The malignant transformation of oral lichen planus and oral lichenoid lesions

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.

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.

Hydroxychloroquine is effective in oral lichen planus: A multicenter, randomized, controlled trial

OBJECTIVES

This study was aimed to evaluate the safety and benefit of short-term application of hydroxychloroquine in the management of atrophic/erosive/ulcerative oral lichen planus (OLP).

METHODS

This multicenter, randomized, controlled, evaluator-blinded, prospective clinical trial was performed from October 1, 2019, to September 1, 2022. A total of 99 patients were randomized to receive systemic use of hydroxychloroquine (n = 50), or topical use of 0.05% dexamethasone (n = 49) for 4 weeks. The response to both treatment modalities was evaluated according to reticulation, hyperemic, and ulceration (RHU) score and visual analog scale (VAS) score.

RESULTS

After 4 weeks of medication, both groups showed substantial reduction in RHU and VAS score (p < 0.05). In hydroxychloroquine group, the average of RHU score was reduced from 10.60 to 7.68 (dropped 27.49%), and the average of VAS score was reduced from 3.74 to 2.47 (dropped 34.09%). There were no differences between the two groups in reduction of RHU score and VAS score (p > 0.05). Single factor analysis found hyperemic area (p = 0.019) and erosive/ulcerative area (p = 0.024) had impacts on drug efficacy of hydroxychloroquine, and logistic regression revealed that no factors (p > 0.05) influenced its efficacy.

CONCLUSION

These findings indicate hydroxychloroquine is a safe and effective agent in treating atrophic/erosive/ulcerative OLP.

The Clinical Behavior and Recurrence Patterns of Oral Cavity Cancer in Oral Lichen Planus Patients

OBJECTIVES

Oral lichen planus (OLP) is a chronic inflammatory disorder involving epithelia with squamous differentiation. Although described as a potential malignant precursor, the characteristics of malignancies arising among these patients are not widely described. Our goal was to describe the patterns of disease recurrence of patients with oral cavity squamous cell carcinoma (OSCC) arising on the background of OLP.

METHODS

A retrospective analysis of all surgically treated patients with OSCC at a university-affiliated tertiary care center between 2000 and 2020.

RESULTS

Two hundred seventy-nine patients with OSCC treated surgically were included. Forty (14.3%) had OLP. The mean age of patients with OLP was 70.9 years compared with 64.3 years for non-OLP patients (p = 0.03). OLP patients had a significantly higher rate of disease recurrence, persistence, or multiple primary disease (70% vs. 33.9%, p < 0.001). The mean number of sequential oncologic events for each patient with recurrence was also significantly higher among OLP patients (1.86 vs. 1.36, p = 0.03), a difference explained by a higher rate of multiple primary presentations (0.71 vs. 0.28, p = 0.008). A significant difference in disease-free survival (DFS) was demonstrated between the groups as patients with OLP had a lower 5-year DFS (34.7% vs. 61.3%, log-rank p value <0.001). On multivariate analysis, OLP was significantly associated with multiple primary events (p < 0.001, Odds ratio = 7.42, 95% confidence interval 2.9-19).

CONCLUSIONS

OSCC patients with OLP background demand close clinical follow-up, as multiple primary disease is significantly more common and the DFS is significantly lower among these patients. A thorough clinical evaluation for all oral cavity subsites is mandatory.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3146-3151, 2024.

The effect of antiresorptive therapy on the prevalence and severity of oral lichen planus: a retrospective study

BACKGROUND

Antiresorptive therapy (AR) disrupts osseous homeostasis and can induce direct irritation over the gastrointestinal mucosa; however, its possible erosive effects on the oral epithelium have not been totally described. Among the most frequent oral erosive lesions, oral lichen planus (OLP) frequently presents as painful mucosal ulcerations, arising from basal membrane inflammatory damage. Thus, the aim of this retrospective study was to describe the association between AR and the incidence of OLP.

METHODS

This case-control study included data from 148 patients (17 patients undergoing AR therapy (AR group) / 131 without AR therapy (Control group)). Each patient record was systematically processed and the association between AR drugs and OLP clinical characteristics within both groups was assessed.

RESULTS

The erosive form of OLP was significantly more frequent in the AR group than in the Control group (p = 0.029). Indeed, the AR treatment using alendronic acid (41.2%) was the most frequently reported. Additionally, the erosive form of OLP showed the strongest association with pain and burning sensation among the OLP types (p < 0.050). However, disease worsening and AR consumption were not significantly associated (p = 0.150).

CONCLUSIONS

Patients under AR therapy show more clinical symptoms associated to the erosive type of OLP. Regardless of the AR therapy, the erosive type of OLP is associated with more severe symptoms.

Oral bacteriome and oral potentially malignant disorders: A systematic review of the associations

INTRODUCTION

Periodontal bacteria can infiltrate the epithelium, activate signaling pathways, induce inflammation, and block natural killer and cytotoxic cells, all of which contribute to the vicious circle of carcinogenesis. It is unknown whether oral dysbiosis has an impact on the etiology or prognosis of OPMD.

AIMS

Within this paradigm, this work systemically investigated and reported on the composition of oral microbiota in patients with oral potentially malignant disorders (OPMD) versus healthy controls.

METHODS

Observational studies that reported next generation sequencing analysis of oral tissue or salivary samples and found at least three bacterial species were included. Identification, screening, citation analysis, and graphical synthesis were carried out.

RESULTS

For oral lichen planus (OLP), the bacteria with the highest abundance were Fusobacterium, Capnocytophaga, Gemella, Granulicatella, Porphyromonas, and Rothia; for oral leukoplakia (OLK), Prevotella. Streptococci levels in OLK and OLP were lower. The usage of alcohol or smoke had no effect on the outcomes.

CONCLUSIONS

An increase in periodontal pathogenic bacteria could promote the development and exacerbation of lichen. Effective bacteriome-based biomarkers are worthy of further investigation and application, as are bacteriome-based treatments.

Successful Treatment of Erosive Lichen Planus With Tofacitinib: A Case Series and Review of the Literature

Lichen planus (LP) is an inflammatory disease that affects the skin, hair, nails and mucous membranes. Erosive LP is a chronic and difficult-to-treat subtype of lichen planus, characterized by lesions on mucosal surfaces, particularly in the oral and genital areas. The prevalence of erosive LP has not been determined. To date, treatment has consisted of surgical intervention, photodynamic therapy, laser therapy, and systemic or topical drugs, including steroids and immunomodulatory agents. LP usually need longer periods of treatment and are known as precancerous lesions with a 0.4% to 12% conversion rate. In addition, nearly 25% of patients who develop erosive LP of the vulva are resistant to topical corticosteroids, which are the first choice of treatment. This study reports 6 cases with a mean age of 3.33 years, who were diagnosed with erosive LP lesions and previously failed in treatment with local, intralesional, and systemic steroids, and hydroxychloroquine. These patients were then treated with 10 mg of tofacitinib per day. Interestingly, with the new treatment, the patients' mean overall satisfaction score was 9.16 out of 10 (range: 8-10), the mean pain relief score was 9.16 out of 10 (range: 9-10) and patients' symptom improvement also began an average of 1.33 months after starting treatment (range: 1-2.5 months).

