Intraexaminer and interexaminer reliability in the diagnosis of oral epithelial dysplasia

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.

Demystifying oral epithelial dysplasia: a histological guide

Oral epithelial dysplasia is a histologically diagnosed potentially premalignant disorder of the oral mucosa, which carries a risk of malignant transformation to squamous cell carcinoma. The diagnosis and grading of oral epithelial dysplasia is challenging, with cases often referred to specialist oral and maxillofacial pathology centres for second opinion. Even still there is poor inter-examiner and intra-examiner agreement in a diagnosis. There are a total of 28 features of oral epithelial dysplasia listed in the 5th edition of World Health Organization classification of tumours of the head and neck. Each of these features is poorly defined and subjective in its interpretation. Moreover, how these features contribute to dysplasia grading and risk stratification is even less well defined. This article discusses each of the features of oral epithelial dysplasia with examples and provides an overview of the common mimics, including the normal histological features of the oral mucosa which may mimic atypia. This article also highlights the paucity of evidence defining these features while offering suggested definitions. Ideally, these definitions will be refined, and the most important features identified to simplify the diagnosis of oral epithelial dysplasia. Digital whole slide images of the figures in this paper can be found at: https://www.pathogenesis.co.uk/r/demystifying-dysplasia-histology-dataset.

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.

Abnormal p53 Immunohistochemical Patterns Shed Light on the Aggressiveness of Oral Epithelial Dysplasia

The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of mild, moderate, and severe dysplasia is considered by many the gold standard in predicting the risk of malignant transformation. Unfortunately, some low-grade lesions, with or without dysplasia, progress to squamous cell carcinoma (SCC) in short periods. As a result, we are proposing a new approach to characterize oral dysplastic lesions that will help identify lesions at high risk for malignant transformation. We included a total of 203 cases of oral epithelial dysplasia, proliferative verrucous leukoplakia, lichenoid, and commonly observed mucosal reactive lesions to evaluate their p53 immunohistochemical (IHC) staining patterns. We identified 4 wild-type patterns, including scattered basal, patchy basal/parabasal, null-like/basal sparing, mid-epithelial/basal sparing, and 3 abnormal p53 patterns, including overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, and null. All cases of lichenoid and reactive lesions exhibited scattered basal or patchy basal/parabasal patterns, whereas human papillomavirus-associated oral epithelial dysplasia demonstrated null-like/basal sparing or mid-epithelial/basal sparing patterns. Of the oral epithelial dysplasia cases, 42.5% (51/120) demonstrated an abnormal p53 IHC pattern. p53 abnormal oral epithelial dysplasia was significantly more likely to progress to invasive SCC when compared to p53 wild-type oral epithelial dysplasia (21.6% vs 0%, P < .0001). Furthermore, p53 abnormal oral epithelial dysplasia was more likely to have dyskeratosis and/or acantholysis (98.0% vs 43.5%, P < .0001). We propose the term p53 abnormal oral epithelial dysplasia to highlight the importance of utilizing p53 IHC stain to recognize lesions that are at high risk of progression to invasive disease, irrespective of the histologic grade, and propose that these lesions should not be graded using the conventional grading system to avoid delayed management.

Proceedings of the North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Oral Cavity Dysplasia: Why Does Histologic Grading Continue to be Contentious?

Head and neck squamous cell carcinoma (HNSCC) is the world's 6th most common malignancy. Oral cavity SCC (OCSCC) represents approximately one third of the HNSCC cases diagnosed annually in the United States. Despite therapeutic advances, OCSCC is frequently lethal, with a modest 5-year survival. Because OCSCC is often preceded by premalignant lesions, it is an ideal disease for screening initiatives. The conventional visual and tactile exam (CVTE), coupled with a tissue biopsy, remains the gold standard. However, CVTE alone cannot reliably differentiate between reactive/inflammatory and dysplastic lesions. Further, the histologic diagnosis of dysplasia is subjective in nature and a highly imperfect predictor of malignant transformation. This prognostic uncertainty creates a significant clinical management dilemma-watchful waiting with increased patient psychological and economic burdens versus unnecessary aggressive treatment. As such, the development and validation of novel diagnostic platforms such as Artificial Intelligence (AI) and prognostic molecular biomarkers may help address these critical unmet clinical needs.

Deep learning-based pathology image analysis predicts cancer progression risk in patients with oral leukoplakia

BACKGROUND

Oral leukoplakia (OL) is associated with an increased risk for oral cancer (OC) development. Prediction of OL cancer progression may contribute to decreased OC morbidity and mortality by favoring early intervention. Current OL progression risk assessment approaches face large interobserver variability and is weakly prognostic. We hypothesized that convolutional neural networks (CNN)-based histology image analyses could accelerate the discovery of better OC progression risk models.

METHODS

Our CNN-based oral mucosa risk stratification model (OMRS) was trained to classify a set of nondysplastic oral mucosa (OM) and a set of OC H&E slides. As a result, the OMRS model could identify abnormal morphological features of the oral epithelium. By applying this model to OL slides, we hypothesized that the extent of OC-like features identified in the OL epithelium would correlate with its progression risk. The OMRS model scored and categorized the OL cohort (n = 62) into high- and low-risk groups.

RESULTS

OL patients classified as high-risk (n = 31) were 3.98 (95% CI 1.36-11.7) times more likely to develop OC than low-risk ones (n = 31). Time-to-progression significantly differed between high- and low-risk groups (p = 0.003). The 5-year OC development probability was 21.3% for low-risk and 52.5% for high-risk patients. The predictive power of the OMRS model was sustained even after adjustment for age, OL site, and OL dysplasia grading (HR = 4.52, 1.5-13.7).

CONCLUSION

The ORMS model successfully identified OL patients with a high risk of OC development and can potentially benefit OC early diagnosis and prevention policies.

Automated detection of premalignant oral lesions on whole slide images using convolutional neural networks

INTRODUCTION

Oral epithelial dysplasia (OED) is a precursor lesion to oral squamous cell carcinoma, a disease with a reported overall survival rate of 56 percent across all stages. Accurate detection of OED is critical as progression to oral cancer can be impeded with complete excision of premalignant lesions. However, previous research has demonstrated that the task of grading of OED, even when performed by highly trained experts, is subject to high rates of reader variability and misdiagnosis. Thus, our study aims to develop a convolutional neural network (CNN) model that can identify regions suspicious for OED whole-slide pathology images.

METHODS

During model development, we optimized key training hyperparameters including loss function on 112 pathologist annotated cases between the training and validation sets. Then, we compared OED segmentation and classification metrics between two well-established CNN architectures for medical imaging, DeepLabv3+ and UNet++. To further assess generalizability, we assessed case-level performance of a held-out test set of 44 whole-slide images.

RESULTS

DeepLabv3+ outperformed UNet++ in overall accuracy, precision, and segmentation metrics in a 4-fold cross validation study. When applied to the held-out test set, our best performing DeepLabv3+ model achieved an overall accuracy and F1-Score of 93.3 percent and 90.9 percent, respectively.

CONCLUSION

The present study trained and implemented a CNN-based deep learning model for identification and segmentation of oral epithelial dysplasia (OED) with reasonable success. Computer assisted detection was shown to be feasible in detecting premalignant/precancerous oral lesions, laying groundwork for eventual clinical implementation.

