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.

Salivary Biomarkers for Oral Cancer Detection: An Exploratory Systematic Review

Different efforts have been made to find better and less invasive methods for the diagnosis and prediction of oral cancer, such as the study of saliva as a source of biomarkers. The aim of this study was to perform a scoping review about salivary molecules that have been assessed as possible biomarkers for the diagnosis of oral squamous cell carcinoma (OSCC). A search was conducted using EBSCO, PubMed (MEDLINE), Scopus, and Web of Science. The research question was as follows: which molecules present in saliva have utility to be used as biomarkers for the early detection of oral cancer? Sixty-two studies were included. Over 100 molecules were assessed. Most of the markers were oriented towards the early diagnosis of OSCC and were classified based on their ability for detecting OSCC and oral potentially malignant disorders (OPMDs), OSCC outcome prediction, and the prediction of the malignant transformation of OPMDs. TNF-α, IL-1β, IL-6 IL-8, LDH, and MMP-9 were the most studied, with almost all studies reporting high sensitivity and specificity values. TNF-α, IL-1β, IL-6 IL-8, LDH, and MMP-9 are the most promising salivary biomarkers. However, more studies with larger cohorts are needed before translating the use of these biomarkers to clinical settings.

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.

DNA Image Cytometry for Screening the Carcinogenetic Risk of Oral Potential Malignant Disorders

Background: Oral Submucosal Fibrosis (OSF) and Oral Leukoplakia (OLK) are well-known oral potentially malignant disorders, and cases of Oral Submucosal Fibrosis concomitant Oral Leukoplakia (OSF+OLK) are now being reported clinically. DNA image cytometry is an objective and non-invasive method for monitoring the risk of precancerous lesions in the oral cavity. Methods: A total of 111 patients with clinically characterized oral mucosal lesions underwent simultaneous and independent histopathological and DNA imaging cytometry assessments. Clinical data were also collected for each patient. Results: The frequency of DNA content abnormality was higher in the tongue than in other oral sites (P = 0.003) for OLK. The frequency of DNA content abnormality was higher in the tongue than in other oral sites (P = 0.035) for OSF+OLK. The differences of DNA content abnormality in age, sex, dietary habit, smoking, and alcohol intake were not observed in OLK and OSF+OLK. The study indicates an association between DNA content abnormality and pathological examination in OSF+OLK ( χ2 test, P = 0.007). OLK showed higher sensitivity and specificity than OSF, while the sensitivity and specificity of OSF+OLK are higher than OLK only and OSF only. Conclusion: DNA image cytometry can be utilized as an adjunctive device for the initial detection of oral potentially malignant disorders that require further clinical management.

Analysis of drug factors in 5-aminolevulinic acid photodynamic therapy for oral potentially malignant disorder

OBJECTIVES

This study aimed to analyze the influence of drug factors on the efficacy of 5-aminolevulinic acid (ALA) photodynamic therapy for oral potentially malignant disorder to improve clinical efficacy and promote clinical rational drug use.

METHODS

Literature on the treatment of oral potentially malignant disorder by using ALA photodynamic therapy was collected and analyzed from PubMed, ISI Web of Knowledge database, CNKI, VIP, and Wanfang database.

RESULTS

A total of 690 cases were collected, with an average complete response rate of 65.94%. The groups treated with 16.8% methyl aminolevulinate cream, local topical, once a week, and pre-activation time of 2-4 hours were better than the other subgroups, with average complete response rates of 100%, 66.91%, 78.28%, and 77.54%, respectively.

CONCLUSIONS

Drug factors have direct influence on the curative effect. The development of novel oral ALA formulations from the perspective of drug improvement is an important strategy to improve efficacy.

The value of regular follow-up of oral leukoplakia for early detection of malignant transformation

OBJECTIVES

Evaluate whether regular follow-up of oral leukoplakia (OL) resulted in early detection of malignant transformation (MT).

METHOD

Two hundred and twenty-two consecutive patients with OL (147 females, 75 males); median follow-up period of 64 months (range: 12-300). Three groups were distinguished: group A (n = 92) follow-up at the hospital; group B (n = 84) follow-up by their dentist; group C (n = 46) lost to follow-up.

RESULTS

OLs in group B compared to group A, were smaller in size (<2 cm; p < 0.001), showed more hyperkeratosis (p < 0.001) and less moderate/severe dysplasia (p < 0.001). MT occurred in 45 (20%) patients: 32 (35%) in group A, five (6%) in group B and eight (17%) in group C. There was no significant difference in clinical tumour size between group A (median: 15 mm, range: 1-40) and group B (median: 10 mm, range: 3-25; p = 0.496). Tumour size was smaller for patients in groups A and B (median: 10 mm, range 1-40) compared to group C (median: 33 mm, range: 3-100; p = 0.003). There was a positive correlation between tumour size and interval between the last visit in all patients (p = 0.022).

CONCLUSION

Regular follow-up of OL resulted in early detection of MT. If properly selected, follow-up of OL performed by the dentist seems feasible.

The role of differentiated dysplasia in the prediction of malignant transformation of oral leukoplakia

OBJECTIVE

Oral leukoplakia is the most common oral potentially malignant disorder. Malignant transformation of oral leukoplakia occurs at an annual rate of 1%-7%. WHO-defined classic epithelial dysplasia is an important predictor of malignant transformation of oral leukoplakia, but we have previously shown in a proof of concept study that prediction improves by incorporation of an architectural pattern of dysplasia, also coined as differentiated dysplasia. We aimed to analyze this finding in a larger cohort of patients.

METHOD

For this retrospective study 176 oral leukoplakia patients were included. Biopsies for all patients were assessed for the presence of dysplasia and analyzed for cytokeratin 13 and 17 expression. Moreover, the inter-observer agreement for the diagnosis of differentiated dysplasia was determined.

