Search

It has long been considered that the oral microbiome is tightly connected to oral health and that dysbiotic changes can be detrimental to the occurrence and progression of dysplastic oral mucosal lesions or oral cancer. Improved understanding of the concepts of microbial dysbiosis together with advances in high‐throughput molecular sequencing of these pathologies have charted in greater microbiological detail the nature of their clinical state. This review discusses the bacteriome and mycobiome associated with oral mucosal lesions, oral candidiasis, and oral squamous cell carcinoma, aiming to delineate the information available to date in pursuit of advancing diagnostic and prognostic utilities for oral medicine. [ABSTRACT FROM AUTHOR]

Objective: Oral leukoplakia is the most common oral potentially malignant disorder. Malignant transformation of oral leukoplakia occurs at an annual rate of 1%–7%. WHO‐defined classic epithelial dysplasia is an important predictor of malignant transformation of oral leukoplakia, but we have previously shown in a proof of concept study that prediction improves by incorporation of an architectural pattern of dysplasia, also coined as differentiated dysplasia. We aimed to analyze this finding in a larger cohort of patients. Method: For this retrospective study 176 oral leukoplakia patients were included. Biopsies for all patients were assessed for the presence of dysplasia and analyzed for cytokeratin 13 and 17 expression. Moreover, the inter‐observer agreement for the diagnosis of differentiated dysplasia was determined. Results: In total, 33 of 176 patients developed oral squamous cell carcinoma during follow‐up. Presence of classic epithelial dysplasia increased cancer risk two‐fold (HR = 2.18, p = 0.026). Lesions without classic epithelial dysplasia could be further risk‐stratified by the presence of differentiated dysplasia (HR = 7.36, p < 0.001). Combined classic epithelial and differentiated dysplasia imparted a seven‐fold increased risk of malignant transformation (7.34, p = 0.001). Inter‐observer agreement for the diagnosis of dysplasia, including differentiated dysplasia, was moderate (κ = 0.56, p < 0.001). Discussion: This study emphasizes the importance of the recognition of the architectural pattern of differentiated dysplasia as a separate entity for risk prediction of malignant transformation of oral leukoplakia. Presence of any pattern of dysplasia results in accurate prediction of malignant transformation risk of oral leukoplakia. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) is amongst the most common cancers, with more than 377,000 new cases worldwide each year. OSCC prognosis remains poor, related to cancer presentation at a late stage, indicating the need for early detection to improve patient prognosis. OSCC is often preceded by a premalignant state known as oral epithelial dysplasia (OED), which is diagnosed and graded using subjective histological criteria leading to variability and prognostic unreliability. In this work, we propose a deep learning approach for the development of prognostic models for malignant transformation and their association with clinical outcomes in histology whole slide images (WSIs) of OED tissue sections. We train a weakly supervised method on OED cases (n = 137) with malignant transformation (n = 50) and mean malignant transformation time of 6.51 years (±5.35 SD). Stratified five‐fold cross‐validation achieved an average area under the receiver‐operator characteristic curve (AUROC) of 0.78 for predicting malignant transformation in OED. Hotspot analysis revealed various features of nuclei in the epithelium and peri‐epithelial tissue to be significant prognostic factors for malignant transformation, including the count of peri‐epithelial lymphocytes (PELs) (p < 0.05), epithelial layer nuclei count (NC) (p < 0.05), and basal layer NC (p < 0.05). Progression‐free survival (PFS) using the epithelial layer NC (p < 0.05, C‐index = 0.73), basal layer NC (p < 0.05, C‐index = 0.70), and PELs count (p < 0.05, C‐index = 0.73) all showed association of these features with a high risk of malignant transformation in our univariate analysis. Our work shows the application of deep learning for the prognostication and prediction of PFS of OED for the first time and offers potential to aid patient management. Further evaluation and testing on multi‐centre data is required for validation and translation to clinical practice. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Objective: To use large‐scale electronic health record (EHR) data to develop machine learning models predicting malignant transformation of oral lesions. Methods: A multi‐institutional health system database was used to identify a retrospective cohort of patients with biopsied oral lesions. The primary outcome was malignant transformation. Chart review and automated system database queries were used to identify a range of demographic, clinical, and pathologic variables. Machine learning was used to develop predictive models for progression to malignancy. Results: There were 2192 patients with a biopsied oral lesion, of whom 1232 had biopsy proven oral dysplasia. There was malignant transformation in 34% of patients in the oral lesions dataset, and in 54% of patients in the dysplasia subset. Multiple machine learning‐based models were trained on the data in two experiments, (a) including all patients with biopsied oral lesions and (b) including only patients with biopsy‐proven dysplasia. In the first experiment, the best machine learning models predicted malignant transformation among the biopsied oral lesions with an area under the curve (AUC) of 86%. In the second experiment, the random forest model predicted malignant transformation among lesions with dysplasia with an AUC of 0.75. The most influential features were dysplasia grade and the presence of multiple lesions, with smaller influences from other features including anemia, histopathologic description of atypia, and other prior cancer history. Conclusion: With diverse features from EHR data, machine learning approaches are feasible and allow for generation of models that predict which oral lesions are likely to progress to malignancy. Level of Evidence: 3 Laryngoscope, 133:1156–1162, 2023 [ABSTRACT FROM AUTHOR]

