An appraisal of highest quality studies reporting malignant transformation of oral lichen planus based on a systematic review

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.

Validity of nomograms for predicting cancer risk in oral leukoplakia and oral lichen planus

OBJECTIVES

This study assessed the validity of nomograms for predicting malignant transformation (MT) among patients with oral leukoplakia (OL) and oral lichen planus (OLP).

MATERIALS AND METHODS

Two nomograms were identified following a systematic search. Variables to interrogate both nomograms were obtained for a retrospective OL/OLP cohort. Then, the nomograms were applied to estimate MT probabilities twice and their average was used to calculate the discriminatory performance, calibration, and potential net benefit of the models. Subgroup analyses were performed for patients with OL, OLP, and oral epithelial dysplasia.

RESULTS

Predicted probabilities were mostly significantly higher among OL/OLP patients who developed MT compared to those who did not (p = <0.001-0.034). AUC values and Brier scores of the nomograms were 0.644-0.844 and 0.040-0.088 among OL patients and 0.580-0.743 and 0.008-0.072 among OLP patients. Decision curve analysis suggested that the nomograms had some net benefit for risk stratification. However, the models did not best binary dysplasia grading in discriminatory validity and net benefit among patients with OL and oral epithelial dysplasia.

CONCLUSION

Nomograms for predicting MT may have satisfactory validity among patients with OL than OLP, but they do not outperform binary dysplasia grading in risk stratification of OL.

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.

Prevalence of oral lichen planus in patients with diabetes mellitus: A cross-sectional study

OBJECTIVES

Oral lichen planus, a chronic inflammatory immune disease, occurs in the oral mucosa. We aimed to assess the prevalence and possible influencing factors of oral lichen planus in patients with diabetes mellitus.

SUBJECTS AND METHODS

This cross-sectional study involved 525 patients with diabetes mellitus and 525 controls. We collected information on blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

RESULTS

Oral lichen planus was significantly more prevalent in the diabetes mellitus/type 2 diabetes mellitus group than in the controls (2.3%/2.2% vs. 0.6%, p = 0.019/0.022). There was no significant association between patients with diabetes mellitus with and those without oral lichen planus in age (p = 0.195), sex (p = 0.390), blood glucose level (p = 1), duration of diabetes (p = 0.638), diabetic complications (p = 1), treatment methods (p = 0.962), other systemic diseases (p = 0.891) and medication history (p = 0.848).

CONCLUSIONS

Diabetes mellitus was associated with oral lichen planus; there was a higher prevalence of oral lichen planus in patients with diabetes mellitus/type 2 diabetes mellitus than in those without diabetes. Oral lichen planus development in patients with diabetes mellitus was not significantly associated with age, sex, blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

Leveraging artificial intelligence for perioperative cancer risk assessment of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are mucosal conditions with an inherent disposition to develop oral squamous cell carcinoma. Surgical management is the most preferred strategy to prevent malignant transformation in OPMDs, and surgical approaches to treatment include conventional scalpel excision, laser surgery, cryotherapy, and photodynamic therapy. However, in reality, since all patients with OPMDs will not develop oral squamous cell carcinoma in their lifetime, there is a need to stratify patients according to their risk of malignant transformation to streamline surgical intervention for patients with the highest risks. Artificial intelligence (AI) has the potential to integrate disparate factors influencing malignant transformation for robust, precise, and personalized cancer risk stratification of OPMD patients than current methods to determine the need for surgical resection, excision, or re-excision. Therefore, this article overviews existing AI models and tools, presents a clinical implementation pathway, and discusses necessary refinements to aid the clinical application of AI-based platforms for cancer risk stratification of OPMDs in surgical practice.

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.

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.

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.

Early Diagnosis of Oral Cancer: A Complex Polyhedral Problem with a Difficult Solution

Oral and oropharyngeal cancers are a growing problem, accounting for 377,713 and 98,412 new cases per year all over the world and 177,757 and 48,143 deaths annually, respectively. Despite the substantial improvement in diagnostic procedures and treatment techniques in recent years, the mortality rate has not decreased substantially in the last 40 years, which is still close to 50% of cases. The major cause responsible for this high mortality is associated with the high percentage of oral cancers diagnosed in advanced stages (stages III and IV) where the treatment harbors poor efficacy, resulting in challenges, mutilations, or disability. The main reason for cancer to be diagnosed at an advanced stage is a diagnostic delay, so it is critical to reduce this delay in order to improve the prognosis of patients suffering from oral cancer. The causes of oral cancer diagnostic delay are complex and concern patients, healthcare professionals, and healthcare services. In this manuscript, oral cancer diagnostic delay is critically reviewed based on current evidence, as well as their major causes, main problems, and potential improvement strategies.

Changes in the lesion surface suggesting transformation of oral potentially malignant disorders to malignancy - a report of eight cases

BACKGROUND

In the case of oral potentially malignant disorders (OPMD), the possibility of malignant transformation of the lesion necessitates a decision on the need for an additional biopsy at each visit. Among many clinical characteristics, change on the lesion surface is one of the important factors that determine the need for additional biopsy at each visit. The purpose of the study was to provide information on the characteristics of lesions related to malignant transformation during the follow-up period of OPMD.

