Oral cancer and oral potentially malignant disorders

Salivary metabolomics in oral potentially malignant disorders and oral cancer patients-a systematic review with meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to assess the diagnostic potential of salivary metabolomics in the detection of oral potentially malignant disorders (OPMDs) and oral cancer (OC).

MATERIALS AND METHODS

A systematic review was performed in accordance with the 3rd edition of the Centre for Reviews and Dissemination (CRD) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Electronic searches for articles were carried out in the PubMed, Web of Science, and Scopus databases. The quality assessment of the included studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale (NOS) and the new version of the QUADOMICS tool. Meta-analysis was conducted whenever possible. The effect size was presented using the Forest plot, whereas the presence of publication bias was examined through Begg's funnel plot.

RESULTS

A total of nine studies were included in the systematic review. The metabolite profiling was heterogeneous across all the studies. The expression of several salivary metabolites was found to be significantly altered in OPMDs and OCs as compared to healthy controls. Meta-analysis was able to be conducted only for N-acetylglucosamine. There was no significant difference (SMD = 0.15; 95% CI - 0.25-0.56) in the level of N-acetylglucosamine between OPMDs, OC, and the control group.

CONCLUSION

Evidence for N-acetylglucosamine as a salivary biomarker for oral cancer is lacking. Although several salivary metabolites show changes between healthy, OPMDs, and OC, their diagnostic potential cannot be assessed in this review due to a lack of data. Therefore, further high-quality studies with detailed analysis and reporting are required to establish the diagnostic potential of the salivary metabolites in OPMDs and OC.

CLINICAL RELEVANCE

While some salivary metabolites exhibit significant changes in oral potentially malignant disorders (OPMDs) and oral cancer (OC) compared to healthy controls, the current evidence, especially for N-acetylglucosamine, is inadequate to confirm their reliability as diagnostic biomarkers. Additional high-quality studies are needed for a more conclusive assessment of salivary metabolites in oral disease diagnosis.

Malignant and non-malignant oral lesions classification and diagnosis with deep neural networks

OBJECTIVES

Given the increasing incidence of oral cancer, it is essential to provide high-risk communities, especially in remote regions, with an affordable, user-friendly tool for visual lesion diagnosis. This proof-of-concept study explored the utility and feasibility of a smartphone application that can photograph and diagnose oral lesions.

METHODS

The images of oral lesions with confirmed diagnoses were sourced from oral and maxillofacial textbooks. In total, 342 images were extracted, encompassing lesions from various regions of the oral cavity such as the gingiva, palate, and labial mucosa. The lesions were segregated into three categories: Class 1 represented non-neoplastic lesions, Class 2 included benign neoplasms, and Class 3 contained premalignant/malignant lesions. The images were analysed using MobileNetV3 and EfficientNetV2 models, with the process producing an accuracy curve, confusion matrix, and receiver operating characteristic (ROC) curve.

RESULTS

The EfficientNetV2 model showed a steep increase in validation accuracy early in the iterations, plateauing at a score of 0.71. According to the confusion matrix, this model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions was 64% and 80% respectively. Conversely, the MobileNetV3 model exhibited a more gradual increase, reaching a plateau at a validation accuracy of 0.70. The MobileNetV3 model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions, according to the confusion matrix, was 64% and 82% respectively.

CONCLUSIONS

Our proof-of-concept study effectively demonstrated the potential accuracy of AI software in distinguishing malignant lesions. This could play a vital role in remote screenings for populations with limited access to dental practitioners. However, the discrepancies between the classification of images and the results of "non-malignant lesions" calls for further refinement of the models and the classification system used.

CLINICAL SIGNIFICANCE

The findings of this study indicate that AI software has the potential to aid in the identification or screening of malignant oral lesions. Further improvements are required to enhance accuracy in classifying non-malignant lesions.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Three-Dimensional Spheroid Configurations and Cellular Metabolic Properties of Oral Squamous Carcinomas Are Possible Pharmacological and Pathological Indicators