Introduction: Clinical management of oral potentially malignant disorders relies on accurate histopathological assessment of the presence and grade of oral epithelial dysplasia. While adjunctive laboratory tests have provided useful prognostic information, none are in widespread clinical use. This study was performed to assess the clinical utility of two contemporary oral epithelial dysplasia grading systems. Methods: Patients were identified from a clinical database. Oral epithelial dysplasia grading was performed by three oral and maxillofacial pathologists blinded to clinical outcome using the WHO 2017 system and a binary classification. The primary outcome measure was the development of oral squamous cell carcinoma, termed 'malignant transformation'. Results: One hundred thirty‐one cases satisfied the inclusion criteria, of which 23 underwent malignant transformation. There was substantial inter‐rater agreement between the study pathologists for both grading systems, measured using kappa statistics (κ = 0.753 – 0.784). However, there was only moderate agreement between the consensus WHO 2017 dysplasia grade for the study against the original grade assigned by a pool of six pathologists in the context of the clinical service (κ = 0.491). Higher grade categories correlated with an increased risk of developing cancer using both grading systems. Conclusion: This study demonstrates that the WHO 2017 and binary grading systems are reproducible between calibrated pathologists and that consensus reporting is likely to improve the consistency of grading. The WHO and binary systems were prognostically comparable. We recommend that institutions implement consensus oral epithelial dysplasia grading and prospectively audit the effectiveness of risk stratifying their patients with oral potentially malignant disorders. (249 words). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: To analyse the clinical and histological characteristics from a series of oral leukoplakias, leukoerythroplakias, erythroplakias and actinic cheilitis diagnosed in a 14‐year period. Methods: The files were reviewed and all cases diagnosed as leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis were selected. Clinical information was obtained from the biopsy submission forms, and histological review was performed in all cases. Results: Final sample included 953 lesions, mostly affecting females (534, 56%), and 87.5% of the patients were 41 to 80 years old. The most commonly affected regions were the lower lip (20.1%), tongue (18.1%) and buccal mucosa (16.9%). Leukoplakias, actinic cheilitis, leukoerythroplakias and erythroplakias represented, respectively, 74.6%, 15.2%, 9.3% and 0.8% of the sample. Most cases presented no dysplasia (42.1%) or mild dysplasia (33.5%). Lesions in the tongue, floor of mouth and lower lip, as well as lesions that presented hyperparakeratosis, showed higher frequencies of moderate dysplasia and severe dysplasia/carcinoma in situ. The most common histological criteria were the increase in number and size of nucleoli, loss of polarity of the basal cells and variations in cellular size and shape. Classification by the binary system showed that 7% were high‐risk lesions. Conclusion: All histological criteria for classification of oral epithelial dysplasia recommended by the World Health Organization showed increased frequency as grading increased. Additional criteria seem to be useful in grading oral epithelial dysplasia, such as the presence of normal and abnormal superficial mitotic figures and endophytic epithelial proliferation. [ABSTRACT FROM AUTHOR]

