World Workshop on Oral Medicine VII: Prognostic biomarkers in oral leukoplakia: A systematic review of longitudinal studies

Architectural and cytological features of epithelial dysplasia associated with transformation risk

OBJECTIVES

This study explored associations between histological features of dysplasia and malignant transformation, as well as genomic copy number alterations.

MATERIALS AND METHODS

Overall, 201 samples were collected from patients of oral leukoplakia. The associations of dysplastic features with malignant transformation and copy number alterations were investigated by Cox proportional hazards regression analysis and the Mann-Whitney U-test.

RESULTS

Eight individual histological features, such as irregular epithelial stratification (p = 0.001), mitoses high in epithelium (p = 0.033), extension of changes along minor gland ducts (p < 0.001), etc., were associated with greater risk of malignant transformation. A model including histological features and age showed good performance for predicting malignant transformation (area under receiver operating characteristic curve: 0.806). Irregular epithelial stratification (p = 0.007), abnormal nuclear shape (p = 0.005), abnormal cell size (p = 0.004), etc. were associated with greater genomic instability.

CONCLUSIONS

A Cox proportional hazards model using eight histological features and patient age reliably predicted the malignant potential of oral epithelial dysplasia. Identification of these histological features closely related to malignant transformation may aid the management of oral potentially malignant disorders and early detection of oral squamous cell carcinoma.

Metastatic patterns and treatment options for head and neck cutaneous squamous cell carcinoma (Review)

According to current predictions, one-fifth of all Americans will develop skin cancer during their lifetime. Cutaneous squamous cell carcinoma (cSCC) most commonly occurs in the head and neck region, which is the area of the body with the highest level of sun exposure. High-risk head and neck cSCC (HNcSCC) is a broad category with numerous high-risk factors that are associated with unfavorable results. In cSCC staging systems, clinical and tumor traits that are likely to result in poor outcomes are identified. Metastasis occurs in ~2.5% of patients with cSCC, most often in the local lymph nodes, and there is some indication that lymph node metastasis has a distinct pattern based on the tumor site. Current findings on tumor molecular targets have suggested the use of systemic treatments, particularly immunotherapy (such as cemiplimab, pembrolizumab and nivolumab), over radiotherapy or chemotherapy for this type of metastasis. However, when used simultaneously with immunotherapy, radiotherapy may be beneficial in the treatment of metastatic HNcSCC by improving the efficacy of immunotherapy. The present review aims to assess the existing literature on metastatic HNcSCC pathways and treatment options, in order to define current and future directions. Notably, there is an urgent need to identify patients who may benefit from local or systemic cancer treatments. The treatment of lymph node metastasis presents a therapeutic challenge and requires comprehensive management.

Podoplanin could be a predictive biomarker of the risk of patients with oral leukoplakia to develop oral cancer: A systematic review and meta-analysis

OBJECTIVES

The aim of this study is to identify and analyze the existing literature on the utility of podoplanin to predict the risk of malignancy development (MD) in patients previously diagnosed with oral leukoplakia (OL).

METHODS

A systematic review and meta-analysis (SRMA) was performed though a search strategy using several electronic databases and a combination of keywords related to podoplanin and MD of OL, until 15 May, 2022 (PROSPERO CRD42022329326). Evaluation of the risk of bias (ROB) was performed using the Quality in Prognosis Studies Tool. The meta-analyses were estimated using fixed-effect models.

RESULTS

From 421 articles, 6 studies were finally included, that enrolled 546 patients with OL, of whom 125 presented with an oral cancer during follow-up (32 to 90 months). Some limitations regarding the ROB were identified mostly related to small sample sizes, short follow-up times, lack of information on covariables in the included studies and lack of accuracy (including sensitivity and specificity). Meta-analysis of 6 studies reveal that high expression of podoplanin carries a pooled hazard ratio (HR) of 3.72 (95% CI, 2.40-5.76; p < 0.00001) for MD without statistical heterogeneity (I2  = 0%, p = 0.53).

CONCLUSION

The results of this SRMA support the role of podoplanin immunohistochemical expression as a potential predictive biomarker to assess the risk of malignancy development in oral leukoplakia.

Proliferative verrucous leukoplakia: a general dental practitioner-focused clinical review

Proliferative verrucous leukoplakia (PVL) is a distinct type of oral leukoplakia which has the potential to enlarge or develop into new areas of leukoplakia coupled with areas of a warty surface texture. PVL is usually diagnosed from the fifth decade onwards and is more common in female patients. The most frequent sites involved tend to be gingivae, followed by buccal mucosa and lateral border of tongue. It is one of the oral potentially malignant conditions with a high risk of malignant transformation. It is important for general dental practitioners (GDPs) to identify such lesions to facilitate referral for further investigation and diagnosis. Management is challenging with long-term monitoring and surgical excision when appropriate; however, PVL tends to recur following surgical excision. This article provides an up-to-date review tailored for GDPs on the present knowledge of PVL and illustrates the management challenges with clinical cases.

Oral leukoplakia classification and staging system with incorporation of differentiated dysplasia

OBJECTIVES

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

PATIENT AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Biomarkers of malignant transformation in oral leukoplakia: from bench to bedside

Oral leukoplakia is a common precursor lesion of oral squamous cell carcinoma, which indicates a high potential of malignancy. The malignant transformation of oral leukoplakia seriously affects patient survival and quality of life; however, it is difficult to identify oral leukoplakia patients who will develop carcinoma because no biomarker exists to predict malignant transformation for effective clinical management. As a major problem in the field of head and neck pathologies, it is imperative to identify biomarkers of malignant transformation in oral leukoplakia. In this review, we discuss the potential biomarkers of malignant transformation reported in the literature and explore the translational probabilities from bench to bedside. Although no single biomarker has yet been applied in the clinical setting, profiling for genomic instability might be a promising adjunct.