METHODS

Eight patients (four men and four women) with OPMD that transformed into malignancy during long-term follow-up were included and their mean age was 65.8 ± 12.4 years. Clinical information and histopathological diagnosis were investigated at the initial visit and during the long-term follow-up period. The focus was on information on changes on the lesion surface at the time the lesion was confirmed to be malignant. The period from initial diagnosis to dysplasia and from dysplasia to malignancy was also investigated.

RESULTS

The OPMD diagnoses were oral lichen planus or oral lichenoid lesions (n = 2), oral leukoplakia (n = 5), and hyperplastic candidiasis (n = 1). During the follow-up period of the lesions, when dysplasia was obtained by additional biopsy, changes in the lesions consisted of an increase in the size of the white or red area. The lesion surface of the OPMD showed verrucous, papillary, exophytic, corrugated, and ulcerative changes at the time of malignancy diagnosis. The period for the initial lesion to become dysplasia, from dysplasia to malignancy, and from the initial lesion to malignancy was very variable.

CONCLUSIONS

Attention should be paid to verrucous, papillary, exophytic, corrugated, and ulcerative changes on the lesion surface of OPMD. Considering that the period for OPMD to become malignant is highly variable, a longer follow-up of the lesion is necessary.

American Association of Oral and Maxillofacial Surgeon's Position Paper on Oral Mucosal Dysplasia R2

Oral potentially malignant disorders (OPMDs) of the oral mucosa include leukoplakia, erythroplakia, erythroleukoplakia, lichen planus, and oral lichenoid lesions, each with varying incidences of dysplastic disease at the time of presentation and each with observed incidences of malignant transformation over time. The primary goal of the management of dysplasia, therefore, includes their early detection and treatment prior to malignant transformation. The recognition and management of these OPMDs and an understanding of their potential progression to oral squamous cell carcinoma will reduce the morbidity and mortality associated with these lesions with expedient and properly executed treatment strategies that will have a positive effect on patient survival. It is the purpose of this position paper to discuss oral mucosal dysplasia in terms of its nomenclature, epidemiology, types, natural history, and treatment to acquaint clinicians regarding the timing of biopsy, type of biopsy, and follow-up of patients with these lesions of the oral mucosa. This position paper represents a synthesis of existing literature on this topic with the intention of closing gaps in our understanding of oral mucosal dysplasia while also stimulating new thinking to guide clinicians in the proper diagnosis and management of OPMDs. The fifth edition of the World Health Organization classification of head and neck tumors published in 2022 represents new information regarding this topic and a construct for this position paper.

Oral Cavity Squamous Cell Carcinoma Risk Factors: State of the Art

Head and neck (HN) squamous cell carcinomas (SCCs) originate from the epithelial cells of the mucosal linings of the upper aerodigestive tract, which includes the oral cavity, the pharynx, the larynx, and the sinonasal cavities. There are many associated risk factors, including alcohol drinking coupled with tobacco use, which accounts for 70% to 80% of HNSCCs. Human papilloma virus (HPV) is another independent risk factor for oropharyngeal SCC, but it is only a minor contributor to oral cavity SCC (OSCC). Betel quid chewing is also an established risk factor in southeast Asian countries. However, OSCC, and especially oral tongue cancer, incidence has been reported to be increasing in several countries, suggesting risk factors that have not been identified yet. This review summarizes the established risk factors for oral cavity squamous cell carcinomas and examines other undemonstrated risk factors for HNSCC.

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.

Psychological Functioning of Women Diagnosed with Lichen Planus and Other Diseases of the Oral Cavity-Explorative Study

The role of psychosocial factors in the development of changes in lichen planus and other diseases of the oral cavity has been implicated, but is still understudied. Therefore, the aim of our study was to describe the specific profile of psychological functioning of patients with these diseases, including the role of temperamental traits, action-oriented personality components, and self-esteem. In total, 94 adult women participated in the study: (1) with lichen planus (LP; n = 46; M_age = 54.80, SD = 12.53), (2) with other oral conditions (n = 25; M_age = 34.76, SD = 16.03), (3) without chronic disease (n = 24; M_age = 40.96, SD = 13.33). The following questionnaires were used: ZKA-PQ/SF, Polish Adaptive and Maladaptive Perfectionism Questionnaire, ACS-90, PROCOS, and MSEI. Results indicated no significant differences in temperament dimensions between studied groups. However, women diagnosed with LP presented lower levels of maladaptive perfectionism and social support than healthy women. Furthermore, women with LP also obtained lower scores for social resourcefulness and higher scores for moral self-approval than healthy women. Summarizing, patients with LP often use compensatory mechanisms that negatively affect their social functioning; thus diagnostic/therapeutic programs directed towards those group should be holistic, including psychologists and psychiatrists who support patients' psychological well-being.