The Utility of Frozen Sections in the Evaluation of Clear Margins in Oral Squamous Cell Carcinomas: A Cross-Sectional Study From a Tertiary Care Center

Background and objective

Head and neck cancers are prevalent in Pakistan. Oral squamous cell carcinomas are primarily treated via surgical removal, and complete surgical resection is the paramount prognostic factor. A resection margin of 5 mm on the final histopathology report has been accepted as adequate in the existing literature. Negative margins on the frozen section do not guarantee adequate disease-free resections on the final histopathology report. In this study, we aimed to ascertain how accurately tumor-free margins can be detected on frozen sections, which are reported intraoperatively compared to permanent sections of the same tissues reported after proper staining in oral squamous cell carcinoma patients.

Methods

A cross-sectional study was conducted at a tertiary care hospital in Karachi, Pakistan; 94 patients presenting between January and October 2016 were included in this study and a total of 432 tumor margins were assessed.

Results

Among the total 94 patients included in the study, 79% were male and 21% were female. Buccal mucosa was the most commonly involved subsite (57%), followed by the tongue (25%). The most common T stage was T4 (33%), followed by T2 and T3 at 28% and 21% respectively, while the most common N stage was N0 (55%) followed by N1 at 16% and N2 at 22%. The sensitivity of the frozen section in comparison to the permanent section was found to be 50%, while specificity was calculated to be 99.8%. The positive predictive value was 75% and the negative predictive value was 99.3%.

Conclusion

The frozen section is a highly useful tool for the evaluation of tumor margins. However, while it has high diagnostic accuracy rates, it can produce altered results and therefore requires high clinical correlation.

Immunohistochemical staining patterns of p53 predict the mutational status of TP53 in oral epithelial dysplasia

Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.1 locus, and immunohistochemical analysis for p53 (p53-IHC), in 40 OED cases. We detected 20 mutations in 16 (40%) OED cases, and four cases, each harbored two mutations. FISH analysis revealed six of 24 cases (25%) had a deletion on 17p13.1, and four cases had concurrent TP53 mutations and 17p13.1 deletion (2-hit). Also, the increased frequency of TP53 mutations in higher degrees of OED implies acquisition of the mutation is a major event toward OSCC. p53-IHC revealed that overall cases could be categorized into four patterns that correlate well with the mutational status of TP53. Especially, two patterns, broad p53 expression type (pattern HI) and p53 null type (pattern LS), strongly correlated with a missense mutation and nonsense mutation, respectively. Furthermore, seven of the 40 cases progressed to SCC, and six of these seven cases presented pattern HI or LS. Therefore, patterns HI and LS have a high risk for malignant transformation if excisional treatment is not performed irrespective of the dysplasia grade. Although the current WHO classification mainly focuses on morphological criteria for the diagnosis of OED, interobserver discrepancy appears in some instances of the OED diagnosis. Our immunohistochemical analysis supports a more accurate pathological diagnosis for OED in cases of low dysplastic changes or of differential diagnosis with non-dysplastic lesions.

Expression of p53, p63, podoplanin and Ki-67 in recurring versus non-recurring oral leukoplakia

Oral leukoplakia (OL), a potentially malignant disorder, recurs in 40% of cases after surgical removal. Recurrence is a risk factor for malignant transformation. We aimed to examine the prognostic significance of four biomarkers related to cell proliferation: p53, p63, podoplanin (PDPN) and Ki-67 in predicting recurrence. Formalin-fixed-paraffin-embedded specimens from excised OL (n = 73, 33 recurrent; 40 non-recurrent) were collected in a prospective study. Immunohistochemistry was used to visualise expression of p53, p63, PDPN and Ki-67. Image analysis software was used for quantification of p53-, p63- and Ki-67-expressing cells, while PDPN was analysed visually. The expression of all four proteins were higher in recurrent compared with non-recurrent OL, only expression of p53 was statistically significant. In uni- and multivariable Cox regression analyses of individual markers, expression of p63 was significantly associated with higher recurrence risk (p = 0.047). OL with a combined high expression of both p53 and p63 had a significantly higher risk to recur [Log Rank, p = 0.036; multivariate Cox, HR: 2.48 (1.13–5.44; p = 0.024)]. Combination of p53 and p63 expression may be used as a prognostic biomarker for recurrence of OL.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Recurrence and malignant transformation rates of high grade oral epithelial dysplasia over a 10 year follow up period and the influence of surgical intervention, size of excision biopsy and marginal clearance in a UK regional maxillofacial surgery unit

OBJECTIVES

To determine the overall recurrence rate (RR) and malignant transformation rate (MTR) of high grade oral mucosal epithelial dysplasias (HGOED).

MATERIALS & METHODS

A clinicopathological review of records of patients diagnosed with a unifocal HGOED between 2004 and 2016 on incisional biopsy who then underwent excision. The mean duration of follow-up was 47.7 months (±29.9 SD).

RESULTS

Full demographic, historical and histopathological data were available for 120 patients. Six were lost to follow-up after excisional biopsy. Invasive squamous cell carcinoma (SCC) was present in 19 (18.3%) excisions. HGOED affected the lateral and ventral tongue in 58% of patients. Fourteen (11.7%) were not treated surgically but kept under surveillance. The overall RR was 34.7% (33 patients) and MTR 17.8% (17 patients). Four of the 14 (28.6%) patients who had not had the HGOED excised developed SCC, by contrast to the 13 of the 106 (12.3%) who had been treated. RR was significantly associated with positive excision margins (p = 0.007; OR = 3.6) and a clinical presentation of erythroplakia (p = 0.023; OR = 1.5). MTR was significantly associated with age (p = 0.034), clinical appearance (p = 0.030), site (p = 0.007), treatment received (p = 0.012) and positive excision margins (p = 0.007). The mean time for recurrence to develop was 62 months (±31.5 SD) (range 22-144 months), that for malignant transformation was 50 months (±32.5 SD) (range 8-97 months).

CONCLUSION

Patients with HGOED require follow-up for at least 10 years after treatment. Younger age, homogeneous clinical appearance, complete excision, a larger excision specimen and clear margins all improve prognosis.

Binary and WHO dysplasia grading systems for the prediction of malignant transformation of oral leukoplakia and erythroplakia: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to examine the evidence of the binary histologic grading system capacity for predicting malignant transformation and to compare it with that of the WHO systems.

MATERIAL AND METHODS

A systematic review was conducted, using PubMed, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO databases without any language or timeframe restrictions. Studies were included if they compared the binary and the WHO histologic grading systems in the prediction of malignant transformation of oral epithelial dysplasia (OED).

RESULTS

The capacity of the WHO and binary grading systems to predict malignant transformation ranged from 16 to 80% and from 5 to 80%, respectively. The pooled malignant transformation rate of lesions classified as severe dysplasia or carcinoma in situ by the WHO grading was 40% (95% confidence interval (CI), 0.02-0.87; I² = 92%; P = 0.00), while the corresponding value for lesions classified as high-risk by the binary grading system was 31% (95% CI, 0.00-0.84; I² = 97%; P = 0.00). Overall, there was no significant difference in prognostication accuracy between the WHO and the binary systems (odds ratio = 2.02; 95% CI, 0.88-4.64).

CONCLUSIONS

Although some studies suggest that the binary system is associated with lower inter-rater variability when grading OED, the evidence remains inconclusive on whether this system is superior to that of the WHO at predicting malignant transformation.

CLINICAL RELEVANCE

The reproducibility of the binary system has the potential to be better for prognostic purposes. However, there is no high-quality evidence to confirm if this advantage may assist clinicians in decision-making.