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.

What can we learn from treatments of oral lichen planus?

Oral lichen planus (OLP), a T-lymphocyte-mediated disease of the oral mucosa, has a complex pathogenesis that involves a number of factors. The disease is characterized by recurrent episodes and requires continuous follow up, and there is no curative treatment available. Erosive lichen planus, among others, has a risk of malignant transformation and requires standardized treatment to control its progression. Different clinical subtypes of oral lichen planus require appropriate treatment. Pharmacological treatments are the most widely available and have the greatest variety of options and a number of novel pharmacological treatments are presented as highlights, including JAK enzyme inhibitors. The second is photodynamic therapy, which is the leading physiological treatment. In addition, periodontal treatment and psychological treatment should not be neglected. In this review, we briefly discuss the most recent developments in therapies for oral lichen planus after summarizing the most widely used clinical treatments, aiming to provide different proposals for future clinical treatment.

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.

Oral Adverse Events Associated with BRAF and MEK Inhibitors in Melanoma Treatment: A Narrative Literature Review

BACKGROUND

Melanoma cancer represents the most lethal type of skin cancer originating from the malignant transformation of melanocyte cells. Almost 50% of melanomas show the activation of BRAF mutations. The identification and characterization of BRAF mutations led to the development of specific drugs that radically changed the therapeutic approach to melanoma.

METHODS

We conducted a narrative review of the literature according to a written protocol before conducting the study. This article is based on previously conducted studies. We identified articles by searching electronic databases (Medline, Google Scholar and PubMed). We used a combination of "melanoma", "Braf-Mek inhibitors", " targeted therapy" and "oral side effects".

RESULTS

Eighteen studies were reported in this article showing the relationship between the use of targeted therapy in melanoma cancer and the development of oral side effects, such as mucositis, hyperkeratosis and cellular proliferation.

CONCLUSION

Targeted therapy plays an important role in the treatment of melanoma cancer, showing a notable increase in response rate, prolonged progression-free survival and overall survival in BRAF-mutated melanoma patients. Oral side effects represent a common finding over the course of treatment. However, these adverse effects can be easily managed in a multidisciplinary approach involving collaboration between medical oncologists and dental doctors.

Bridging the gaps: management of lichen planus subtypes in a joint dermatology-oral surgery clinic

Lichen planus (LP) presents with a range of clinical subtypes. It can affect the outer skin, involve the nails and present with alopecia and mucosal symptoms to varying degrees. LP of the outer skin mostly shows a self-limiting course; however, this is not the case for lichen planopilaris and the mucosa-affecting subtypes. The pathogenesis of LP is still incompletely understood. As a result, an effective, targeted therapy is currently lacking and different immunomodulatory approaches are being used in clinical practice. The management of patients with severe oral LP mucosae can be particularly challenging. Although the true risk remains controversial, oral LP is considered a risk factor for the development of squamous cell carcinoma and there is a need for regular screening. The quality of life in patients with LP is significantly impaired because of frequent clinical visits, pain, soreness, inability to eat certain foods, side effects to medication, frustrating therapy attempts and worry regarding cancer risk. We highlight here the advantages of an interdisciplinary dermatology and oral surgery clinic, which can address the domains of tooth status, nutrition, pain and malignant transformation and optimized patient management.

An improved scoring system for monitoring oral lichen planus: A preliminary clinical study

OBJECTIVES

To design an improved oral lichen planus (OLP) scoring system, which can be widely applied.

SUBJECTS AND METHODS

A new scoring system that took reticulation, hyperemia and ulceration (RHU) into account, named as RHU scoring system, was designed for OLP patients' management. The patients were also scored for the reticulation/erythema/ulcer (REU) scoring system, physician global assessment (PGA), numerical rating scale (NRS) and Oral Health Impact Profile-14 (OHIP-14). The reliability and validity analyses were utilized to assess the RHU scoring system. We further applied the RHU scoring system to examine the treatment outcomes of topical dexamethasone sodium phosphate and general hydroxychloroquine hydrochloride among OLP patients.

RESULTS

Forty-eight OLP patients from two medical centers were recruited. This new scoring system has reliability with an internal consistency index Cronbach α 0.49. The Pearson correlation of RHU score with PGA and REU score were 0.891 and 0.675 (p < 0.05) respectively, reflecting satisfactory standard validity. A 10% change in RHU score was used as the disease condition evaluation standard, reflecting satisfactory discriminating validity (t = -5.821, p < 0.001). During follow-ups, scores of all scales decreased at each re-visit. The drop between each visit of OHIP-14 fluctuated compared with the RHU system and NRS.

CONCLUSIONS

As a semi-quantitative score system, the RHU scoring system can reflect the severity of OLP patients with hyperemia and ulceration lesions more accurately and sensitively compared with other score systems, which provides the potential to be widely used.

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.

Artificial Intelligence-Based Diagnosis of Oral Lichen Planus Using Deep Convolutional Neural Networks

OBJECTIVE

 The aim of this study was to employ artificial intelligence (AI) via convolutional neural network (CNN) for the separation of oral lichen planus (OLP) and non-OLP in biopsy-proven clinical cases of OLP and non-OLP.

MATERIALS AND METHODS

 Data comprised of clinical photographs of 609 OLP and 480 non-OLP which diagnosis has been confirmed histopathologically. Fifty-five photographs from the OLP and non-OLP groups were randomly selected for use as the test dataset, while the remaining were used as training and validation datasets. Data augmentation was performed on the training dataset to increase the number and variation of photographs. Performance metrics for the CNN model performance included accuracy, positive predictive value, negative predictive value, sensitivity, specificity, and F1-score. Gradient-weighted class activation mapping was also used to visualize the important regions associated with discriminative clinical features on which the model relies.

RESULTS

 All the selected CNN models were able to diagnose OLP and non-OLP lesions using photographs. The performance of the Xception model was significantly higher than that of the other models in terms of overall accuracy and F1-score.

CONCLUSIONS

 Our demonstration shows that CNN models can achieve an accuracy of 82 to 88%. Xception model performed the best in terms of both accuracy and F1-score.

Comparison of topical purslane & topical 0.1% triamcinolone acetonide in the management of oral lichen planus - a double blinded clinical trial

AIM AND BACKGROUND

Oral lichen planus (OLP) is a chronic autoimmune mucocutaneous disorder of unknown etiology and treatment is targeted at alleviating symptoms. At present, corticosteroids are the mainstay treatment, and their side effects hamper their long-term use, demanding alternative therapy. This study intended to assess the efficacy of topical purslane (Portulaca oleracea) at two concentrations, 5% and 10%, in OLP and to compare the level of clinical improvement in comparison to topical 0.1% triamcinolone acetonide gel.

