, Fisher's exact, and one-way ANOVA tests. A p-value less than 0.05 was considered statistically significant.

Results

Comparison of the nuclear area and cellular area showed a statistically significant difference between study groups in basal and parabasal layer (P < 0.05). Comparison of the nuclear-to-cytoplasm ratio showed a statistically significant difference between study groups in basal (P < 0.05) but not in the parabasal region (P = 0.681).

Conclusion

We showed a significant difference in the nuclear and cellular area, nuclear-to-cytoplasm ratio between OLPs and OLRs, and healthy controls, but there was no statistically significant difference between OLPs and OLRs. Thus, these parameters cannot be applied to differentiate diagnoses between OLPs and OLRs.

Topical clobetasol treatment for oral lichen planus can cause adrenal insufficiency

OBJECTIVE

Glucocorticoids suppress the hypothalamic-pituitary-adrenal axis, which may lead to glucocorticoid-induced adrenal insufficiency. The study aimed to investigate the prevalence of this state in patients with oral lichen planus treated with topical clobetasol propionate.

METHODS

In this cross-sectional study, 30 patients with oral lichen planus receiving long-term (>6 weeks) clobetasol propionate gel 0.025% were invited to participate. Adrenal function was assessed by measuring morning plasma cortisol after a 48-h withdrawal of clobetasol treatment. In patients with plasma cortisol <280 nmol/L, a cosyntropin stimulation test was performed.

RESULTS

Twenty-seven patients were included. Twenty-one (78%) patients presented with plasma cortisol ≥280 nmol/L (range 280-570 nmol/L), and six (22%) <280 nmol/L (range 13-260 nmol/L). Five of these six patients underwent cosyntropin stimulation that revealed severe adrenal insufficiency in two patients (cortisol peak 150 nmol/L and 210 nmol/L) and mild adrenal insufficiency in three patients (cortisol peak 350-388 nmol/L).

CONCLUSION

In this study, approximately 20% of patients receiving intermittent topical glucocorticoid treatment for oral lichen planus had glucocorticoid-induced adrenal insufficiency. It is essential for clinicians to be aware of this risk and to inform patients about the potential need for glucocorticoid stress doses during intercurrent illness.

Inflammatory cytokines mediating the effect of oral lichen planus on oral cavity cancer risk: a univariable and multivariable mendelian randomization study

BACKGROUND

While observational studies and experimental data suggest a link between oral lichen planus (OLP) and oral cavity cancer (OCC), the causal relationship and the role of inflammatory cytokines remain unclear.

METHODS

This study employed a univariable and multivariable Mendelian Randomization (MR) analysis to investigate the causal relationship between OLP and the risk of OCC. Additionally, the potential role of inflammatory cytokines in modulating this association was explored. Instrumental variables were derived from genetic variants associated with OLP (n = 377,277) identified in Finngen R9 datasets, with 41 inflammatory cytokines as potential mediators, and OCC (n = 4,151) as the outcome variable. Analytical methods including Inverse Variance Weighted (IVW), Weighted Median, MR-Egger, and MR-PRESSO were utilized to assess the causal links among OLP, inflammatory cytokines, and OCC risk. Multivariable MR (MVMR) was then applied to quantify the mediating effects of these cytokines in the relationship between OLP and increased OCC risk.

RESULTS

MR analysis provided strong evidence of a causal relationship between OLP (OR = 1.417, 95% CI = 1.167-1.721, p < 0.001) and the risk of OCC. Furthermore, two inflammatory cytokines significantly influenced by OLP, IL-13 (OR = 1.088, 95% CI: 1.007-1.175, P = 0.032) and IL-9 (OR = 1.085, 95% CI: 1.005-1.171, P = 0.037), were identified. Subsequent analysis revealed a significant causal association only between IL-13 (OR = 1.408, 95% CI: 1.147-1.727, P = 0.001) and higher OCC risk, establishing it as a potential mediator. Further, MVMR analysis indicated that IL-13 (OR = 1.437, 95% CI = 1.139-1.815, P = 0.002) mediated the relationship between OLP and OCC, accounting for 8.13% of the mediation.

CONCLUSION

This study not only elucidates the potential causal relationship between OLP and the risk of OCC but also highlights the pivotal mediating role of IL-13 in this association.

Prognosis of oral epithelial dysplasia in individuals with and without oral lichen planus

OBJECTIVES

To investigate the role of oral lichen planus (OLP) on the long-term prognosis of oral epithelial dysplasia (OED).