Comparison between two cell collecting methods for liquid-based brush biopsies: a consecutive and retrospective study

Background

This study compares two different cell collectors, the Orcellex Brush (rigid brush) and the Cytobrush GT (nylon brush), using liquid-based cytology. A comparison of their obtainment procedures was also considered. The aim was to determine the diagnostic accuracy for detection of malignancy in oral brush biopsies. PICO-Statement: In this consecutive and retrospective study we had as population of interests, patients with oral lesions, the intervention was the brush biopsy with two different cell collectors and the control was healthy oral mucosa. The outcome of the study was to compare both cell collectors.

Methods

From 2009 to 2018, 2018 patients with oral lesions were studied using the nylon brush (666 cases) and rigid brush (1352 cases). In the first cohort five smears per patient were taken with the nylon brush, while each patient received one smear with the rigid brush in the second cohort. These were further processed in a liquid-based procedure. Cytological evaluations were categorised into ‘negative’, which were considered as negative, whereas ‘doubtful’, ‘suspicious’ and ‘positive’ cytological results were overall considered as positive for malignancy in comparison to the final histological diagnoses. Additionally, the clinical expenditure for each collector was estimated.

Results

2018 clinically and histologically proven diagnoses were established, including 181 cases of squamous cell carcinomas, 524 lichen, 454 leukoplakias, 34 erythroplakias and 825 other benign lesions. The sensitivity and specificity of the nylon brush was 93.8% (95% CI 91.6–95.5%) and 94.2% (95% CI 91.8–95.5%) respectively, whereas it was 95.6% (95% CI 94.4–96.6%) and 84.9% (95% CI 83.8–87.5%) for the rigid brush. The temporal advantage using the plastic brushes was 4×  higher in comparison to the nylon brush. The risk suffering from a malignant oral lesion when the result of the brushes was positive, suspicious, or doubtful was significantly high for both tests (nylon brush OR: 246.3; rigid brush OR: 121.5).

Conclusions

Both systems have a similar sensitivity, although only the rigid brush achieved a satisfactory specificity. Additional methods, such as DNA image cytometry, should also be considered to improve the specificity. Furthermore, the rigid brush proved to be more effective at taking a sufficient number of cells, whilst also being quicker and presenting less stress for the patient.

Clinicopathologic factors associated with malignant transformation of oral leukoplakias: a retrospective cohort study

It is clinically challenging to identify oral leukoplakias that have a high risk of undergoing malignant transformation. The aim of this retrospective study was to elucidate the associations between malignant transformation of oral leukoplakias and various clinicopathologic factors. Patients with a diagnosis of clinical oral leukoplakia, verified through histopathologic examination and with access to digital images of the lesion, were retrospectively included for the period 2003-2013. Using the clinical images, all lesions were re-evaluated regarding diagnosis and clinical subtype. Of the 234 included patients, with a median follow-up of 9 years, 27 (11.5%) developed oral squamous cell carcinoma. Among the clinicopathologic factors investigated, non-homogeneous oral leukoplakia (OL), OL with dysplasia, and OL localized to the tongue showed statistically significant increased rates of malignant transformation in the multivariate Cox regression analysis. Non-homogeneous OL showed a 15.2-times higher transformation rate than homogenous OL (P<0.001). Dysplastic leukoplakias developed into carcinomas 2.4-times more often than did non-dysplastic leukoplakias (P=0.048). OL located on the tongue showed a 2.8-times higher malignant transformation rate than OLs at other oral locations (P=0.018), when other locations were combined into one group. Non-homogeneous OL, OL with dysplasia, and OL localized to the tongue have higher transformation rates.

The impact of close surgical margins on recurrence in oral squamous cell carcinoma

BACKGROUND

Close margins influence treatment and outcome in patients with oral squamous cell carcinoma (OSCC). This study evaluates 187 cases of surgically treated OSCC regarding the impact of close margins on recurrence-free survival (RFS) and disease-specific survival (DSS).

METHODS

Predictors of worsened outcome were identified using Kaplan-Meier analysis and multivariate Cox regression analysis.

RESULTS

Tumour size [HR:1.70(0.95-3.08)], nodal status [HR:2.15(1.00-4.64)], presence of extracapsular spread (ECS) [HR:6.36(2.41-16.74)] and smoking history [HR:2.87(1.19-6.86)] were associated with worsened RFS. Similar factors were associated with worsened DSS. Close margins did not influence RFS or DSS.

CONCLUSIONS

While most conventional risk factors for OSCC conferred a worsened outcome, close margins did not. One explanation for this would be that close margins (< 5 mm) are equivalent to clear margins and the cutoff definition for a close margin should be re-evaluated. Lack of standardized pathology could also reduce accuracy of reporting of close surgical margins.

The Potential of Raman Spectroscopy in the Diagnosis of Dysplastic and Malignant Oral Lesions

Simple Summary

Raman spectroscopy, a light scattering technique that provides the biochemical fingerprint of a sample, was used on samples taken from patients with cancer and precancerous lesions. This information was then used to build a classifier to identify cancer and the precancerous phases. The ability to distinguish cancerous tissue from normal and precancerous tissue is diagnostically crucial as it can alter the patients’ prognosis and management. Moreover, as cellular changes are often present at the tumour margin, the ability to distinguish these changes from cancer can help in preserving more of the tissue and maintaining aesthetics and functionality for the patient.

Abstract

Early diagnosis, treatment and/or surveillance of oral premalignant lesions are important in preventing progression to oral squamous cell carcinoma (OSCC). The current gold standard is through histopathological diagnosis, which is limited by inter- and intra-observer errors and sampling errors. The objective of this work was to use Raman spectroscopy to discriminate between benign, mild, moderate and severe dysplasia and OSCC in formalin fixed paraffin preserved (FFPP) tissues. The study included 72 different pathologies from which 17 were benign lesions, 20 mildly dysplastic, 20 moderately dysplastic, 10 severely dysplastic and 5 invasive OSCC. The glass substrate and paraffin wax background were digitally removed and PLSDA with LOPO cross-validation was used to differentiate the pathologies. OSCC could be differentiated from the other pathologies with an accuracy of 70%, while the accuracy of the classifier for benign, moderate and severe dysplasia was ~60%. The accuracy of the classifier was lowest for mild dysplasia (~46%). The main discriminating features were increased nucleic acid contributions and decreased protein and lipid contributions in the epithelium and decreased collagen contributions in the connective tissue. Smoking and the presence of inflammation were found to significantly influence the Raman classification with respective accuracies of 76% and 94%.

Proliferative Verrucous Leukoplakia: An Expert Consensus Guideline for Standardized Assessment and Reporting

The many diverse terms used to describe the wide spectrum of changes seen in proliferative verrucous leukoplakia (PVL) have resulted in disparate clinical management. The objective of this study was to produce an expert consensus guideline for standardized assessment and reporting by pathologists diagnosing PVL related lesions. 299 biopsies from 84 PVL patients from six institutions were selected from patients who had multifocal oral leukoplakic lesions identified over several years (a minimum follow-up period of 36 months). The lesions demonstrated the spectrum of histologic features described in PVL, and in some cases, patients developed oral cavity squamous cell carcinoma (SCC). An expert working group of oral and maxillofacial and head and neck pathologists reviewed microscopic features in a rigorous fashion, in combination with review of clinical photographs when available. The working group then selected 43 single slide biopsy cases for whole slide digital imaging (WSI) review by members of the consensus conference. The digital images were then reviewed in two surveys separated by a washout period of at least 90 days. Five non-PVL histologic mimics were included as controls. Cases were re-evaluated during a consensus conference with 19 members reporting on the cases. The best inter-observer diagnostic agreement relative to PVL lesions were classified as "corrugated ortho(para)hyperkeratotic lesion, not reactive" and "SCC" (chi-square p = 0.015). There was less than moderate agreement (kappa < 0.60) for lesions in the "Bulky hyperkeratotic epithelial proliferation, not reactive" category. There was ≥ moderate agreement (> 0.41 kappa) for 35 of 48 cases. This expert consensus guideline has been developed with support and endorsement from the leadership of the American Academy of Oral and Maxillofacial Pathology and the North American Society of Head and Neck Pathologists to recommend the use of standardized histopathologic criteria and descriptive terminology to indicate three categories of lesions within PVL: (1) "corrugated ortho(para)hyperkeratotic lesion, not reactive;" (2) "bulky hyperkeratotic epithelial proliferation, not reactive;" and (3) "suspicious for," or "squamous cell carcinoma." Classification of PVL lesions based on a combination of clinical findings and these histologic descriptive categories is encouraged in order to standardize reporting, aid in future research and potentially guide clinical management.

