Calibration improves the agreement in grading oral epithelial dysplasia-Findings from a National Workshop in Malaysia.

INTRODUCTION: A major pitfall of many of the established oral epithelial dysplasia (OED) grading criteria is their lack of reproducibility and accuracy to predict malignant transformation. The main objective of this study was to determine whether calibration of practicing oral pathologists on OED grading could improve the reproducibility of the WHO 2017 and the binary OED grading systems. METHODS: A nationwide online exercise was carried out to determine the influence of calibration on the reproducibility of the WHO 2017 and the binary OED grading systems. RESULTS: A significant improvement was observed in the inter-observer agreement for the WHO 2017 OED grading system (K 0.196 vs. 0.448; Kw 0.357 vs. 0.562) after the calibration exercise. The significant difference (p = 0.027) in the level of agreement between those with five or more years and less than 5 years of experience was no more observed (p = 0.426) after the calibration exercise. The percent agreement for binary grading was significantly higher (91.8%) for buccal mucosal lesions as compared to lesions on the tongue after the calibration exercise. CONCLUSION: This study validates the significance of calibration in improving the reproducibility of OED grading. The nationwide exercise resulted in a statistically significant improvement in the inter-observer agreement for the WHO 2017 OED grading system among a large number of oral pathologists. It is highly recommended that similar exercises should be organized periodically by professional bodies responsible for continuing education among oral pathologists to improve the reliability of OED grading for optimal treatment of oral potentially malignant disorders.

Salivary biomarkers: Effective diagnostic tool for oral leukoplakia and oral squamous cell carcinoma.

OBJECTIVE: To identify potential salivary biomarkers for the diagnosis and monitoring of disease progression in oral squamous cell carcinoma and oral leukoplakia. MATERIALS AND METHODS: An advance search from PubMed and Hindawi was performed with keywords; oral leukoplakia/oral squamous cell carcinoma, salivary biomarker and diagnosis/prognosis. An additional search of articles was done through a manual search from the Google Scholar database. RESULTS: Twenty studies involving salivary biomarkers as diagnostic tools for oral squamous cell carcinoma and/or oral leukoplakia were identified. A narrative review was carried out. CONCLUSION: Single or multiple salivary biomarkers reported by most studies have shown great potential as diagnostic tools for oral squamous cell carcinoma and oral leukoplakia. However, the validation of sensitivity and specificity should be carried out to ensure the accuracy of the biomarkers. Furthermore, a standardised method for saliva collection should be established to prevent variability in the expression of biomarkers.

High referral accuracy for oral cancers and oral potentially malignant disorders using telemedicine.

OBJECTIVE: To evaluate the accuracy of MeMoSA®, a mobile phone application to review images of oral lesions in identifying oral cancers and oral potentially malignant disorders requiring referral. SUBJECTS AND METHODS: A prospective study of 355 participants, including 280 with oral lesions/variants was conducted. Adults aged ≥18 treated at tertiary referral centres were included. Images of the oral cavity were taken using MeMoSA®. The identification of the presence of lesion/variant and referral decision made using MeMoSA® were compared to clinical oral examination, using kappa statistics for intra-rater agreement. Sensitivity, specificity, concordance and F1 score were computed. Images were reviewed by an off-site specialist and inter-rater agreement was evaluated. Images from sequential clinical visits were compared to evaluate observable changes in the lesions. RESULTS: Kappa values comparing MeMoSA® with clinical oral examination in detecting a lesion and referral decision was 0.604 and 0.892, respectively. Sensitivity and specificity for referral decision were 94.0% and 95.5%. Concordance and F1 score were 94.9% and 93.3%, respectively. Inter-rater agreement for a referral decision was 0.825. Progression or regression of lesions were systematically documented using MeMoSA®. CONCLUSION: Referral decisions made through MeMoSA® is highly comparable to clinical examination demonstrating it is a reliable telemedicine tool to facilitate the identification of high-risk lesions for early management.

Image collection and annotation platforms to establish a multi-source database of oral lesions.