RESULTS

In total, 33 of 176 patients developed oral squamous cell carcinoma during follow-up. Presence of classic epithelial dysplasia increased cancer risk two-fold (HR = 2.18, p = 0.026). Lesions without classic epithelial dysplasia could be further risk-stratified by the presence of differentiated dysplasia (HR = 7.36, p < 0.001). Combined classic epithelial and differentiated dysplasia imparted a seven-fold increased risk of malignant transformation (7.34, p = 0.001). Inter-observer agreement for the diagnosis of dysplasia, including differentiated dysplasia, was moderate (κ = 0.56, p < 0.001).

DISCUSSION

This study emphasizes the importance of the recognition of the architectural pattern of differentiated dysplasia as a separate entity for risk prediction of malignant transformation of oral leukoplakia. Presence of any pattern of dysplasia results in accurate prediction of malignant transformation risk of oral leukoplakia.

Aging and oral squamous cell carcinoma development: the role of cellular senescence

The gradual accumulation and inadequate renewal of senescent cells over time drive organismal aging. Senescent cells undergo altered gene expression and release inflammatory mediators collectively termed the senescence-associated secretory phenotype (SASP), which significantly contributes to a spectrum of age-related disorders, including cancer. In the context of carcinogenesis, the SASP produced by senescent cells has been implicated in the promotion of epithelial cancers, including oral squamous cell carcinoma (OSCC), the most common form of oral cancer. Senescent cells within the tumor microenvironment release factors that amplify the growth and invasiveness of neighboring cancer cells. Senotherapeutics, including senolytics and senomorphics, emerge as promising modalities to target senescent cells and their associated inflammatory factors, thereby opening novel avenues for augmenting the efficacy of cancer treatments. Here, we review the general aspects of cellular senescence, focusing on the relation between senescence-related inflammation with cancer development. We also analyze the available evidence linking cellular senescence with OSCC, highlighting possible clinical applications.

Oral leukoplakia classification and staging system with incorporation of differentiated dysplasia

OBJECTIVES

A classification and staging system for oral leukoplakia (OL) was introduced to promote uniform reporting. In this system, size and the histopathologic diagnosis are assessed and combined in a staging system. The various stages could be predictive for malignant transformation of OL. Differentiated dysplasia (DD) was recently recognized as an important architectural pattern of dysplasia and is highly associated with malignant transformation (MT) of OL. In the present study, DD was incorporated in the OL-system. The aim of the present study was to test the adapted system on a cohort of patients with OL.

PATIENT AND METHODS

The group consisted of 140 patients. The size, absence or presence and degree of classic dysplasia (CD) and DD were incorporated into the OL-system.

RESULTS

In 31/140 patients, MT occurred. Size was not statistically significant with MT (p = 0.422). The presence of dysplasia was predictive for MT (p = 0.003), whereby severe CD and DD were highly statistically significant for MT (p = 0.008). Stage IV was statistically significant for MT (p = 0.011).

CONCLUSIONS

The present study emphasizes the value of the slightly modified OL-system with incorporation of DD in uniform reporting of OL and the value in predicting MT.

Evaluation of crystallization patterns in oral potentially malignant disorders and oral malignancies: A prospective study

Background

Oral cancers are often detected at late stages, and patients usually had a 50% chance of a 5-year survival rate. Oral cancer usually has an early precancerous stage before its actual malignant transformation. Although there are various approaches to diagnose the early stages of cancer, there is one less explored, cost-effective, and simple technique known as the crystallization test. The aim of the study was to evaluate the crystallization patterns in tobacco users, oral potentially malignant disorders (OPMDs), and oral malignancies.

Materials and Methods

Fifteen patients with oral malignancies, 15 patients with oral potentially malignant disorders, 15 tobacco users, and 15 healthy individuals participated in the crystallization test. Single blood drop was used to perform this test and the obtained crystal patterns were analyzed.

Results

This test had a sensitivity of 93.3%, 80.0%, and 20.0% for oral malignancies, oral Potentially Malignant Disorders (PMDs), and tobacco users, respectively. Chi-square analysis revealed a highly significant transverse form between OPMDs and oral malignancies (P < 0.05).

Conclusion

Crystallization test was found to be a sensitive, reliable, economical, and less invasive procedure for screening of oral PMDs and oral malignancies under strictly maintained physical conditions.

Oral cancer and precancer in Oral Pathology and Medicine curricula of Mexican dental schools

OBJECTIVE

To identify the teaching-learning process characteristics of Oral Pathology and Medicine (OP&M) related to oral potentially malignant disorders (OPMDs) and oral cancer (OC), in the dental schools' curricula in Mexico, to analyze the approach given to this topic worldwide, and to provide the possible solution strategies.

MATERIALS AND METHODS

Questionnaires were sent to OP&M deans and professors from public Mexican Universities to explore the curriculum and academic profile of the dental schools. The recommendations gathered from a workshop with expert professors on the challenges in OPMD/OC teaching were reported.

RESULTS

Twenty-two dental schools participated (22 deans, 30 professors). The most widely used strategies were clinical-case resolving (86%) and presentations (73%). Although 77.3% of the programs included maxillofacial lesions, only 40.9% contemplated OPMD/OC. Only 45% of the programs developed community activities for early OC detection. The workshop recommendations were (i) multidisciplinary approach to OPMD/OC teaching, involving OP&M professors in other dental and nondental courses; (ii) implementation of the most effective teaching techniques (currently, problem-based learning and clinical-case presentation) in OP&M curricula; (iii) education of OP&M professors on teaching-learning processes.

CONCLUSIONS

These recommendations from the Mexican context, integrated with similar experiences from other countries could contribute to develop a unique, internationally acknowledged OP&M curriculum.

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.