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.

Epithelial Dysplasia in Actinic Cheilitis: Microscopic Study of 70 Cases from Brazil

To compare two grading systems of epithelial dysplasia-World Health Organization (WHO) and binary system (BS) -in actinic cheilitis (AC). Seventy cases diagnosed as AC in an Oral Pathology Laboratory from Brazil in the last 12 years were retrospectively retrieved, including the demographic data of each patient. All conventionally stained slides were reviewed, and epithelial dysplasia was evaluated by two independent observers using both WHO and BS grading systems. Data correlation was performed using kappa and chi-square tests (p < 0.05). Most patients were white men with a mean age of 57 years old and history of chronic exposure to sunlight. Most of the lesions were clinically described as whitish plaques with irregular surface located in the lower lip semi-mucosa. Most cases were microscopically graded as severe epithelial dysplasia and low-risk by both observers. The interobserver and intraobserver agreement between systems was slight. All reddish lesions were graded as severe epithelial dysplasia, showing an equal distribution between low and high-risk grading. Most ulcerated lesions showed severe epithelial dysplasia but was graded as low-risk of malignant transformation. Statistical significance was observed among the presence of "irregular stratification", severe epithelial dysplasia and high-risk lesions (p < 0.05) likewise among the presence of "loss of polarity of basal cells" and "drop-shaped ridges" (p < 0.05) with high-risk lesions. The absence of "increased mitotic figures", "dyskeratosis" and "keratin pearls" (p < 0.05) were strongly correlated to low-risk lesions. The presence of "hyperchromasia" was statistically significant with severe epithelial dysplasia (p < 0.05) as well the absence of "atypical mitotic figures" with low-risk lesions (p < 0.05). Although there was slight agreement between microscopic grading systems, microscopic analysis indicated that architectural epithelial changes individually may be the more reliable criteria to indicate the risk of malignant transformation in AC in both grading systems.

The Histopathology of Oral Cancer Pain in a Mouse Model and a Human Cohort

Oral cancer patients often have severe, chronic, and mechanically induced pain at the site of the primary cancer. Oral cancer pain is initiated and maintained in the cancer microenvironment and attributed to release of mediators that sensitize primary sensory nerves. This study was designed to investigate the histopathology associated with painful oral cancers in a preclinical model. The relationship of pain scores with pathologic variables was also investigated in a cohort of 72 oral cancer patients. Wild-type mice were exposed to the carcinogen, 4-nitroquinoline 1-oxide (4NQO). Nociceptive (pain) behavior was measured with the dolognawmeter, an operant device and assay for measuring functional and mechanical allodynia. Lesions developed on the tongues and esophagi of the 4NQO-treated animals and included hyperkeratoses, papillomas, dysplasias, and cancers. Papillomas included lesions with benign and dysplastic pathological features. Two histologic subtypes of squamous cell carcinomas (SCCs) were identified-SCCs with exophytic and invasive components associated with papillary lesions (pSCCs) and invasive SCCs without exophytic histology (iSCCs). Only the pSCC subtype of tongue cancer was associated with nociceptive behavior. Increased tumor size was associated with greater nociceptive behavior in the mouse model and more pain experienced by oral cancer patients. In addition, depth of invasion was associated with patient-reported pain. The pSCC histology identifies 4NQO-induced tongue cancers that are expected to be enriched for expression and release of nociceptive mediators.

Expression of invadopodia markers can identify oral lesions with a high risk of malignant transformation

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity and is usually preceded by a range of premalignant tissue abnormalities termed oral potentially malignant disorders. Identifying malignant transformation is critical for early treatment and consequently improved survival and decreased morbidity. Invadopodia (INV) are specialized subcellular structures required for cancer cell invasion. We developed a new method to visualize INV in keratinocytes using fluorescent immunohistochemistry (FIHC) and semi‐automated images analysis. The presence of INV was used to determine the risk of malignant transformation. We analyzed 145 formalin‐fixed, paraffin‐embedded (FFPE) oral biopsy samples from 95 patients diagnosed as nondysplastic, dysplastic, and OSCC including 49 patients whose lesions transformed to OSCC (progressing) and 46 cases that did not transform to OSCC (control). All samples were stained for Cortactin, tyrosine kinase substrate with five SH3 domains (Tks5) and matrix metallopeptidase 14 (MMP14) using FIHC, imaged using confocal microscopy and analyzed using a multichannel colocalization analysis. The areas of colocalization were used to generate an INV score. Using the INV score, we were able to identify progressing lesions with a sensitivity of 75–100% and specificity of 72–76%. A positive INV score was associated with increased risk of progression to OSCC. Our results suggest that INV markers can be used in conjunction with the current diagnostic standard for early detection of OSCC.

Architectural Alterations in Oral Epithelial Dysplasia are Similar in Unifocal and Proliferative Leukoplakia

The current WHO histopathologic criteria for oral epithelial dysplasia (ED) are based on architectural and cytologic alterations, and do not address other histopathologic features of ED. Here we propose new diagnostic criteria including architectural, organizational, and cytologic features for oral ED. Cases of unifocal leukoplakia (UL) and proliferative leukoplakia (PL) with clinical photographs and follow-up information were identified. Only cases that showed minimal cytologic atypia or mild ED were used to demonstrate critical architectural changes as defined in this study. Eight biopsies from eight UL patients and 34 biopsies from four PL patients were included. The biopsies showed (a) corrugated, verrucous or papillary architecture, (b) hyperkeratosis with epithelial atrophy, (c) bulky squamous epithelial proliferation, and (d) demarcated hyperkeratosis and "skip" segments. The architectural alterations defined here are as important as the currently used criteria for the diagnosis of ED. Clinicopathologic correlation when diagnosing oral ED is also of the utmost importance in accurate diagnosis.

Grading systems of oral cavity pre-malignancy: a systematic review and meta-analysis

PURPOSE

Oral potentially malignant disorders (OPMDs) may have varying degrees of oral epithelial dysplasia (OED). Traditional grading schemes separate OED into three-tiers (mild, moderate, and severe). Alternatively, a binary grading system has been previously proposed that stratifies OED into low-risk and high-risk categories based on a quantitative threshold of dysplastic pathologic characteristics. This systematic review evaluates the predictive value of a binary OED grading system and examines agreement between pathologists.

METHODS

This meta-analysis queried 4 databases (PubMed, Ovid-MEDLINE, Cochrane, and SCOPUS) and includes 4 studies evaluating binary OED grading systems. Meta-analysis of proportions and correlations was performed to pool malignant transformation rates (MTR), risk of malignant transformation between OED categories, and measures of interobserver agreement.