Efficacy of Platelet-Rich Plasma Therapy in Oral Lichen Planus: A Systematic Review

Background and Objectives: Oral lichen planus (OLP) is an autoimmune, mucocutaneous, oral potentially malignant disorder (OPMD), which characteristically manifests with chronic, recalcitrant lesions, with frequent flare-ups and remissions. The precise etiopathogenesis of OLP is still debatable, although it is believed to be a T-cell-mediated disorder of an unidentified antigen. Despite the availability of various treatments, no cure for OLP exists due to its recalcitrant nature and idiopathic etiology. Platelet-rich plasma (PRP) has antioxidant, anti-inflammatory, and immunomodulatory properties, in addition to its regulatory action on keratinocyte differentiation and proliferation. These salient properties substantiate the possible role of PRP in the treatment of OLP. Our systematic review focuses on assessing the therapeutic potential of PRP as a treatment modality in OLP. Materials and Methods: We conducted a detailed literature search for studies assessing PRP as a therapeutic regimen in OLP, using the Google Scholar and PubMed/MEDLINE search engines. The search was limited to studies published from January 2000 to January 2023 and included a combination of Medical Subject Heading (MeSH) terms. ROBVIS analysis was carried out for the assessment of publication bias. Descriptive statistics were performed using Microsoft Excel. Results: This systematic review included five articles that met the inclusion criteria. Most of the included studies demonstrated that PRP treatment considerably ameliorated both objective and subjective symptoms in OLP subjects, with comparable efficacy to the standard corticosteroid treatment. Further, PRP therapy offers the added benefit of minimal adverse effects and recurrences. Conclusion: This systematic review suggests that PRP has significant therapeutic potential for treating OLP. However, further research with larger sample sizes is imperative to corroborate these findings.

Differential proteomic expression in indolent versus transforming oral lichen planus

Oral lichen planus (OLP) confers an approximately 1% risk of transformation to oral squamous cell carcinoma (OSCC). Early identification of high-risk OLP would be very helpful for optimal patient management. We aimed to discover specific tissue-based protein biomarkers in patients with OLP who developed OSCC compared to those who did not. We used laser capture microdissection- and nanoLC-tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens in patients with indolent OLP (no OSCC after at least 5-year follow-up, n = 6), transforming OLP (non-dysplastic epithelium with lichenoid inflammation marginal to OSCC, n = 6) or normal oral mucosa (NOM, n = 5). Transforming OLP protein profile was enriched for actin cytoskeleton, mitochondrial dysfunction and oxidative phosphorylation pathways. CA1, TNNT3, SYNM and MB were overexpressed, and FBLN1 was underexpressed in transforming OLP compared with indolent OLP. Integrin signalling and antigen presentation pathways were enriched in both indolent and transforming OLP compared with NOM. This proteomic study provides potential biomarkers, such as CA1 overexpression, for higher-risk OLP. While further validation studies are needed, we propose that epithelial-mesenchymal transition may be involved in OLP carcinogenesis.

Vitamin D in the Treatment of Oral Lichen Planus: A Systematic Review

Oral lichen planus (OLP) is a chronic mucocutaneous condition that affects up to 2% of the general population, and typically presents with long-standing, non-responsive lesions, with episodes of exacerbation and remissions. The etiopathogenesis of OLP is still unclear, although, it has been postulated that it is most likely a T-cell-mediated condition of an unknown antigen. The treatment remains a challenge with no defined treatment strategy. Vitamin D has anti-inflammatory and immunomodulatory properties, along with its regulatory effect on keratinocyte proliferation and differentiation; thus, suggesting its possible role in the treatment of OLP. This systematic review aims to evaluate the therapeutic role of vitamin D in OLP treatment. We searched PubMed/MEDLINE, and Google scholar search engines for studies evaluating vitamin D as a treatment modality in OLP from January 2000 to August 2022. Articles were searched with the combination of Medical Subject Heading (MeSH) terms. A web platform for visualizing risk-of-bias assessment was used in this review, and descriptive statistics were calculated. Out of the seventeen retrieved studies, five articles meeting the inclusion criteria were considered in this systematic review. All the included studies demonstrated significant amelioration in the OLP symptoms in patients who were given vitamin D supplements as an adjuvant to the conventional steroid therapy and or placebo. This systematic review signifies the role of vitamin D as adjuvant therapy for OLP. However, more studies with larger sample size are required to validate these results.

Experimental and clinical trial investigations of phyto-extracts, phyto-chemicals and phyto-formulations against oral lichen planus: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Bio-assay guided phytoextracts and derived phytoconstituents reported having multipotent biological activities and nearly 60-80% of the global population still using natural regimens as an alternative therapeutic source. This study focused on the ethnopharmacological and experimental evidence of natural remedies that are effective in treating oral lichen planus (OLP), a chronic T-cell mediated autoimmune disease that is associated with oral cancer transmission.

AIM OF THE REVIEW

A number of studies have shown that antioxidants and antiinflammatory phytoextracts and phyto-constituents are effective against OLP. In this systematic review, we summarize the details of experimentally assessed ancient Traditional Chinese Medicine (TCM), Indian Ayurveda or Ayurvedic Medicine, and Japanese Kampo Medicine (JKM) regimens (crude extracts, individual phytochemicals, and phyto-formulations) that reduce oral lesion, severity index and pain associated with OLP based on studies conducted in vivo, in vitro, and in randomized controlled trials (RCTs).