MATERIALS AND METHODS

After sample size determination, thirty-four subjects confirmed histopathologically with OLP were included in the study. They were divided into 3 groups, Group 1(Control) was treated with 0.1% triamcinolone acetonide, and Group 2(Case) and 3 (Case) were treated with topical purslane 5% and 10%, respectively. They were examined at baseline, 14 days, 30 days, 60 days, and 90 days. Clinical improvement was then analyzed at the end of 90 days using a visual analog scale (VAS) and Thongprasom's criteria.

RESULTS

The study was analyzed statistically and a P value of < 0.05 was considered statistically significant. Intragroup comparison revealed a statistically significant difference between the five time periods (baseline, 14 days, 30 days, 60 days, and 90 days) for the study variables (burning sensation, pain, lesion score, clinical response, symptomatic response) for all three groups (p = 0.001). Alleviation of all symptoms and remission of the lesion were noted for all three groups at the end of three months.

CONCLUSION

Purslane is a magical herb with a plethora of rich nutrients, ease in accessibility and devoid of side effects. It was concluded that its preparation is beneficial and can be a safer alternative long-term drug for the management of OLP.

CLINICAL SIGNIFICANCE

With available literature evidence, our present study is the first of its kind to formulate a topical gel with purslane to treat symptomatic OLP. Our study had a longer follow-up of 3 months compared to other studies in the literature.

Malignant Transformation of Oral Lichen Planus: A Case Report

Oral lichen planus (OLP) is a chronic auto-immune disease associated with cell-mediated immunologic dysfunction whose etiology remains unknown. Malignant transformation into squamous cell carcinoma (SCC) is the most feared complication of OLP. It is actually recognized as a potentially malignant disorder with an unspecified risk of transformation, and it is suggested to closely monitor diagnosed patients. In this paper, we discuss the case of a 62-year-old female patient, a non-smoker, and non-drinker, who initially presented with painful erosive lesions on the edentulous mandibular ridge, the buccal mucosa, and the floor of the mouth. Clinical and histological findings led to the diagnosis of OLP with no signs of oral epithelial dysplasia. Malignant transformation into SCC was reported eight months after the first presentation.

Rate of Malignant Transformation Differs Based on Diagnostic Criteria for Oral Lichenoid Conditions: A Systematic Review and Meta-Analysis of 24,277 Patients

OBJECTIVES

This systematic review and meta-analysis aims to evaluate the evidence on the malignant potential of oral lichenoid conditions (OLCs) including oral lichen planus (OLP), oral lichenoid lesions (OLL), and lichenoid mucositis dysplasia (LMD). In addition, it aims to compare the rate of malignant transformation (MT) in OLP patients diagnosed according to different diagnostic criteria, and to investigate the possible risk factors for OLP MT into OSCC.

MATERIALS AND METHODS

A standardized search strategy was applied across four databases (PubMed, Embase, Web of Science, and Scopus). Screening, identification and reporting followed the PRISMA framework. Data on MT were calculated as a pooled proportion (PP), subgroup analyses and possible risk factors for MT were pooled as odds ratios (ORs).

RESULTS

Among 54 studies with 24,277 patients, the PP for OLCs MT was 1.07% (95% CI [0.82, 1.32]). The estimated MT rate for OLP, OLL and LMD was 0.94%, 1.95% and 6.31%, respectively. The PP OLP MT rate using the 2003 modified WHO criteria group was lower than that using the non-2003 criteria (0.86%; 95% CI [0.51, 1.22] versus 1.01%; 95% CI [0.67, 1.35]). A higher odds ratio of MT was observed for red OLP lesions (OR = 3.52; 95% CI [2.20, 5.64]), smokers (OR = 1.79; 95% CI [1.02, 3.03]), alcohol consumers (OR = 3.27, 95% CI [1.11, 9.64]) and those infected with HCV (OR = 2.55, 95% CI [1.58, 4.13]), compared to those without these risk factors.

CONCLUSIONS

OLP and OLL carry a low risk of developing OSCC. MT rates differed based on diagnostic criteria. A higher odds ratio of MT was observed among red OLP lesions, smokers, alcohol consumers, and HCV-positive patients. These findings have implications for practice and policies.

Emerging potential of phototherapy in management of symptomatic oral lichen planus: A systematic review of randomised controlled clinical trials

Phototherapy incorporating photobiomodulation therapy and antimicrobial photodynamic therapy has been utilised as antioxidants in symptomatic oral lichen planus (OLP) management; however, its role of intervention remains controversial. The aim of this systematic review of CRD42021227788 PROSPERO (an international prospective register of systematic reviews in health and social care) registration number was to oversee and determine phototherapy efficacy in patients with symptomatic OLP, identifying and bridging the literature gaps by proposing recommendations for future studies. A search strategy was developed in consistent with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Various electronic databases were exercised to search for randomised controlled clinical trials (RCTs). Several search engines were employed to analyse a total of 177 studies of which nine included. A wide range of utilised laser and light-emitted diode wavelengths between 630 and 808 nm and irradiance ranged between 10 and 13 mW/cm² were noted. 67% of studies reported a high risk of bias and a high heterogeneity obtained from numerical data for quantitative analysis, therefore meta-analysis was impossible to conduct. Despite inconsistency and diversity in phototherapy parameters, treatment protocols, photosensitiser (type, concentration and method of application) and outcome assessment tools, the majority of the studies showed positive results compared with standard care treatments. Hence, a necessity to perform well-designed RCTs with robust methodology is warranted, after acknowledging the current drawbacks and addressing the suggested recommendations highlighted in our review. Moreover, advanced knowledge in understanding further phototherapy-antioxidants molecular mechanistic in symptomatic OLP is required.

Oral cavity carcinoma in patients with and without a history of lichen planus: A comparative analysis

BACKGROUND

Oral potentially malignant disorders (OPMD) are associated with the risk of malignant transformation (MT) into oral cavity carcinoma (OCC). Oral lichen planus (OLP) is one of the most common OPMDs in western countries. Although there is a substantial amount of research on progression to cancer, a specific analysis of the clinical characteristics and prognosis of cancer developed in patients with a history of OLP versus patients without a history of OLP has not been investigated so far.

METHODS

Retrospective evaluation of 82 patients treated for OCC with a known history of OLP compared to a representative sample of 82 patients treated for OCC without a known history of LP. Comparative analyses were performed on age at presentation, sex, TNM staging, clinical characteristics, pathology characteristics, 2- and 5-year overall survival (OS), and disease-free survival (DFS).