RESULTS

Pooled analysis of 629 lesions from 4 different studies found a six-time increased odds of malignant transformation in high-risk lesions over low-risk lesions [odds ratio (OR) 6.14, 95% 1.18-15.38]. Reported ORs ranged from 2.8 to 22.4. The overall MTR was 26.8%, with the high-risk and low-risk lesions having MTRs of 57.9% (95% CI 0.386-0.723) and 12.7% (95% CI - 0.210 to 0.438), respectively. Pooled unweighted interobserver kappa values for the binary grading system and three-tiered system were 0.693 (95% CI 0.640-0.740) and 0.388 (95% CI 0.195-0.552), respectively.

CONCLUSION

Binary grading of OED into low-risk and high-risk categories may effectively determine malignant potential, with improved interobserver agreement over three-tiered grading. Improved grading schemes of OED may help guide management (watchful waiting vs. excision) of these OPMDs.

Long-term follow-up of oral epithelial dysplasia: A hospital based cross-sectional study

Background/purpose

Oral epithelial dysplasia (OED) is characterized histopathologically by cellular and morphological changes that remain the single most important factor predicting risk for subsequent development of invasive neoplasia. Hence the aims of the present study were to determine the rate of malignant change of OED in a group of patients followed-up for a number of years, and hence determine factors likely to influence this malignant change, and to describe the clinical characteristics of patients who developed recurrence of OED and second dysplastic lesions.

Materials and methods

This is hospital based cross-sectional study of all biopsy reports with histologically confirmed OED between 2012 and 2018 were retrospectivelly reviewed.

Results

A total of 359 patients with histologically confirmed OED were reviewed, twenty (5.5%) of the 359 patients developed an invasive squamous cell carcinoma (SCC) of the oral mucosa over a period of 2 to 274 months with mean transformation time of 3.3 years.

Conclusion

The high risk of malignant transformation of OED seems to be related to patients older than 50 years when lesions were on the floor of mouth with severe dysplastic changes.

Demographic and Clinicopathologic Features of Actinic Cheilitis and Lip Squamous Cell Carcinoma: a Brazilian Multicentre Study

Data on the occurrence and clinicopathological characteristics of actinic cheilitis (AC) and lip squamous cell carcinoma (LSCC) are well studied; however, they are based on studies limited to a single centre. Herein, we described the frequency of AC and LSCC submitted to microscopic examination from representative geographic regions of Brazil. A retrospective multicentre study was performed on biopsies obtained from 1953 to 2018 at 10 Brazilian oral and maxillofacial pathology centres. A total of 198,709 biopsy specimens were surveyed. Sociodemographic data and clinicopathologic characteristics were analysed. A total of 2017 cases of ACs (1.0%) and 850 cases of LSCCs (0.4%) were recorded. A strong fair-skinned (> 87%) male (> 70%) predilection was observed in both conditions. The mean age was 54.8 ± 18.7 for individuals with AC and 57.8 ± 19.0 for individuals with LSCC. The most commonly affected site was the lower lip (> 90%). This is a large multicentre study of AC and LSCC from Brazil. The frequency and clinicopathological features of AC and LSCC were similar to those described worldwide. This study provides robust and representative epidemiological data of these conditions for the scientific community.

Incorporation of differentiated dysplasia improves prediction of oral leukoplakia at increased risk of malignant progression

Oral leukoplakia is the most common oral potentially malignant disorder with a malignant transformation rate into oral squamous cell carcinoma of 1-3% annually. The presence and grade of World Health Organization defined dysplasia is an important histological marker to assess the risk for malignant transformation, but is not sufficiently accurate to personalize treatment and surveillance. Differentiated dysplasia, known from differentiated vulvar intraepithelial neoplasia, is hitherto not used in oral dysplasia grading. We hypothesized that assessing differentiated dysplasia besides World Health Organization defined (classic) dysplasia will improve risk assessment of malignant transformation of oral leukoplakia. We investigated a retrospective cohort consisting of 84 oral leukoplakia patients. Biopsies were assessed for dysplasia presence and grade, and the expression of keratins 13 (CK13) and 17, known to be dysregulated in dysplastic vulvar mucosa. In dysplastic oral lesions, differentiated dysplasia is as common as classic dysplasia. In 25 out of 84 (30%) patients, squamous cell carcinoma of the upper aerodigestive tract developed during follow-up. Considering only classic dysplasia, 11 out of 56 (20%) patients with nondysplastic lesions progressed. With the incorporation of differentiated dysplasia, only 2 out of 30 (7%) patients with nondysplastic lesions progressed. The risk of progression increased from 3.26 (Hazard ratio, p = 0.002) when only classic dysplasia is considered to 7.43 (Hazard ratio, p = 0.001) when classic and differentiated dysplasia are combined. Loss of CK13, combined with presence of dysplasia, is associated with greater risk of malignant progression (p = 0.006). This study demonstrates that differentiated dysplasia should be recognized as a separate type of dysplasia in the oral mucosa and that its distinction from classic dysplasia is of pathological and clinical significance since it is a strong (co)prognostic histopathological marker for oral malignant transformation. In oral lesions without dysplasia and retained CK13 staining the risk for progression is very low.

SOX2 Expression Is an Independent Predictor of Oral Cancer Progression

Potentially malignant oral lesions, mainly leukoplakia, are common. Malignant transformation varies widely, even in the absence of histological features such as dysplasia. Hence, there is a need for novel biomarker-based systems to more accurately predict the risk of cancer progression. The pluripotency transcription factor SOX2 is frequently overexpressed in cancers, including oral squamous cell carcinoma (OSCC), thereby providing a link between malignancy and stemness. This study investigates the clinical relevance of SOX2 protein expression in early stages of oral carcinogenesis as a cancer risk biomarker, and also its impact on prognosis and disease outcome at late stages of OSCC progression. SOX2 expression was evaluated by immunohistochemistry in 55 patients with oral epithelial dysplasia, and in 125 patients with OSCC, and correlated with clinicopathological data and outcomes. Nuclear SOX2 expression was detected in four (7%) cases of oral epithelial dysplasia, using a cut-off of 10% stained nuclei, and in 16 (29%) cases when any positive nuclei was evaluated. Univariate analysis showed that SOX2 expression and histopathological grading were significantly associated with oral cancer risk; and both were found to be significant independent predictors in the multivariate analysis. Nuclear SOX2 expression was also found in 49 (39%) OSCC cases, was more frequent in early tumor stages and N0 cases, and was associated with a better survival. In conclusion, SOX2 expression emerges as an independent predictor of oral cancer risk in patients with oral leukoplakia. These findings underscore the relevant role of SOX2 in early oral tumorigenesis rather than in tumor progression.

Interobserver and intraobserver variability affecting the assessment of loss of autofluorescence of oral mucosal lesions

OBJECTIVES

The assessment of loss of tissue autofluorescence (LAF) has been proposed as an adjunct to comprehensive oral examination to enhance the detection of mucosal lesions harbouring dysplasia or carcinoma. The assessment of LAF is not based on completely objectified parameters therefore intraobserver and interobserver variability cannot be neglected alongside the issue of correct interpretation of LAF. The present study evaluated intraobserver and interobserver variability in the clinical assessment of LAF as performed by oral medicine practitioners (OMPs) or general dental practitioners (GDPs).

MATERIALS AND METHODS

Couples of clinical pictures, acquired under white incandescent dental operatory light and during the assessment of LAF performed by VELscope were retrieved. Four OMPs and eight GDPs were asked to assess the pictures and to score the LAF. Kappa statistics allowed the assessment of intra- and inter-observer related variability.