Wolf in sheep's clothing - Oral proliferative verrucous leukoplakia: Progression with longitudinal molecular insights

BACKGROUND

Oral proliferative verrucous leukoplakia (OPVL) is a chronic form of oral leukoplakia that progresses to a multifocal disease with confluent, exophytic and proliferative features. The clinical differential diagnosis for OPVL includes frictional keratosis, leukoplakia, chronic hyperplastic candidiasis, squamous papilloma, verrucous hyperplasia, verrucous carcinoma and squamous cell carcinoma. In this study, we aimed to delineate the dynamic changes in molecular signature during OPVL progression. We compare to a cohort of oral cavity keratinizing squamous cell carcinoma (OSCC) patients covering the spectrum of verrucous carcinoma to invasive squamous cell carcinoma including cytologically bland cuniculatum variant.

METHODS

Samples from a large OPVL lesion that exhibited a histopathologic continuum of OPVL progression.

RESULTS

Canonical hotspot TERT promoter mutations were identified in all patients. TERT C228T was dominant and mutually exclusive with TERT C250T. In patients with TERT C250T, there was concurrent PI3 point mutation. TP53 mutations were also consistently found (8/10). At the protein level, p53 was abnormal, with loss of function and gain of function.

CONCLUSIONS

OPVL is a pathology that shows proximity to the gene expression profile of OSCC, highlighting signatures in common that can be important targets for drug treatment, as well as in the development of diagnostic and prognostic strategies for this disease.

Follow-up study of veterans with white and red oral mucosal lesions at Veterans Affairs Dental Clinics

OBJECTIVES

This analysis examined the clinical and histopathological characteristics of white and red oral mucosal lesions and patient lifestyle behaviors to understand how the lesions changed over 19-23 years, including among patients who developed oral and pharyngeal cancer.

MATERIALS AND METHODS

Seventy-five individuals with red and/or white oral mucosal lesions with clinical diagnoses of smokeless tobacco lesions, leukoplakia, erythroplakia, lichen planus, ulcer, and virus-associated lesions were identified in six Veterans Affairs Medical Center Dental Clinics (VAMC) from 1996 to 2001. Biopsy results and patients' sociodemographic, medical, and tobacco/alcohol use characteristics were obtained. Study dentists used standardized forms to capture information about the lesions. Study participants were re-examined at intervals through January 2002. In 2020, a retrospective review of VAMC and public records ascertained whether participants developed oral cancer or died.

RESULTS

The most common red or white oral mucosal lesions among the 75 study participants were leukoplakia (36.0%), smokeless tobacco lesions (26.7%), virus-associated lesions (18.7%), and lichen planus (16.0%). Lesions in 11% of participants with leukoplakia and one-third of participants with lichen planus persisted for 5 years or more. Dysplasia was present in four participants with leukoplakia. Seventeen percent of participants developed a new white or red oral mucosal lesion. Five patients (6.1%) developed oral or pharyngeal cancer, four among participants with leukoplakia (one with prior dysplasia) and one among participants with lichen planus. Four of the cancers developed 6-20 years after enrollment, and only one was at the original lesion site.

CONCLUSIONS

The occurrence of oral and pharyngeal cancers in some study participants with white and red oral mucosal lesions many years after enrollment reinforces the need for patients, dentists, and health care systems to have better methods to identify and assess the malignant potential of oral lesions, monitor patients over time, and intercept high-risk oral lesions before they become cancerous.

Elucidating the Genetic Landscape of Oral Leukoplakia to Predict Malignant Transformation

PURPOSE

Oral leukoplakia is the most common oral potentially malignant disorder with an annual malignant transformation rate of 1% to 5%. Consequently, oral leukoplakia patients have a 30% to 50% lifetime risk to develop oral squamous cell carcinoma. Although risk factors for malignant transformation of oral leukoplakia have been investigated, no definitive risk stratification model has been proposed. Next-generation sequencing can elucidate the genetic landscape of oral leukoplakia, which may be used to predict the risk for malignant transformation.

EXPERIMENTAL DESIGN

We investigated a retrospective cohort of 89 oral leukoplakia patients, and analyzed their oral leukoplakia lesions for the presence of genomic copy-number alterations and mutations in genes associated with oral squamous cell carcinoma.

RESULTS

In 25 of 89 (28%) patients, oral squamous cell carcinoma developed during follow-up. Seventy-nine of 89 (89%) oral leukoplakias harbored at least one genetic event. Copy-number alterations were present in 61 of 89 (69%) oral leukoplakias, most commonly gains of chromosome regions 8q24 (46%) and 20p11 (20%) and loss of 13q12 (19%). Mutations were present in 59 of 89 (66%) oral leukoplakias, most commonly in TP53 (28%), FAT1 (20%), and NOTCH1 (13%). Genetic data were combined with the presence of dysplasia to generate a prediction model, identifying three groups with a distinct risk for malignant transformation.

CONCLUSIONS

We provide an extensive description of genetic alterations in oral leukoplakia and its relation to malignant transformation. On the basis of our data we provide a model for the prediction of malignant transformation of oral leukoplakia using dysplasia and genetic markers.