Is OLP potentially malignant? A clue from ZNF582 methylation

OBJECTIVE

Whether oral lichen planus (OLP) was potentially malignant remains controversial. Here, we examined associations of ZNF582 methylation (ZNF582^m ) with OLP lesions, dysplastic features and squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

This is a case-control study. ZNF582^m was evaluated in both lesion and adjacent normal sites of 42 dysplasia, 90 OSCC and 43 OLP patients, whereas ZNF582^m was evaluated only in one mucosal site of 45 normal controls. High-risk habits affecting ZNF582^m such as betel nut chewing and cigarette smoking were also compared in those groups.

RESULTS

OLP lesions showed significantly lower ZNF582^m than those of dysplasia and OSCC. At adjacent normal mucosa, ZNF582^m increased from patients of OLP, dysplasia, to OSCC. In addition, ZNF582^m at adjacent normal sites in OLP patients was comparable to normal mucosa in control group. Dysplasia/OSCC patients with high-risk habits exhibited significantly higher ZNF582^m than those without high-risk habits. However, ZNF582^m in OLP patients was not affected by those high-risk habits.

CONCLUSIONS

OLP is unlikely to be potentially malignant based on ZNF582^m levels. ZNF582^m may also be a potential biomarker for distinguishing OLP from true dysplastic features and OSCC, and for monitoring the malignant transformation of OLP, potentially malignant disorders with dysplastic features and OSCC.

Revisiting the evidence of photodynamic therapy for oral potentially malignant disorders and oral squamous cell carcinoma: an overview of systematic reviews

BACKGROUND

This study summarized the available evidence about the use of photodynamic therapy (PDT) for the management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC).

METHODS

An overview of systematic reviews was undertaken based on the 2020 PRISMA statement. Electronic searches were performed in five databases. Studies published up to November 2022 were included. Risk of bias was assessed with the AMSTAR 2 tool.

RESULTS

A total of 30 studies enrolling 9,245 individuals with OPMD (n=7,487) or OSCC (n=1,758) met the selection criteria. All studies examined the efficacy and/or safety of PDT. OPMD were investigated individually in 82.8% of the studies, the most common being oral lichen planus and actinic cheilitis. OSCC was addressed separately in 10.3% of the studies, while only 6.9% evaluated both OPMD and OSCC. Fourteen different types of photosensitizers were described. PDT was used according to the following setting parameters: 417-670 nm, 10-500 mW/cm², 1.5-200 J/cm², and 0.5-143 minutes. Regarding OPMD, leukoerythroplakia showed the best response rates, while oral lichen planus presented a partial or no response in nearly 75% of documented cases. A complete response was observed in 85.9% of OSCC cases, while 14.1% had no resolution.

CONCLUSION

Overall, the response to PDT depended on the type of OPMD/OSCC and the parameters used. Although PDT is an emerging candidate for the treatment of OPMD and OSCC, there is heterogeneity of the methodologies used and the clinical data obtained, particularly regarding the follow-up period.

Changes in quality of life over time in patients diagnosed with oral leukoplakia: A prospective longitudinal study

BACKGROUND

Oral leukoplakia (OL) is one of the most prevalent oral potentially malignant disorders (OPMD). Although there is emerging evidence that quality of life (QoL) is impaired in subjects with OL; studies to date are based on single and heterogenous point-in-time assessments. The aim of this study was to ascertain if QoL scores change over time in individuals diagnosed with OL.

METHODS

Forty-one individuals with OL were administered the Short Generic Health Questionnaire (SF-12) and the discipline-specific Oral Potentially Malignant Disorder Questionnaire (OPMDQ) at four points in time: at the time of clinical diagnosis, at the post-biopsy review (confirmed diagnosis), and at 3- and 6-month follow-up appointments. Responses were compared between the four time points.

RESULTS

No significant differences were observed in the SF-12 questionnaire scores over time. However, a general improvement in the participants' life quality was evident over the 6-month period under investigation in the domains of psychological and social well-being (p = 0.0027) and effect of treatment on daily life (p = 0.0317) as well as in the total score (p = 0.0005) of the OPMDQ. Age, gender, medical status, tobacco/alcohol use, lesion site, size, the presence of dysplasia and treatment did not impact QoL scores over time.

CONCLUSIONS

QoL scores of OL subjects may improve with time. Our results suggest that studies examining QoL in individuals with OL should be controlled for time at which the participants are surveyed.

Machine learning for detection and classification of oral potentially malignant disorders: A conceptual review

Oral potentially malignant disorders represent precursor lesions that may undergo malignant transformation to oral cancer. There are many known risk factors associated with the development of oral potentially malignant disorders, and contribute to the risk of malignant transformation. Although many advances have been reported to understand the biological behavior of oral potentially malignant disorders, their clinical features that indicate the characteristics of malignant transformation are not well established. Early diagnosis of malignancy is the most important factor to improve patients' prognosis. The integration of machine learning into routine diagnosis has recently emerged as an adjunct to aid clinical examination. Increased performances of artificial intelligence AI-assisted medical devices are claimed to exceed the human capability in the clinical detection of early cancer. Therefore, the aim of this narrative review is to introduce artificial intelligence terminology, concepts, and models currently used in oncology to familiarize oral medicine scientists with the language skills, best research practices, and knowledge for developing machine learning models applied to the clinical detection of oral potentially malignant disorders.

Associations between clinical and histopathological characteristics in oral leukoplakia

OBJECTIVES

To identify possible associations between patients' demographics and habits and the clinical aspects and histopathological characteristics of oral leukoplakia (OL) at patients' first visit.

METHOD

A total of 140 consecutive patients with OL at a single institute between 1997 and 2019. All biopsies were microscopically examined for classic dysplasia (CD) (WHO definition oral epithelial dysplasia) and differentiated dysplasia (DD) known from differentiated vulvar intraepithelial neoplasia. Clinical characteristics were correlated to histopathological diagnosis and odds ratios (OR) were calculated.