RESULTS

Pictures of 109 lesions representative of all oral mucosal sites and clinical appearances were selected. OMPs had a better intraobserver agreement than GDPs (substantial versus moderate). The moderate (k = 0.506) interobserver agreement observed among both OMPs and GDPs in a 2-score model (positive versus negative), lowered down to poor values only among GDPs when a 3-score or 4-score model (including uncertain judgements) was applied.

CONCLUSIONS

A good agreement (k>0.8) was never observed and the present results are similar to previously reported data about conventional oral examination. Irrespective of the diagnostic accuracy, the assessment of AF seems not to be able to improve observer-related variability in the clinical assessment of oral mucosal lesions.

The Emerging Role of NANOG as an Early Cancer Risk Biomarker in Patients with Oral Potentially Malignant Disorders

NANOG, a key regulator of pluripotency and self-renewal in embryonic and adult stem cells, is frequently overexpressed in multiple cancers, including oral squamous cell carcinoma (OSCC). It has been frequently associated with poor outcomes in epithelial cancers, and recently implicated in laryngeal tumorigenesis. On this basis, we investigated the role of NANOG protein expression as an early cancer risk biomarker in oral potentially malignant disorders (OPMD), and the impact on prognosis and disease outcomes in OSCC patients. NANOG expression was evaluated by immunohistochemistry in 55 patients with oral epithelial dysplasia, and 125 OSCC patients. Correlations with clinical and follow-up data were assessed. Nuclear NANOG expression was detected in 2 (3.6%) and cytoplasmic NANOG expression in 9 (16.4%) oral dysplasias. NANOG expression increased with the grade of dysplasia. Cytoplasmic NANOG expression and the histopathological grading were significantly correlated with oral cancer risk, although dysplasia grading was the only significant independent predictor of oral cancer development in multivariate analyses. Cytoplasmic NANOG expression was also detected in 39 (31%) OSCC samples. Positive NANOG expression was significantly associated with tobacco and alcohol consumption, and was more frequent in pN0 tumors, early I-II stages. These data unveil the clinical relevance of NANOG in early stages of OSCC tumorigenesis rather than in advanced neoplastic disease. NANOG expression emerges as an early predictor of oral cancer risk in patients with OPMD.

The White Lesion, Hyperkeratosis, and Dysplasia

Laryngeal mucosal precursor lesions represent a challenging clinical entity. Updated classification systems allow for grade-based categorization. Multiple management options exist, with treatment decisions made jointly by physician and patient and focused on both appropriate lesion treatment and preservation of laryngeal structure and function. Traditional methods include cold steel and CO₂ laser excision, with newer modalities using angiolytic lasers for lesion ablation. Both operating room-based and office-based treatment options exist, and there are advantages and disadvantages to each approach. Research is ongoing to advance the understanding of lesion biology, and to optimize prevention and treatment.

Inter-observer Variability in the Diagnosis of Proliferative Verrucous Leukoplakia: Clinical Implications for Oral and Maxillofacial Surgeon Understanding: A Collaborative Pilot Study

The use of diverse terminology may lead to inconsistent diagnosis and subsequent mistreatment of lesions within the proliferative verrucous leukoplakia (PVL) spectrum. The objectives of this study were: (a) to measure inter-observer variability between a variety of pathologists diagnosing PVL lesions; and (b) to evaluate the impact of diverse terminologies on understanding, interpretation, and subsequent treatment planning by oral and maxillofacial surgeons (OMFS). Six oral pathologists (OP) and six head and neck pathologists (HNP) reviewed 40 digitally scanned slides of PVL-type lesions. Inter-observer agreement on diagnoses was evaluated by Fleiss' kappa analysis. The most commonly used diagnostic terminologies were sent to ten OMFS to evaluate their resulting interpretations and potential follow-up treatment approaches. The overall means of the surgeons' responses were compared by Student t test. There was poor inter-observer agreement between pathologists on the diagnosis of PVL lesions (κ = 0.270), although there was good agreement (κ = 0.650) when diagnosing frankly malignant lesions. The lowest agreement was in diagnosing verrucous hyperplasia (VH) with/without dysplasia, atypical epithelial proliferation (AEP), and verrucous carcinoma (VC). The OMFS showed the lowest agreement on identical categories of non-malignant diagnoses, specifically VH and AEP. This study demonstrates a lack of standardized terminology and diagnostic criteria for the spectrum of PVL lesions. We recommend adopting standardized criteria and terminology, proposed and established by an expert panel white paper, to assist pathologists and clinicians in uniformly diagnosing and managing PVL spectrum lesions.

Abrasive cytohistology of squamous epithelial lesions

Objective:

To describe a method to retrieve cellular and tissue elements of oral squamous epithelium obtained by abrasive methods and to conduct investigations by cytohistology.

Method:

We developed a special gelatine pocket suitable for paraffin embedding of sparse material obtained from brush biopsies (BBs). This was subjected to combined evaluation of a cytological (smear) and histological examination of the ‘tissue sections’ – referred as cytohistology. Four diagnostic categories were applied for evaluation. Other special diagnostic methods were also applied in addition to recording dysplasia.

Results:

A total of 51, 755 BBs from suspicious lesions of the oral mucosa (mostly oral potentially malignant disorders – OPMD) were evaluated for the presence of carcinoma or dysplasia; in all, 1.7% were positive, 78.2% were negative for any epithelial atypia, 16.8% atypical and 3.3% inadequate. All BBs also had cytohistological evaluation. A ‘positive’ diagnosis by cytohistology was a reliable indicator of dysplasia or carcinoma, requiring further incisional/excisional biopsy. In the ‘atypical’ category, a variety of lesions were found, about half being dysplasia or carcinoma. This category challenges the clinician for further clinical, therapeutic and/or excisional examination. In ‘negative’ cases with persistence of the lesion, a re-examination in 1-year sequence is recommended.

Conclusion:

Cytohistology of material derived by abrasive methods allows earlier detection of dysplasia/carcinoma. A number of additional oncological and non-oncological findings make this method a valuable non-invasive diagnostic procedure for oral mucosal lesions.

Potential role of nuclear magnetic resonance spectroscopy to identify salivary metabolite alterations in patients with head and neck cancer

The analysis of the salivary metabolomic profile may offer an early phase approach to assess the changes associated with a wide range of diseases including head and neck cancer. The aim of the present study was to investigate the potential of nuclear magnetic resonance (NMR) spectroscopy for detecting the salivary metabolic changes associated with head and neck squamous cell carcinoma (HNSCC). Unstimulated whole-mouth saliva samples collected from HNSCC patients (primary tumour was located either in the larynx or in the oral cavity) and healthy controls were analysed by ¹H-NMR spectroscopy. Reliably identified salivary metabolites were quantified and the determined concentration values were compared group-wise using a Mann-Whitney U-test. Multivariate discrimination function analysis (DFA) was conducted to identify such a combination of metabolites, when considered together, that gives maximum discrimination between the groups. HNSCC patients exhibited significantly increased concentrations of 1,2-propanediol (P=0.032) and fucose (P=0.003), while proline levels were significantly decreased (P=0.043). In the DFA model, the most powerful discrimination was achieved when fucose, glycine, methanol and proline were considered as combined biomarkers, resulting in a correct classification rate of 92.1%, sensitivity of 87.5% and specificity of 93.3%. To conclude, NMR spectrometric analysis was revealed to be a feasible approach to study the metabolome of saliva that is sensitive to metabolic changes in HNSCC and straightforward to collect in a non-invasive manner. Salivary fucose was of particular interest and therefore, controlled longitudinal studies are required to assess its clinical relevance as a diagnostic biomarker in HNSCC.