RESULTS

It was shown that patients with a history of LP were significantly younger at first presentation than patients without a history of LP (mean age difference 6.7 years, 95% CI 3.1-10.3, p < 0.05). Also, patients with a history of OLP were in higher proportion females. The main pathological stage at presentation was significantly lower in the OLP group (p < 0.05). The 2-year survival analysis showed that DFS and OS were significantly lower in patients without a known history of OLP, with a hazard ratio (HR) of 3.1 (95% CI 1.4-6.8) and HR of 2.6 (95% CI 1.3-5.3), respectively. The 5-year survival analysis showed that DFS and OS were significantly lower in patients without a known history of OLP, with a hazard ratio of 3.1 (95% CI 1.6-6.2) and of 2.9 (95% CI 1.5-5.6), respectively.

CONCLUSIONS

Cancer arising from OLP has peculiar characteristics compared to cancer in naïve patients. It most commonly affects younger patients, women, and nonsmokers. It is usually diagnosed at earlier stages and appears to have less aggressive behavior at presentation. Moreover, when 2- and 5-year survival is analyzed, it appears that patients in OLP group have an overall and a disease-free survival advantage. These results suggest that cancer from OLP is less aggressive and thus has a potential biological difference with cancer arising in non-OLP patients. Further clinical and basic investigations are needed to confirm the results of this study.

Narrow-band imaging features of oral lichenoid conditions: A multicentre retrospective study

OBJECTIVE

Narrow-band imaging (NBI), which highlights epithelial intrapapillary capillary loops (IPCLs) classified into five patterns (0 toIV) with increasing correlation to malignancy, has demonstrated effectiveness for detection of oral squamous cell carcinoma (OSCC). Lack of standardised procedures limits its use for routine inspection of oral lichenoid lesions including oral lichen planus (OLP), oral lichenoid lesion (OLL) and oral lichenoid reaction (OLR). The aim of this study was to analyse IPCL patterns of such lesions, assessing correlations with histopathological outcomes.

MATERIALS AND METHODS

A multicentre, retrospective study was performed on 84 patients who underwent NBI and subsequent biopsy for suspected OLP/OLL/OLR. Patients were examined with Evis Exera III NBI system. Recorded NBI video endoscopies were evaluated to assess IPCL patterns and correlated with histopathological outcomes.

RESULTS

No significant differences were detected among OLP/OLL/OLR on NBI inspection. All lichenoid lesions were significantly related to low-grade (0-II) IPCL patterns, clearly distinguishable from OSCC, showing pattern IV (p < 0.05).

CONCLUSIONS

NBI cannot discern among OLP/OLL/OLR lesions. Interpretation should be modulated when assessing lichenoid lesions. NBI has potential to discern malignant transformation occurring in lichenoid lesions undergoing long-term follow-up, as IPCL pattern IV may be used as a clinical marker of malignancy arising in chronic inflammatory lesions.

Oral immune-mediated disorders with malignant potential/association: An overview

A group of oral disorders or conditions, which may result from, or could be triggered by an abnormality in the normal immune response of an individual are known as oral immune-mediated disorders. Some of these disorders have malignant potential, while others are associated with malignancy. In this overview, we will discuss a few of the oral diseases (such as oral lichen planus, primary Sjogren's syndrome, systemic lupus erythematosus, dermatitis herpetiformis, and linear immunoglobulin A bullous dermatosis, to name a few), which are caused due to irregularity in the immune system and are either associated with malignancy or capable of undergoing malignant transforming, thereby increasing the morbidity and mortality rate.

The Taq 1 polymorphism of Vitamin D receptor gene is associated with oral cancer and preoral cancer in North Indian population

BACKGROUND

Oral cancer is known as one of the most common cancers, with a poor prognosis, related to delayed clinical diagnosis, either due to the lack of particular biomarkers related to the disease or costly therapeutic alternatives.

AIMS AND OBJECTIVES

In this study association of single nucleotide polymorphism (Taq1, T>C) in Vitamin D receptor gene with oral cancer and pre oral cancer was studied.

MATERIALS AND METHODS

Total 230 patients of precancerous oral lesions (Leukoplakia 70, Oral Sub mucous fibrosis 90, Lichen Planus 70), 72 oral cancer patients and 300 healthy control subjects were genotyped by PCR-RFLP methods. Chi-square test was used for calculation of genotype and allele frequencies.

RESULTS

Mutant genotype CC as well as C allele were found to significantly decrease the risk of oral disease (P value=0.04, OR=0.60 and P value=0.02, OR=0.75 respectively). In particular, compared to non smokers, smokers with TC & CC genotypes were at decrease risk of oral diseases (P value=0.0001, OR=0.04). The mutant allele genotype CC as well as the mutant allele C showed protective association with leukoplakia (P value=0.01, OR=0.39 & P value=0.009, OR=0.59 respectively). However, individual with CC genotype had developed high cell differentiated grade at diagnosis (OR= 3.78, P value= 0.008).

CONCLUSIONS

This study concludes that VDR (Taq1) polymorphism is associated with oral cancer and pre oral cancer susceptibility in North Indian population.

Oral Squamous Cell Carcinomas Developing from Oral Lichen Planus: A 5-21 year Retrospective Study

Background and Aims

There is insufficient data regarding clinical characteristics, relapse rates, as well as lymph node metastasis of squamous cell carcinomas of the oral cavity (OSCC) developing from oral lichen planus (OLP-OSCC). The aim of this retrospective study was to evaluate clinical characteristics, as well as relapse, recurrence and survival rates of OLP-OSCC.

Methods

In a retrospective monocenter analysis, all consecutive patients with an OSCC treated in the time period 1st January 2000-December 31 2016 were reviewed. All patients with OSCC developing from OLP/OLL (oral lichenoid lesions) were identified and analyzed for epidemiological data, risk profile, location of primary tumor, pTNM classification, lymph node metastasis, primary therapy, recurrence, and outcome.

Results

A total of 103 patients (45%♂/ 55%♀) with an average age of 62 ± 14 year were included in this study. At the time of initial diagnosis, 17% (n = 18) of patients had cervical metastases (CM) whereas only 11% (11 patients) displayed advanced tumor sizes (T > 2). T-status (p = 0.003) and histopathological grading (p = 0.001) had an impact on the incidence of CM. 39.6% of the patients developed a relapse after an average of 24 months with a mean of two recurrences per patient. Advanced tumor size had a significant impact on the 5 year overall survival and was associated with disease-free survival of the patients (p < 0.001, respectively p = 0.004).

Conclusion

Although initial lymph node metastases were not more frequent, more aggressive recurrence patterns compared to OSCC were seen for OLP-OSCC. Therefore, based on the study results, a modified recall for these patients is suggested.

Outcome and long-term treatment protocol for topical tacrolimus in oral lichen planus

BACKGROUND AND OBJECTIVE

Topical tacrolimus has been shown to be beneficial in the treatment of oral lichen planus (OLP). However, long-term effects and its optimal application protocol with gradual reduction have not been studied. Accordingly, we analysed the clinical response of OLP to tacrolimus in our daily clinical practice with a focus on the optimal long-term therapeutic scheme.

