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

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.

Fraxin alleviates oral lichen planus by suppressing OCT3-mediated activation of FGF2/NF-κB pathway

Oral lichen planus (OLP) is a carcinogenic chronic inflammatory oral disease, which lacks effective treatments. Fraxin is an active ingredient of the traditional Chinese medicine Qin Pi, which has an anti-inflammatory effect, but its effect on OLP is unclear. The aim of this study was to investigate the therapeutic effect of fraxin on OLP and the underlying mechanism. Human immortalized keratinocytes (HaCat) were incubated with fraxin (10, 20, or 40 µM) for 48 h and then treated with 10 µg/mL LPS for 24 h. Cell viability and apoptosis were detected. Next, the interaction between OCT3 and FGF2 was predicted by online database and verified by Co-IP analysis. Fraxin, Ad-OCT3, sh-OCT3, and sh-FGF2 were, respectively, applied to treat LPS-incubated HaCat cells, and cell viability, apoptosis, and secretion of inflammatory factors were detected with MTT, flow cytometry, and ELISA assays. Then, the involvement of OCT3 and FGF2 in the prevention of fraxin on HaCat cells from LPS-induced cell apoptosis and inflammation was investigated through multiple rescue experiments. In addition, OLP models were constructed in VDR-/- mice and NOD/SCID mice by injecting with human OLP pathological tissue homogenates to verify the therapeutic effect of fraxin on OLP. Fraxin treatment increased cell viability and reduced cell apoptosis and the secretion of IL-6 and TNF-α in a dose-dependent manner. OCT3 was significantly upregulated in oral mucosa tissues of OLP mice. OCT3 silencing inhibited LPS-induced cell apoptosis and secretion of inflammatory factors. Fraxin incubation reduced the expression of OCT3, and OCT3 interacted with FGF2 to upregulate FGF2 protein. FGF2 silencing reduced the expression of p-p65/NF-κB protein and improved LPS-induced cell apoptosis and secretion of inflammatory factors. OCT3 overexpression increased the expression of FGF2 and p-p65/NF-κB proteins, rh-FGF2 aggravated this effect, while FGF2-Neu-Ab reversed this effect. The results of in vivo experiments showed that fraxin alleviated cell apoptosis and inflammation in oral buccal mucosa tissues of OLP mice. Fraxin inhibited cell apoptosis and inflammation by suppressing OCT3-mediated activation of the FGF2/NF-κB pathway, alleviating the progression of OLP.

A cytomics-on-a-chip platform and diagnostic model stratifies risk for oral lichenoid conditions

OBJECTIVE

A small fraction of oral lichenoid conditions (OLC) have potential for malignant transformation. Distinguishing OLCs from other oral potentially malignant disorders (OPMDs) can help prevent unnecessary concern or testing, but accurate identification by nonexpert clinicians is challenging due to overlapping clinical features. In this study, the authors developed a 'cytomics-on-a-chip' tool and integrated predictive model for aiding the identification of OLCs.

STUDY DESIGN

All study subjects underwent both scalpel biopsy for histopathology and brush cytology. A predictive model and OLC Index comprising clinical, demographic, and cytologic features was generated to discriminate between subjects with lichenoid (OLC+) (N = 94) and nonlichenoid (OLC-) (N = 237) histologic features in a population with OPMDs.

RESULTS

The OLC Index discriminated OLC+ and OLC- subjects with area under the curve (AUC) of 0.76. Diagnostic accuracy of the OLC Index was not significantly different from expert clinician impressions, with AUC of 0.81 (P = .0704). Percent agreement was comparable across all raters, with 83.4% between expert clinicians and histopathology, 78.3% between OLC Index and expert clinician, and 77.3% between OLC Index and histopathology.

CONCLUSIONS

The cytomics-on-a-chip tool and integrated diagnostic model have the potential to facilitate both the triage and diagnosis of patients presenting with OPMDs and OLCs.

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.

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.

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.

Possible interplay of diabetes mellitus and thyroid diseases in oral lichen planus: A pooled prevalence analysis

The existence of a comorbidity between diabetes mellitus (DM) as well as between thyroid diseases (TD) and oral lichen planus (OLP), respectively, was substantially demonstrated. However, there is not enough attention to the concurrent status of both TD and DM in OLP patients. Herein, this short communication aimed to compare 1) the prevalence of DM when TD was concurrently investigated and that of DM when TD status was ignored; 2) the prevalence of TD when DM was concurrently investigated and that of TD when DM status was ignored in the studies. The pooled prevalence (9.86 %; 95 % confidence intervals [CI], 9.22-10.53 %) of DM when TD was concurrently investigated was significantly higher than that (8.13 %; 95%CI, 8.03-9.12 %) when TD status was not investigated in OLP patients. The pooled prevalence (12.48 %; 95%CI, 11.77-13.22 %) of TD when DM was concurrently investigated was significantly higher than that (10.45 %; 95%CI, 9.52-11.46 %) when DM status was not investigated in OLP patients. Thus, it is logical to presume for the first time that there is possible interplay of DM and TD in OLP occurrence. TD and DM should serve as important confounding factors each other in clinical investigation on OLP and associated comorbidities.

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.

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.