Oral epithelial dysplasia, atypical verrucous lesions and oral potentially malignant disorders: focus on histopathology

The term oral potentially malignant disorders (OPMDs) describes a recognizable group of mucosal diseases that have a risk of progressing to squamous cell carcinoma. Oral leukoplakia, the most common OPMD, has a 1% prevalence and reported malignant transformation rates of 2% to 5%. Other OPMDs include erythroplakia, erythroleukoplakia, submucous fibrosis, lesions of reverse smokers, and inherited genetic disorders, such as Fanconi anemia. The histopathologic assessment of OPMDs is an area of subjectivity, and oral epithelial dysplasia (OED) is fraught with both interrater variability and intrarater variability. Both architectural and cytologic changes are utilized when developing criteria for grading OED. However, the concept of atypical verrucous lesions, particularly as it pertains to proliferative verrucous leukoplakia, suffers from lack of histopathologic diagnostic criteria. Histopathologic mimics of OPMDs, including reactive/regenerative epithelium, frictional keratosis, and infection, can result in patient mismanagement. This review will focus specifically on the histologic features of OED, including human papillomavirus-associated dysplasia, as well as the histologic features of atypical verrucous keratoses/hyperplasia, particularly those that arise in the setting of proliferative verrucous leukoplakia along with OPMD mimics.

Oral Brush Liquid-Based Cytology: A Study of Concordance between a Cytotechnologist and a Cytopathologist

OBJECTIVE

Oral cancer accounts for almost 40% of all cancers in the Indian subcontinent. Techniques like oral scrape cytology are helpful in early diagnosis of premalignant lesion and thus prevention of malignant transformation. The purpose of this study is to evaluate the performance of cytotechnologists in assessing the adequacy and preliminary diagnostic accuracy of oral brush liquid-based cytology.

STUDY DESIGN

110 oral brush liquid-based cytology smears were prospectively screened by a cytotechnologist for adequacy assessment, and a preliminary diagnosis was recorded. Smears were subsequently studied by the reporting cytopathologist for the final diagnosis. The performance of the cytotechnologist in the assessment of adequacy and the preliminary diagnosis were compared with the final interpretation rendered by the cytopathologist.

RESULTS

There was no significant difference in adequacy assessment between both observers, and good concordance was observed in the identification of frankly malignant lesions; however, in premalignant cases, complete agreement in all the cases was not observed. Maximum numbers of discrepant cases were seen in high-grade squamous intraepithelial lesions, 4/17 were downgraded to low-grade squamous intraepithelial lesions and 2/17 to negative for intraepithelial lesion or malignancy, respectively.

CONCLUSION

Trained cytotechnologists are capable of assessing the adequacy and identifying the malignancy in oral brush liquid-based cytology smears, and hence there is potential for them to perform initial screening of such cases.

Clinical Significance and Biological Role of HuR in Head and Neck Carcinomas

Background

Hu-antigen R (HuR) is a posttranscriptional regulator of several target mRNAs, implicated in carcinogenesis. This review aims to present the current evidence regarding the biological role and potential clinical significance of HuR in head and neck carcinomas.

Methods

The existing literature concerning HuR expression and function in head and neck carcinomas is critically presented and summarised.

Results

HuR is expressed in the majority of the examined samples, showing higher cytoplasmic levels in malignant or premalignant cases. Moreover, HuR modulates several genes implicated in biological processes important for malignant transformation, growth, and invasiveness. HuR seems to be an adverse prognosticator in patients with OSCCs, whereas a correlation with a more aggressive phenotype is reported in several types of carcinomas.

Conclusions

A consistent role of HuR in the carcinogenesis and progression of head and neck carcinomas is suggested; nevertheless, further studies are warranted to expand the present information.

Inter- and Intra-Observer Variability in Diagnosis of Oral Dysplasia

Background:

Oral potentially malignant disorders (OPMDs) are lesions from which malignancy is more likely to develop that from other tissues. The potential for malignant transformation of OPMDs is estimated by determining the degree of dysplastic changes in the epithelium. Dysplasia grading has been criticized for lack of reproducibility and poor predictive value but is still considered the gold standard for diagnosing OPMDs. Since grading of dysplasia is based on architectural and cytological changes, there can be considerable inter- and intra-observer variability due to subjective impressions. This aim in this study was to assess the degree of agreement between two pathologists grading dysplasia in the same patients and review the existing grading system.

Materials and Methods:

In this hospital-based cross-sectional study, 100 patients with clinically diagnosed OPMDs were subjected to biopsy followed by histopathological examination. The slides were examined by two pathologists using WHO and binary systems of classification and both were blinded to the clinical and each other’s histological diagnosis. For statistical analysis the Chi square test was applied.

Results:

Statistical analysis showed poor inter-observer variability with P values of 0.8 using the WHO classification and 0.3 using the binary classification.

Conclusion:

Our study provides evidence that the existing systems for grading dysplasia are not competent to rule out subjectivity. There is a need for a classification system that can overcome this drawback.

Oral potentially malignant disorders: risk of progression to malignancy

Oral potentially malignant disorders (OPMDs) have a statistically increased risk of progressing to cancer, but the risk varies according to a range of patient- or lesion-related factors. It is difficult to predict the risk of progression in any individual patient, and the clinician must make a judgment based on assessment of each case. The most commonly encountered OPMD is leukoplakia, but others, including lichen planus, oral submucous fibrosis, and erythroplakia, may also be seen. Factors associated with an increased risk of malignant transformation include sex; site and type of lesion; habits, such as smoking and alcohol consumption; and the presence of epithelial dysplasia on histologic examination. In this review, we attempt to identify important risk factors and present a simple algorithm that can be used as a guide for risk assessment at each stage of the clinical evaluation of a patient.

The dynamics of gene expression changes in a mouse model of oral tumorigenesis may help refine prevention and treatment strategies in patients with oral cancer

A better understanding of the dynamics of molecular changes occurring during the early stages of oral tumorigenesis may help refine prevention and treatment strategies. We generated genome-wide expression profiles of microdissected normal mucosa, hyperplasia, dysplasia and tumors derived from the 4-NQO mouse model of oral tumorigenesis. Genes differentially expressed between tumor and normal mucosa defined the “tumor gene set” (TGS), including 4 non-overlapping gene subsets that characterize the dynamics of gene expression changes through different stages of disease progression. The majority of gene expression changes occurred early or progressively. The relevance of these mouse gene sets to human disease was tested in multiple datasets including the TCGA and the Genomics of Drug Sensitivity in Cancer project. The TGS was able to discriminate oral squamous cell carcinoma (OSCC) from normal oral mucosa in 3 independent datasets. The OSCC samples enriched in the mouse TGS displayed high frequency of CASP8 mutations, 11q13.3 amplifications and low frequency of PIK3CA mutations. Early changes observed in the 4-NQO model were associated with a trend toward a shorter oral cancer-free survival in patients with oral preneoplasia that was not seen in multivariate analysis. Progressive changes observed in the 4-NQO model were associated with an increased sensitivity to 4 different MEK inhibitors in a panel of 51 squamous cell carcinoma cell lines of the aerodigestive tract. In conclusion, the dynamics of molecular changes in the 4-NQO model reveal that MEK inhibition may be relevant to prevention and treatment of a specific molecularly-defined subgroup of OSCC.