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

The purpose of this systematic review and meta‐analysis was to estimate the overall and type‐specific prevalence of human papillomavirus (HPV) DNA in oral epithelial dysplasia and assess p16INK4a overexpression in relation to HPV‐status. A systematic literature search identified 31 eligible studies (832 cases) evaluating the presence of HPV DNA in oral epithelial dysplasia cases by PCR. Of these, six studies evaluated p16INK4a overexpression in relation to HPV‐status. The overall pooled prevalence of HPV DNA in oral epithelial dysplasia was 27.2% (95% CI: 17.6‐38.1). We observed substantial interstudy heterogeneity, which could not be explained by differences in continent, tissue type, or severity of epithelial dysplasia. HPV16 was the predominant genotype detected. Moreover, 62.2% of HPV positive and 17.8% of HPV negative oral epithelial dysplasia samples stained intensively positive for p16INK4a. This meta‐analysis found that 27% of oral epithelial dysplasia harbor HPV DNA. Whether this represents a transient infection or has a carcinogenic role is unknown. [ABSTRACT FROM AUTHOR]

Aim: The COVID‐19 pandemic has resulted in society experiencing unprecedented challenges for health care practitioners and facilities serving at the frontlines of this pandemic. With regard to oral cancer, there is a complete absence of literature regarding the long‐term impact of pandemics on patients with oral potentially malignant disorders (OPMDs). The objective of this article is to put forth an institutional multidisciplinary approach for the evaluation and management of OPMDs. Methods: A multidisciplinary approach was put formalized within our institution to risk stratify patients based on need for in‐person assessment vs telehealth assessment during the COVID‐19 pandemic. Results: With judicious risk stratification of patients based on clinical features of their OPMD and with consideration of ongoing mitigation efforts and regional pandemic impact, providers are able to safely care for their patients. Conclusions: The COVID‐19 pandemic has required health care practitioners to make novel decisions that are new to us with development of creative pathways of care that focused on patient safety, mitigation efforts, and clinical management of disease processes. The care of patients with OPMDs requires special considerations especially as patients at high risk for severe COVID‐19 illness are also higher risk for the development of OPMDs. [ABSTRACT FROM AUTHOR]

Potentially malignant lesions, commonly referred to as dysplasia, are associated with malignant transformation by mechanisms that remain unclear. We recently reported that increased Wnt secretion promotes the nuclear accumulation of β‐catenin and expression of target genes in oral dysplasia. However, the mechanisms accounting for nuclear re‐localization of β‐catenin in oral dysplasia remain unclear. In this study, we show that endosomal sequestration of the β‐catenin destruction complex allows nuclear accumulation of β‐catenin in oral dysplasia, and that these events depended on the endocytic protein Rab5. Tissue immunofluorescence analysis showed aberrant accumulation of enlarged early endosomes in oral dysplasia biopsies, when compared with healthy oral mucosa. These observations were confirmed in cell culture models, by comparing dysplastic oral keratinocytes (DOK) and non‐dysplastic oral keratinocytes (OKF6). Intriguingly, DOK depicted higher levels of active Rab5, a critical regulator of early endosomes, when compared with OKF6. Increased Rab5 activity in DOK was necessary for nuclear localization of β‐catenin and Tcf/Lef‐dependent transcription, as shown by expression of dominant negative and constitutively active mutants of Rab5, along with immunofluorescence, subcellular fractionation, transcription, and protease protection assays. Mechanistically, elevated Rab5 activity in DOK accounted for endosomal sequestration of components of the destruction complex, including GSK3β, Axin, and adenomatous polyposis coli (APC), as observed in Rab5 dominant negative experiments. In agreement with these in vitro observations, tissue immunofluorescence analysis showed increased co‐localization of GSK3β, APC, and Axin, with early endosome antigen 1‐ and Rab5‐positive early endosomes in clinical samples of oral dysplasia. Collectively, these data indicate that increased Rab5 activity and endosomal sequestration of the β‐catenin destruction complex leads to stabilization and nuclear accumulation of β‐catenin in oral dysplasia. [ABSTRACT FROM AUTHOR]

Background: The prognosis of human cancer depends on the deregulations of many molecular patterns. In recent years, a great interest in the intracellular signaling mechanisms related to nitric oxide (NO)-induced carcinogenesis has appeared, as one of the most preeminent prognostic markers for many types of neoplasms. In this study, we identify the levels of iNOS and nitrotyrosine in the sample of normal oral mucosa (NOM), oral leukoplakia (OL), and oral squamous cell carcinoma (OSCC).Methods: Quantitative polymerase chain reactions (qPCRs) were utilized to detect the NOS2 levels in fresh-frozen tissue samples of NOM (n = 6), OL (n = 20), and OSCC (n = 15). Moreover, the immunohistochemical method was used to examine the levels of iNOS and nitrotyrosine in 85 cases of OSCC (39 cases without metastases and 46 with metastases), 42 cases of OL, and 16 cases of NOM.Results: There are rising tendencies in the iNOS mRNA and protein levels during human oral carcinogenesis. Similar findings were obtained in the nitrotyrosine staining. Furthermore, iNOS and nitrotyrosine immunostaining are associated with several clinical-pathological features of OSCC (site, presence of metastasis, staging, recidivism, and survival).Conclusions: The NO-signaling pathway plays a vital role in the development and progression of human oral dysplastic and neoplastic diseases. Nitrotyrosine was a significant marker for the discrimination of OSCC prognosis and survival. [ABSTRACT FROM AUTHOR]