MATERIALS AND METHODS

Experimental, clinical and RCT investigation reports were gathered and presented according to PRISMA-2020 format. Briefly, the information was obtained from PubMed, ScienceDirect, Wiley journal library, Scopus, Google Scholar with ClinicalTrials.gov (a clinical trial registry database operated by the National Library of Medicine in the United States). Further, individual phytochemical structures were verified from PubChem and ChemSpider databases and visualized by ChemDraw 18.0 software.

RESULTS

We summarized 11 crude phytoextracts, 7 individual phytochemicals, 9 crude formulations, 8 specific TCM and JKM herbal cocktails, and 6 RCTs/patents corroborated by multiple in vitro, in vivo and enzyme assay methods. Briefly, plants and their family name, used plant parts, reported phytochemicals and their chemical structure, treatment doses, and duration of each experiment were presented more concisely and scientifically.

CONCLUSION

Documentation of evidence-based natural ethnomedicines or remedies could be useful for promoting them as potential, cost-effective and less toxic alternatives or as complementary to commonly prescribed steroids towards the control of OLP.

Hallmarks of Cancer Expression in Oral Lichen Planus: A Scoping Review of Systematic Reviews and Meta-Analyses

Oral lichen planus (OLP) is a common chronic inflammatory disease of unknown etiology and likely autoimmune nature that is currently considered an oral potentially malignant disorder, implying that patients suffering from this process are at risk of developing oral cancer in their lifetime. The molecular alterations that develop in OLP and that make the affected oral epithelium predisposed to malignancy are unknown, although, as in other autoimmune diseases (ulcerative colitis, primary biliary cirrhosis, etc.), they may be linked to oncogenesis-promoting effects mediated by the inflammatory infiltrate. So far there is no in-depth knowledge on how these hallmarks of cancer are established in the cells of the oral epithelium affected by OLP. In this scoping review of systematic reviews and meta-analyses the state of evidence based knowledge in this field is presented, to point out gaps of evidence and to indicate future lines of research. MEDLINE, Embase, Cochrane Library and Dare were searched for secondary-level studies published before October 2022. The results identified 20 systematic reviews and meta-analyses critically appraising the hallmarks tumor-promoting inflammation (n = 17, 85%), sustaining proliferative signaling (n = 2, 10%), and evading growth suppressors (n = 1, 5%). No evidence was found for the other hallmarks of cancer in OLP. In conclusion, OLP malignization hypothetically derives from the aggressions of the inflammatory infiltrate and a particular type of epithelial response based on increased epithelial proliferation, evasion of growth-suppressive signals and lack of apoptosis. Future evidence-based research is required to support this hypothesis.

Challenges in the Early Diagnosis of Oral Cancer, Evidence Gaps and Strategies for Improvement: A Scoping Review of Systematic Reviews

Simple Summary

Oral cancer presents a worldwide incidence of 377,713 new cases and 177,757 deaths per year (GLOBOCAN, IARC, WHO). Oral squamous cell carcinoma (OSCC) accounts for approximately 90% of oral malignancies and has a 5-year mortality rate close to 50%. We aim to better understand, based on the evidence, and to discuss in depth, the reasons for the diagnostic delay of oral cancer by reviewing systematic reviews and meta-analyses. We also aim to, identify gaps in evidence, recommend future lines of research that should be implemented, and formulate strategies for improvement.

Abstract

Oral cancer is a growing problem, accounting for 377,713 worldwide new cases per year, and 177,757 deaths annually and representing a 5-year mortality rate close to 50%, which is a considerable mortality that has not decreased substantially in the last 40 years. The main cause of this high mortality is related to the diagnosis of a high percentage of oral cancers in advanced stages (stages III and IV) in which treatment is complex, mutilating or disabling, and ineffective. The essential cause of a cancer diagnosis at a late stage is the delay in diagnosis, therefore, the achievement of the objective of improving the prognosis of oral cancer involves reducing the delay in its diagnosis. The reasons for the delay in the diagnosis of oral cancer are complex and involve several actors and circumstances—patients, health care providers, and health services. In this paper, we present the results of a scoping review of systematic reviews on the diagnostic delay in oral cancer with the aim to better understand, based on the evidence, and discuss in depth, the reasons for this fact, and to identify evidence gaps and formulate strategies for improvement.

Hallmarks of Cancer Applied to Oral and Oropharyngeal Carcinogenesis: A Scoping Review of the Evidence Gaps Found in Published Systematic Reviews

Simple Summary

This scoping review of systematic reviews aims to accurately assess the degree of existing scientific evidence on the cancer hallmarks proposed in 2011 by Hanahan and Weinberg, in the form of systematic reviews and meta-analyses, applied to oral potentially malignant disorders, oral cavity and oropharyngeal squamous cell carcinomas, in order to point out gaps in evidence and lines of research that should be implemented in the future to improve the malignant transformation prediction, diagnosis and/or prognosis of these diseases.