OBJECTIVE: To describe the development of a platform for image collection and annotation that resulted in a multi-sourced international image dataset of oral lesions to facilitate the development of automated lesion classification algorithms. MATERIALS AND METHODS: We developed a web-interface, hosted on a web server to collect oral lesions images from international partners. Further, we developed a customised annotation tool, also a web-interface for systematic annotation of images to build a rich clinically labelled dataset. We evaluated the sensitivities comparing referral decisions through the annotation process with the clinical diagnosis of the lesions. RESULTS: The image repository hosts 2474 images of oral lesions consisting of oral cancer, oral potentially malignant disorders and other oral lesions that were collected through MeMoSA® UPLOAD. Eight-hundred images were annotated by seven oral medicine specialists on MeMoSA® ANNOTATE, to mark the lesion and to collect clinical labels. The sensitivity in referral decision for all lesions that required a referral for cancer management/surveillance was moderate to high depending on the type of lesion (64.3%-100%). CONCLUSION: This is the first description of a database with clinically labelled oral lesions. This database could accelerate the improvement of AI algorithms that can promote the early detection of high-risk oral lesions.

Overexpression of gamma glutamyl hydrolase predicts extranodal extension in squamous cell carcinoma of the oral cavity.

OBJECTIVE: Extranodal extension (ENE) is an important prognostic factor in oral squamous cell carcinoma (OSCC). However, ENE is only confirmed postoperatively by histologic assessment of the lymph nodes after neck dissection. Accurate identification of ENE preoperatively would help in management of OSCC. STUDY DESIGN: We determined the expression of molecular markers gamma glutamyl hydrolase (GGH), cyclin-dependent kinase inhibitor-3 (CDKN3), and chromobox homolog-7 (CBX7) using immunohistochemistry in OSCC clinical samples (n = 35). The intensity of staining was scored using a semiquantitative index (HSCORE). The association between clinicopathologic parameters and expression of molecular markers with ENE status was analyzed using chi-square test. RESULTS: The number of positive nodes and the highest anatomic level of nodal involvement significantly correlated with ENE (P < .05). High GGH expression was significantly associated with ENE (P < .05), with an increased risk for ENE (odds ratio [OR] 9.9, 95% CI 1.08-91.47, P = .04), whereas no significant association was seen for CDKN3 and CBX7 expression with ENE. However, a trend toward significance was observed with a high level of CDKN3 and a low level of CBX7 expression with ENE. CONCLUSIONS: Gamma glutamyl hydrolase offers potential as a predictor for ENE in OSCC, whereas the role of CDKN3 and CBX7 need to be validated in a larger sample.

Transcriptional analysis highlights three distinct immune profiles of high-risk oral epithelial dysplasia.

Oral potentially malignant disorders (OPMD) are precursors of oral squamous cell carcinoma (OSCC), and the presence of oral epithelial dysplasia (OED) in OPMD confers an increased risk of malignant transformation. Emerging evidence has indicated a role for the immune system in OPMD disease progression; however, the underlying immune mechanisms remain elusive. In this study, we used immune signatures established from cancer to delineate the immune profiles of moderate and severe OED, which are considered high-risk OPMD. We demonstrated that moderate and severe OEDs exhibit high lymphocyte infiltration and upregulation of genes involved in both immune surveillance (major histocompatibility complex-I, T cells, B cells and cytolytic activity) and immune suppression (immune checkpoints, T regulatory cells, and tumor-associated macrophages). Notably, we identified three distinct subtypes of moderate and severe OED: immune cytotoxic, non-cytotoxic and non-immune reactive. Active immune surveillance is present in the immune cytotoxic subtype, whereas the non-cytotoxic subtype lacks CD8 immune cytotoxic response. The non-immune reactive subtype showed upregulation of genes involved in the stromal microenvironment and cell cycle. The lack of T cell infiltration and activation in the non-immune reactive subtype is due to the dysregulation of CTNNB1, PTEN and JAK2. This work suggests that moderate and severe OED that harbor the non-cytotoxic or non-immune reactive subtype are likely to progress to cancer. Overall, we showed that distinct immune responses are present in high-risk OPMD, and revealed targetable pathways that could lead to potential new approaches for non-surgical management of OED.