Salivary miRNAs Expression in Potentially Malignant Disorders of the Oral Mucosa and Oral Squamous Cell Carcinoma: A Pilot Study on miR-21, miR-27b, and miR-181b

(1) Background: Oral potentially malignant disorders (OPMD) represent a fundamental challenge for clinicians, considering the possibility of progression into oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Several studies have examined the expression of miRNAs in humans as diagnostic and prognostic biomarkers. Among these, miR-21, miR-27b, and miR-181b proved to be promising. This cohort study evaluated the different expressions of those miRNAs in the saliva of patients with OPMD and OSCC. (2) Methods: Patients with a clinical diagnosis of OPMD and/or OSCC were enrolled; saliva samples were collected; miRNAs were extracted and quantified via qRT-PCR was performed. Data were analyzed by subgroups based on the histopathological diagnosis (OSCC and the grade of OED) using the ΔΔCt method. Saliva from 10 healthy donors was used as the control. One-way ANOVA and Kruskal-Wallis tests were performed to assess the differences between groups. (3) Results: 23 patients for the OPMD group (6 with no dysplasia, 7 with low-grade, and 10 with high-grade dysplasia) and 10 with OSCC were analyzed. MiR-21 did not show any variation among groups; miR-27b was under-expressed in dysplastic lesions (p = 0.046); miR-181b was upregulated in high-grade dysplasia (p = 0.006), increasing with the degree of dysplasia, and decreasing in OSCCs. (4) Conclusions: Salivary miR-27b and miR-181b could be promising biomarkers for oral dysplasia. Further studies are needed to clarify their feasibility.

Podoplanin Expression Independently and Jointly with Oral Epithelial Dysplasia Grade Acts as a Potential Biomarker of Malignant Transformation in Oral Leukoplakia

Our aim was to evaluate the expression of biomarkers, CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin in oral leukoplakias (OL) and to assess their potential for prediction of malignant transformation (MT). We analyzed the expression of CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin by immunohistochemistry in 52 OL, comprised of 41 low-grade (LG) dysplasia and 11 high-grade (HG) cases. Twelve healthy normal tissues (NT) were also included. Univariate and multivariate analysis were performed to evaluate any association with MT. Variable expression among the studied markers was observed, with a significant increase of high expression from NT to LG and HG cases in CD44v6 (p = 0.002), P53 (p = 0.002), P73 (p = 0.043), and podoplanin (p < 0.001). In multivariate analysis, cases with high podoplanin score showed a significant increased risk of MT (HR of 10.148 (95% CI of 1.503−68.532; p = 0.017). Furthermore, podoplanin combined with binary dysplasia grade obtained a HR of 10.238 (95% CI of 2.06−50.889; p = 0.004). To conclude, CD44v6, p53, p73, and podoplanin showed an increasing expression along the natural history of oral carcinogenesis. Podoplanin expression independently or combined with dysplasia grade could be useful predictive markers of MT in OL.

A Systematic Review of MicroRNA Signatures Associated with the Progression of Leukoplakia with and without Epithelial Dysplasia

Oral cancer is a significant public health issue, being the eighth most common cancer worldwide with over 300,000 cases diagnosed annually. Early diagnosis and adequate management of oral potentially malignant disorders (OPMDs) before transformation into oral squamous cell carcinoma (OSCC) is critical to reduce deaths, morbidity, and to improve overall prognosis. MicroRNAs (miRNAs) are small noncoding RNAs involved in the post-transcriptional regulation of protein expression and implicated in the control of numerous cellular pathways and impacting physiological, developmental, and pathological processes. Dysregulation of miRNAs has been reported in many cancers and has been demonstrated to play a critical role in cancer initiation, progression, apoptosis, invasion and metastasis. This systematic review provides a comprehensive summary of the prevailing literature on miRNA signatures in OPMDs, specifically leukoplakia with or without oral epithelial dysplasia, and their utility in predicting malignant transformation into OSCC. Eighteen articles describing 73 unique and differentially expressed microRNAs met the criteria for inclusion in this review. We reviewed the characteristics and methodology for each of these studies and assessed the sensitivity and specificity of the studied miRNAs in predicting malignant transformation. This systematic review highlights the significant interest in miRNAs and their tremendous potential as prognostic markers for predicting the malignant transformation of OPMDs into OSCC.

Expression of spindle assembly checkpoint proteins BubR1 and Mad2 expression as potential biomarkers of malignant transformation of oral leukoplakia: an observational cohort study

Background

The Spindle Assembly Checkpoint (SAC) is a surveillance mechanism essential to ensure the accuracy of chromosome segregation during mitosis. Our aim was to evaluate the expression of SAC proteins in oral carcinogenesis, and to assess their potential in predicting malignant transformation of oral leukoplakia.

Material and Methods

We analysed the immunoexpression of BubR1, Mad2, Bub3, and Spindly proteins in 64 oral biopsies from 52 oral leukoplakias and 12 normal tissues. Univariate and multivariate analysis were performed to evaluate predictive factors for malignant transformation (MT).

Results

We observed that BubR1 and Mad2 were more highly expressed in high dysplasia grade lesions than in low grade or normal tissues (P<0.05). High expression of Spindly was significantly correlated with a high Ki-67 score (P=0.004). Six (11.5%) oral leukoplakias underwent malignant transformation. In univariate analysis, the binary dysplasia grade (high grade) (P<0.001) was associated with a higher risk of malignant transformation as well as high BubR1 (P<0.001) and high Mad2 (P=0.013) expression. In multivariate analysis, high expression of BubR1 and Mad2 when combined showed an increased risk for malignant transformation (P=0.013; HR of 4.6, 95% CI of 1.4-15.1).

Conclusions

Our findings reveal that BubR1 and Mad2 were associated with an increased risk for malignant transformation independently of histological grade and could be potential and useful predictive risk markers of malignant transformation in oral leukoplakias.

Key words:BubR1, Mad2, Spindly, Bub3, Oral Leukoplakia, epithelial dysplasia, Oral squamous cell carcinoma.

Understanding the complex pathogenesis of oral cancer: A comprehensive review

The pathogenesis of oral cancer is a complex and multifactorial process that requires a deep understanding of the underlying mechanisms involved in the development and progress of malignancy. The ever-improving comprehension of the diverse molecular characteristics of cancer, the genetic and epigenetic alterations of tumor cells, and the complex signaling pathways that are activated and frequently cross talk open up promising horizons for the discovery and application of diagnostic molecular markers and set the basis for an era of individualized management of the molecular defects underlying and governing oral premalignancy and cancer. The purpose of this article is to review the key molecular concepts that are implicated in oral carcinogenesis, especially focusing on oral squamous cell carcinoma, and to review selected biomarkers that play a substantial role in controlling the so-called "hallmarks of cancer," with special reference to recent advances that shed light on their deregulation during the different steps of oral cancer development and progression.