Background: Oral squamous cell carcinoma (OSCC), which may arise from oral dysplasia, is one of the most prevalent cancers around the world. In recent years, all-trans retinoic acid (ATRA) has shown great potential in cancer treatment. However, the molecular mechanism for the anti-tumor effects of ATRA remains unclear.Materials and Methods: After treated with ATRA, inhibition of cell proliferation of OSCC and oral dysplasia cell lines, CAL27 and DOK, respectively, was analyzed by a Cell Counting Kit-8 (CCK8) assay. The cell cycle arrest, cell apoptosis induction, and PD-L1 expression level were measured by flow cytometry. A small molecular inhibitor was utilized to block STAT3 pathway, and the related proteins expression was measured by Western Blot.Results: The present study demonstrated that ATRA inhibited cell proliferation at 5-75 μmol/L, arrested cell cycle at S and G2-phase, induced apoptosis effect in OSCC, and oral dysplasia cell line, CAL27 and DOK, respectively. ATRA led to inhibition of p-STAT3, p-JAK2, increased the level of p-ERK, and significantly decreased the PD-L1 expression. Moreover, targeting STAT3 signaling increased (P < .001) the level of cleaved caspase-3 and effectively (P < .001) decreased the expression of cyclin A2 and PD-L1. The effect of ATRA on cell growth inhibition, apoptosis induction, and PD-L1 expression decrease was significantly (P < .05) enhanced after the STAT3 signaling blockade.Conclusion: These findings suggested that ATRA-induced anti-tumor effects and downregulated PD-L1 expression via STAT3 signaling inhibition in both OSCC and oral dysplasia. [ABSTRACT FROM AUTHOR]

Background: Oral mucosal dysplasia is a histologic feature of potentially malignant disorders that is associated with the risk of transformation to carcinoma. Dysplastic cells use many strategies during their transformation to cancer, including escape from the immune mediated destruction. We hypothesized that adaptive immunity is inhibited by activation of distinct immune checkpoint molecules, such as indoleamine 2,3-dioxygenase 1 (IDO1) and programmed death-ligand 1 (PD-L1).Methods: We collected 63 oral dysplasia samples from 47 patients. Nine biopsies from alveolar mucosa were taken during wisdom teeth extractions were used as healthy controls. Tissue samples were stained and scored for IDO1 and PD-L1. Additionally, dysplasia grades and inflammatory cell infiltration were evaluated. Eight patients were followed up to 36 months to evaluate dysplasia progression, inflammation, and immune checkpoint molecules expression.Results: Dysplastic epithelium had significantly lower IDO1 expression than that of healthy controls. PD-L1 positive cells in the lamina propria were mainly in dysplastic samples and seldom in healthy controls. Dysplasia grade was associated negatively with epithelium IDO1 and positively with IDO1 and PD-L1 expression in the lamina propria. There was a positive association between dysplasia grade and level of inflammatory cell infiltration. During follow-up, dysplasia grade, inflammatory cell infiltration, and the immune checkpoint expression fluctuated over time.Conclusions: Immune checkpoint molecules IDO1 and PD-L1 are modulated during oral epithelial dysplastic changes, and their expression is associated with inflammatory cell infiltration in the lamina propria. As immune checkpoint molecules expression fluctuates over time, these molecules are not useful as biomarkers for oral mucosal dysplasia progression. [ABSTRACT FROM AUTHOR]