The objective of the current study was to elucidate the clinicopathological significance and appearance of in vitro three-dimension (3D) spheroid models of oral malignant tumors that were prepared from four pathologically different squamous cell carcinoma (OSCC; low-grade; SSYP and MO-1000, intermediate-grade; LEM2) and oral adenosquamous carcinoma (OASC; high-grade; Mesimo) obtained from patients with different malignant stages. To characterize the biological significance of these cell lines themselves, two-dimensional (2D) cultured cells were subjected to cellular metabolic analysis by a Seahorse bioanalyzer alongside the measurement of the cytotoxicity of cisplatin (CDDP). The appearance of their 3D spheroids was then observed by phase contrast microscopy, and both 2D and 3D cultured cells were subject to trypsin digestion and qPCR analysis of factors related to oncogenic signaling and other related analyses. ATP-linked respiration and proton leaking were significantly different among the four cell lines, and the malignant stages of these cultures were significantly associated with increased ATP-linked respiration and decreased proton leakage. Alternatively, the appearances of these 3D spheroids were also significantly diverse among them, and their differences increased in the order of LEM2, MO-1000, SSYP, and Mesimo. Interestingly, these orders were exactly the same in that the efficacies of CDDP-induced cytotoxicity increased in the same order. qPCR analysis indicated that the levels of expression of oncogenic signaling-related factors varied among these four cell lines, and the values for fibronectin and a key regulator of mitochondrial biogenesis, PGC-1α, were prominently elevated in cultures of the worst malignant Mesimo cells. In addition, although 0.25% trypsin-induced destruction was comparable among all four 2D cultured cells, the values for the 3D spheroids were also substantially varied among these cultures. The findings reported herein indicate that cellular metabolic functions and 3D spheroid architectures may be valuable and useful indicators for estimating the pathological and drug-sensitive aspects of OSCC and OASC malignancies.

Role of Hemidesmosomes in Oral Carcinogenesis: A Systematic Review

BACKGROUND

Oral cancers have limited diagnostic tools to aid clinical management. Current evidence indicates that alterations in hemidesmosomes, the adhesion complexes primarily involved in epithelial attachment to the basement membrane, are correlated to cancer phenotype for multiple cancers. This systematic review aimed to assess the experimental evidence for hemidesmosomal alterations, specifically in relation to oral potentially malignant disorders and oral squamous cell carcinomas.

METHODS

We conducted a systemic review to summarise the available literature on hemidesmosomal components and their role in oral pre-cancer and cancer. Relevant studies were retrieved from a comprehensive search of Scopus, Ovid MEDLINE, Ovid Embase and Web of Science.

RESULTS

26 articles met the inclusion criteria, of which 19 were in vitro studies, 4 in vivo studies, 1 in vitro and in vivo study, and 2 in vitro and cohort studies. Among them, 15 studies discussed individual alpha-6 and/or beta-4 subunits, 12 studies discussed the alpha-6 beta-4 heterodimers, 6 studies discussed the entire hemidesmosome complex, 5 studies discussed bullous pemphigoid-180, 3 studies discussed plectin, 3 studies discussed bullous pemphigoid antigen-1 and 1 study discussed tetraspanin.

CONCLUSION

Heterogeneity in cell type, experimental models, and methods were observed. Alterations in hemidesmosomal components were shown to contribute to oral pre-cancer and cancer. We conclude that there is sufficient evidence for hemidesmosomes and their components to be potential biomarkers for evaluating oral carcinogenesis.

Oral Potentially Malignant Disorders: Etiology, Pathogenesis, and Transformation Into Oral Cancer

Among oral diseases, oral cancer is a critical health issue due to its life-threatening potential. Globocan, in its 2020 report, estimated ∼0.37 million new cases of oral cancer, with the majority of them coming from the Asian continent. The WHO has anticipated a rise in the incidences of oral cancer in the coming decades. Various factors, such as genetic, epigenetic, microbial, habitual, and lifestyle factors, are closely associated with oral cancer occurrence and progression. Oral lesions, inherited genetic mutations (dyskeratosis congenital syndrome), and viral infections (HPV) are early signs of oral cancer. Lesions with dysplastic features have been categorized under oral potentially malignant disorders (OPMDs), such as oral leukoplakia, erythroplakia, oral submucous fibrosis (OSMF), and proliferative verrucous leukoplakia, are assumed to have a high risk of malignancy. The incidence and prevalence of OPMDs are recorded as being high in South-Asian countries. Early detection, prevention, and treatment of OPMDs are needed to prevent its malignant transformation into oral cancer. Many advanced diagnostic techniques are used to predict their progression and to assess the risk of malignant transformation. This communication provides insight into the importance of early detection and prevention of OPMDs.