RESULTS

A total of 96 females and 44 males, mean age 58 years, were presented. OLs were found mainly on the tongue (41%) and floor of mouth (FOM) (18%). Homogeneous OLs (58%) were associated with smoking, FOM and size <2cm and non-homogeneous OLs (42%) with non-smokers. No dysplasia was present in 40% and any dysplasia (AD) in 60%. Tongue OLs were correlated with AD (OR:6.0) and CD (OR:5.7). FOM OLs were correlated with CD (OR:4.5). DD was correlated with non-homogeneous OLs (OR:2.6).

CONCLUSIONS

CD was most frequently observed in tongue and FOM OLs, while DD was associated with non-homogeneous OLs. In this series of patients, there was no consistent reliable association between the clinical and histopathological features and clinical characteristics can therefore not substitute microscopic examination of biopsies.

Doctoral: A smartphone-based decision support tool for the early detection of oral potentially malignant disorders

Oral potentially malignant disorders can be defined as mucosal lesions and conditions with an increased risk of malignant transformation. Oral potentially malignant disorders are a significant health burden, and they are often diagnosed late due to scant attention to routine dental practice and the low number of specialized oral medicine centres. This report summarizes the DoctOral experience, a research initiative, providing a free smartphone-based decision support tool for the general medical/dental practitioner; the tool is based on the clinical appearance of oral lesions. Captured, oral pictures can be immediately examined via interactive decision trees and constructed on the smartphone. Such decision trees are expressed in standard formats, and they are readily accessible for facilitating the completion of a hypothetical diagnostic path. Since October 2017 the DoctOral mobile app has been downloaded by 10K + users, achieving a score of 4.8 out of 5. DoctOral also supports an unfolding joint initiative, called DoctOralAI: this involves selecting reference images, with which to create an open-source model, and perform a Case-Based Reasoning method, both of which are combined with machine learning. The DoctOral mobile app has revolutionized oral pathology by providing dental students and professionals with an interactive platform for recognizing and diagnosing oral lesions.

Critical update, systematic review, and meta-analysis of oral erythroplakia as an oral potentially malignant disorder

Background

Oral erythroplakia has been classically considered as the potentially malignant disorder with the highest rate of malignant development into squamous cell carcinoma. This critical systematic review and meta‐analysis aim to estimate the malignant development rate of oral erythroplakia and identify the associated risk factors.

Methods

We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and LILACS, with keywords “erythroplakia,” “erythroplasia,” “malignant transformation,” “malignant development,” “malignization,” “carcinogenesis,” “oral cancer,” “oral squamous cell carcinoma,” “mouth neoplasm,” and “prognosis.” Meta‐analysis was conducted using a random‐effects model.

Results

Ten observational studies with 441 patients met the inclusion criteria, whose mean malignant development rate was 12.7% and with a mean follow‐up period of patients of 6.66 years. In the initial biopsy, 42.8% of oral erythroplakia were already squamous cell carcinoma. The buccal mucosa was the most frequent location of oral erythroplakia, but the floor of the mouth was the most common site of malignant development. All patients who underwent malignant development showed epithelial dysplasia on the initial diagnostic biopsy.

Conclusion

Overall malignant development rate of OE in the meta‐analysis was 19.9%. We could not associate any specific clinicopathological feature with the malignant development. The presence of epithelial dysplasia in the initial biopsy remains the worst prognostic factor. Further observational studies on OE are needed, with well‐established diagnostic criteria and good clinical follow‐up, in order to identify the true risk of malignant development of oral erythroplakia and the related risk factors.

Single-Cell RNA Sequencing Analysis for Oncogenic Mechanisms Underlying Oral Squamous Cell Carcinoma Carcinogenesis with Candida albicans Infection

Oral squamous cell carcinoma (OSCC) carcinogenesis involves heterogeneous tumor cells, and the tumor microenvironment (TME) is highly complex with many different cell types. Cancer cell-TME interactions are crucial in OSCC progression. Candida albicans (C. albicans)-frequently pre-sent in the oral potentially malignant disorder (OPMD) lesions and OSCC tissues-promotes malignant transformation. The aim of the study is to verify the mechanisms underlying OSCC car-cinogenesis with C. albicans infection and identify the biomarker for the early detection of OSCC and as the treatment target. The single-cell RNA sequencing analysis (scRNA-seq) was performed to explore the cell subtypes in normal oral mucosa, OPMD, and OSCC tissues. The cell composi-tion changes and oncogenic mechanisms underlying OSCC carcinogenesis with C. albicans infec-tion were investigated. Gene Set Variation Analysis (GSVA) was used to survey the mechanisms underlying OSCC carcinogenesis with and without C. albicans infection. The results revealed spe-cific cell clusters contributing to OSCC carcinogenesis with and without C. albicans infection. The major mechanisms involved in OSCC carcinogenesis without C. albicans infection are the IL2/STAT5, TNFα/NFκB, and TGFβ signaling pathways, whereas those involved in OSCC carcinogenesis with C. albicans infection are the KRAS signaling pathway and E2F target down-stream genes. Finally, stratifin (SFN) was validated to be a specific biomarker of OSCC with C. albicans infection. Thus, the detailed mechanism underlying OSCC carcinogenesis with C. albicans infection was determined and identified the treatment biomarker with potential precision medicine applications.

Malondialdehyde Level and Tissue Apoptosis Count as an Early-Detection Marker of Oral Potentially Malignant Disorders

OBJECTIVES

 The malondialdehyde (MDA) level and TA count represent the progression of oral potentially malignant disorders (OPMD) to malignancy and thus may be used as an indicator of oral epithelial dysplasia (OED). This study aimed to determine the MDA level and tissue apoptosis (TA) count in oropharyngeal tissue of Wistar rats exposed to sidestream cigarette smoke.

MATERIALS AND METHODS

 Wistar rats were divided into three groups: T4 group (4-week cigarette smoke exposure), T8 group (8-week cigarette smoke exposure), and control group, which was not exposed to cigarette smoke. The oropharyngeal tissue of the rats from each group was examined histopathologically to count the number of apoptotic cells, and then the blood serum was made to measure the MDA level.