Risk factors for oral epithelial dysplasias to become malignant: clinical implications

There is a lack of effective clinical management of oral epithelial dysplasias to reduce their risk of malignant transformation and considerable gaps in knowledge regarding the most effective means of treating such lesions. A retrospective cohort of biopsy-confirmed oral epithelial dysplasias consecutively diagnosed in the period 1995-2014 and followed-up until 2017 was identified from pathology department files. Demographic, clinical and follow-up information was collected. Multivariate Cox proportional-hazards models were performed to evaluate sociodemographic, clinical and pathological factors associated with progression to oral squamous cell carcinoma. The study included 144 oral epithelial dysplasias, of which 42% progressed to oral cancer at the end of follow-up (21 years). Clinical aspect of the lesion was described for 77 (53.5%) of the patients. Treatment, age, grade of the lesion and diagnostic period were independent prognostic factors for progression. When considering only patients with described clinical aspect, only treatment and grade of the lesion were independently associated with cancer. The results from this non-selected retrospective cohort of oral epithelial dysplasias underscore the existing limitations of the current standard-of-care of the patients and provide novel insights on the management of these lesions with and without described clinical aspect. Well-designed, robust prospective studies, a homogenized staging system and multidisciplinary treatment guidelines are warranted.

An active surveillance program in oral preneoplasia and translational oncology benefit

OBJECTIVE

We desired to establish an active surveillance clinic for head and neck cancer. In this review we examined.

METHODS

We examined the natural history of human oral carcinogenesis, the types of preneoplastic lesions, and efforts at oral chemoprevention over the past decades for presentation here.

RESULTS

We established a clinic and program for patients with oral premalignant lesions approximately over 15 years ago based on an unmetneed for this service. We have completed over 4000 outpatient visits for this cohort and have a place for referrals of difficult oral lesions. We have leveraged this population for multiple federally funded trials on oral cancer prevention as well as specimen banking.

CONCLUSION

There is need for routine active surveillance for oral preneoplastic conditions in patients at high risk for conversion to cancer. There are no effective durable treatment or preventions for these individuals and we have attempted to fill this unmet need with our program.

Prognostic biomarkers for malignant transformation of oral potentially malignant disorders: a scoping review protocol

OBJECTIVE

This scoping review aims to identify and systematically map the available evidence concerning the prognostic biomarkers for malignant transformation of oral potentially malignant disorders (OPMDs), and to identify and analyze possible knowledge gaps in this field of literature.

INTRODUCTION

It is hypothesized that diagnosis and treatment of oral cancer in its early stages may be the key to improving the prognosis and reducing treatment-related consequences. Oral potentially malignant disorders represent tissue alterations with a higher risk of malignant transformation compared to the normal mucosa. Therefore, the study of prognostic biomarkers for OPMD could represent new diagnosis and therapeutic targets and, consequently, contribute to the reduction of oral cancer burden worldwide.

INCLUSION CRITERIA

Longitudinal studies investigating prognostic biomarkers regarding the malignant transformation of OPMD will be included. The initial OPMD diagnosis and the malignant transformation must have been confirmed by histopathological analysis. To achieve minimal heterogeneity, studies that assess biomarkers in other locations (blood, plasma or others) will be excluded.

METHODS

Five electronic databases and three grey literature databases will be consulted. No restrictions regarding publication date will be applied. Only studies published in the Latin (Roman) alphabet, which comprises most of the European languages, will be included. Study selection will be performed by two authors in a two-phase process; if any disagreement arises, a third author will be consulted to make a final decision. Data extraction will be performed by two authors using a standardized extraction tool. The results will be described in details accordantly with the aims of this scoping review.

Recurrence in Oral Premalignancy: Clinicopathologic and Immunohistochemical Analysis

Oral leukoplakia (OL) has a propensity for recurrence and malignant transformation (MT). Herein, we evaluate sociodemographic, clinical, microscopic and immunohistochemical parameters as predictive factors for OL recurrence, also comparing primary lesions (PLs) with recurrences. Thirty-three patients with OL, completely removed either by excisional biopsy or by laser ablation following incisional biopsy, were studied. Selected molecules associated with the STAT3 oncogenic pathway, including pSTAT3, Bcl-xL, survivin, cyclin D1 and Ki-67, were further analyzed. A total of 135 OL lesions, including 97 PLs and 38 recurrences, were included. Out of 97 PLs, 31 recurred at least once and none of them underwent MT, during a mean follow-up time of 48.3 months. There was no statistically significant difference among the various parameters in recurrent vs. non-recurrent PLs, although recurrence was most frequent in non-homogeneous lesions (p = 0.087) and dysplastic lesions recurred at a higher percentage compared to hyperplastic lesions (34.5% vs. 15.4%). Lower levels of Bcl-xL and survivin were identified as significant risk factors for OL recurrence. Recurrences, although smaller and more frequently homogeneous and non-dysplastic compared to their corresponding PLs, exhibited increased immunohistochemical expression of oncogenic molecules, especially pSTAT3 and Bcl-xL. Our results suggest that parameters associated with recurrence may differ from those that affect the risk of progression to malignancy and support OL management protocols favoring excision and close monitoring of all lesions.