Immunohistochemical evaluation of survivin in oral lichen planus and oral squamous cell carcinoma - a retrospective study

Introduction

Oral cancer is a multistep process involving enhanced activation of proto-oncogenes. Survivin (anti-apoptotic protein) is one of such proto-oncogenes that contribute to the carcinogenesis by deregulating cell proliferation. Expression of these proteins in cancerous and pre-cancerous lesions helps a better understanding of the etiology, treatment and prognosis.

Aim

To evaluate qualitative and quantitative expression of survivin in healthy mucosa, oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC).

Methods

A total of 70 cases of formalin fixed paraffin embedded blocks, of which 20 healthy mucosa, 20 OSCC and 30 OLP were included in the study and stained immunohistochemically using antibodies against survivin monoclonal antibody. 4 μm sections were stained immunohistochemically, both nuclear and cytoplasmic staining was considered as positive for surviving. Positive and negative stained cells were counted with the help of Olympus BX51 rarefaction microscope and were analyzed quantitatively using image analysis pro plus software. Representative fields were randomly selected at 40× high power magnification. Values obtained were evaluated and tabulated for statistical analysis.

Results

There was a statistically significant relation between the expressions of survivin among healthy mucosa, OLP, OSCC with a p value of 0.001.

Conclusion

Presence of survivin expression in healthy mucosa, OLP and OSCC, which is an inhibitor of apoptosis protein, can be identified as a useful diagnostic tool for the identification of precancerous lesions and conditions which are at higher risk for progression into invasive carcinoma.

Association between oral lichen planus and systemic conditions and medications: Case-control study

OBJECTIVE

The aim of this study is to investigate the association between oral lichen planus (OLP) and a variety of systemic conditions, medication, and supplement usage.

MATERIALS AND METHOD

A total of 156 patients diagnosed with OLP and 156 controls at Columbia University Irving Medical Center from 2000 to 2013 were selected as part of the matched (1:1) case-control study. Demographics, systemic conditions, prescription medications and supplements were extracted from the patients' medical records. A univariable conditional logistic regression (CLR) analysis was performed to calculate unadjusted odds ratio, to identify significant variables associated with OLP (p < .10). Significant variables were further tested using multivariable CLR analysis with both forward and backward selection to calculate adjusted odds ratio (aOR) and further distinguish variables associated with OLP (p < .05).

RESULTS

This analysis identified six significant variables: thyroid disorder (aOR:5.1,95%CI:2.3-11.2), any form of cancer (aOR:3.4,95%CI:1.4-8.4), type 2 diabetes (aOR:2.8,95%CI:1.2-6.3), hyperlipidemia (aOR:2.3,95%CI:1.3-4.1), oral sedative usage (aOR:6.3,95%CI:1.8-22.5), and vitamin D supplementation (aOR:2.7,95%Cl:1.3-6.0).

CONCLUSION

Thyroid disorders, cancer, type 2 diabetes, hyperlipidemia, sedatives, and vitamin D supplementation were found to be associated with OLP. Additional investigation is required to explore these associations, which could shed light on the potential mechanism of OLP and reinforce the idea that oral lesions could be predicative of previously undetected systemic conditions.

Concurrent chronic hyperplastic candidosis and oral lichenoid lesion as adverse events of secukinumab therapy

Secukinumab (Cosentyx®) is an IL-17A inhibitor which is used for the management of psoriasis, active psoriatic arthritis or ankylosing spondylitis. Oral adverse events of secukinumab therapy are not widely appreciated. This article highlights the presentation of two concurrent oral adverse events of secukinumab therapy; namely chronic hyperplastic candidosis (CHC) and oral lichenoid lesion (OLL). This is the first documented case report of CHC occurring as a consequence of secukinumab therapy, and represents a new adverse effect which general and specialist oral health practitioners should be aware of. This case highlights the importance of correlating the presence of oral lesions with the patient's medical history, keeping up to date with the development of new medications and pharmacotherapeutics, having a deep understanding of underlying biological processes related to various oral diseases, and appreciating the use of clinical adjunctive devices. Accurate diagnosis is key to formulating a correct management plan.