Abstract

In 2000 and 2011, Hanahan and Weinberg published two papers in which they defined the characteristics that cells must fulfil in order to be considered neoplastic cells in all types of tumours that affect humans, which the authors called “hallmarks of cancer”. These papers have represented a milestone in our understanding of the biology of many types of cancers and have made it possible to reach high levels of scientific evidence in relation to the prognostic impact that these hallmarks have on different tumour types. However, to date, there is no study that globally analyses evidence-based knowledge on the importance of these hallmarks in oral and oropharyngeal squamous cell carcinomas. For this reason, we set out to conduct this scoping review of systematic reviews with the aim of detecting evidence gaps in relation to the relevance of the cancer hallmarks proposed by Hanahan and Weinberg in oral and oropharyngeal cancer, and oral potentially malignant disorders, and to point out future lines of research in this field.

Autoimmune disorders in oral lichen planus: systematic review and meta-analysis

OBJECTIVES

The association of OLP with other autoimmune processes points to the possibility that OLP-affected patients are actually developing an autoimmune status that predisposes them to autoaggression against different targets. This systematic review and meta-analysis aims to evaluate the current evidence on the prevalence of autoimmune disorders in patients with OLP and their magnitude of association.

METHODS

We searched PubMed, Embase, Web of Science, Scopus databases for studies published before May 2021, with no limitation in regards to their publication date or language. We evaluated the quality of studies, carried out meta-analyses and performed heterogeneity, subgroups, meta-regression and small-study effects analyses.

RESULTS

Inclusion criteria were met by 153 studies (23,327 patients). Our results indicate the existence of high prevalences and a frequent association between OLP and some autoimmune disorders, especially in regards to thyroid disease (PP=7.96%,95%CI=6.32-9.75; OR=1.99, 95%=1.60-2.49,p<0.001) and diabetes mellitus (PP=9.41%,95%CI=8.16-10.74; OR=1.64, 95%CI=1.34-2.00,p<0.001).

CONCLUSIONS

Our study demonstrates the existence of a comorbidity between autoimmune thyroid diseases an as well as between diabetes mellitus and OLP, respectively. Quality of evidence should be upgraded on other autoimmune diseases (fibromyalgia, gastrointestinal disorders, rheumatic diseases, Sjögren's syndrome, lupus erythematosus and dermatological diseases) for which the current data do not allow us to know whether they are really associated with OLP.

Substance P and Neurokinin 1 Receptor in Chronic Inflammation and Cancer of the Head and Neck: A Review of the Literature

Head and neck cancer is a growing worldwide public health problem, accounting for approximately 1,500,000 new cases and 500,000 deaths annually. Substance P (SP) is a peptide of the tachykinin family, which has roles related to a large number of physiological mechanisms in humans. The implications of SP in carcinogenesis have recently been reported through the stimulation of the neurokinin 1 receptor (NK1R), or directly, through the effects derived from the constitutive activation of NK1R. Consequently, SP/NK1R seems to play relevant roles in cancer, upregulating cell proliferation, cell migration and chronic inflammation, among other oncogenic actions. Furthermore, there is growing evidence pointing to a central role for SP in tumour progression, singularly so in laryngeal and oral squamous cell carcinomas. The current narrative review of the literature focuses on the relationship between the SP/NK1R system and chronic inflammation and cancer in the head-and-neck region. We described a role for SP/NK1R in the transition from chronic inflammation of the head and neck mucosa, to preneoplastic and neoplastic transformation and progression.

State of Evidence on Oral Health Problems in Diabetic Patients: A Critical Review of the Literature

Diabetes mellitus (DM) is a global health problem, having recognized that in the next 20 years the number of diabetic patients in the world will increase to 642 million. DM exerts enormous repercussions on general health diabetic (especially derived from vascular, cardiac, renal, ocular, or neurological affectation). It entails in addition a high number of deaths directly related to the disease, as well as a high health care cost, estimated at $673 billion annually. Oral cavity is found among all the organs and systems affected in the course of DM. Important pathologies are developed with higher prevalence, such as periodontitis (PD), alterations in salivary flow, fungal infections, oral cancer, and oral potentially malignant disorders (OPMD). It has been proven that PD hinders the metabolic control of DM and that the presence of PD increases the possibility for developing diabetes. Despite the relevance of these oral pathologies, the knowledge of primary care physicians and diabetes specialists about the importance of oral health in diabetics, as well as the knowledge of dentists about the importance of DM for oral health of patients is scarce or non-existent. It is accepted that the correct management of diabetic patients requires interdisciplinary teams, including dentists. In this critical review, the existing knowledge and evidence-degree on the preventive, clinical, diagnosis, prognosis, and therapeutic aspects of oral diseases that occur with a significant frequency in the diabetic population are developed in extension.