METHODS

Retrospective single-centre cohort study using the 2007-2019 database of the Head and Neck Cancer and Oral Medicine units of University College London Hospital. The exposure of interest was the presence of OLP, and the prognostic outcomes included the development of new primary episodes of OED, progression to malignancy and mortality. Cox proportional hazard and Poisson regression models were performed.

RESULTS

A total of 299 patients, of whom 144 had OED arising on the background of OLP (OLP/OED) and 155 had OED without underlying OLP (non-OLP/OED), were included. A pre-existing diagnosis of OLP was significantly associated with a twofold increased risk of subsequent primary OED events (HR = 2.02, p = 0.04), which also developed faster (1.46 vs. 2.96 years, p = 0.04) and with more involvement of non-cancer-prone sites (p = 0.001) than in the non-OLP/OED group. There was no difference between groups in the progression to malignancy or mortality.

CONCLUSIONS

Oral lichen planus/OED patients are at higher risk of multiple episodes of primary OED, which can develop faster and at non-cancer-prone sites as compared to non-OLP/OED individuals. Further research is needed to clarify the effects of OLP upon progression to OSCC and mortality.

An Evidence-Based Update on the Potential for Malignancy of Oral Lichen Planus and Related Conditions: A Systematic Review and Meta-Analysis

A systematic review and a meta-analysis is presented on published articles on the malignant transformation of oral lichen planus (OLP) and related conditions, which, based on current evidence, updates an earlier systematic review published by our research group that included publications until November 2018. In this updated study (Nov-2023) we searched MEDLINE, Embase, Web of Science, and Scopus. We evaluated the methodological quality of studies (QUIPS tool) and carried out meta-analyses. The inclusion criteria were met by 101 studies (38,083 patients), of which, 20 new primary-level studies (11,512 patients) were published in the last 5 years and were added to our updated study. The pooled malignant transformation ratio was 1.43% (95% CI = 1.09-1.80) for OLP; 1.38% (95% CI = 0.16-3.38) for oral lichenoid lesions; 1.20% (95% CI = 0.00-4.25) for lichenoid reactions; and 5.13% (95% CI = 1.90-9.43) for OLP with dysplasia. No significant differences were found between the OLL or LR groups and the OLP subgroup (p = 0.853 and p = 0.328, respectively), and the malignant transformation was significantly higher for the OLP with dysplasia group in comparison with the OLP group (p = 0.001). The factors that had a significant impact with a higher risk of malignant transformation were the presence of epithelial dysplasia, a higher methodological quality, the consumption of tobacco and alcohol, the location of lesions on the tongue, the presence of atrophic and erosive lesions, and infection by the hepatitis C virus. In conclusion, OLP behaves as an oral potentially malignant disorder (OPMD), whose malignancy ratio is probably underestimated as a consequence essentially of the use of inadequate diagnostic criteria and the low methodological quality of the studies on the subject.

Artificial intelligence for classification and detection of oral mucosa lesions on photographs: a systematic review and meta-analysis

OBJECTIVE

This study aimed to review and synthesize studies using artificial intelligence (AI) for classifying, detecting, or segmenting oral mucosal lesions on photographs.

MATERIALS AND METHOD

Inclusion criteria were (1) studies employing AI to (2) classify, detect, or segment oral mucosa lesions, (3) on oral photographs of human subjects. Included studies were assessed for risk of bias using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). A PubMed, Scopus, Embase, Web of Science, IEEE, arXiv, medRxiv, and grey literature (Google Scholar) search was conducted until June 2023, without language limitation.

RESULTS

After initial searching, 36 eligible studies (from 8734 identified records) were included. Based on QUADAS-2, only 7% of studies were at low risk of bias for all domains. Studies employed different AI models and reported a wide range of outcomes and metrics. The accuracy of AI for detecting oral mucosal lesions ranged from 74 to 100%, while that for clinicians un-aided by AI ranged from 61 to 98%. Pooled diagnostic odds ratio for studies which evaluated AI for diagnosing or discriminating potentially malignant lesions was 155 (95% confidence interval 23-1019), while that for cancerous lesions was 114 (59-221).

CONCLUSIONS

AI may assist in oral mucosa lesion screening while the expected accuracy gains or further health benefits remain unclear so far.

CLINICAL RELEVANCE

Artificial intelligence assists oral mucosa lesion screening and may foster more targeted testing and referral in the hands of non-specialist providers, for example. So far, it remains unclear if accuracy gains compared with specialized can be realized.