Fourier Transform Infrared Spectroscopy in Oral Cancer Diagnosis

Oral cancer is one of the most common cancers worldwide. Despite easy access to the oral cavity and significant advances in treatment, the morbidity and mortality rates for oral cancer patients are still very high, mainly due to late-stage diagnosis when treatment is less successful. Oral cancer has also been found to be the most expensive cancer to treat in the United States. Early diagnosis of oral cancer can significantly improve patient survival rate and reduce medical costs. There is an urgent unmet need for an accurate and sensitive molecular-based diagnostic tool for early oral cancer detection. Fourier transform infrared spectroscopy has gained increasing attention in cancer research due to its ability to elucidate qualitative and quantitative information of biochemical content and molecular-level structural changes in complex biological systems. The diagnosis of a disease is based on biochemical changes underlying the disease pathology rather than morphological changes of the tissue. It is a versatile method that can work with tissues, cells, or body fluids. In this review article, we aim to summarize the studies of infrared spectroscopy in oral cancer research and detection. It provides early evidence to support the potential application of infrared spectroscopy as a diagnostic tool for oral potentially malignant and malignant lesions. The challenges and opportunities in clinical translation are also discussed.

Three-Dimensional Cell Culture Models to Investigate Oral Carcinogenesis: A Scoping Review

Three-dimensional (3-D) cell culture models, such as spheroids, organoids, and organotypic cultures, are more physiologically representative of the human tumor microenvironment (TME) than traditional two-dimensional (2-D) cell culture models. They have been used as in vitro models to investigate various aspects of oral cancer but, to date, have not be widely used in investigations of the process of oral carcinogenesis. The aim of this scoping review was to evaluate the use of 3-D cell cultures in oral squamous cell carcinoma (OSCC) research, with a particular emphasis on oral carcinogenesis studies. Databases (PubMed, Scopus, and Web of Science) were systematically searched to identify research applying 3-D cell culture techniques to cells from normal, dysplastic, and malignant oral mucosae. A total of 119 studies were included for qualitative analysis including 53 studies utilizing spheroids, 62 utilizing organotypic cultures, and 4 using organoids. We found that 3-D oral carcinogenesis studies had been limited to just two organotypic culture models and that to date, spheroids and organoids had not been utilized for this purpose. Spheroid culture was most frequently used as a tumorosphere forming assay and the organoids cultured from human OSCCs most often used in drug sensitivity testing. These results indicate that there are significant opportunities to utilize 3-D cell culture to explore the development of oral cancer, particularly as the physiological relevance of these models continues to improve.

Oral potentially malignant disorders: A consensus report from an international seminar on nomenclature and classification, convened by the WHO Collaborating Centre for Oral Cancer

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening period was considered to make essential changes to the 2007 classification. In the current update, most entities were retained with minor changes to their definition. There is sufficient evidence for an increased risk of oral cancer among patients diagnosed with "oral lichenoid lesions" and among those diagnosed with oral manifestations of 'chronic graft-versus-host disease'. These have now been added to the list of OPMDs. There is, to date, insufficient evidence concerning the malignant potential of chronic hyperplastic candidosis and of oral exophytic verrucous hyperplasia to consider these conditions as OPMDs. Furthermore, due to lack of clear evidence of an OPMD in epidermolysis bullosa this was moved to the category with limited evidence. We recommend the establishment of a global research consortium to further study the natural history of OPMDs based on the classification and nomenclature proposed here. This will require multi-center longitudinal studies with uniform diagnostic criteria to improve the identification and cancer risk stratification of patients with OPMDs, link them to evidence-based interventions, with a goal to facilitate the prevention and management of lip and oral cavity cancer.

The Application of Next-Generation Sequencing to Define Factors Related to Oral Cancer and Discover Novel Biomarkers

Despite the introduction of next-generation sequencing in the realm of DNA sequencing technology, it is not often used in the investigation of oral squamous cell carcinoma (OSCC). Oral cancer is one of the most frequently occurring malignancies in some parts of the world and has a high mortality rate. Patients with this malignancy are likely to have a poor prognosis and may suffer from severe facial deformity or mastication problems even after successful treatment. Therefore, a thorough understanding of this malignancy is essential to prevent and treat it. This review sought to highlight the contributions of next-generation sequencing (NGS) in unveiling the genetic alterations and differential expressions of miRNAs involved in OSCC progression. By applying an appropriate eligibility criterion, we selected relevant studies for review. Frequently identified mutations in genes such as TP53, NOTCH1, and PIK3CA are discussed. The findings of existing miRNAs (e.g., miR-21) as well as novel discoveries pertaining to OSCC are also covered. Lastly, we briefly mention the latest findings in targeted gene therapy and the potential use of miRNAs as biomarkers. Our goal is to encourage researchers to further adopt NGS in their studies and give an overview of the latest findings of OSCC treatment.