A novel lncRNA LOLA1 may predict malignant progression and promote migration, invasion, and EMT of oral leukoplakia via the AKT/GSK-3β pathway

Although dysregulation and dysfunction of long noncoding RNAs (lncRNAs) have been implicated in malignant behavior of oral squamous cell carcinoma (OSCC), whether aberrant lncRNAs play a role in the carcinogenesis of oral leukoplakia (OL) as the best-known precursor of OSCC remains undetermined. Differentially expressed lncRNAs in the occurrence and progression of OL were studied by microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). We found a novel key lncRNA n386251 that we named LOLA1 (lncRNA oral leukoplakia progressed associated 1) in the OL progression. The results of qRT-PCR revealed that LOLA1 aberrant expression was validated in tissue samples and cell lines from the normal oral mucosa, OL to OSCC. Fluorescent in situ hybridization showed that LOLA1 expression localized predominately at the cytoplasm of Leuk1 cells. Cell function assays showed that LOLA1 significantly influenced cell migration, invasion, and epithelial-mesenchymal transition (EMT) protein expression. Potential mechanism experiments revealed that AKT/GSK-3β signaling was involved in the regulatory mechanism of LOLA1 in OL progression. Remarkably, Kaplan-Meier analysis revealed that LOLA1 overexpression could predict malignant events of OL progression to OSCC. In conclusion, the current study for the first time profiled and validated the key lncRNAs related to OL progression. Importantly, we demonstrated that a novel lncRNA LOLA1 upregulation was associated with OL malignant progression, suggesting LOLA1 may be a predictive biomarker. Moreover, LOLA1 may promote migration, invasion, and EMT process in OL malignant progression via AKT/GSK-3β pathway.

Molecular landscape of head and neck cancer and implications for therapy

Head and neck squamous cell carcinomas (HNSCC) arising from the oral cavity, pharynx, and larynx constitute the 6^th most common human cancer. Human papillomavirus (HPV)-positive tumours are distinct from HPV-negative counterparts, with HPV status affording clear clinical utility, prognostic benefit and better treatment outcomes. In contrast to their HPV-positive counterparts, HPV-negative tumours are characterized by high mutational load and chromosomal aberrations, with varying copy number alteration (CNA) profiles. HNSCC are distinct tumours at the chromosomal, gene and expression levels, with additional insight gained from immune profiling. Based on mutational analyses, HNSCC are categorized as HPV-positive, HPV-negative CNA-silent, and HPV-negative CNA-high tumours. Furthermore, gene expression profiling segregates these tumours into atypical, classical, basal, and mesenchymal, with clear differences observed between tumours of the oral cavity, oropharynx, hypopharynx and larynx. Additional immune profiling further classifies tumours as either immune-active or immune-exhausted. The clinical utility and impact of these tumour molecular subtypes however remains to be determined. HNSCC harbor high levels of somatic mutations. They display loss at 3p and 18q and gain at 3q and 8q, with mutations in CDKN2A, TP53, CCND1, EGFR, PIK3CA, PTEN, NOTCH1, NSD1, FAT1, AJUBA and KMT2D. Important pathways include the p53 and RB pathways which are involved in cell cycle control and are frequently lost in HPV-negative tumours, the WNT-β-catenin pathway related to the mesenchymal subtype and smoking etiology, and the PI3K pathway which includes the most common genetic alteration in HPV-positive HNSCC. Understanding the mutational, genomic and transcriptomic landscape of HNSCC has leveraged better therapeutic approaches to manage this group of diseases, and it is hoped that additional insight into the molecular subtypes of HNSCC and its specific subsites will further drive improved strategies to stratify and treat patients with this debilitating disease.

Recurrences following treatment of proliferative verrucous leukoplakia: A systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis were made of the incidence of recurrences in patients with proliferative verrucous leukoplakia (PVL) subjected to different types of treatment.

METHODS

The study was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. A literature search was made in the Medline (PubMed), EMBASE, and Web of Science databases, together with a manual search, covering the period from 1985 to January 2020, with no language restrictions. Studies were included if they described treatments applied to at least 10 patients with the corresponding outcomes. Methodological quality was evaluated using Jadad scale and Newcastle-Ottawa tool. Global incidence was calculated by random effects meta-analysis using the Comprehensive Meta-analysis version 3.0 software. Publication bias was assessed using funnel plots and the Duval and Tweedie trim and fill method.

RESULTS

Of the 922 identified articles, 12 were found to meet the inclusion criteria. Most of them presented moderate or low risk of bias. A total of 397 patients were analyzed. The mean age was 62.34 years and 248 were women (62.5%). The mean follow-up was 79.3 months. The most frequent treatment was surgical removal with a cold scalpel or laser (339 patients). A total of 232 subjects presented lesion recurrence. The combination of proportions global effect meta-analysis yielded a recurrence rate of 67.2% (95% CI: 48.3-81.8), with the absence of publication bias.

CONCLUSIONS

There is not enough scientific evidence to conclude that any treatment strategy is able to reduce the recurrence in PVL.

The role of icIL-1RA in keratinocyte senescence and development of the senescence-associated secretory phenotype

There is compelling evidence that senescent cells, through the senescence-associated secretory phenotype (SASP), can promote malignant transformation and invasion. Interleukin-1 (IL-1) is a key mediator of this cytokine network, but the control of its activity in the senescence programme has not been elucidated. IL-1 signalling is regulated by IL-1RA, which has four variants. Here, we show that expression of intracellular IL-1RA type 1 (icIL-1RA1), which competitively inhibits binding of IL-1 to its receptor, is progressively lost during oral carcinogenesis ex vivo and that the pattern of expression is associated with keratinocyte replicative fate in vitro We demonstrate that icIL-1RA1 is an important regulator of the SASP in mortal cells, as CRISPR/Cas9-mediated icIL-1RA1 knockdown in normal and mortal dysplastic oral keratinocytes is followed by increased IL-6 and IL-8 secretion, and rapid senescence following release from RhoA-activated kinase inhibition. Thus, we suggest that downregulation of icIL-1RA1 in early stages of the carcinogenesis process can enable the development of a premature and deregulated SASP, creating a pro-inflammatory state in which cancer is more likely to arise.