Podoplanin expression in oral potentially malignant disorders and oral squamous cell carcinoma

Background

Podoplanin is a type I transmembrane sialomucin-like glycoprotein that is specifically expressed in lymphatic endothelial cells. Studies have shown that assessment of podoplanin expression in the epithelial cells can be used to predict the malignant transformation of potentially malignant disorders and the metastatic tendency of primary head and neck squamous cell carcinoma. The aim of our study was to compare the expression of podoplanin in oral leukoplakia, oral submucous fibrosis and oral squamous cell carcinoma with that in normal buccal mucosa by immunohistochemical methods.

Material and Methods

Immunohistochemical expression of podoplanin was analyzed in 20 cases each of oral leukoplakia, oral submucous fibrosis, oral squamous cell carcinoma and normal buccal mucosa, with monoclonal antibody D2-40. The expression of podoplanin was graded from grade 0-4.

Results

There was a statistically significant upregulation of the grades of podoplanin expression in oral squamous cell carcinoma(100%), oral submucous fibrosis (90%) and oral leukoplakia (65%) when compared to that in normal mucosa(35%). Podoplanin expression increased with decrease in grades of differentiation in oral squamous cell carcinoma . Podoplanin expression in the samples of oral submucous fibrosis was higher than that in oral leukoplakia.

Conclusions

Evaluation of podoplanin expression in the epithelial cells of oral dysplastic lesions may provide valuable information to predict their risk of malignant transformation.

Key words:Immunohistochemistry, Oral leukoplakia, Oral submucous fibrosis, Podoplanin, Squamous cell carcinoma.

Evaluation and Management of Oral Potentially Malignant Disorders

Oral potentially malignant disorders (OPMDs) refer to epithelial lesions and conditions with an increased risk for malignant transformation; oral leukoplakia is the most commonly encountered. Overall, OPMDs have a low risk for malignant transformation, yet the challenge is the difficulty to reliably identify and predict which patients with OPMDs are at the highest risk for malignant transformation. Future research is needed to elucidate the molecular aspects of OPMDs, to improve current diagnostic strategies, leading to personalized management.

Chairside molecular imaging of aberrant glycosylation in subjects with suspicious oral lesions using fluorescently labeled wheat germ agglutinin

BACKGROUND

Aberrant sialylation is accepted as a carcinogenic biomarker. In previous work, fluorescently labeled wheat germ agglutinin (WGA) distinguished between cancerous and normal oral biopsies. The purpose of this study was to investigate WGA-fluorescein isothiocyanate (FITC) as a point-of-care tool for detecting oral malignant and dysplastic lesions in vivo.

METHODS

Subject recruitment was divided into two groups: (1) the clinically normal oral mucosa group; or (2) the presence of clinically suspicious oral lesion(s) group. A WGA-FITC solution was topically applied to observable lesions or to half the subject's mouth (sagittal plane) if lesions were absent. Fluorescent molecular imaging was used to evaluate WGA-FITC localization.

RESULTS

Fluorescent imaging in 55 subjects demonstrated that WGA-FITC could detect histopathologically-confirmed cancerous and dysplastic lesions with high sensitivity (100% and 81%, respectively) and specificity (82%).

CONCLUSION

This study supports in vivo fluorescent molecular imaging of WGA-FITC to visualize aberrant sialic acid expression associated with carcinogenesis. This technique resulted in the immediate chairside detection of oral cancerous and dysplastic lesions.

Evaluating oral epithelial dysplasia classification system by near-infrared Raman spectroscopy

Until now, the classification system of oral epithelial dysplasia is still based on the architectural and cytological changes, which relies on the observation of pathologists and is relatively subjective. The purpose of present research was to discriminate the oral dysplasia by the near-infrared Raman spectroscope, in order to evaluate the classification system. We collected Raman spectra of normal mucosa, oral squamous cell carcinoma (OSCC) and dysplasia by near-infrared Raman spectroscope. The biochemical variations between different stages were analyzed by the characteristic peaks in the subtracted mean spectra. Gaussian radial basis function support vector machines (SVM) were used to establish the diagnostic models. At the same time, principal component analysis (PCA) and linear discriminant analysis (LDA) were used to verify the results of SVM. Raman spectral differences were observed in the range between 730~1913 cm-1. Compared with normal mucosa, high contents of protein and DNA in oral dysplasia and OSCC were observed. There were no significant or gradual variation of Raman peaks among different dysplastic grades. The accuracies of comparison between mild, moderate, severe dysplasia with OSCC were 100%, 44.44%, 71.15%, which elucidated the low modeling ability of support vector machines, especially for the moderate dysplasia. The analysis by PCA-LDA could not discriminate the stages, either. Combined with support vector machines, near-infrared Raman spectroscopy could detect the biochemical variations in oral normal, OSCC and dysplastic tissues, but could not establish diagnostic model accurately. The classification system needs further improvements.

Automatic Classification of Cancerous Tissue in Laserendomicroscopy Images of the Oral Cavity using Deep Learning

Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer of the oral epithelium. Despite their high impact on mortality, sufficient screening methods for early diagnosis of OSCC often lack accuracy and thus OSCCs are mostly diagnosed at a late stage. Early detection and accurate outline estimation of OSCCs would lead to a better curative outcome and a reduction in recurrence rates after surgical treatment. Confocal Laser Endomicroscopy (CLE) records sub-surface micro-anatomical images for in vivo cell structure analysis. Recent CLE studies showed great prospects for a reliable, real-time ultrastructural imaging of OSCC in situ. We present and evaluate a novel automatic approach for OSCC diagnosis using deep learning technologies on CLE images. The method is compared against textural feature-based machine learning approaches that represent the current state of the art. For this work, CLE image sequences (7894 images) from patients diagnosed with OSCC were obtained from 4 specific locations in the oral cavity, including the OSCC lesion. The present approach is found to outperform the state of the art in CLE image recognition with an area under the curve (AUC) of 0.96 and a mean accuracy of 88.3% (sensitivity 86.6%, specificity 90%).

Nomogram for risk prediction of malignant transformation in oral leukoplakia patients using combined biomarkers

OBJECTIVE

Squamous cell carcinomas (SCC) are the most common malignancies in the oral mucosa; these carcinomas have been preceded by potentially malignant oral disorders (PMODs), mostly oral leukoplakia (OL). No specific biomarker has been widely accepted for predicting the risk of malignant transformation of PMODs. The aim of this study was to develop an accurate prediction model for the malignant transformation of OL using clinical variables and candidate biomarkers.

MATERIALS AND METHODS

To achieve this goal, 10 candidate biomarkers that had previously been reported as useful molecules were investigated: P53, Ki-67, P16, β-catenin, c-jun, c-met, insulin like growth factor II mRNA-binding protein (IMP-3), cyclooxygenase (COX-2), podoplanin (PDPN) and carbonic anhydrase 9 (CA9). For this study, malignant transformed (n=22, median interval of malignant conversion: 3.3years) and untransformed (n=138) OL specimens with median follow-up period of 11.3years (range: 4.6-23.2years) were immunohistochemically stained.

RESULTS

Using univariate Cox regression analysis, all biomarkers were proven to be significant for predicting malignant transformation in OL. To reach the highest prediction accuracy, the repeated simulation was performed, revealing that the combination of P53 and CA9 with the clinical factors including age and degree of dysplasia achieved the highest prediction accuracy. We constructed a nomogram with the identified prognostic factors for predicting the 5-, 10-, and 15-year progression free survival of OL.

CONCLUSIONS

The proposed nomogram may be useful for the accurate and individual prediction of the transformation to SCC in OL patients and may help clinicians offer appropriate treatments and follow up.