METHODS

Retrospective analysis of all consecutive patients diagnosed with OLP and treated with topical tacrolimus (0.03% oral rinse) in a clinical setting between 2015 and 2020. The objective clinical response was measured by a 4-point scale (complete remission, major remission, partial remission and no response), and subjective impairment by a 3-point scale (severe, moderate and none).

RESULTS

Fifty-seven patients (74% women; median age: 66 years) were included. Fifty-six (98%) patients had prior treatment with topical steroids. After introduction of tacrolimus, objective remission (major or complete) was reached by 28%, 62%, 87% and 97% of patients after 3, 6, 12 and 24 months respectively. Subjective remission was reported by 16%, 48%, 69% and 83% after 3, 6, 12 and 24 months of treatment respectively. The treatment frequency could be gradually reduced from initially twice daily to once daily or less in 28%, 61%, 78% and 87% after 3, 6, 12 and 24 months respectively; 41% of patients completely suspended the treatment at one point, but 67% of them experienced a relapse after a median time of 3.3 months. Four patients (7%) developed a squamous cell carcinoma (SCC) during the observation period. Otherwise, there were only few and minor side-effects.

CONCLUSION

Topical tacrolimus can be an effective second-line therapy for OLP refractory to potent topical corticosteroids. The therapy frequency can often be reduced during the maintenance period. Both signs of clinical activity and subjective impairment should guide therapy. Regular follow-up is necessary to recognize possible SCC.

Clinical Evaluation of Dexamethasone Plus Gentamycin Mouthwash Use in Combination with Total Glucosides of Paeony for Treatment of Oral Lichen Planus without Fungal Infection: A Comparative Study with Long-Term Follow-Up

Background: Oral lichen planus (OLP) is a common chronic inflammatory disease of the oral mucosa and considered a potential malignant disease, for which a method for complete cure is lacking. The dexamethasone and gentamicin mouthwash, combined with total glucosides of paeony (TGP), was tested in the treatment of OLP patients without fungal infection, with a view to provide evidence that may assist in resolving the dilemma. Methods: A randomized and single-blind clinical trial of 48 non-erosive and erosive OLP patients was conducted, with the patients divided into two groups. Group A was treated with dexamethasone plus gentamycin mouthwash and Group B received an additional TGP capsule together with the aforementioned mouthwash. All the patients were followed up with four times, at 2 weeks, 1 month, 3 months, and 6 months. The clinical manifestations, sign score, and VAS scale were recorded. The total effective rate (%) was defined as (cases of complete resolution + cases of partial resolution)/total cases observed × 100%. Results: A total of 43 patients completed all follow-up appointments. Among the 21 patients in Group A, the total effective rate was 61.9%. Of the 22 patients in Group B, the total effective rate was 89.66%. The clinical manifestation, sign score, and VAS of the two groups all indicated improvements, and there were significant differences between the two groups (p < 0.05). Conclusions: Dexamethasone plus gentamycin mouthwash combined with TGP treatment for OLP patients is a safe and effective treatment of OLP.

Therapeutic strategies for oral lichen planus: State of the art and new insights

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa. Several clinical subtypes of OLP have been reported, including the reticular and erosive one. On the one hand, reticular OLP is usually asymptomatic and is characterized by white streaks surrounded by well-defined erythematous borders. On the other hand, erosive OLP shows ulcerations and erosions surrounded by erythematous mucosa. While reticular OLP is relatively easy to control, erosive OLP is extremely painful and refractory to therapies, limiting the quality of life of the patients. In addition, treating erosive OLP is extremely tricky, and a gold standard treatment has not yet been established. However, several therapeutic approaches have been reported as effective, including systemic corticosteroids, systemic retinoids, and anti-interleukin (IL)-17/anti-IL-23 drugs. Indeed, our group and other several authors reported the effectiveness of anti-IL17, anti-IL12/23, and anti-IL23 agents in refractory OLP, highlighting the urgency of clinical studies on the use of anti-IL agents in OLP patients. In this paper, we reviewed the English- and German-language literature about therapeutic strategies for treating OLP, focusing on new systemic therapies for erosive OLP.

Squamous cell carcinoma in a patient with lichen planus of the oral mucosa

Lichen planus refers to dermatoses with frequent, often isolated, lesions of the oral mucosa. In the presence of rashes only on the oral mucosa, the diagnosis is difficult. At the same time, erosive-ulcerative forms of the disease present the greatest differential diagnostic difficulties. Cases that do not heal for a long time and are not amenable to treatment should be especially alert to the doctor due to the risk of malignancy. The article describes a rare clinical case of squamous cell carcinoma of the oral mucosa in a 52-year-old patient with an erosive-ulcerative form of lichen planus of the oral cavity, characterized by a chronic long-term course, torpidity to therapy and simultaneous damage to the genital mucosa. The presented case emphasizes the importance of a thorough clinical examination, with a histological examination of the biopsy in order to monitor changes in the lesions.

Oral Lichen Planus and Mutated TP53-A Road to Cancer?

The malignant potential of oral lichen planus (OLP) has been discussed and disputed for decades. The lesions are often characterized by strong expression of the TP53 protein in the basal layer of the mucosa. In 2002, we reported the presence of TP53 mutations in nine out of 27 OLP lesions tested. At follow-up in 2009, one case of oral squamous cell cancer (OSCC) had occurred in a different site six years later. In contrast, in another case, TP53 mutation persisted for years without malignant transformation. In a longitudinal study of eight selected patients with OSCC or different pre-malignant lesions, it was concluded that TP53 mutations could occur early or late in the development of OSCC. A follow-up in the present, almost 20 years later, revealed that one further case of OSCC had occurred in a TP53-mutated case of OLP, 21 years after the first sample was taken, again in a different site. With this second case, this small study now points towards a risk of developing OSCC in TP53-mutated OLP lesions. A review of recent literature indicates a growing consensus that OLP should be regarded as a potentially pre-malignant lesion. Several protein markers have been studied, but none proved useful for prediction of malignant progression. The great majority of published studies are retrospective, and it has been suggested that multi-centre prospective studies will be needed to reach a definitive answer on the malignant potential of OLP, and particularly, to identify contributing factors. Screening for TP53 mutations could help to identify the subgroup of OLP patients that is truly at risk of developing oral cancer.