State of Evidence on Oral Health Problems in Diabetic Patients: A Critical Review of the Literature

Diabetes mellitus (DM) is a global health problem, having recognized that in the next 20 years the number of diabetic patients in the world will increase to 642 million. DM exerts enormous repercussions on general health diabetic (especially derived from vascular, cardiac, renal, ocular, or neurological affectation). It entails in addition a high number of deaths directly related to the disease, as well as a high health care cost, estimated at $673 billion annually. Oral cavity is found among all the organs and systems affected in the course of DM. Important pathologies are developed with higher prevalence, such as periodontitis (PD), alterations in salivary flow, fungal infections, oral cancer, and oral potentially malignant disorders (OPMD). It has been proven that PD hinders the metabolic control of DM and that the presence of PD increases the possibility for developing diabetes. Despite the relevance of these oral pathologies, the knowledge of primary care physicians and diabetes specialists about the importance of oral health in diabetics, as well as the knowledge of dentists about the importance of DM for oral health of patients is scarce or non-existent. It is accepted that the correct management of diabetic patients requires interdisciplinary teams, including dentists. In this critical review, the existing knowledge and evidence-degree on the preventive, clinical, diagnosis, prognosis, and therapeutic aspects of oral diseases that occur with a significant frequency in the diabetic population are developed in extension.

State of Evidence on Oral Health Problems in Diabetic Patients: A Critical Review of the Literature

Diabetes mellitus (DM) is a global health problem, having recognized that in the next 20 years the number of diabetic patients in the world will increase to 642 million. DM exerts enormous repercussions on general health diabetic (especially derived from vascular, cardiac, renal, ocular, or neurological affectation). It entails in addition a high number of deaths directly related to the disease, as well as a high health care cost, estimated at $673 billion annually. Oral cavity is found among all the organs and systems affected in the course of DM. Important pathologies are developed with higher prevalence, such as periodontitis (PD), alterations in salivary flow, fungal infections, oral cancer, and oral potentially malignant disorders (OPMD). It has been proven that PD hinders the metabolic control of DM and that the presence of PD increases the possibility for developing diabetes. Despite the relevance of these oral pathologies, the knowledge of primary care physicians and diabetes specialists about the importance of oral health in diabetics, as well as the knowledge of dentists about the importance of DM for oral health of patients is scarce or non-existent. It is accepted that the correct management of diabetic patients requires interdisciplinary teams, including dentists. In this critical review, the existing knowledge and evidence-degree on the preventive, clinical, diagnosis, prognosis, and therapeutic aspects of oral diseases that occur with a significant frequency in the diabetic population are developed in extension.

Gene signatures associated with barrier dysfunction and infection in oral lichen planus identified by analysis of transcriptomic data

Oral lichen planus (OLP) is one of the most prevalent oral mucosal diseases, but there is no cure for OLP yet. The aim of this study was to gain insights into the role of barrier dysfunction and infection in OLP pathogenesis through analysis of transcriptome datasets available in public databases. Two transcriptome datasets were downloaded from the Gene Expression Omnibus database and analyzed as whole and as partial sets after removing outliers. Differentially expressed genes (DEGs) upregulated in the dataset of OLP versus healthy epithelium were significantly enriched in epidermal development, keratinocyte differentiation, keratinization, responses to bacterial infection, and innate immune response. In contrast, the upregulated DEGs in the dataset of the mucosa predominantly reflected chemotaxis of immune cells and inflammatory/immune responses. Forty-three DEGs overlapping in the two datasets were identified after removing outliers from each dataset. The overlapping DEGs included genes associated with hyperkeratosis (upregulated LCE3E and TMEM45A), wound healing (upregulated KRT17, IL36G, TNC, and TGFBI), barrier defects (downregulated FRAS1 and BCL11A), and response to infection (upregulated IL36G, ADAP2, DFNA5, RFTN1, LITAF, and TMEM173). Immunohistochemical examination of IL-36γ, a protein encoded by one of the DEGs IL36G, in control (n = 7) and OLP (n = 25) tissues confirmed the increased expression of IL-36γ in OLP. Collectively, we identified gene signatures associated with hyperkeratosis, wound healing, barrier defects, and response to infection in OLP. IL-36γ, a cytokine involved in both wound repair and antimicrobial defense, may be a possible therapeutic target in OLP.

Depression, anxiety, and stress in oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

We present this systematic review and meta-analyses to evaluate current evidence on the prevalence of depression, anxiety, and stress in patients with oral lichen planus and their magnitude of association.

MATERIAL AND METHODS

We searched PubMed, Embase, Web of Science, Scopus, PsycInfo, and Google Scholar for studies published before January 2021. We evaluated the quality of studies using a specific method for systematic reviews addressing prevalence questions, designed by the Joanna Briggs Institute. We carried out meta-analyses and performed heterogeneity, subgroups, meta-regression, and small-study effects analyses.

RESULTS

Fifty-one studies (which recruited 6,815 patients) met the inclusion criteria. Our results reveal a high prevalence of depression (31.19%), anxiety (54.76%), and stress (41.10%) in oral lichen planus. Furthermore, OLP patients presented a significantly higher relative frequency than control group without OLP for depression (OR = 6.15, 95% CI = 2.73-13.89, p < 0.001), anxiety (OR = 3.51, 95% CI = 2.10-5.85, p < 0.001), and stress (OR = 3.64, 95% CI = 1.48-8.94, p = 0.005), showing large effect sizes. Subgroups meta-analyses showed the relevance of the participation of psychologists and psychiatrists in the diagnosis of depression, anxiety, and stress in patients with OLP. Multivariable meta-regression analysis showed the importance of the comorbidity of depression-anxiety in patients with OLP.