Oral Lichen Planus: An Update on Diagnosis and Management

Oral lichen planus (OLP) is a chronic inflammatory disease whose pathogenesis involves a T-cell mediated, epithelium-directed inflammation in response to unknown antigen(s). The disease evolves by intermittent flares and displays polymorphous clinical features (reticular, erosive, atrophic, plaque, papular, bullous, etc.). When present, symptoms vary depending on the clinical form and range from discomfort to severe pain. Topical superpotent corticosteroids constitute the first-line treatment of symptomatic flares, whereas a wide range of second/third-line treatments are available among topical calcineurin inhibitors, systemic corticosteroids, systemic retinoids, topical/systemic immunomodulators, etc. Follow-up of patients is necessary to detect transformation into squamous cell carcinoma, occurring in approximately 1% of patients.

CircHLA-C: A significantly upregulated circRNA co-existing in oral leukoplakia and oral lichen planus

BACKGROUND

Oral leukoplakia (OLK) and oral lichen planus (OLP) are common precancerous lesions of the oral mucosa. The role of circular RNAs (circRNAs) in OLK and OLP is unclear. The aim of this study was to evaluate the circRNA expression profiles of OLK and OLP, and further explore the potential role of circRNAs in the pathogenesis of these two diseases.

METHODS

High throughput sequencing technology was performed to detect the differentially expressed circRNA in OLK (n = 6), OLP (n = 6), oral squamous cell carcinoma (n = 6), and normal oral mucosa tissues (n = 6). Expression of selected circRNAs was validated by qRT-PCR, enzyme tolerance assay, and Sanger sequencing. Expanded sample size validation was done in 20 tissue pairs. The biological processes and signal pathways involved in differential circRNA were analyzed by GO and KEGG enrichment. TargetScan and MiRanda were used to predict miRNAs downstream of circRNA and draw competitive endogenous RNA network diagram.

RESULTS

Forty-nine circRNAs were significantly altered in OLK and OLP, including 30 upregulated and 19 downregulated circRNAs. The five selected circRNAs were validated by qRT-PCR, Sanger sequencing, and RNase R assay. GO and KEGG analyses indicated that the upregulated circHLA-C may be involved in the biological process of immune function of OLK and OLP. Bioinformatics analysis indicated that circHLA-C may be involved in the progression of OLK and OLP as a ceRNA. In validation with expanded sample size, PCR results showed that circHLA-C expression was significantly upregulated in OLK and OLP. ROC analysis indicated that circHLA-C has potential diagnostic value with good accuracy and specificity.

CONCLUSION

Our study revealed that circHLA-C is the most significantly upregulated circRNA co-existing in OLK and OLP, and we preliminarily discuss the role of circHLA-C in the etiopathogenesis and progression of OLK and OLP.

Morphea Involving the Lips and Gingiva: A Rare Case Report

Morphea is a subtype of scleroderma that does not involve Raynaud's phenomenon or internal organ involvement. It is a connective tissue disease that features the excessive deposition of collagen in the dermis and subcutaneous tissue, leading to a thickening of the dermis and subcutaneous tissue, eventually forming a scar-like lesion. We represent a 19-year-old male Saudi patient displaying a white patch on the marginal gingiva of tooth #21 and multiple yellowish papules on the outer surface of the lip. Both teeth #21 and #22 have experienced recession and bone loss. The patient's clinical history and histopathology revealed characteristic features of localized scleroderma. A treatment was proposed involving immunosuppressants, methotrexate, and pimecrolimus cream along with topical corticosteroids and excimer laser therapy (308 nm). The patient followed the treatment plan for a full month and the white patch quickly improved for the patient. Afterward, the patient has been taking only methotrexate with a significant but gradual improvement. In this paper, we discuss the differential diagnosis to be considered and present an unusual occurrence of localized scleroderma in the oral cavity.

Non-Coding RNAs as Potential Targets for Diagnosis and Treatment of Oral Lichen Planus: A Narrative Review

Oral lichen planus (OLP) is a chronic inflammatory disease that is characterized by the infiltration of T cells into the oral mucosa, causing the apoptosis of basal keratinocytes. OLP is a multifactorial disease of unknown etiology and is not solely caused by the malfunction of a single key gene but rather by various intracellular and extracellular factors. Non-coding RNAs play a critical role in immunological homeostasis and inflammatory response and are found in all cell types and bodily fluids, and their expression is closely regulated to preserve normal physiologies. The dysregulation of non-coding RNAs may be highly implicated in the onset and progression of diverse inflammatory disorders, including OLP. This narrative review summarizes the role of non-coding RNAs in molecular and cellular changes in the oral epithelium during OLP pathogenesis.