Abstract: Background: Smoking and alcohol increase the risk of head and neck cancer and affect treatment outcomes. Interventions modifying these behaviors may improve posttreatment outcomes and survival. We systematically reviewed evidence of the effectiveness of smoking/alcohol interventions in head and neck cancer and oral dysplasia. Methods: The AMED, CINAHL, Embase, MEDLINE, and Web of Science databases were searched for randomized controlled trials (RCTs) of smoking/alcohol interventions in people with head and neck cancer. A qualitative synthesis of the studies was conducted. Results: Three RCTs were identified: 2 smoking interventions and 1 smoking and alcohol intervention. One intervention, which was comprised of a smoking intervention based on Cognitive Behavioral Therapy and pharmacologic management compared to usual care, reduced smoking prevalence. Conclusion: Further research is required into the underlying mechanisms that lead to cessation and interventions that include both pharmacological and behavioral therapy. Future RCTs should include suitable control conditions and sufficient power to assess clinical outcomes. [ABSTRACT FROM AUTHOR]

ABSTRACT Optical diagnosis techniques offer several advantages over traditional approaches, including objectivity, speed, and cost, and these label-free, noninvasive methods have the potential to change the future workflow of cancer management. The oral cavity is particularly accessible and, thus, such methods may serve as alternate/adjunct tools to traditional methods. Recently, in vivo human clinical studies have been initiated with a view to clinical translation of such technologies. A comprehensive review of optical methods in oral cancer diagnosis is presented. After an introduction to the epidemiology and etiological factors associated with oral cancers currently used, diagnostic methods and their limitations are presented. A thorough review of fluorescence, infrared absorption, and Raman spectroscopic methods in oral cancer diagnosis is presented. The applicability of minimally invasive methods based on serum/saliva is also discussed. The review concludes with a discussion on future demands and scope of developments from a clinical point of view. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2403-E2411, 2016 [ABSTRACT FROM AUTHOR]

Precancerous lesions have been studied because of their carcinogenic potential and their association with squamous cell carcinoma (SCC) has been reported. In the tumour microenvironment, the processes of angiogenesis and tissue remodelling are regulated by a family of proteins (Hedgehog) described as being able to modulate epithelial/mesenchymal interactions. The objective of this study was to perform a comparative study of precancerous lesions and SCCs by immunohistochemistry for the presence of Sonic, Gli2, SMO and Patched proteins, members of the Hedgehog pathway. Sixteen cases diagnosed as actinic cheilitis associated with SCC were compared to normal oral mucosa. The sections were subjected to immunohistochemistry and the positively stained cells were counted by morphometric analysis. There was a significant progressive increase in expression of all proteins of the Hedgehog pathway, both in the epithelium and in the connective tissue, when sections of normal mucosa, dysplasia and carcinoma were compared (P < 0.05). Thus, one may suggest that the Hedgehog pathway in tumour transformation influences SCC, and more studies should be conducted to expand the understanding of the role of these proteins in neoplastic transformation. [ABSTRACT FROM AUTHOR]

Objectives: Diagnostic delay in oral oncology could be improved if general dentists had a reliable and easy‐to‐use first‐level diagnostic test to rule out the presence of oral dysplasia or carcinoma. Microbiopsy has been proved to have high sensitivity and high negative predictive value in a clinical setting characterized by high prevalence of disease. Moreover, it has been proved to be easily performed by general dentists. This study aimed to determine the negative predictive value of microbiopsy in routine dental practice: a clinical setting characterized by low prevalence of disease. Methods: Within the frame of a previous study, general dentists from the Metropolitan Area of Turin performed microbiopsy for each oral mucosal lesion detected during their practice. The clinical outcome of 129 lesions negative at microbiopsy was checked by a query performed through the database of the Piedmont Cancer Registry, covering the population of the Metropolitan Area of Turin, with particular reference to cancer involving the mouth (ICD‐10:C03‐06). This allowed us to define “true negative” cases and to calculate the negative predictive value of microbiopsy. Results: In a mean follow‐up of 7.5 years (range 7–9 years), with a dropout rate of 7.7%, no case of tumour involving the mouth was observed, thus revealing a negative predictive value approaching 100%. Conclusions: Microbiopsy represents an easy‐to‐use and reliable first‐level test able to aid general dentists to select patients requiring an oral medicine assessment in a short time and definitely to avoid diagnostic delay in oncologically relevant oral mucosal lesions. [ABSTRACT FROM AUTHOR]