First isolation and identification of Cystobasidium calyptogenae from the oral samples of an elderly patient presenting with angular cheilitis.

BACKGROUND: Angular cheilitis, an infection mainly caused by Candida yeasts, is featured by the appearance of inflammatory lesions at the bilateral corners of the mouth, particularly in patients with poor oral hygiene, ill-fitting dentures and old age. The first isolation of an atypical yeast, Cystobasidium calyptogenae, from oral samples of a patient presenting with angular cheilitis is discussed in this study. CASE PRESENTATION: Angular cheilitis was diagnosed in a 60-year-old denture-wearing woman who presented with an irritation fibroma on her right lower buccal sulcus over the premolar region. Primary cultures of her oral swab and oral rinse samples grew a pure culture of an uncommon yeast strain resembling Rhodotorula sp. Sequence analysis of the yeast internal transcribed spacer (ITS) gene region and D1D2 domain showed highest similarity (99.6% and 100%, respectively) to C. calyptogenae CBS 9125 type strain. Following 2 weeks of treatment with miconazole/fusidic acid and mouthwash, the oral lesion showed improvement with less erythema. C. calyptogenae was not isolated from the patient's oral samples upon repeat sampling. CONCLUSION: This is the first report on the isolation of C. calyptogenae from human oral samples. The ability of C. calyptogenae to grow at 37 °C and the fact that it was the only yeast species isolated from the patient's oral samples suggests its pathogenic potential and possible involvement in angular cheilitis. The ubiquitous nature of the Cystobasidium yeast is believed to increase the likelihood of opportunistic infections among immunocompromised individuals. As Cystobasidium is phenotypically indistinguishable from Rhodotorula, an emerging opportunistic pathogen, surveillance using molecular identification in clinical settings is essential in providing accurate diagnosis and treatment of uncommon yeast infections.

A validated predictive model for risk of nodal metastasis in node negative oral squamous cell carcinoma of the buccal mucosa and tongue.

BACKGROUND: Lymph node metastasis in oral squamous cell carcinoma (OSCC) is influenced by clinical and histopathological variables. The aim of this study was to develop a simple model to predict nodal metastasis of OSCC in clinically negative necks (cN0). METHODS: Data from patients who underwent surgery for treatment of OSCC of the tongue or buccal mucosa with neck dissection were used for model development and validation. RESULTS: Nodal metastasis was significantly associated with gender, age, tumor size, site, pattern of invasion and depth of invasion on univariate analysis. All the five variables except age were retained at the variable selection step of the model development and were used in the final model because it was not significant at 0.10 significance level after adjusting for other variables. Regression coefficients of the model were used to estimate risks of nodal metastases for each combination of clinicopathological characteristics. A 10-fold cross-validation was used to assess the model. The average of the resultant 10 AUCs (along with its 95% confidence interval estimated using bootstrap) was used as the overall validated measure of the model. A risk chart was produced using probability of nodal metastasis predicted by the model for each combination of five characteristics. The model's ability to identify patients with nodal metastases as assessed by the area under the ROC curve (AUC) was 0.752. CONCLUSION: The model based on established clinicopathological variables has been internally validated on a large cohort of patients and offers practicability for use in OSCCs of the tongue and buccal mucosa.

Barriers to early detection and management of oral cancer in the Asia Pacific region.

OBJECTIVE: Oral cancer is amenable to early detection but remains a prominent cause of mortality in the Asia Pacific region. This study aimed to identify barriers to early detection and management of oral cancer in the Asia Pacific region. METHODS: A mixed-methods approach was employed triangulating findings from a survey and focus groups. The survey was conducted among seven representative members of the Asia Pacific Oral Cancer Network (APOCNET) across six countries. Focus groups were conducted to gain deeper insights into the findings of the survey. RESULTS: The identified barriers were a lack of national cancer control strategies and cancer registries and the limited availability of trained health care professionals. Overcoming these challenges in the Asia Pacific region where resources are scarce will require collaborative partnerships in data collection and novel approaches for continuous professional training including eLearning. Further, to overcome the lack of trained health care professionals, innovative approaches to the management of oral potentially malignant lesions and oral cancer including telemedicine were suggested. CONCLUSION: The findings of this study should be taken into account when charting national cancer control plans for oral cancer and will form the basis for future collaborative studies in evaluating effective measures to improve oral cancer detection and management in low- and middle-income countries.