Oral lichenoid lesion in association with chemotherapy treatment for non-Hodgkin lymphoma or lichen planus? Review of the literature and report of two challenging cases

Background

The diagnosis of oral lichenoid lesions (OLL) remains a challenge for clinicians and pathologists. Although, in many cases, OLL cannot be clinically and histopathologically distinguishable from oral lichen planus (OLP), one important difference between these lesions is that OLL has an identifiable etiological factor, e.g. medication, restorative material, and food allergy. The list of drugs that can cause OLL is extensive and includes anti-inflammatory drugs, anticonvulsants, antihypertensives, antivirals, antibiotics, chemotherapeutics, among others. This work aimed to perform a literature review of OLL related to chemotherapy drugs and to report two cases of possible OLL in patients with B-cell and T-cell non-Hodgkin lymphomas in use of chemotherapy and adjuvant medications. We also discuss the challenge to clinically and histopathologically differentiate OLL and OLP.

Case presentation

In both cases, oral lesions presented reticular, atrophic, erosive/ulcerated, and plaque patterns. The diagnosis of OLL was initially established in both cases by the association of histopathology and history of onset of lesions after the use of medications. Although the patients have presented a significant improvement in the oral clinical picture for more than 2 years of follow-up, they still have some lesions.

Conclusion

A well-detailed anamnesis associated with the drug history, temporal relationship of the appearance of the lesions, and follow-up of patients are fundamental for the diagnosis of OLL related to drugs. Nevertheless, its differentiation from OLP is still a challenge.

Overestimated risk of transformation in oral lichen planus

OBJECTIVES

Oral lichen planus (OLP) was classified as an oral potentially malignant disorder due to the association with oral squamous cell carcinoma (OSCC). However, the malignant potential of OLP has been controversial. Whether epithelial dysplasia should be differentiated from OLP and lichenoid dysplasia could be identified as a pathological entity has been the subject of debate.

MATERIALS AND METHODS

We recruited a large retrospective cohort with 3568 patients, and 10 of them developed OSCC. These cases were reviewed retrospectively to investigate association between OLP and OSCC.

RESULTS

In 10 cases of OSCC, three of them were primary cancers distinct from the site with OLP, two were malignant transformation of proliferative verrucous leukoplakia, and five were malignant transformation of oral leukoplakia. All OSCC is not transformed from OLP. Therefore, previous insights into OLP might have overestimated its transformation risk. There may be the reasons: I. did not distinguish OLP from epithelial dysplasia, II. neglect of oral leukoplakia with dysplasia developed in the course after OLP, III. misdiagnosis in the early stage of proliferative verrucous leukoplakia.

CONCLUSION

The pathological and molecular biological features of OLP differed from those of oral leukoplakia and OSCC. Strict control of the diagnostic criteria for OLP and close surveillance during the course could contribute to correctly identify the origin of OSCC and avoid overestimating the risk of OLP transformation.

Prevalence of oral lichen planus among north Indian population: a descriptive epidemiological study

The aim: oral lichen planus is a chronic inflammatory disease affecting the oral mucous membrane. It can present in various clinical forms: reticular, papular, plaque-like, atrophic, erosive and bullous. Though the exact etiology is not certain - autoimmunity, trauma, stress, and habits are considered as etiological factors. Oral lichen planus has been classified as a premalignant lesion. The present study aims to describe the prevalence of oral lichen planus in a sample of north Indian population. Materials and methods: the present study was conducted in the outpatient department of Dentistry, GMC Badaun. The parameters recorded were age, gender and site affected. The data was collected and analysed. Results: a total of 6263 patients reported to the outpatient department of dentistry out of which 43 patients were diagnosed with oral lichen planus. The overall prevalence of oral lichen planus was found to be 0.69 %. The mean age of disease presentation was 37.5 years. A higher prevalence of oral lichen planus was reported in females compared to males with a ratio of 1:1.15. Most affected site was found to be buccal mucosa bilaterally (58.14 %). Conclusion: the present study estimated the overall prevalence of oral lichen planus as well as its distribution according to age, gender and site in north Indian population. This could contribute to the precise assessment of the disease for better policy making for better treatment and management of oral lichen planus.

Dental material allergies and oral soft tissue reactions

Dental materials can cause reactions to the oral mucosa and present to the general dental practitioner. These are often referred to as 'allergies' but are frequently lichenoid reactions. Most of these are related to dental amalgam restorations and can be remedied by replacing the restoration with another suitable material. Other metals, including gold, palladium, nickel and chrome, have also been reported to trigger mucosal changes. Less commonly, issues arise from other restorative materials, including denture acrylics, composites and glass polyalkenoates. Reactions are also reported due to endodontic and sealing materials. It is unclear what role skin 'patch' testing has in managing dental material allergies. This article aims to give the practitioner a clearer picture of dental material allergy issues and how they should be approached in primary dental practice.

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.

French guidelines for the management of oral lichen planus (excluding pharmacological therapy)

INTRODUCTION

Oral lichen is a chronic inflammatory disease for which diagnostic management and follow-up are heterogeneous given the absence of specific guidelines in France. Our objective was to develop French multidisciplinary guidelines for the management of oral lichen.

MATERIALS AND METHODS

Working groups from the Groupe d'Etude de la Muqueuse Buccale (GEMUB) formulated a list of research questions and the corresponding recommendations according to the "formal consensus" method for developing practice guidelines. These recommendations were submitted to a group of experts and the degree of agreement for each recommendation was assessed by a scoring group.

RESULTS

Twenty-two research questions, divided into 3 themes (nosological classification and initial assessment, induced oral lichenoid lesions, and follow-up) resulted in 22 recommendations. Initial biopsy for histology is recommended in the absence of reticulated lesions. Biopsy for direct immunofluorescence is recommended for ulcerated, erosive, bullous types and for diffuse erythematous gingivitis. Management should include a periodontal and dental check-up, and investigation for extra-oral lesions. Hepatitis C testing is recommended only if risk factors are present. Definitions, triggering factors and the management of "induced oral lichenoid lesions" were clarified. Oral lichen must be monitored by a practitioner familiar with the disease at least once a year, using objective tools.

CONCLUSION

This formalised consensus of multidisciplinary experts provides clinical practice guidelines on the management and monitoring of oral lichen.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Tumours of the Oral Cavity and Mobile Tongue

The fifth chapter of the upcoming fifth edition of the 2022 World Health Organization Classification of Tumours of the Head and Neck titled Tumours of the oral cavity and mobile tongue, has had some modifications from the 2017 fourth edition. A new section "Non-neoplastic Lesions", introduces two new entries: necrotizing sialometaplasia and melanoacanthoma. The combined Oral potentially malignant disorders and Oral epithelial dysplasia section in the 2015 WHO has now been separated and submucous fibrosis and HPV-associated dysplasia are also discussed in separate sections. Carcinoma cuniculatum and verrucous carcinoma are described in dedicated sections, reflecting that the oral cavity is the most common location in the head and neck for both these entities which have distinct clinical and histologic features from conventional squamous cell carcinoma. This review summarizes the changes in Chapter 5 with special reference to new additions, deletions, and sections that reflect current clinical, histological, and molecular advances.