Difficulties in the Prognostic Study of Oral Leukoplakia: Standardisation Proposal of Follow-Up Parameters

Oral leukoplakia is the most prevalent potentially malignant disorder of the oral cavity. To evaluate its potential for malignancy, appropriate documentation of the biological parameters is crucial, allowing the patients' progression to be assessed. We hypothesized a lack of standardization in the parameters employed for the prognostic study of oral leukoplakia; our aims were to determine the different parameters used for follow-up according to definition, importance, and frequency of use, and to provide a standardization proposal of follow-up research. We made a scoping review to identify papers with the keywords “leukoplakia,” “oral,” and “follow-up” published until June 2019 in English, Spanish and Portuguese literature through an online search in PUBMED, SCIELO, and SCOPUS databases. In total, 514 articles were initially identified, and fifty-nine publications were selected, of which 37 were retrospective. The reports included a total of 18,660 patients between 13 and 98 years old, with a mean age of 57.6 years. Tobacco and alcohol habits were positive for 77 and 37% of the patients, respectively. Our results showed that reported leukoplakias were predominantly located on buccal mucosa (40.4%), were homogeneous (60.8%), multiple (59.9%), smaller than 2 cm (74.4%) and histopathologically non-dysplastic (71%). The mean follow-up time was 55 months, with a 13% malignant transformation rate. The categorization and definition of multiple variables were notably diverse. Age, sex, habits (tobacco and alcohol), site, size, distribution, morphology, degree of dysplasia, and evolution were the chosen parameters for our proposal. The current study reflected the lack of consensus found in the literature regarding parameters for diagnosis or follow-up, impacting negatively on clinical and research results. standardization comprises an efficient way to facilitate the prognosis assessment of oral leukoplakia, being beneficial for clinical practice, and enabling better quality information to apply in research.

Tissue biomarkers for predicting the risk of oral cancer in patients diagnosed with oral leukoplakia: A systematic review

OBJECTIVES

We performed a systematic review to evaluate the published biomarkers related to oral leukoplakia (OL), aiming to identify the biomarkers that indicate any future risk of cancer in patients with oral leukoplakia.

METHODS

A search strategy was developed for three main electronic databases: PubMed, Cochrane Library, and EBSCO, and also for Google Scholar, until February 28, 2020. The study selection was performed in a two-phase process aiming at studies assessing tissue biomarkers for "malignant transformation of OL." Risk of bias analysis of included studies was performed using the Quality in Prognosis Studies Tool.

RESULTS

From 3,130 articles initially identified by searching databases, a total of 46 studies were included in this systematic review, with a combined sample of 3,783 patients, of whom 1,047 presented with malignant transformation of a previously diagnosed OL as reported by the authors. The cancer incidence in the whole group was 27.6% (range: 5.4% to 54.1%). The studies were derived from different geographic areas, including Asia (n = 21), Europe (n = 15), North America (n = 9), and Oceania (n = 1). There were 49 different molecular biomarkers evaluated in the 46 included studies: p53 and podoplanin proteins were the most frequently reported, followed by abnormalities at particular chromosomal loci (e.g., LOH). Risk of bias analysis revealed concerns associated with "measurement of prognostic factor," "study confounding" and "statistical analysis and reporting."

CONCLUSIONS

Substantial heterogeneity and lack of standardized reporting of data among the studies were identified. The most promising biomarkers reported to have a significant association with the malignant transformation in OL included podoplanin and chromosomal loci abnormalities. A critical examination of the follow-up studies on OL published so far indicated that tissue biomarkers that could predict the risk of oral cancer in patients with OL are still in a discovery phase.

Leukoplakia and Immunology: New Chemoprevention Landscapes?

Oral potentially malignant disorders (OPMDs) comprise a range of clinical-pathological alterations frequently characterized by an architectural and cytological derangements upon histological analysis. Among them, oral leukoplakia is the most common type of these disorders. This work aims to analyze the possible use of drugs such as immunochemopreventive agents for OPMDs. Chemoprevention is the use of synthetic or natural compounds for the reversal, suppression, or prevention of a premalignant lesion conversion to malignant form. Experimental and in vivo data offer us the promise of molecular prevention through immunomodulation; however, currently, there is no evidence for the efficacy of these drugs in the chemoprevention action. Alternative ways to deliver drugs, combined use of molecules with complementary antitumor activities, diet influence, and better definition of individual risk factors must also be considered to reduce toxicity, improve compliance to the protocol treatment and offer a better individualized prevention. In addition, we must carefully reconsider the mode of action of many traditional cancer chemoprevention agents on the immune system, such as enhancing immunosurveillance and reversing the immune evasion. Several studies emphasize the concept of green chemoprevention as an alternative approach to accent healthy lifestyle changes in order to decrease the incidence of HNSCC.

Molecular, genomic and mutational landscape of oral leukoplakia

Oral leukoplakia (OLK) and its more aggressive clinical variant proliferative verrucous leukoplakia (PVL) remain enigmatic disorders clinically and histopathologically. Despite decades of research into both, there has been only incremental advancement in our understanding of their aetiology and pathogenesis and only minimal improvement in effective management strategies. Currently, no specific prognostic genetic or molecular marker has been reported for leukoplakia. There is, however, an emerging body of evidence characterising the genomic and transcriptomic profile of OLK. Regardless of the significance of cellular and architectural features of OLK and PVL, it is clear from studies reported in this review that new emerging evidence points to the presence of premalignant molecular subtypes of leukoplakia which require further investigation. This up-to-date review explores the contemporary genomic, transcriptomic and mutational landscape of leukoplakia broadly, discusses concepts that may not be widely recognised or accepted and purposefully highlights studies with juxtaposed findings in an effort to challenge dogma. It also highlights the urgent need for a concerted international effort of original collaborative research which will only occur by pooling collective efforts, resources and intellect to define the molecular fingerprint of this enigmatic disorder, in the hope it will better inform diagnosis, stratification and treatment.