Clinicohistological Characteristics of Patients with Oral Lichenoid Mucositis: A Retrospective Study for Dental Hospital Records

Oral lichenoid mucositis (OLM) of the oral mucosa is a histological diagnosis mainly characterised by a band of inflammatory infiltrate in lamina propria and basal cell degeneration. These features describe oral lichen planus or oral lichenoid reaction. However, it could be seen in oral dysplasia. The study aimed to assess the demographics and clinicohistological characteristics of patients with OLM and their relevance to dysplastic changes in the oral mucosa. This was a cross-sectional and retrospective study of archived and electronic records of individuals with histological confirmation of OLM at King Saud University Medical City, Saudi Arabia. The descriptive and correlation assessments were used to describe the demographics and clinicohistological characteristics and their associations, respectively [p < 0.05]. The analysis included 140 records of patients with histological confirmation of OLM with a mean age of 47 (±13), and 57% (n = 81) were females. Notably, 40% of patients had at least one medical condition, mainly diabetes mellitus, 74% were asymptomatic, and 52% had lesions in the buccal mucosa. Dysplasia was seen in 18 (12%) of the 140 reviewed records. Regarding the associations between study variables, dysplastic changes were associated with the male gender [p = 0.024] and were of no significance with increased age [p = 0.594]. Moreover, having oral symptoms was associated with older age [p < 0.001], medical history of diabetes [p = 0.0132] and hypertension [p < 0.001]. The present study findings could help indicate the individuals with histologically confirmed OLM who suffer the most from the clinical disease and have an increased risk of dysplastic changes. Therefore, symptomatic management and long-term follow-up can be planned accordingly.

Direct immunofluorescence cannot be used solely to differentiate among oral lichen planus, oral lichenoid lesion, and oral epithelial dysplasia

Background/purpose

Some red and white lesions may have similar manifestations, making them difficult to be diagnosed. A direct immunofluorescence (DIF) assay can assist in making a final diagnosis of oral lichen planus (OLP). The aim of this study was to evaluate and compare the DIF profile in patients who had the clinical presentations of OLP and were histopathologically diagnosed with OLP, OLL (oral lichenoid lesion), or OED (oral epithelial dysplasia).

Materials and methods

The data were obtained from the medical records of 136 patients with the clinical presentations of OLP. Demographic information, histopathological diagnosis, malignant transformation, and DIF results were collected and analyzed.

Results

In this study, 117 patients (86.0%) were DIF-positive, while 19 patients (14.0%) were DIF-negative. The highest DIF-positivity rate was in the OLP group (88.9%) followed by the OLL (83.7%), and the OED groups (81%). There were no significant differences in DIF-positivity rate, type of immunoreactants, location, or interpretation among these groups. Shaggy fibrinogen at the basement membrane zone (BMZ) was the most common DIF pattern in all groups.

Conclusion

The DIF assay alone cannot be regarded as sufficient evidence for OLP, OLL, and OED differentiation. A histopathological examination is required to determine the presence of epithelial dysplasia or malignancy. To diagnose dysplastic lesions with the clinical manifestations of OLP, careful clinicopathologic correlation is mandatory. Due to the lack of scientific evidence to identify the primary pathology and the ongoing malignancy risk of epithelial dysplasia, meticulous long-term follow-up plays a crucial role in patient management.

Oral lichen planus and related lesions. What should we accept based on the available evidence?

Recent new terminologies have been proposed for lesions in the sphere of oral lichen planus (OLP) that theoretically present unique aetiological, clinical, prognostic or management characteristics different from those of the so-called typical forms of OLP. We aimed to critically analyse what concepts and terminologies related to OLP should we accept based on the available evidence. A review of the literature was carried out in order to critically analyse the concepts and terminologies related to OLP. New concepts and terminologies include oral lichenoid lesions; contact lichenoid reactions, drug lichenoid reactions or those in the context of graft-versus-host disease; chronic ulcerative stomatitis; lichen planus pemphigoid; and some lesions that are difficult to categorise, such as OLP with features of proliferative verrucous leukoplakia and lichenoid lesions of the upper labial mucosa. A multidisciplinary, multicontinent working group has recently published a guideline with recommendations for modifying definitions and terminologies associated with a disease, among which a reasoned, evidence-based justification for the proposed change is considered essential. An in-depth analysis of the newly proposed terms for OLP-related lesions shows that many of them are not justified. In this paper, we set out our position on the basis of the existing evidence on the appropriateness of the use of these new terms.