Identification of Potential Key Biomarkers and Immune Infiltration in Oral Lichen Planus

Background

Oral lichen planus (OLP) is a chronic autoimmune oral mucosal disease that seriously affects the life quality of the patients. But till now, the exact etiology and pathogenesis of OLP remain unclear. Our study is aimed at finding the key molecules and pathways involved in the pathogenesis mechanisms of OLP, providing more effective therapeutic strategies for OLP.

Methods

Data from GSE52130 were downloaded from GEO datasets for analysis. Then, we carried out enrichment analysis of the differentially expressed genes (DEGs) using Gene Ontology (GO) and KEGG pathway analyses. Next, the CIBERSORT algorithm was used to assess immune cell infiltration in OLP patients. Furthermore, we also constructed a protein-protein interaction network using STRING and Cytoscape and simultaneously sought potential transcription factors plug-in including MCODE CytoHubba and iRegulon. In addition, ROC analysis was employed to assess the diagnostic performance of these hub genes. Lastly, we identified 6 promising novel drugs to treat OLP through Connectivity Map.

Results

We illustrated that 255 DEGs were mainly enriched in the focal adhesion pathway and metabolism pathways. Besides, Cibersort analysis showed that M1 macrophages, T follicular helper cells, and T regulatory cells are more infiltrated in OLP samples. In addition, ROC analysis demonstrated that these hub genes owned higher diagnostic value in OLP, in which SPRR1B had the highest diagnostic value. And we also predicted that SOX7 was the most relevant transcription factor of those hub genes. Lastly, through the CMap database, we identified 6 small molecules as possible treatment drugs of OLP.

Conclusion

Our research identified that SPRR1B could be used as potential biomarkers for the early diagnosis of OLP. In addition, as a chronic autoimmune oral mucosal disease, OLP has different infiltration types of immune cells. Furthermore, 6 small molecules were proposed as promising novel treatment drugs for OLP patients. Therefore, our research may provide new impetus for the development of effective OLP biological treatment options.

Esophageal squamous cell cancer in Plummer-Vinson syndrome: Is lichen planus a missing link?

This retrospective study analyzed the occurrence of esophageal squamous cell cancer (ESCC) in a cohort of patients with Plummer-Vinson syndrome (PVS) and mucosal lichen planus (LP). ESCC occurred in 6.2% cases of PVS, more than half of whom had associated oral LP. Mucosal LP and PVS together may increase the predisposition to ESCC.

Clinical assessment for the detection of oral cavity cancer and potentially malignant disorders in apparently healthy adults

BACKGROUND

The early detection of oral cavity squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD), followed by appropriate treatment, may improve survival and reduce the risk for malignant transformation respectively. This is an update of a Cochrane Review first published in 2013.

OBJECTIVES

To estimate the diagnostic test accuracy of conventional oral examination, vital rinsing, light-based detection, mouth self-examination, remote screening, and biomarkers, used singly or in combination, for the early detection of OPMD or OSCC in apparently healthy adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 October 2020), MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. We conducted citation searches, and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the test accuracy of any of the aforementioned tests in detecting OPMD or OSCC during a screening procedure. Diagnosis of OPMD or OSCC was provided by specialist clinicians or pathologists, or alternatively through follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction, and quality assessment were carried out by at least two authors independently and in duplicate. Studies were assessed for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). We reported the sensitivity and specificity of the included studies. We provided judgement of the certainty of the evidence using a GRADE assessment.

MAIN RESULTS

We included 18 studies, recruiting 72,202 participants, published between 1986 and 2019. These studies evaluated the diagnostic test accuracy of conventional oral examination (10 studies, none new to this update), mouth self-examination (four studies, two new to this update), and remote screening (three studies, all new to this update). One randomised controlled trial of test accuracy directly evaluated conventional oral examination plus vital rinsing versus conventional oral examination alone. There were no eligible studies evaluating light-based detection or blood or salivary sample analysis (which tests for the presence of biomarkers for OPMD and OSCC). Only one study of conventional oral examination was judged as at overall low risk of bias and overall low concern regarding applicability. Given the clinical heterogeneity of the included studies in terms of the participants recruited, setting, prevalence of the target condition, the application of the index test and reference standard, and the flow and timing of the process, the data could not be pooled within the broader categories of index test. For conventional oral examination (10 studies, 25,568 participants), prevalence in the test accuracy sample ranged from 1% to 51%. For the seven studies with prevalence of 10% or lower, a prevalence more comparable to the general population, the sensitivity estimates were variable, and ranged from 0.50 (95% confidence interval (CI) 0.07 to 0.93) to 0.99 (95% CI 0.97 to 1.00); the specificity estimates were more consistent and ranged from 0.94 (95% CI 0.88 to 0.97) to 0.99 (95% CI 0.98 to 1.00). We judged the overall certainty of the evidence to be low, and downgraded for inconsistency and indirectness. Evidence for mouth self-examination and remote screening was more limited. We judged the overall certainty of the evidence for these index tests to be very low, and downgraded for imprecision, inconsistency, and indirectness. We judged the evidence for vital rinsing (toluidine blue) as an adjunct to conventional oral examination compared to conventional oral examination to be moderate, and downgraded for indirectness as the trial was undertaken in a high-risk population.

AUTHORS' CONCLUSIONS

There is a lack of high-certainty evidence to support the use of screening programmes for oral cavity cancer and OPMD in the general population. Frontline screeners such as general dentists, dental hygienists, other allied professionals, and community healthcare workers should remain vigilant for signs of OPMD and OSCC.

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

Simple Summary

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

Abstract

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

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Fractal Dimension and Texture Analysis of Lesion Autofluorescence in the Evaluation of Oral Lichen Planus Treatment Effectiveness

BACKGROUND

Oral Lichen planus (OLP) is a chronic inflammatory disease. Topical steroids are used as the treatment of choice. The alternative is photodynamic therapy (PDT). The study aimed to fabricate optimal biodegradable matrices for methylene blue or triamcinolone acetonide because of a lack of currently commercially available carriers that could adhere to the mucous.

METHODS

The study was designed as a 12-week single-blind prospective randomized clinical trial with 30 patients, full contralateral split-mouth design. Matrices for steroid and photosensitizer and laser device were fabricated. Fractal and texture analysis of photographs, taken in 405, 450, 405 + 450 nm wavelength, of lesions was performed to increase the objectivity of the assessment of treatment.

RESULTS

We achieved two total responses for treatment in case of steroid therapy and one in the case of PDT. Partial response was noted in 17 lesions treated using local steroid therapy and 21 in the case of PDT. No statistically significant differences were found between the effectiveness of both used methods. Statistically significant differences in fractal dimension before and after treatment were observed only in the analysis of photographs taken in 405 + 450 nm wavelength.