Gene expression analysis of autofluorescence margins in leukoplakia and oral carcinoma: A pilot study

OBJECTIVES

Autofluorescence is considered a useful technique in the early detection of oral mucosal alterations. However, its efficacy to discriminate tumor margins is still under debate. The purpose of this pilot study was to confirm the existence of molecular divergence from the center of a lesion compared to white light and autofluorescence (VELscope^TM ) visualized margins in leukoplakia and oral carcinoma.

MATERIALS AND METHODS

Molecular divergence from the center of the lesion to white light and VELscope^TM defined margins was compared in patients with leukoplakia (n = 3) and oral carcinoma (n = 4). Expression profiling of 45 selected genes was performed through custom-made TaqMan arrays. Gene Ontology was used for biological pathway analysis.

RESULTS

Irrespective of pathology, the greatest molecular divergence existed between the center of the lesion and both white light and VELscope^TM margins. VELscope^TM and white light margins were also molecularly distinct in oral carcinoma samples. Indeed, the white light margin retained molecular abnormalities observed in the center of the lesion thus suggesting the existence of a "partially transformed" cell population.

CONCLUSION

Despite the limited low number of patients, our data confirm the benefit of combining autofluorescence with conventional oral examination in identifying surgical margins during biopsy procedures for leukoplakia and oral carcinoma.

DNA aneuploidy with image cytometry for detecting dysplasia and carcinoma in oral potentially malignant disorders: A prospective diagnostic study

BACKGROUND

Current evidence on diagnostic value of aneuploidy with DNA image cytometry (ICM) using brushings for oral potentially malignant disorders (OPMD) is limited by sample size and inconsistent classification criteria of aneuploidy. This study aimed to explore the optimal cut-off values of DNA content and evaluate the diagnostic accuracy of DNA-ICM for detecting dysplasia and/or carcinoma in OPMD.

MATERIALS AND METHODS

A total of 401 consecutive patients with OPMD were enrolled in this prospective diagnostic study. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination respectively.

RESULTS

When the optimal cut-off of at least one aneuploid cell with DNA index (DI) ≥2.3, the area under the curves (AUC) was 0.735 and positive predictive value was 92.7% for detecting dysplasia within OPMD. When the optimal cut-off of at least one aneuploid cell with DI ≥ 3.5, the AUC was 0.851 and negative predictive values was 96.8% for detecting carcinoma within OPMD. Importantly, multivariate analysis revealed that aneuploidy with DI ≥ 2.3 in OPMD was significantly associated with dysplasia risk (adjusted OR, 5.52; 95%CI, 2.90-10.51; P < .001), and aneuploidy with DI ≥ 3.5 in OPMD was strongly associated with malignant risk (adjusted OR, 21.05; 95%CI, 9.34-47.41; P < .001).

CONCLUSIONS

This largest-scale diagnostic study optimized the criteria of aneuploidy cytology for noninvasive detection of oral dysplasia and carcinoma within OPMD. DNA aneuploidy in OPMD was an independent marker that strongly associated with oral dysplasia/carcinoma. Our findings suggest that DNA-ICM may serve as a useful noninvasive adjunctive tool for oral cancer and OPMD screening.

Malignant transformation of oral leukoplakia: a follow-up study

OBJECTIVE

The main objective of the study was to identify the determinants that contribute to the malignant transformation of oral leukoplakia in a group of patients managed in secondary care. A secondary objective was to compare two dysplasia grading systems to determine their utility in assessing the prognosis.

MATERIAL AND METHODS

The cohort consisted of 93 patients diagnosed during the period 2009-2013. The variables recorded and analysed included age and sex, clinical presentation (colour) and severity of oral epithelial dysplasia (OED) scored by the WHO (2005) and the binary grading systems. The planned management included excision of high-grade dysplasia and observation of low-grade dysplasia lesions based on the WHO grading system. Patient factors were transcribed from the pathology records and updated using a questionnaire sent out to the whole group of patients. Data were analysed using χ² test and Kaplan-Meier analysis (P < 0.05).

RESULTS

Complete follow-up data were available for 93 patients. Malignant transformation occurred in 7 patients (7.5%) during a mean follow-up period of 30 months. Among the surgically excised group (n = 51), a recurrence of oral leukoplakia was noted in 16 patients (31%). WHO OED grading (P = 0.02) and the presence of red areas (P = 0.012) were useful in predicting malignant transformation with severe epithelial dysplastic lesions and red and white mixed lesions showing higher rates.

CONCLUSION

Leukoplakias (7.5%) transformed over a mean follow-up period of 30 months. Dysplasia grading and the clinical appearance by colour (mixed white and red) were significant predictors of malignant transformation CLINICAL SIGNIFICANCE: Patients with erythroleukoplakia and those diagnosed with moderate or severe epithelial dysplasia require more intensive interventions as such lesions have a higher risk of developing a malignancy.

Oral potentially malignant disorders: A scoping review of prognostic biomarkers

This scoping review aimed to map evidence regarding biomarkers for malignant transformation of oral potentially malignant disorders (OPMD). Seventy-three longitudinal studies investigating prognostic biomarkers for OPMD malignant transformation were included, encompassing 5612 disorders and 108 biomarkers, of which 72 were investigated by immunohistochemistry. Most biomarkers were assessed in one or two studies, while five (p53, Ki-67, podoplanin, p16, and DNA ploidy) were analyzed in five or more studies. All studies investigating podoplanin (n = 8) reported a significant association between positive/high immunoexpression and malignant transformation. Similarly, all studies assessing DNA ploidy (n = 5) found that aneuploidy or gross genomic aberrations were significantly associated with malignant transformation. Included studies often presented mixed data from different OPMD subtypes, inadequate description of population characteristics, and lack of adjusted analysis for confounding factors. One hundred and eight biomarkers were identified and, from these, podoplanin immunoexpression and DNA ploidy were considered promising candidates for future long-term clinical research.