Clinico-pathological correlation of optical fluorescence imaging in oral mucosal lesions

OBJECTIVES

This study aimed to identify clinical and pathological characteristics of oral mucosal lesions that may be predictive of optical autofluorescence imaging patterns.

METHODS

Clinical data and archival histopathological material were collected from patients who presented with at least one oral mucosal lesion and underwent assessment via conventional oral examination, optical autofluorescence imaging and histopathological analysis. An open-source digital pathology image analysis software was used to perform histomorphometric measurements. Classification and regression trees were used to determine histopathological characteristics most predictive of a clinical autofluorescence outcome.

RESULTS

Histomorphometric features associated with tissue architecture, epithelial changes, inflammation and vasculature were found to be significantly associated with autofluorescence patterns. Diascopic fluorescence was found to be significantly predicted by lichenoid inflammation and was significantly associated with a diagnosis of oral lichen planus. Loss of autofluorescence with partial blanching was significantly associated with histopathological features noted in dysplastic and malignant lesions.

CONCLUSIONS

This study provides evidence for the use of diascopic fluorescence as a technique to aid in clinical differentiation of benign inflammatory lesions from potentially malignant pathology. Based on the findings of this study, optical fluorescence imaging is a technique of added value in discernment of oral mucosal lesions, and our results support its clinical use.

Benign Alveolar Ridge Keratosis: Clinical and Histopathologic Analysis of 167 Cases

Benign alveolar ridge keratosis (BARK), the intraoral counterpart of cutaneous lichen simplex chronicus, is a reactive hyperkeratosis caused by trauma or friction that presents as a poorly demarcated white papule or plaque on the keratinized mucosa of the retromolar pad or alveolar ridge mucosa (often edentulous). This is a clinical and histopathologic analysis of BARK including evaluation of p53 expression in selected cases. One hundred and sixty-seven cases of BARK were identified from 2016 to 2017 and 112 (67.1%) occurred in males with a median age of 56 years (range 15-86). The retromolar pad was affected in 107 (64.1%) cases and the edentulous alveolar mucosa in 60 (35.9%) cases, with 17.4% of the cases presenting bilaterally. BARK showed hyperkeratosis often with wedge-shaped hypergranulosis and occasional focal parakeratosis. The epithelium exhibited acanthosis and surface corrugation with tapered rete ridges often interconnected at the tips. The study for p53 performed in 12 cases showed less than 25% nuclear positivity. BARK is a distinct benign clinicopathologic entity caused by friction, which should be clearly distinguished from true leukoplakia, a potentially malignant disorder.

Oral keratosis of unknown significance shares genomic overlap with oral dysplasia

OBJECTIVES

To identify molecular characteristics of keratosis of unknown significance and to nominate pathways of molecular progression to oral cancer. Our work could provide a rationale for monitoring and treating these lesions definitively.

METHODS

Patients with oral leukoplakia were eligible for our prospective observational study. We correlated alterations in cancer-associated genes with clinical and histopathologic variables (keratosis of unknown significance vs. moderate-to-severe dysplasia) and compared these alterations to a previously molecularly characterized oral cancer population.

RESULTS

Of 20 enrolled patients, 13 (65%) had evidence of keratosis of unknown significance, while seven (35%) had dysplasia. Nine patients (45%) developed oral cancer (4/13 with keratosis of unknown significance, 5/7 with dysplasia). At a median follow-up of 67 (range 22-144) months, median overall survival was significantly shorter for patients with dysplasia (hazard ratio 0.11, p = .02). KMT2C and TP53 alterations were most frequent (75% and 35%, respectively). There were molecular similarities between keratosis of unknown significance and dysplasia patients, with no significant differences in mutational frequency among genes with ≥15% rate of alteration.