Background When used in oral medicine clinics, microbiopsy is able to obtain tissue fragments suitable for a highly sensitive first-level diagnosis of dysplastic/malignant alterations in oral mucosal lesions. If feasible by general dentists, this sampling technique could reduce the diagnostic delay for oral malignant and premalignant lesions. This study assesses the adequacy of microbiopsy samples when taken by general dentists. Methods Fifty dentists, without specific training on oral medicine, volunteered for enrolment. They were given brief training and asked to prospectively sample any mucosal lesion observed during their routine practice. The sample adequacy features were assessed. Results The dentists sampled 152 lesions; there were 92.1% of adequate samples (140/152), and the BMZ was visible in 78.6% of these (110/140). Neither the clinical aspect nor lesion site affected either the adequacy or the presence of BMZ. Conclusions The high adequacy rate observed and the advantages histological specimens have over cytological ones go to support the feasibility of microbiopsy taken by general dentists for the characterization of oral mucosal lesions and in selecting those requiring further assessment in specialized oral medicine centres. [ABSTRACT FROM AUTHOR]

Background Human papilloma virus is a risk factor for oropharyngeal cancer. Evidence for a similar aetiological role in the development of oral dysplasia or its transformation to oral cancer is not as clear. Meta-analyses estimate the prevalence of high-risk human papilloma virus ( HPV) serotypes to be three times higher in pre-malignant lesions and cancer than in normal oral mucosa. However, this does not imply a causal relationship. Conflicting results are reported from the few studies examining the prognostic significance of HPV positivity in the development of oral cancer. We aimed to examine the ability of p16 INK4a protein expression, a surrogate marker of HPV infection, to predict malignant progression in a large cohort of oral dysplasia patients. Methods One hundred forty eight oral dysplasia cases underwent immunohistochemical analysis using a monoclonal antibody against p16 INK4a. Clinical factors were also collated on each case. Slides were double scored independently by two trained observers. Univariate analyses using both logistic and Cox regression models were performed. Results Thirty nine of 148 cases progressed to cancer. Ten of 148 cases (7%) were p16 INK4a positive. High grade of dysplasia ( P = 0.0002) and lesion morphology ( P = 0.03) were found to be prognostic of malignant progression. p16 INK4a score was not prognostic in this cohort ( P = 0.29). This did not change with a time to event analysis ( P = 0.24). Conclusion Few studies have assessed the aetiological role of HPV in cancer development from dysplastic lesions. Our study, using one of the largest cohorts of oral dysplasia, demonstrated a low rate of p16 INK4a positivity and was unable to confirm a prognostic ability for this biomarker. [ABSTRACT FROM AUTHOR]

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E-cadherin in oral squamous cell carcinoma ( OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E-cadherin proteins in paraffin-embedded specimens of oral leukoplakia ( OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double-immunofluorescence analysis of Twist and E-cadherin expression in OSCC cell lines. Significant differences in Twist and E-cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia ( r = −0,512; P < 0.001). Western blot and double-immunofluorescence analysis showed differences in Twist and E-cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E-cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E-cadherin in the prediction of risk of oral epithelium malignant transformation. [ABSTRACT FROM AUTHOR]

With the unreliability of epithelial dysplasia as a predictor to determine the risk of future malignant development, subjectivity associated in evaluating clysplasia by pathologists and paucity of biomarkers that could accurately predict the progression risks in oral potentially malignant disorders (PMDs), eradication of the lesions appears to be the most desirable approach to minimize the risk of invasive cancer formation. Interventions, such as surgery and chemoprevention, have not shown promising long-term results in the treatment of these lesions, and lack of guidelines and general consensus on their management has incited much anxiety and doubts in both patients and community clinicians. Topical photoclynamic therapy (PDT) is a minimally invasive and minimally toxic technique that in recent years has shown great promise in the management of PMDs. In this review, we describe the historical developments in the field of PDT, its basic mechanisms, as well as related clinical studies, and its challenges in the management of oral PMDs. Based on its high efficacy and low side effects, its high patient acceptance/compliance, the simplicity of the procedure and its minimal pretreatment preparation, topical PDT is believed to have potential to play an important role in the management of PMDs, especially of the low-grade dysplasia. [ABSTRACT FROM AUTHOR]