World Workshop on Oral Medicine VII: Prognostic biomarkers in oral leukoplakia and proliferative verrucous leukoplakia-A systematic review of retrospective studies

OBJECTIVE

To systematically review retrospective studies examining prognostic potentials of candidate biomarkers to stratify malignant progression of oral leukoplakia (OL) and proliferative verrucous leukoplakia (PVL).

MATERIALS AND METHODS

A systematic literature search of PubMed, EMBASE, Evidence-Based Medicine and Web of Science databases targeted literature published through 29 March 2018. Inter-rater agreement was ascertained during title, abstract and full-text reviews. Eligibility evaluation and data abstraction from eligible studies were guided by predefined PICO questions and bias assessment by the Quality in Prognosis Studies tool. Reporting followed Preferred Reporting Items for Systematic Review and Meta-Analysis criteria. Biomarkers were stratified based on cancer hallmarks.

RESULTS

Eligible studies (n = 54/3,415) evaluated 109 unique biomarkers in tissue specimens from 2,762 cases (2,713 OL, 49 PVL). No biomarker achieved benchmarks for clinical application to detect malignant transformation. Inter-rater reliability was high, but 65% of included studies had high "Study Confounding" bias risk.

CONCLUSION

There was no evidence to support translation of candidate biomarkers predictive of malignant transformation of OL and PVL. Systematically designed, large, optimally controlled, collaborative, prospective and longitudinal studies with a priori-specified methods to identify, recruit, prospectively follow and test for malignant transformation are needed to enhance feasibility of prognostic biomarkers predicting malignant OL or PVL transformation.

Screening for oral cancer: Future prospects, research and policy development for Asia

Although the incidence of oral cavity cancer is high among low and middle income countries in Asia where the risk habits (tobacco smoking, tobacco chewing and betel quid use) are common, the benefits for introducing oral cancer screening for the whole population in these countries still remains controversial. It is disappointing, but not surprising that many of studies, without control arms, could not provide a clear answer as to whether screening is effective in reducing mortality or combating rising incidence trends. Only one Indian study that reported a randomized controlled trial (RCT) elucidated that mass screening for high risk groups could significantly reduce the cancer mortality or down-stage cancers detected by screening. Several professional organizations that considered any potential benefits of oral cancer screening remain unconvinced that the current knowledge on its natural history, available tests and interventions to treat potentially malignant disorders satisfy the desirable criteria to recommend organized screening for oral cancer. In this review we discuss advantages and disadvantages for oral cancer screening particularly with reference to high incidence countries in Asia. If screening is undertaken, we propose that it is targeted to high risk groups and to combine screening with education on risky life-styles so that overall incidence can be reduced in the future. Further research on increasing public awarenes and impact of professional education such as e-learning to reduce diagnostic delays, studies on the natural history of oral potentially malignant disorders and cancer, comprehensive tobacco and areca nut cessation programs, developing tools to identify high-risk individuals and high-risk lesions are proposed.

Clincopathological characteristics and treatment outcomes of oral leukoplakia by carbon dioxide laser excision in the elderly patients

Background

Older age is one of the factors associated with malignant transformation of oral leukoplakia (OL). The purpose of this study is to analyze the clincopathological features and treatment outcomes of OL in the elderly patients.

Methods

The demographic data and histopathological results of the patients (age ≥ 65) who received carbon dioxide laser surgery for OL from 2002 to 2017 were analyzed statistically.

Results

There were 53 males and 16 females, with a mean age 71.2 ± 4.9. The follow‐up time was 42.5 ± 35.2 months. In the univariate analysis, morphology, pathology, and area were found to be factors associated with postoperative recurrence. Among these factors, pathology and area were the independent predictive factors for recurrence in the multivariate logistic regression model. Malignant transformation occurred in 8 of 69 patients (11.6%).

Conclusions

The pathological high‐risk dysplasia and area of OL were the two prognostic factors for postoperative recurrence.

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.

Comparative Evaluation of Saliva's Oxidant-Antioxidant Status in Patients with Different Clinicopathological Types of Oral Leukoplakia

Objectives

Despite advancements in the management of oral cancer, the mortality rate associated with it still remains a matter of concern. Early identification and intervention of precursor lesions such as leukoplakia have always been emphasized, as this can drastically improve the scenario. The oxidative stress has been implicated in the pathogenesis of several diseases, including oral cancer. The aim of this study was to evaluate salivary oxidant and antioxidant levels in patients with different clinicopathological stages of oral leukoplakia.

Materials and Methods

An analytical study with case-control study design was conducted. Forty newly diagnosed cases of oral leukoplakia were considered in the case group. The equal number of age- and gender-matched subjects was included in the control study group. Unstimulated whole-saliva supernatant was used to determine the levels of lipid peroxidation, glutathione S-transferase, nitrites, and uric acid using ultraviolet visible spectrophotometer. The statistical comparisons were performed by independent Student's unpaired t test and one-way analysis of variance with post hoc analysis. Correlation analysis was performed among salivary parameters and with baseline variables.

Results

End products of free radical damage and nitrite levels were significantly increased in patients with oral leukoplakia compared to controls. Conversely, levels of glutathione S-transferase and uric acid were significantly decreased in the study group in comparison with healthy subjects. Similar trends were seen along the clinical stages and histopathological grades of leukoplakia.

Conclusion

Elevated levels of reactive species with a concomitant reduction in antioxidants in leukoplakia indicate its potential as an early diagnostic marker.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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