Effectiveness of "OralDETECT": a Repetitive Test-enhanced, Corrective Feedback Method Competency Assessment Tool for Early Detection of Oral Cancer.

Early diagnosis of oral cancer results in less aggressive treatment and improves the quality of life and overall 5-year survival rate. Well-trained dental professionals can play a crucial role in the early detection of oral cancers. The present study aims to determine the effectiveness of the training program "OralDETECT", a spaced repetitive, test-enhanced learning tool with a corrective feedback mechanism for early detection of oral cancer. Thirty-two dentists and 259 dental students from three Malaysian dental schools were involved in this study. All participants were trained and calibrated to recognize oral potentially malignant disorders (OPMD) and oral cancer using "OralDETECT", which is comprised of a series of pre-test, lecture, post-tests and review sessions. The percentage of correct answers (scores) for each test given by the participants was calculated and analysed using a paired t test. It was found that the overall percentage of diagnostic accuracy for both dental professionals and student groups increased to above 80% from the pre-tests to the final post-tests. There was a significant improvement in overall scores between the pre-tests and all three post-tests for the dental professional groups and the student groups. The diagnostic accuracy for individual OPMD and lesions suspicious of oral cancer also increased to above 80% for both groups. The results of our study demonstrate that the "OralDETECT" is an efficient and effective competency tool which can be used to train dental professionals and students for the early detection of OPMD and oral cancer.

Expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins as predictive markers for relapse in oral squamous cell carcinoma (OSCC).

BACKGROUND: Local relapse of oral squamous cell carcinoma in non-involved mucosal surgical margins indicated possibility of field alteration in the margins, which could be predicted with certain biomarkers. The objectives were to evaluate the expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins and the association of clinicopathological prognosticators with local relapse in oral squamous cell carcinoma. METHODS: Surgical margins from the study (relapse) group (n = 23), control (non-relapse) group (n = 32) and normal oral mucosa (n = 5) were immunohistochemically stained using Ki-67, Cornulin and ISG15 antibodies. Association between expression of markers and clinicopathological prognosticators with local relapse in oral squamous cell carcinoma was analyzed statistically. RESULTS: The study group surgical margins demonstrated significantly decreased Cornulin expression (p = 0.032). Low Cornulin expression was significantly associated with local relapse (p = 0.004) and non-tongue primary tumor (p = 0.013). Although not significantly associated with local relapse, expression of Ki-67 was significantly reduced in female patients (p = 0.041). Age above 57.5 years, Chinese & Indian ethnicity, alcohol consumption, epithelial dysplasia in surgical margins, and type III and IV patterns of invasion of tumor were also significantly related to local relapse. Regression analysis showed low expression of Cornulin (p = 0.018), and increased patient's age (p = 0.008) were predictors of local relapse in oral squamous cell carcinoma, with 34-fold risk and 18-fold risk, respectively. Expression of Ki-67 and ISG15 did not show significant association with local relapse in oral squamous cell carcinoma. CONCLUSION: Low expression of Cornulin is an independent predictor of relapse in oral squamous cell carcinoma.

DNA Vaccines Targeting Novel Cancer-Associated Antigens Frequently Expressed in Head and Neck Cancer Enhance the Efficacy of Checkpoint Inhibitor.