CONCLUSIONS

Our systematic review and meta-analysis show that patients with OLP suffer a higher prevalence of depression, anxiety, and stress, being more frequent than in general population. Clinical relevance In the dental clinic, especially dentists should be aware of depression, anxiety, and stress in OLP patients to achieve a correct referral.

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.

Dysplasia in oral lichen planus: relevance, controversies and challenges. A position paper

Background

Patients with oral lichen planus (OLP) have an increased risk of oral cancer. For this reason, OLP is classified as an oral potentially malignant disorder. However, the precise personal (or individual) risk is unknown. Recent meta-analytical studies have reported that dysplastic OLP may transform to cancer in around 6% of cases, while the rate of transformation is lower (<1.5%) in non-dysplastic cases. The presence of epithelial dysplasia has emerged as the most powerful indicator for assessing cancer risk in oral potentially malignant disorders in routine practice. However, the general acceptance of epithelial dysplasia as an accompanying histologic feature in OLP is subject to great controversy. Many pathologists consider the presence of dysplasia as a criterion to exclude OLP when routinely reporting on this disease. This practice, widespread among oral pathology professionals, has resulted in the underestimation of the potential for malignancy of OLP.

Material and Methods

A review of the literature was carried out in order to critically analyze the relevance, controversies and challenges encountered across the diagnosis of epithelial dysplasia in OLP.

Results

12 studies have been published examining dysplastic changes in OLP, reporting Figures ranging from 0.54% to 25% of cases with dysplasia in the first diagnostic biopsy. The diagnosis of dysplasia in the OLP poses an additional difficulty due to the fact that the affected oral epithelium per se develops changes related to autoimmune aggression. Among the most frequent histological features of OLP that develops dysplasia are basal cell hyperplasia with basaloid appearance, loss of basal cells polarity, cellular and nuclear pleomorphism and irregular stratification.

Conclusions

Epithelial dysplasia should not be considered an exclusion criterion for OLP; its evaluation requires experienced pathologists in this field.

Key words:Oral lichen planus, epithelial dysplasia, oral cancer.

The Characteristics of Patients with Oral Lichen Planus and Malignant Transformation-A Retrospective Study of 271 Patients

Introduction: Oral lichen planus (OLP) is a chronic inflammatory disease with an unknown etiology rating among oral potentially malignant disorder. The aim of the study was to determine the epidemiological and clinical characteristics of the patients with OLP and rate of malignant transformation. Patients and methods: Data were obtained from the medical records of 271 patients referred to the Oral Medicine Unit at the University Hospital in Hradec Králové diagnosed with oral lichen planus in the period of 2003–2020. The records were retrospectively analyzed. The following clinical data were retrieved from the medical charts: gender, age, systemic diseases, alcohol and tobacco consumption, localization/clinical appearance of lesions, distribution of the lesions, presence of the symptoms, treatment provided and malignant transformation. Results: A total of 271 charts of patients with confirmed diagnosis of OLP were retrospectively analyzed, of whom, 66.4% (180/271) were women and 33.6% (91/271) were men. The mean age of the patients was 56.0 (18.2–85.0) years. The median follow-up of all patients was 15.2 months. Overall, 2 patients (2/271, 0.74%) meeting the above-mentioned criteria for malignant transformation were identified during the follow-up period. Both patients suffered from erosive type OLP and developed squamous cell carcinoma of the tongue. Conclusions: This retrospective study is in concordance with other studies showing the similar profile and clinical features of the patients with OLP. Malignant transformation rate was 0.74%.

Efficacy and safety of topical administration of tacrolimus in oral lichen planus: An updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Symptomatic oral lichen planus is a common chronic T-cell-mediated disorder characterized by pain and inflammation. The meta-analysis aimed to compare and evaluate the effects and safety of tacrolimus for treating patients with symptomatic oral lichen planus.

METHODS

A comprehensive literature review was performed, including PubMed, the Cochrane Library, Embase, and Web of Science published up to and including December 2020. ClinicalTrials.gov was searched for ongoing trials. There were no restrictions on language or date of publication. Using the Cochrane Collaboration tool, we assessed the risk of bias for randomized controlled trials and estimated the proportion of between-trial heterogeneity.

RESULTS

A total of 9 RCTs evaluating the effects of tacrolimus were included in this study. The results revealed no significant difference in clinical resolution and relapse between tacrolimus and corticosteroids. However, tacrolimus may be more likely to cause mild adverse effects. In particular, clinical resolution was not significantly different between tacrolimus and clobetasol propionate, and between tacrolimus and triamcinolone acetonide, while tacrolimus was more likely to cause adverse effects than triamcinolone acetonide and clobetasol propionate. Moreover, there was no significant difference in pain resolution between tacrolimus and clobetasol. Furthermore, adverse effects were not significantly different between tacrolimus and pimecrolimus.