CONCLUSIONS

Photodynamic therapy and topical steroid therapy are effective methods for treating OLP. Using a carrier offers the possibility of a more predictable and effective method of drug delivery into the mucous membrane. Autofluorescence enables the detection of lesions especially at the early stage of their development.

Clinical relevance of interdental papilla biopsy in chronic erosive gingivitis (desquamative gingivitis): retrospective bicentric study of 148 specimens

Background

Chronic erosive gingivitis, also called desquamative gingivitis, defines a clinical picture that can be generated by several inflammatory and immune diseases. Pathology is therefore essential for the differential diagnosis. However, when the gingival lesion is initial, exclusive or predominant, selecting the biopsy site and protocol may be problematic due to tissue fragility. Especially since there are few studies on the subject, the aim of our study was to assess the protocol, diagnostic relevance and tolerance of an original protocol using interdental papilla biopsy.

Methods

We conducted a retrospective bicentric study, from October 2011 to July 2019, including all patients with a chronic erosive gingivitis who had received, for diagnostic purposes, a interdental papilla biopsy.

Results

The contribution levels for the two hospital departments were 94.7% and 97.1%, respectively. No postoperative complication was recorded in the short or long term.

Conclusion

The interdental papilla biopsy protocol is perfectly adapted to the anatomopathological examinations required to establish differential diagnosis of chronic erosive gingivitis. This surgical protocol is simple to perform, non iatrogenic with a very good tolerance and and accessible to all clinicians. It is highly efficient with an excellent contribution level.

ClinicalTrials NCT04293718 (March 3, 2020). Health Data Hub N° F20201109083211 (November 9, 2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01820-9.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

BACKGROUND

Squamous cell carcinoma is the most common form of malignancy of the oral cavity, and is often proceeded by oral potentially malignant disorders (OPMD). Early detection of oral cavity squamous cell carcinoma (oral cancer) can improve survival rates. The current diagnostic standard of surgical biopsy with histology is painful for patients and involves a delay in order to process the tissue and render a histological diagnosis; other diagnostic tests are available that are less invasive and some are able to provide immediate results. This is an update of a Cochrane Review first published in 2015.

OBJECTIVES

Primary objective: to estimate the diagnostic accuracy of index tests for the detection of oral cancer and OPMD, in people presenting with clinically evident suspicious and innocuous lesions.

SECONDARY OBJECTIVE

to estimate the relative accuracy of the different index tests.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were also searched for ongoing trials to 20 October 2020. No restrictions were placed on the language or date of publication when searching the electronic databases. We conducted citation searches, and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting OPMD or oral cavity squamous cell carcinoma: vital staining (a dye to stain oral mucosa tissues), oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

MAIN RESULTS

This update included 63 studies (79 datasets) published between 1980 and 2020 evaluating 7942 lesions for the quantitative meta-analysis. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (22 datasets), oral cytology (24 datasets), light-based detection or oral spectroscopy (24 datasets). Nine datasets assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis. Two studies were classed as being at low risk of bias across all domains, and 33 studies were at low concern for applicability across the three domains, where patient selection, the index test, and the reference standard used were generalisable across the population attending secondary care. The summary estimates obtained from the meta-analysis were: - vital staining: sensitivity 0.86 (95% confidence interval (CI) 0.79 to 0.90) specificity 0.68 (95% CI 0.58 to 0.77), 20 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; - oral cytology: sensitivity 0.90 (95% CI 0.82 to 0.94) specificity 0.94 (95% CI 0.88 to 0.97), 20 studies, sensitivity moderate-certainty evidence, specificity moderate-certainty evidence; - light-based: sensitivity 0.87 (95% CI 0.78 to 0.93) specificity 0.50 (95% CI 0.32 to 0.68), 23 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; and - combined tests: sensitivity 0.78 (95% CI 0.45 to 0.94) specificity 0.71 (95% CI 0.53 to 0.84), 9 studies, sensitivity very low-certainty evidence, specificity very low-certainty evidence.

AUTHORS' CONCLUSIONS

At present none of the adjunctive tests can be recommended as a replacement for the currently used standard of a surgical biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for oral cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation. Potentially eligible studies of blood and salivary biomarkers were excluded from the review as they were of a case-control design and therefore ineligible. In the absence of substantial improvement in the tests evaluated in this updated review, further research into biomarkers may be warranted.

Oral Lichen Planus: risk factors of malignant transformation and follow up. Ten years retrospective study

Background

Oral Lichen Planus (OLP) is an inflammatory chronic disease. Modified World Health Organization (WHO) diagnostic criteria (2003) suggest diagnosing OLP both clinically and histologically. Furthermore, it is known the potential of malignant transformation of OLP, especially those affecting mucosa. Aims of this retrospective study on 100 patients were i) to estimate the timing of transformation of OLP lesions in OSCC in a cohort of patients observed between 2008 and 2018; ii) to assess risk factors of OLP patients diagnosed with OSCC; iii) to analyse forms of OLP evolved in cancer.

Material and Methods

A database of 100 patients diagnosed with OLP was evaluated and clinical, histological features of lesions, habits of patients and systemic diseases were analysed in a follow up ranged between 5 and 10 years.

Results

Mean time of malignant transformation was 31,62± 18,26 months; however, 4 malignant transformations out of 8 occurred about after 4 years of observation. Furthermore, Odds ratios for risk factors showed an association between malignant transformation and location.

Conclusions

More focused attention on follow-up scheduling and designing could be a valuable resource in early diagnosis and cancer prevention in OLP patients.

Key words:Oral Lichen Planus, Oral Cancer, Malignant transformation, risk factors.

Malignant transformation of oral lichen planus: a retrospective study of 565 Japanese patients

Background

Oral lichen planus (OLP) is a chronic inflammatory oral mucosa disease that is recognized as an oral potentially malignant disorder. However, the potentially malignant nature of OLP remains unclear.

Methods

We designed this study to examine the demographic and clinical characteristics of patients with OLP and evaluate the associated malignant transformation rate. A total of 565 patients with a clinical and histopathological diagnosis of OLP who presented at our department between 2001 and 2017 were retrospectively studied. Patients who had clinical and histopathological features of oral lichenoid lesions (OLLs) classified as oral lichenoid contact lesions, oral lichenoid drug reactions and oral lichenoid lesions of graft-versus-host disease were excluded.

Results

The study population included 123 men and 442 women aged 21–93 years (mean ± standard deviation, 60.5 ± 11.8). The 565 patients were followed up for a duration of 55.9 ± 45.3 months, during which 4 (0.7%) patients developed squamous cell carcinoma (SCC). In three of these 4 patients who developed SCC, the clinical type of OLP was the red type.

Conclusions

Our results suggested that OLP was associated with a low risk of malignant transformation. We recommend regular follow-up for OLP patients and clear differentiation of oral epithelial dysplasia and OLLs to enable early detection of malignant transformation. Further investigation of the clinical risk factors associated with malignant transformation is necessary.