Molecular markers for predicting oral cancer development in premalignant oral leukoplakia (OL) are urgently needed. The objective of this study was to examine the expression patterns of cancer stem cell markers ALDH1 and CD133 in samples from patients with OL, and determine their prognostic values for subsequent development of oral cancer. Immunohistochemistry for ALDH1 and CD133 was performed in samples from a cohort of 141 patients with biopsy-proven OL who received a mean follow-up of 5.5 years. Patient clinicopathologic and follow-up data were analyzed. Expression of ALDH1 and CD133 was observed in 54 (38.3%) and 32 (22.7%) of 141 patients with OL, respectively. Kaplan-Meier analysis showed that 48.1% patients with ALDH1-positivity developed oral cancer compared with 12.6% those with ALDH1-negativity ( p < 0.001). Meanwhile, 59.4% patients with CD133-positivity developed oral cancer compared with 16.5% those with CD133-negativity ( p < 0.001). Multivariate analysis revealed that ALDH1 and CD133 expression was associated with 4.17-fold [95% confidence interval (CI), 1.96-8.90; p < 0.001] and 2.86-fold (95% CI, 1.48-5.55; p = 0.002) increased risk of OL transformation, respectively. Collectively, these data demonstrated for the first time that the expression of ALDH1 and CD133 correlated with malignant transformation in a large series of patients with OL who received a long-term follow-up, which suggests that they may serve as predictors to identify OL with a high risk of oral cancer development. [ABSTRACT FROM AUTHOR]

Background Laser-induced autofluorescence (LIAF) and diffuse reflectance (DR) were collectively used in this clinical study to improve early oral cancer diagnosis and tissue grading. Methods LIAF and DR emission from oral mucosa were recorded on a fiber-optic spectrometer by illumination with a 404-nm diode laser and tungsten halogen lamp in 36 healthy volunteers and 40 lesions of 20 patients. Results Absorption dips in LIAF spectra at 545 and 575 nm resulting from changes in oxygenated hemoglobin were corrected using DR spectra of the same site. These corrected spectra were curve-fitted using Gaussian spectral functions to determine constituent emission peaks and their relative contribution. The Gaussian peak intensity and area ratios F500/F635 and F500/F685 were found to be useful indicators of tissue transformation. The diagnostic capability of various ratios in differentiating healthy, hyperplastic, dysplastic, and squamous cell carcinomas (SCCs) were examined using discrimination scatterplots. Conclusions The LIAF/DR technique, in conjunction with curve-fitting, differentiates different grades of dysplasia and SCC in this clinical trial and proves its potential for early detection of oral cavity cancer and tissue grading. © 2009 Wiley Periodicals, Inc. Head Neck, 2010 [ABSTRACT FROM AUTHOR]

An oral examination for the assessment for malignant and potentially malignant oral mucosal lesions is routine in general dental practice. It may be uncommon for general dental practitioners to encounter oral cancer, with anecdotal reports suggesting that this occurs about once every 10 years in a busy general dental practice. However, potentially malignant oral mucosal lesions are relatively common, occurring in about 2.5% of the population. This update highlights the epidemiology, risk factors, diagnosis and management of these oral mucosal lesions. [ABSTRACT FROM AUTHOR]

Background: The epithelial cell adhesion molecule (Ep-CAM) is involved in cell signaling, migration, proliferation, cell-cycle regulation, and cancer metastasis. Methods: This study used an immunohistochemical technique to examine the expression of Ep-CAM protein in 84 specimens of oral squamous cell carcinoma (OSCC), 98 specimens of oral epithelial dysplasia (OED, 31 mild, 41 moderate, and 26 severe OED cases), and 15 specimens of normal oral mucosa (NOM). Results: We found that the mean Ep-CAM labeling indices (LIs) decreased significantly from NOM (80 ± 18%) and mild OED (76 ± 14%) through moderate OED (66 ± 22%) and severe OED (55 ± 20%) to OSCC samples (46 ± 16%, P < 0.001). A significant correlation was found between the lower mean Ep-CAM LI and OSCCs with larger tumor size ( P = 0.003), positive lymph node metastasis ( P = 0.022), more advanced clinical stages ( P < 0.001), cancer recurrence ( P = 0.021), or extracapsular spread of lymph node ( P = 0.015). However, only Ep-CAM LI < 50% ( P < 0.0001) was identified as an independent unfavorable prognosis factor by multivariate analyses with Cox proportional hazard regression model. Kaplan–Meier curve showed that OSCC patients with an Ep-CAM LI < 50% had a significantly poorer cumulative survival than those with an Ep-CAM LI ≥ 50% ( P < 0.00001, log-rank test). Conclusions: We conclude that the decreased expression of Ep-CAM protein is an early event in oral carcinogenesis. The Ep-CAM LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients. [ABSTRACT FROM AUTHOR]