CONCLUSIONS

This systematic review and meta-analysis of 9 clinical trials supported the short-term application of tacrolimus as an effective regimen in OLP patients resistant to other topical and systemic therapies. Furthermore, the adverse effects of tacrolimus were minor and transient and did not affect tacrolimus' continued application.

Lichen planus - a clinical guide

Lichen planus (LP) is a chronic lichenoid inflammatory disorder of the skin, mucosa and of the appendages. LP is classically characterized by the presence of a rich infiltration of inflammatory T cells, which migrate in the upper part of the dermis, arranged in a band-like pattern. Different sub types of the disease have been so far described. Albeit LP is clinically well defined, the disease still represents a therapeutic enigma. Especially with regard to mucosal or scalp affecting LP types, which often present a recalcitrant and treatment unresponsive course, efficacious therapeutic options are still lacking. Thus, LP represents a disease with a high psychosocial burden. Yet, development in the deciphering of LP pathogenesis reveals possible new druggable targets, thus paving the way for future therapeutic options. In this clinical guide, we summarize the current clinical knowledge and therapeutic standards and discuss the future perspective for the management of LP.

Lichenoid dysplasia is not a distinct pathological entity

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Oral Potentially Malignant Disorders (OPMD): What is the clinical utility of dysplasia grade?

INTRODUCTION

Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to develop invasive cancer. The questions of what process dysplasia grading best represents and what clinical utility dysplasia grading may have are explored.

AREAS COVERED

This narrative review is based on PubMed search with emphasis on papers since 2010. Epithelial dysplasia as a precursor lesion of cancer and dysplasia grading as a risk assessment tool for progression to cancer are discussed. The close clinical association of dysplasia with known carcinogens, alcohol, and tobacco products is presented.

EXPERT OPINION

Oral epithelial dysplasia is often, associated with prolonged exposure to tobacco and alcohol products. With reduction of carcinogen exposure, dysplasia is known to regress in some cases. It is proposed that histologic dysplasia grade together with macroscopic images of dysplastic clinical lesions be used as an educational tool to incentivize patients to reduce their known carcinogen exposure. This strategy has the potential to reduce lesion progression thereby reducing the disease burden of oral cancer.

The role of CD68+ and CD163+ macrophages in immunopathogenesis of oral lichen planus and oral lichenoid lesions

Macrophages are phagocytic cells with essential participation in immunological events of the oral cavity. However, the role of these cells in oral lichen planus (OLP) and oral lichenoid lesions (OLL) remains unclear. The present study aimed to evaluate the density of macrophages in OLP and OLL, and to compare it with that of oral inflammatory fibrous hyperplasia (OIFH) (control group). 14 cases of OLP, 14 cases of OLL and 14 cases of OIFH were selected for immunohistochemical analysis of CD68⁺ (M1) and CD163⁺ (M2) macrophage expression. CD68⁺ and CD163⁺ macrophages densities were measured in the intraepithelial and subepithelial areas. The statistical tests used were multivariate analysis of variance, as well as a correlation and linear regression. OLP has more CD68+ macrophages when comparing with OLL (p = 0.001) and OIFH (p = 0.045). There is a very strong relationship between the macrophages types (p < 0.0001) in OLP and OLL. The linear regression showed that to OLL development (p < 0.0001/R^2' = 0.9584), the presence of different types of macrophages are more essential than to OLP (p < 0.0001/R^2' = 0.8983). However, in the OLP these dependencies are also largely. CD68⁺ macrophages may be associated with immunopathogenesis of OLP, indicating a pro-inflammatory activity and regulatory role in the type of T-cell response. Besides, CD68⁺ macrophages can cooperate in the diagnosis of OLP. These results are essential to future studies that seek a therapeutic target for OLP and OLL.

Oral cancer development in lichen planus and related conditions-3.0 evidence level: A systematic review of systematic reviews

A systematic review of systematic reviews-aka overview of reviews, a novel type of study design providing a tertiary level of evidence-is presented on systematic reviews (SR) and meta-analyses (MTA) evaluating the cancer development in oral lichen planus (OLP), oral lichenoid lesions (OLL), and oral lichenoid reactions (OLR). We searched for SR-MTA published before January 2021. We evaluated the methodological quality of SR-MTA using AMSTAR2 and checked the quality of evidence. Inclusion criteria were met by seven SR-MTA. Oral cancer ratios ranged between 0.44% and 2.28% for OLP, between 1.88% and 3.80% for OLL, and 1.71% for OLR. Significant factors on cancer development reported in SR-MTA were the presence of epithelial dysplasia, the consumption of tobacco and alcohol, the infection by the hepatitis C virus, the presence of atrophic and erosive lesions, and the location on the tongue. Only, one of the SRs assessed the quality of evidence, and most of them were judged to be of critically low methodological quality. In conclusion, based on the reported evidence on cancer incidence in OLP, our results reaffirm classifying OLP as an oral potentially malignant disorder. In relation to OLLs and OLRs, larger studies are necessary to provide further scientific evidence in this regard. Future follow-up studies on OLP and related lesions should be carried out under stricter criteria that improve their quality of evidence and methodological quality.