CONCLUSIONS

Among patients with leukoplakia, both patients with keratosis of unknown significance and patients with dysplasia developed oral cancer. Molecular alterations between these two groups were similar at this sample size.

The role of cyclin-dependent kinases in oral potentially malignant disorders and oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a major global health problem with a relatively low-moderate 5-year survival rate. OSCC is often preceded by lesions and conditions known as oral potentially malignant disorders (OPMDs) that have an increased risk of malignant transformation. Despite advances in diagnostic technology and cancer research, the prognosis of OSCC remains poor as it is frequently detected a late stage. Understanding the molecular pathways involved in oral carcinogenesis provides a platform to identify biomarkers that may allow the early detection of OSCC and accurate prediction of the malignant potential of OPMDs. In addition, specific molecular inhibitors can be developed to target these important pathways and allow advanced therapeutic management to improve the prognosis of this malignancy. A common feature across a number of different cancers is the dysfunction of cell cycle moderator proteins known as cyclin-dependent kinases. This review summarises the current literature regarding the role of cyclin-dependent kinases in oral carcinogenesis with a particular focus on cyclin-dependent kinases 4 (CDK4) and 6 (CDK6). This is of particular relevance as CDK4 and CDK6 inhibitors have shown some promising results in other cancer types and are interesting potential treatments for OSCC.

CDK4, CDK6, cyclin D1 and Notch1 immunocytochemical expression of oral brush liquid-based cytology for the diagnosis of oral leukoplakia and oral cancer

OBJECTIVES

This study aimed to investigate the feasibility of using oral liquid-based brush cytology (OLBC) coupled with immunocytochemistry as a minimally invasive approach to stratify the cancer risk in patients with oral leukoplakia.

METHODS

Fifty-five patients diagnosed with either oral leukoplakia (OLK) or oral squamous cell carcinoma (OSCC) were recruited. All patients underwent oral brush biopsy followed by surgical biopsy. 275 liquid-based cytology preparations were made. Pap-stained OLBC slides were assessed using the modified 2014 Bethesda Cytology system. The expression of CDK4, CDK6, cyclin D1, and Notch 1 was immunocytochemically analysed and compared against the histopathological diagnosis. A combined index score of OLBC grading and protein expression was calculated.

RESULTS

A significant association was found between the definitive histopathological diagnosis and the cytological interpretation (P = 0.0005). The index scores of CDK4, CDK6, and cyclin D1 were significantly associated with the development of disease from non-dysplastic epithelium to OSCC. No significant association was observed between the Notch 1 index score and disease stage. The diagnostic accuracy of OLBC showed the highest values of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy: 84.6%, 70.4%, 73.3%, 82.6%, and 78.8%, respectively, compared with the cumulative protein index, CDK4/6 index, and the combined OLBC grading and CDK4/6 index.

CONCLUSION

This study has also demonstrated the efficacy of the use of OLBC in the detection of OED and OSCC, and showed that the use of CDK4, CDK6, cyclin D1, and Notch 1 immunocytochemistry failed to improve the diagnostic accuracy of OLBC suggesting they are not useful in the early detection of OSCC.

Optical fluorescence imaging in oral cancer and potentially malignant disorders: A systematic review

OBJECTIVES

This study aimed to systematically review the efficacy of direct optical fluorescence imaging as an adjunct to comprehensive oral examination in the clinical evaluation, risk assessment and surgical management of oral cancer and potentially malignant disorders.

METHODS

Studies adopting autofluorescence devices, evaluating the efficacy of comprehensive oral examination and optical fluorescence imaging in detection, visualisation or management of oral squamous cell carcinoma or oral potentially malignant disorders, as well as discriminating oral epithelial dysplasia from other mucosal lesions, were included in the literature search across bibliographic databases until October 2018.

RESULTS

Twenty-seven studies were found to be eligible for inclusion in qualitative analysis. Of these, only six studies demonstrated a low risk of bias across all domains of the methodological assessment tool (QUADAS-2). Optical fluorescence imaging demonstrated positive results, with higher sensitivity scores, increased lesion detection and visualisation than comprehensive oral examination alone in the clinical evaluation of oral squamous cell carcinoma and oral potentially malignant disorders.