STATISTICAL ANALYSIS

 Bonferroni test was performed to see the differences in each group for MDA level. While the data from tissue apoptosis were analyzed using Mann-Whitney U test for the significance. All data were considered significant if p < 0.05.

RESULTS

 The MDA level and TA count increased as the duration of cigarette smoke exposure increased. In the T8 group, the MDA level and TA count were significantly higher compared with the T4 and control groups with a p-value < 0.05.

CONCLUSIONS

 Exposure to sidestream cigarette smoke increased the TA count and MDA level in the oropharyngeal tissue of Wistar rats. The TA count and MDA level may be used as markers of OPMD.

Identification of a Gene-Expression-Based Surrogate of Genomic Instability during Oral Carcinogenesis

Simple Summary

New personalized cancer prevention strategies may decrease the mortality of oral cancer that can arise from oral potentially malignant disorders (OPMD). A major cancer hallmark is the acquisition of multiple deletions or amplifications of genomic material fragments leading to genomic instability (GI). Our goal was to identify a set of genes whose expression was associated with GI. A total of 20 genes correlated with GI were identified in two independent datasets of head and neck cancer (including oral cancer). We computed a score of those genes, referred to as the GIN score, in with each sample from multiple validation datasets. We show that the GIN score: (i) was correlated with GI, (ii) increased at different stages of oral carcinogenesis from normal mucosa to oral cancer, and (iii) was associated with malignant transformation of OPMD. The GIN score is a promising biomarker for identifying patients suffering from OPMD with high risk of oral cancer.

Abstract

Background: Our goal was to identify a gene-expression-based surrogate of genomic instability (GI) associated with the transformation of oral potentially malignant disorder (OPMD) into oral squamous cell carcinoma (OSCC). Methods: GI was defined as the fraction of genome altered (FGA). Training sets included the CCLE and TCGA databases. The relevance of the enrichment score of the top correlated genes, referred to as the GIN score, was evaluated in eight independent public datasets from the GEO repository, including a cohort of patients with OPMD with available outcome. Results: A set of 20 genes correlated with FGA in head and neck SCC were identified. A significant correlation was found between the 20-gene based GIN score and FGA in 95 esophagus SCC (r = 0.59) and 501 lung SCC (r = 0.63), and in 33 OPMD/OSCC (r = 0.38). A significantly increased GIN score was observed at different stages of oral carcinogenesis (normal–dysplasia –OSCC) in five independent datasets. The GIN score was higher in 10 OPMD that transformed into oral cancer compared to 10 nontransforming OPMD (p = 0.0288), and was associated with oral-cancer-free survival in 86 patients with OPMD (p = 0.0081). Conclusions: The GIN score is a gene-expression surrogate of GI, and is associated with oral carcinogenesis and OPMD malignant transformation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Oral Cancer Discrimination and Novel Oral Epithelial Dysplasia Stratification Using FTIR Imaging and Machine Learning

The Fourier transform infrared (FTIR) imaging technique was used in a transmission model for the evaluation of twelve oral hyperkeratosis (HK), eleven oral epithelial dysplasia (OED), and eleven oral squamous cell carcinoma (OSCC) biopsy samples in the fingerprint region of 1800–950 cm⁻¹. A series of 100 µm × 100 µm FTIR imaging areas were defined in each sample section in reference to the hematoxylin and eosin staining image of an adjacent section of the same sample. After outlier removal, signal preprocessing, and cluster analysis, a representative spectrum was generated for only the epithelial tissue in each area. Two representative spectra were selected from each sample to reflect intra-sample heterogeneity, which resulted in a total of 68 representative spectra from 34 samples for further analysis. Exploratory analyses using Principal component analysis and hierarchical cluster analysis showed good separation between the HK and OSCC spectra and overlaps of OED spectra with either HK or OSCC spectra. Three machine learning discriminant models based on partial least squares discriminant analysis (PLSDA), support vector machines discriminant analysis (SVMDA), and extreme gradient boosting discriminant analysis (XGBDA) were trained using 46 representative spectra from 12 HK and 11 OSCC samples. The PLSDA model achieved 100% sensitivity and 100% specificity, while both SVM and XGBDA models generated 95% sensitivity and 96% specificity, respectively. The PLSDA discriminant model was further used to classify the 11 OED samples into HK-grade (6), OSCC-grade (4), or borderline case (1) based on their FTIR spectral similarity to either HK or OSCC cases, providing a potential risk stratification strategy for the precancerous OED samples. The results of the current study support the application of the FTIR-machine learning technique in early oral cancer detection.

Evaluating CagA and VacA Oncoproteins of Helicobacter pylori in Oral Potentially Malignant Disorders

Oral Potentially Malignant Disorders such as leukoplakia, lichenplanus, Oral Submucous Fibrosis are most commonly encountered precancerous lesions in India. Although, usage of smoking tobacco has been decreased yet incidence of oral cancer seems to be in increasing trend. Apart from tobacco many non-tobacco causes are associated with the disease. Helicobacter pylori is a curved, flagellated bacterium that has been declared as group I carcinogen by WHO. They are proven causative agent for gastric carcinoma. They have been shown to harbour oral cavity by many authours. They produce onco-protein that causes DNA damage. CagA and VacA are such proteins that modulate certain oncogenes and tumour suppressor genes. In this study we have identified the organism from sub gingival plaque by PCR and those who harboured the organism were further subjected for identification of oncoproteins CagA and VacA by ELISA. This study shows that presence of organism in Oral leucoplakia, oral lichenplanus and Oral Submucous Fibrosis are statistically significant in comparison to control group (p>0.05). The presence of oncoproteins was also statistically significant in comparison to control group. These proteins are shown to accelerate inflammatory pathway thereby hasten the process of tumorigenesis. H.pylori infection as well the virulent strains can be diagnosed from oral cavity in the most non-invasive way at the earliest.