HPV-independent head and neck squamous cell carcinoma (HNSCC) is a common cancer globally. The overall response rate to anti-PD1 checkpoint inhibitors (CPIs) in HNSCC is ~16%. One major factor influencing the effectiveness of CPI is the level of tumor infiltrating T cells (TILs). Converting TILlow tumors to TILhigh tumors is thus critical to improve clinical outcome. Here we describe a novel DNA vaccines to facilitate the T-cell infiltration and control tumor growth. We evaluated the expression of target antigens and their respective immunogenicity in HNSCC patients. The efficacy of DNA vaccines targeting two novel antigens were evaluated with or without CPI using a syngeneic model. Most HNSCC patients (43/44) co-expressed MAGED4B and FJX1 and their respective tetramer-specific T cells were in the range of 0.06-0.12%. In a preclinical model, antigen-specific T cells were induced by DNA vaccines and increased T cell infiltration into the tumor, but not MDSC or regulatory T cells. The vaccines inhibited tumor growth and improved the outcome alone and upon combination with anti-PD1 and resulted in tumor clearance in approximately 75% of mice. Pre-existence of MAGED4B and FJX1-reactive T cells in HNSCC patients suggests that these widely expressed antigens are highly immunogenic and could be further expanded by vaccination. The DNA vaccines targeting these antigens induced robust T cell responses and with the anti-PD1 antibody conferring excellent tumor control. This opens up an opportunity for combination immunotherapy that might benefit a wider population of HNSCC patients in an antigen-specific manner.

Analysis of octamer-binding transcription factor-4 expression in oral leukoplakia.

BACKGROUND: Oral potentially malignant disorders have a risk for malignant transformation but are difficult to reliably identify and predict which patients are at the risk for malignant transformation. OCT4 has been hypothesized to play a key oncogenic driver in a variety of solid tumors. A deeper understanding of the aberrant molecular pathways which lead to carcinogenesis needs to be identified by the potential markers. AIMS: To assess the OCT4 stemness factor in oral leukoplakia for its potential risk to malignant transformation. SETTINGS AND DESIGN: 20 cases of oral leukoplakia were obtained from archives at Oral Cancer Research & Coordinating center (OCRCC) Malaysia Subjects and Methods: 20 cases of oral leukoplakia were assessed by OCT4 immunohistochemically. Oral squamous cell carcinoma was used as a control. RESULT: no expression of OCT 4 was observed in any cases of oral leukoplakia. CONCLUSION: The molecular mechanisms of Oct4 regulation and in particular of its switch on and off in tissues depends upon its microenvironment, which makes it challenging in fundamental and applied research fields of regenerative medicine and cancer therapy. It's better that patients should undergo multiple biopsies for the early detection of malignant transformation with close follow-up during the first two to three years, a large amount of work remains to be done with multi-marker panel investigation, as cure rates have remained constant over three decades.

Survival of Oral Cancer Patients in Different Ethnicities.

Previous studies found that ethnicity influences oral cancer patients' survival; however, most studies were limited to certain ethnic groups particularly from the West, thus of limited relevance to Asians where the disease is most prevalent. We investigated the relationship between ethnicity and patient survival in multi-racial Malaysia. 5-year survival rate was 40.9%. No statistically significant difference was observed in survival between Malays, Chinese, Indians and Indigenous peoples (45.7%, 44.0%, 41.3%, 27.7% respectively). Increased tumor size, lymph node involvement and advanced tumor were predictive of poor survival. We conclude that ethnicity has no effect on survival or its prognostic indicators.

Prevalence of oral cancer, oral potentially malignant disorders and other oral mucosal lesions in Cambodia.

OBJECTIVES: To obtain data on the prevalence of oral mucosal lesions (OMLs) among Cambodians, and to assess the relationship between known risk habits of oral diseases with prevalence of oral potentially malignant disorders (OPMDs). DESIGN: This was a population-based, cross-sectional study whereby subjects were adults aged 18 years old and above. A workshop on the identification of OML was held to train and calibrate dental officers prior to data collection in the field. Sociodemographic and risk habits data were collected via face-to-face interview, whilst presence of OML and clinical details of lesions such as type and site were collected following clinical oral examination by the examiners. Data analysis was carried out using the Statistical Package for Social Science (SPSS) version 12.0. The association between risk habits and risk of OPMD was explored using logistic regression analysis. RESULTS: A total of 1634 subjects were recruited. Prevalence of OML for this population was 54.1%. Linea alba was the most common lesion seen (28.7%). This study showed an overall OPMD prevalence of 5.6%. The most common type of OPMD was leukoplakia (64.8%), followed by lichen planus (30.8%). Subjects who only smoked were found to have an increased risk for OPMD of almost four-fold (RR 3.74, 95%CI 1.89-7.41). The highest risk was found for betel quid chewers, where the increased risk observed was more than six times (RR 6.75, 95%CI 3.32-13.72). Alcohol consumption on its own did not seem to confer an increased risk for OPMD, however when practiced concurrently with smoking, a significant risk of more than five times was noted (RR 5.69 95%CI 3.14-10.29). CONCLUSION: The prevalence of OML was 54.1%, with linea alba being the most commonly occurring lesion. Smoking, alcohol consumption and betel quid chewing were found to be associated with the prevalence of OPMD, which was 5.6%.