CONCLUSIONS

This review provides promising evidence for the utilisation of optical fluorescence imaging as an adjunct to comprehensive oral examination in varying clinical settings. It is important that devices utilising optical fluorescence imaging are viewed strictly as clinical adjuncts and not specifically as diagnostic devices.

"SKILL TO KILL" - Oral cancer and potentially premalignant oral epithelial lesions (PPOELs): A survey approach. Emerging of a new system and professionals

Background:

Oral cancer is said to be the 6th most common cancer in men and 12th in women. Potentially malignant disorders/potentially premalignant oral epithelial lesion (PMDs/PPOELs) have shown an increased risk of progressing to cancer. In this regard, lack of awareness about identification of oral PMDs among healthcare providers in general and oral pathologists in particular is said to be responsible for the diagnostic delay. Oral cancer is said to be the most common cancer in men and 3rd most common in women in the Indian subcontinent. PMDs have shown an increased risk of progressing to cancer. The various rates of conversion include 14%–51% for erythroplakia, 60%–100% for proliferative verrucous leukoplakia and 7%–26% for oral submucous fibrosis (OSMF). In this regard, early detection at PPOEL level will lead to prevention of malignant transformation.

Aims and Objectives:

The purpose of this survey was: 1. To determine if awareness among professionals is essential/key to challenge the progression of PMDs of the oral cavity. 2. To examine and/ordiscern if oral pathologists felt enough was being done to address the issue of early detection and prevention and how the scenario could be improved further.

Materials and Methods:

A survey was designed to assess the interest, zeal, knowledge and skill of healthcare providers in general and oral pathologists in particular in careful examination of the oral cavity and early detection of PMDs. A questionnaire with 18 questions was designed to address these issues/points and distributed among post-graduate students and practicing oral pathologists on online platforms.

Results:

The results of the esurvey were collected, analyzed and the results discussed question wise. The validity and reliability of the questionnaire was assessed and confirmed with Aiken's index for validity and Cronbach's alpha for reliability. Inferential statistical analysis was performed using Chi square test with P = 0.05 being statistically significant.

Conclusion:

On evaluation of the survey, we found that 85% of the surveyees are on agreement that PPOELs should be registered in a standard format and should be included in the list of recognizable diseases. 89.2% and 87.8% of the respondents would like to be part of an active body for early detection and diagnosis and for Cancer screening in our country respectively. In conclusion, the oral pathology fraternity is eager to work for and tackle these PPOELs head on, provided the right opportunities and training are meted out to them.

Expression of P53 Protein and Ki-67 Antigen in Oral Leukoplakia with Different Histopathological Grades of Epithelial Dysplasia

Aims and Objective:

The aim of this study is to investigate the expression of p53 protein and Ki-67 antigen in normal oral mucosa and oral leukoplakia with different grades of dysplasia using immunohistochemistry and to clarify the correlation of the expression of these cell cycle regulatory proteins.

Materials and Methods:

A total of 20 archival tissue blocks obtained from our department which were diagnosed as mild (n = 5), moderate (n = 5), and severe dysplasia (n = 5) with normal mucosa (n = 5) as a control. Positivity of Ki-67 and p53 was analyzed using Statistical Package for the Social Sciences (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0 Armonk, NY:IBM Corp) software.

Results:

All samples showed positive staining for p53 and Ki-67. Statistically significant difference (P < 0.05) was seen between the frequency of occurrence of p53 and Ki-67 pattern of expression among all the groups. The intensity of staining was mild to intense in basal layer as there was a progression toward the severity of the disease. Almost 81.1% correlation existed between p53 and Ki-67 with high correlation and marked relationship.

Conclusion:

Oral leukoplakia represents the most common oral potentially malignant disorder (OPMD). Molecular biological markers such as p53 and Ki-67 are considered to be of great value in the diagnosis and prognostic evaluation of OPMD. Our results emphasize the potential use of p53 protein and Ki-67 antigen as significant molecular markers for early detection of PMDs and its risk of developing oral squamous cell carcinoma.