Ablative fractional laser-assisted photodynamic therapy vs. ablative fractional laser for oral leukoplakia treatment: A randomized, controlled pilot study

BACKGROUND

Ablative fractional laser-assisted photodynamic therapy (AFL-PDT) is explored as an effective method in some premalignant diseases, whereas the effect of AFL-PDT on oral leukoplakia (OL), the best-known precursor of oral squamous cell carcinoma, remains undetermined.

METHODS

Forty-eight patients, histologically diagnosed with OL, were randomized (1:1) to receive either AFL-PDT or ablative fractional laser (AFL) treatment. All patients were followed up at 1, 3, 6 and 12 months postoperatively. The primary endpoints of efficacy and clinical recurrence and the secondary endpoint of side effects were assessed.

RESULTS

Forty-four patients completed the study. The 100% effective cure rate in the AFL-PDT group was higher than that in AFL group (80.9%, P<0.05) with 19.1% difference (95%CI: 0.7-40.0%). Compared to AFL group, recurrence observed at 6 and 12 months post-treatment tended to occur in fewer patients in the AFL-PDT group (P<0.05). No severe adverse events or systemic side effects were observed in either group.

CONCLUSIONS

AFL-PDT may effectively reduce recurrence of OL with high clinical efficacy and good tolerability, suggesting it may be a promising treatment for OL.

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.

Aneuploidy and loss of heterozygosity as risk markers for malignant transformation in oral mucosa

The ability to predict malignant transformation in oral potentially malignant disorders would inform targeted treatment, provide prognostic information and allow secondary prevention. DNA ploidy and loss of heterozygosity assays are already in clinical use, and loss of heterozygosity has been used in prospective clinical trials. This review appraises published evidence of predictive ability and explores interpretation of heterogeneous studies, with different diagnostic methods, criteria and intention. Both methods have a sound biological foundation and have predictive value independent of dysplasia grading and clinical parameters. The application of these two techniques cannot be directly compared because of differences in expression of results and application to populations of different risk. Predicting malignant transformation accurately on an individual patient basis is not yet possible with either technique. However, they are valuable applications to stratify patients for inclusion in trials, identify the lowest risk patients and exclude risk when biopsy results are indeterminate for dysplasia.

Dysplasia and DNA ploidy to prognosticate clinical outcome in oral potentially malignant disorders

BACKGROUND

Oral potentially malignant disorders are a clinical conundrum as there are no reliable methods to predict their behaviour. We combine conventional oral epithelial dysplasia grading with DNA ploidy analysis to examine the validity of this approach to risk assessment in a cohort of patients with known clinical outcomes.

METHODS

Sections from diagnostic biopsies were assessed for oral epithelial dysplasia using the WHO grading system, and DNA ploidy analysis was performed using established methods. Patients reviewed for a minimum of 5 years who did not develop oral squamous cell carcinoma were classified as "non-transforming" cases. Patients that developed oral squamous cell carcinoma ≥ 6 months after the initial diagnostic biopsy were classified as having "malignant transformation."

RESULTS

Ninety cases were included in the study. Seventy cases yielded informative DNA ploidy results. Of these 70 cases, 31 progressed to cancer. Oral epithelial dysplasia grading and DNA ploidy status were both significantly associated with clinical outcome (P < 0.05). Severe dysplasia had a hazard ratio of 3.50 (CI: 1.46, 8.45; P = 0.005) compared to cases with mild dysplasia. Aneuploidy had a hazard ratio of 2.09 (CI: 1.01, 4.32; P = 0.046) compared to cases with a diploid/tetraploid status. Receiver operating characteristic analysis gave an area under the curve of 0.617 for DNA ploidy status and 0.688 when DNA ploidy status was combined with dysplasia grading.

CONCLUSION

Our findings suggest that combining dysplasia grading with DNA ploidy status has clinical utility which could be used to develop novel management algorithms.

The genetic basis of oral leukoplakia and its key role in understanding oral carcinogenesis

Oral leukoplakia (OL) is the most common oral potentially malignant disorder, with a global prevalence of 2%-3%, variable malignant transformation rate and incompletely understood aetiology. Considering the subjectivity in oral dysplasia grading, other evaluation methods have been tested as predictors of malignant transformation. DNA ploidy status and loss of heterozygosity signatures have been shown to be good predictive markers of malignant transformation. However, effective markers to predict which lesions will progress to invasive carcinoma and by which mechanisms remain unclear. Recent evidence suggests that dysplasia progression to carcinoma occurs through neutral clonal evolution (i.e. randomly). We focus on the genetic basis of OL, encompassing the gross chromosomal alterations and single-gene mutations, and discuss such alterations in the context of aetiology, clinical presentation and progression. The deeper we understand the genetic basis of OL, the more we approach a better comprehension of the complex and poorly understood process of oral carcinogenesis.

DNA content abnormality in oral submucous fibrosis concomitant leukoplakia: A preliminary evaluation of the diagnostic and clinical implications

Oral submucous fibrosis (OSF) is an insidious chronic oral and oropharyngeal potentially malignant disorder. Our previously studies reported that DNA image cytometry (ICM) using brushing added in the diagnosis of high-grade dysplasia and staging of oral leukoplakia (OLK). This preliminary study aimed to investigate the abnormal rate of DNA content in 30 cases of OSF including three cases of OSF concomitant OLK and evaluate their the diagnostic and clinical implications with special emphasis on the OSF concomitant OLK. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination, respectively. The results of DNA-ICM analysis showed that all the lesions from the 27 patients with OSF only were identified as normal DNA content. Strikingly, two of three cases of OSF concomitant OLK were identified as abnormal DNA content, and one case of whom progressed to early oral squamous cell carcinoma at the follow-up of 31 months. Collectively, this preliminary evaluation revealed that DNA content abnormality was hardly observed in OSF only; however, it may be usually observed in OSF concomitant OLK, whom should be monitored on a priority basis for early detection of carcinoma. Multicenter large studies are needed to validate the findings of the current study.