Genome wide profiling in oral squamous cell carcinoma identifies a four genetic marker signature of prognostic significance.

BACKGROUND: Cancers of the oral cavity are primarily oral squamous cell carcinomas (OSCCs). Many of the OSCCs present at late stages with an exceptionally poor prognosis. A probable limitation in management of patients with OSCC lies in the insufficient knowledge pertaining to the linkage between copy number alterations in OSCC and oral tumourigenesis thereby resulting in an inability to deliver targeted therapy. OBJECTIVES: The current study aimed to identify copy number alterations (CNAs) in OSCC using array comparative genomic hybridization (array CGH) and to correlate the CNAs with clinico-pathologic parameters and clinical outcomes. MATERIALS AND METHODS: Using array CGH, genome-wide profiling was performed on 75 OSCCs. Selected genes that were harboured in the frequently amplified and deleted regions were validated using quantitative polymerase chain reaction (qPCR). Thereafter, pathway and network functional analysis were carried out using Ingenuity Pathway Analysis (IPA) software. RESULTS: Multiple chromosomal regions including 3q, 5p, 7p, 8q, 9p, 10p, 11q were frequently amplified, while 3p and 8p chromosomal regions were frequently deleted. These findings were in confirmation with our previous study using ultra-dense array CGH. In addition, amplification of 8q, 11q, 7p and 9p and deletion of 8p chromosomal regions showed a significant correlation with clinico-pathologic parameters such as the size of the tumour, metastatic lymph nodes and pathological staging. Co-amplification of 7p, 8q, 9p and 11q regions that harbored amplified genes namely CCND1, EGFR, TPM2 and LRP12 respectively, when combined, continues to be an independent prognostic factor in OSCC. CONCLUSION: Amplification of 3q, 5p, 7p, 8q, 9p, 10p, 11q and deletion of 3p and 8p chromosomal regions were recurrent among OSCC patients. Co-alteration of 7p, 8q, 9p and 11q was found to be associated with clinico-pathologic parameters and poor survival. These regions contain genes that play critical roles in tumourigenesis pathways.

Prognostic significance of VEGF-C in predicting micrometastasis and isolated tumour cells in N0 oral squamous cell carcinoma.

BACKGROUND: Lymph node metastasis in oral squamous cell carcinoma (OSCC) is a well-known independent prognostic factor. However, the identification of occult tumour cells within the lymph nodes has remained a challenge for the pathologist as well as the clinician. OBJECTIVE: The aim of this study was to determine the prevalence of micrometastasis and isolated tumour cells (ITCs) in pathologically staged N0 OSCC of the tongue and buccal mucosa and to assess its correlation with vascular endothelial growth factor C, (VEGF-C) expression in the primary tumour. METHODS: Thirty-four cases of N0 OSCC comprising of 17 cases each from the tongue and buccal mucosa were evaluated by immunohistochemistry for VEGF-C expression. The corresponding lymph nodes from levels I and II were pathologically examined and cross-detected for micrometastasis and ITCs with desmoglein 3 (DSG3). RESULTS: The prevalence of micrometastasis and ITCs in OSCC of the tongue and buccal mucosa was 23.5% and 17.6%, respectively. A total of 12 out of 151 lymph nodes contained micrometastatic tumour foci and ITCs. A higher expression of VEGF-C in the primary tumour was associated with a greater probability for the occurrence of micrometastasis and ITCs in the lymph nodes. CONCLUSION: High expression of VEGF-C in the primary tumour may be a good determinant for detection of occult tumour cells in the lymph nodes of OSCC cases.