Concentric Ring Probe for Bioimpedance Spectroscopic Measurements: Design and Ex Vivo Feasibility Testing on Pork Oral Tissues

Many oral diseases, such as oral leukoplakia and erythroplakia, which have a high potential for malignant transformations, cause abnormal structural changes in the oral mucosa. These changes are clinically assessed by visual inspection and palpation despite their poor accuracy and subjective nature. We hypothesized that non-invasive bioimpedance spectroscopy (BIS) might be a viable option to improve the diagnostics of potentially malignant lesions. In this study, we aimed to design and optimize the measurement setup and to conduct feasibility testing on pork oral tissues. The contact pressure between a custom-made concentric ring probe and tissue was experimentally optimized. The effects of loading time and inter-electrode spacing on BIS spectra were also clarified. Tissue differentiation testing was performed for ex vivo pork oral tissues including palatinum, buccal mucosa, fat, and muscle tissue samples. We observed that the most reproducible results were obtained by using a loading weight of 200 g and a fixed time period under press, which was necessary to allow meaningful quantitative comparison. All studied tissues showed their own unique spectra, accompanied by significant differences in both impedance magnitude and phase (p ≤ 0.014, Kruskal-Wallis test). BIS shows promise, and further studies are warranted to clarify its potential to detect specific pathological tissue alterations.

Oral leukoplakia remains a challenging condition

Crispian Scully had many interests in the realm of oral diseases. But oral leukoplakia was one that piqued his curiosity when he was still an academic neophyte and remained a topic which he studied throughout his enormously productive career. It is easy to understand why. While the clinical manifestations of oral leukoplakia are common, we still do not fully understand why one version of the condition is benign, while another, similar in appearance, progresses to a malignancy. The diagnosis of oral leukoplakia is based on expert clinical and histopathological examamination. Management and treatment of leukoplakia remain challenging especially for large lesions and the proliferative subtype. This review aims to provide a general overview on leukoplakia, explore current challenges in its diagnosis and management and discuss the opportunities to better understand the condition.

Assessing miRNAs profile expression as a risk stratification biomarker in oral potentially malignant disorders: A systematic review

OBJECTIVES

This paper aims to systematically review current findings on altered expression of miRNAs in OPMDs and whether they can be used as risk stratification biomarkers.

METHODS

Studies were collated after searching three different electronic databases: PubMed, Embase, Medline. Additional searches were carried out through cross checking the bibliographies of selected articles. After a thorough selection process made by two of the authors, 40 articles met the inclusion criteria and were included in the review. Studies were assessed and analysed in terms of how the candidate miRNA biomarkers were differentially expressed and validated.

RESULTS

The included studies examined the expression of miRNAs from human specimens (blood serum/plasma, saliva, tissue) as diagnostic or prognostic biomarkers in patients with OPMDs, some of which have been utilised as risk stratification biomarkers for malignant transformation and have showed promising findings.

CONCLUSION

The current evidence to support or refute the prognostic utility of miRNAs in predicting cancer progression in OPMDs is equivocal. Further longitudinal prospective studies with solid study design are warranted.

Expression of Human Papillomavirus DNA and p53 Polymorphisms through Polymerase Chain Reaction in Normal Mucosa and Oral Leukoplakia Individuals with Deleterious Oral Habits

Context:

Oral leukoplakia (OL) is a well-recognized precancerous lesion with various etiological factors. Most commonly deleterious oral habits such as tobacco smoking and viral etiologies mainly human papillomavirus (HPV) play an important role. p53 polymorphisms mostly homozygous Arginine (Arg) allele has a greater risk of degradation by HPV. Hence, HPV infection and p53 polymorphisms may act as synergistic factors for increased the risk of malignant transformation in oral precancerous lesions.

Aims:

The aim of this study is to evaluate the risk of OL and its malignant transformation due to infection by HPV and p53 polymorphisms in the oral biopsy samples through polymerase chain reaction (PCR).

Subjects and Methods:

A total of 40 individuals were involved– 10 individuals were controls without deleterious habits, 15 were controls with deleterious habits, and 15 were with histologically confirmed OL individuals with deleterious habits. PCR and restriction fragment length polymorphism using sma1 enzyme were carried out to evaluate the expression of HPV and p53 polymorphisms.

Statistical Analysis Used:

Chi-square test, Fischer's exact t-test, and odds ratio.

Results:

(1) HPV DNA expression was higher in Leukoplakia individuals than controls. (2) p53 genotype with homozygous Arg was more in HPV-infected individuals.

Conclusions:

To conclude HPV infected OL cases were mostly with Arg/Arg type of p53 polymorphism.