Serum C-reactive protein in oral submucous fibrosis and oral squamous cell carcinoma: A cross-sectional study

Context:

Early detection of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSMF) transforming into malignancy can drastically improve the treatment outcomes and prognosis. Carcinoma development is an intricate complex mechanism and the multifactorial causation makes it more difficult to find specific prognostic and therapeutic biomarkers. Thus, the development of newer diagnostic and predictive approaches that are less invasive, economical and amenable to repeated sampling is imperative. Serum C-reactive protein (CRP) serves a useful marker for prognosis and monitoring of oral potentially malignant disorders (OPMDs) including OSMF as well as OSCC. Secreted by hepatocyte as an acute inflammatory marker, various studies have shown association between serum CRP and presence of OPMDs, as well as with presence and prognosis of OSCC.

Aims:

The aim of this study was to measure and compare serum CRP levels in patients with OSMF and OSCC as compared to healthy individuals and to establish baseline data for serum CRP levels in patients with OSMF and OSCC.

Settings and Design:

Cross-sectional observational prospective study.

Materials and Methodology:

The study includes 150 individuals, with 50 healthy, 50 OSMF and 50 OSCC individuals. Spinreact CRP-turbilatex Kit (SPINREACT) and Prietest-EXP semi-automatic biochemical analyzer were used for quantitative determination of serum CRP.

Statistical Analysis Used:

Data were analyzed by SPSS 16^© (Statistical Package for the Social Sciences) software.

Results:

The mean value of serum CRP in Group I was 2.20 mg/L with standard deviation of 1.74; in Group II, it was 5.40 mg/L with standard deviation of 4.79 mg/L and in Group III, it was 12.17 mg/L with standard deviation of 11.38.

Conclusions:

Serum CRP levels in patients with OSMF were raised, but not statistically significant as compared to the control group. Values of serum CRP were significantly higher in patients with OSCC as compared to the control group, and it was statistically significant; these values also showed positive association with primary tumor size.

Oral HPV16 Prevalence in Oral Potentially Malignant Disorders and Oral Cavity Cancers

The role of human papillomavirus type 16 (HPV16) in oral potentially malignant disorders (OPMD) and oral cavity carcinoma (OC) is still under debate. We investigated HPV16 prevalence in unstimulated saliva, oral rinse samples, oral swabs and tumour biopsies collected from OPMD (n = 83) and OC (n = 106) patients. HPV16 genotype, viral load, physical status (episomal vs. integrated) and tumour p16INK4a expression were determined. Oral HPV16 prevalence was higher in OC than in OPMD, but this difference was not statistically significant (7.5% (8/106) versus 3.6% (3/83), odds ratio (OR): 2.18, 95% confidence interval (CI): 0.56, 8.48, p = 0.26). There was a significant association (p < 0.05) between oral HPV16 infection and heavy tobacco consumption. Real-time PCR results indicated that no integration events occurred in either OPMD or OC cases based on the HPV16 E2/E6 ratio. HPV16 positive OPMD and OC patients had similar HPV16 E2 and E6 viral loads. The inter-rater agreement between tumour p16INK4a expression and oral HPV16 infection was considered as fair (k = 0.361) for OC. Our data suggest that the involvement of HPV16 in oral carcinogenesis is limited.

Comparative evaluation of curcumin and antioxidants in the management of oral submucous fibrosis

AIM

The present study aims to evaluate the efficacy and safety of curcumin in both topical and systemic forms for management of oral submucous fibrosis in comparison with the antioxidants.

METHODS

In this randomized parallel-group single-center trial, 119 patients were enrolled. Group I received antioxidants, group II received curcumin in systemic form and group III received curcumin in both systemic and topical forms. The primary outcomes assessed were interincisal mouth opening and burning sensation using a visual analog scale. The secondary outcomes were tongue protrusion and adverse reactions. The response to treatment was analyzed using ANOVA and Fisher's exact test.

RESULTS

Significant improvement in mouth opening, burning sensation and tongue protrusion was observed in all groups at 12 weeks. Mean improvement in burning sensation did not show statistical difference across the groups. A significant difference between groups II and III for improvement in mouth opening and groups I and III for improvement in tongue protrusion was noted.

CONCLUSION

When administrated in both systemic and topical forms together, curcumin showed better results in the management of oral submucous fibrosis as compared with the systemic form alone or antioxidants. Curcumin has the potential to emerge as an effective alternative to conventionally prescribed medications.

Recent trends in predictive biomarkers for determining malignant potential of oral potentially malignant disorders

Despite of the tremendous advancements in the field of cancer prevention, detection and treatment, the overall prognosis of oral squamous cell carcinoma (OSCC) still remains poor. This can be partly imparted to the lack of early detection of oral potentially malignant disorders (OPMDs), especially those at a higher risk of progression into OSCC. Over years, various specific and non-specific markers have been introduced that could predict the malignant transformation of OPMDs; however detail information on these OPMD markers in a concise manner is lacking. Moreover, their use on daily clinical basis still remains questionable. With continuous research in the field of cytology and genomics, several contemporary biomarkers have been discovered that are not yet foregrounded and proved to be more promising than those used conventionally. Here, in the present paper, we overview several recently concluded predictive biomarkers with special emphasis on their role in molecular pathogenesis of OSCC transformation. These markers can be used for risk assessment of malignant transformation in patients with OPMDs as well as for prophylactic conciliation and fair management of the high-risk OPMD patient group.

Cancer stem cell markers ALDH1 and Bmi1 expression in oral erythroplakia revisited: Implication for driving the process of field cancerization

The correlation of ALDH1 and Bmi1 expression in potentially malignant oral erythroplakia (OE) with oral carcinoma development was reported in our earlier study. Interestingly, a model of field cancerization orchestrated by the cancer stem cells (CSC) was proposed and suggested the identification of CSC-specific markers is useful for prognosis and providing novel targets for prevention and treatment of field cancerization. We revisited the correlation of ALDH1 and Bmi1 expression in OE with the second and multiple carcinomas development. Strikingly, we observed that the expression of ALDH1 and Bmi1 within a single potentially malignant OE lesion significantly correlate with subsequently developing multiple and multifocal carcinomas, which parallels the process of oral field cancerization. Significantly, ALDH1 and Bmi1 are well-defined markers of CSC for head and neck cancer. Consequently, we provided a preliminary evidence for CSC driving the process of field cancerization.

Effectiveness of crystallization test in screening of potentially malignant oral disorders and oral cancer

Aim

This study aims to determine the effectiveness of crystallization test in screening of oral potentially malignant disorders (PMDs) and oral cancer.

Materials and Methods

Thirty patients of oral PMD, 30 patients of oral cancer and 40 normal healthy people were selected. One drop of blood was collected and added to 1 cc of double-distilled water at room temperature to get a final dilution of 6% hemolyzed blood. 0.1-0.2 cc of this blood sample is added to 10 cc of 20% cupric chloride solution and further is subjected to crystallization test.

Results

In the normal healthy group, the pattern was typical with an eccentrically placed center of gravity with needles arranged in radiating fashion. Whereas in oral PMD and cancer groups, there was "transverse form" formation. This test had sensitivity and specificity of about 83.33% and 86.84% for PMDs group and 96.30% and 86.84% for oral cancer group respectively.

Conclusion

Crystallization test was found to be sensitive, reliable, economical and less-invasive procedure for screening of oral PMDs and oral cancer.

Impact of oral potentially malignant disorder subtypes on all-cause and cause-specific mortality in males

OBJECTIVES

To quantify the effect of oral potentially malignant disorder (OPMD) subtypes on mortality from oral cancer and type 2 diabetes among areca nut chewers and/or cigarette smokers.

MATERIALS AND METHODS

A retrospective cohort design was devised to follow 14,749 men attending community-based screening program for oral cancer between 1998 and 2000 and followed until 2010. The Cox proportional hazards regression model was applied to assess the effect of OPMD on death.

RESULTS

A total of 1,291(8.75%) patients were detected as OPMD. Among those free of T2DM at baseline, the elevated risk for death from T2DM was noted for OSF (aHR = 3.62, 95% CI: 1.25-10.51) and erythroplakia (aHR = 5.01, 95% CI: 1.17-21.45). The elevated risk for all-cause death for OPMD was mainly explained by deaths from oral cancer and T2DM but not other causes of death.

CONCLUSIONS

Oral potentially malignant disorder, particularly OSF and erythroplakia, in male cigarette smokers and/or areca nut chewers led to an incremental elevated risk of T2DM mortality in the way of being distal to the occurrence of T2DM, implying that early detection and prevention of OPMD may not only reduce oral cancer mortality but also result in the reduction of T2DM mortality.

Myofibroblasts in oral potentially malignant disorders: Is it related to malignant transformation?

In oral cancer, acquisition of α-smooth muscle actin (α-SMA)-positive fibroblasts, known as myofibroblasts or carcinoma-associated fibroblasts (CAF), is an important event for progression and metastasis. However, the contribution of myofibroblasts in oral potentially malignant disorders (OPMD) remains controversial. This systematic review provides evidence that immunodetection of myofibroblasts may identify oral submucous fibrosis (OSMF) with high risk of malignant transformation, but does not represent an auxiliary tool to predict the malignant potential of leukoplakia and erythroplakia, the most common OPMD.

Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.

[Clinical significance of CD44 and CD133 expression in oral potentially malignant disorder and oral squamous cell carcinoma]

OBJECTIVE

This study aims to investigate the expression and relationship of CD44 and CD133 in normal oral mucosa, oral potentially malignant disorder (OPMD), and oral squamous cell carcinoma (OSCC). This work also analyzes the relationship between such expression and clinical factors. This study intends to evaluate the clinical value of using CD44 and CD133 as indices to evaluate the carcinogenic potential of OPMD.

METHODS

Clinical data from 60 patients with OPMD, 60 patients with OSCC, and 10 cases of normal oral mucosa were analyzed. Double immunohistochemical analysis was applied to investigate the expression of CD44 and CD133 in paraffin sections of normal oral mucosa, OPMD, and OSCC tissues. Subsequently, the relationships between such expression and clinical factors were analyzed.

RESULTS

The positive rates of CD44 expression in the normal oral mucosa, OPMD, and OSCC tissues were 100.00%, 96.67%, and 71.67% (P<0.05), respectively. Meanwhile, the positive rates of CD133 expression in the normal oral mucosa, OPMD, and OSCC tissues were 0.00%, 35.00%, and 63.33% (P<0.05), respectively. The expression of CD44 and CD133 was found to be correlated (P<0.05). Such expression was related to the clinical stages and lymphatic metastasis of OSCC (P<0.05).

CONCLUSIONS

CD44 and CD133 can be used individually as clinical indices to evaluate the carcinogenic potential of OPMD.
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Role of human papillomavirus in oral squamous cell carcinoma and oral potentially malignant disorders: A review of the literature

Human papillomaviruses (HPVs) are epitheliotropic viruses with an affinity for keratinocytes and are principally found in the anogenital tract, urethra, skin, larynx, tracheobronchial and oral mucosa. On the basis of high, but variable frequency of HPV in oral squamous cell carcinoma (OSCC), malignant potential of HPV infection has been hypothesized but not definitely confirmed. The aim of this review was to highlight the genomic structure and possible mechanism of infection and carcinogenesis by HPV in the oral mucosa and to review the frequency of HPV prevalence in OSCC and oral potentially malignant disorders. A computer database search was performed through the use of PubMed from 1994 to 2014. Search keywords used were: HPV and oral cancer, HPV and oral leukoplakia, HPV and oral lichen planus, HPV and OSCC, HPV and verrucous carcinoma, HPV and proliferative verrucous leukoplakia, HPV and oral papilloma.