Background: Overexpression of hypoxia-inducible factor-1α (HIF-1α) has been found to be significantly associated with the tumor invasion, lymph node metastasis, clinical stage, and prognosis of a variety of human cancers. Methods: This study examined the expression of HIF-1α in 57 specimens of oral squamous cell carcinoma (OSCC), 41 specimens of oral epithelial dysplasia (OED, 12 mild, 17 moderate, and 12 severe OED cases), and 14 specimens of normal oral mucosa (NOM) by immunohistochemistry. Results: We found that the mean nuclear HIF-1α labeling indices (LIs) increased significantly from NOM (9 ± 6%) through mild OED (25 ± 18%), moderate OED (41 ± 27%), and severe OED (42 ± 22%) to OSCC samples (55 ± 23%, P < 0.001). A significant correlation was found between the higher mean nuclear HIF-1α LI and OSCCs with larger tumor size ( P < 0.001), regional lymph node metastasis ( P < 0.001), or more advanced clinical stages ( P < 0.001). Only larger tumor size ( P = 0.002) and nuclear HIF-1α LI ≥ 60% ( P = 0.048) were identified as independent unfavorable prognosis factor by multivariate analyses with Cox regression model. Kaplan–Meier curve showed that OSCC patients with a nuclear HIF-1α LI ≥ 60% had a significantly poorer cumulative survival than those with a nuclear HIF-1α LI < 60% (log-rank test, P = 0.022). Conclusions: We conclude that the expression of HIF-1α is an early event in oral carcinogenesis. The nuclear HIF-1α LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients. [ABSTRACT FROM AUTHOR]

Objective: Even though diagnostic oral exfoliative cytology is a useful, economical and practical tool in the diagnosis of oral dysplasia and carcinoma, it is not yet extensively used. The results of conventional exfoliative and liquid-based diagnostic cytology in oral potentially malignant lesions (PML) are herein reported and compared with the histological diagnosis. Methods: Either conventional (89) or liquid-based (384) exfoliative cytology was used for the diagnosis of oral dysplasia/carcinoma in 473 subjects and the results were compared with scalpel biopsy histology. Cells were collected using a Cytobrush device for conventional smears and with a dermatological curette for the liquid-based cytology. The ‘curette technique’ also allowed for the collection of ‘accidental’ tissue fragments, utilized as microbiopsies. Results: Histological diagnosis was squamous carcinoma in 96 of 473 cases, high-grade dysplasia (oral intraepithelial neoplasia two to three) in 24 and other lesions in 353 cases. The smears in the conventional cytology group were inadequate in 12.4%, with an 85.7% sensitivity and a 95.9% specificity. There were 8.8% of inadequate specimens in the liquid-based cytology group; sensitivity was 95.1% and specificity was 99.0%. Conclusions: Although conventional cytology is useful when diagnosing oral PML (better sensitivity and predictive positive value if compared with the cervical smear test with similar specificity) and can improve the accuracy of histological diagnosis, liquid-based cytology gives better results, as it not only enhances both sensitivity and specificity, but also provides material for further investigation (AgNORs, DNA, microbiopsies, etc.). [ABSTRACT FROM AUTHOR]

Background: Collagen XVIII is a ubiquitous basement membrane (BM) component and a precursor of endostatin. Methods: Using immunohistochemistry and in situ hybridization, we studied the expression and localization of collagen XVIII in different stages of normal oral wound healing, epithelial dysplasia and squamous cell carcinoma (SCC). Results: In mild epithelial dysplasias collagen XVIII appeared as a continuous signal in the BM, whereas in severe epithelial dysplasias and in the invasive areas of oral SCCs collagen XVIII was absent. In situ hybridization showed that collagen XVIII mRNA expression did not decrease in severe dysplasia or oral carcinoma samples when compared with the mild dysplasias. Conclusions: The results indicate that the absence of collagen XVIII protein in severe oral dysplasias is related to the processing of the protein rather than to changes in mRNA expression. [ABSTRACT FROM AUTHOR]

Abstract. Accurate, predictive assessment of the behaviour and progression of oral cancers and precancers remains elusive in clinical practice. Archival tissue specimens from 10 previously treated patients with oral lesions of known clinical outcome (3 years post-treatment) were re-examined histopathologically, and proliferative cell labelling indices (LIs) determined for Ki67, cyclin A and histone mRNA cell cycle markers. While histone mRNA labelling ultimately proved unreliable, both Ki67 and cyclin A LIs demonstrated a clear trend for enhanced labelling to occur in increasingly dysplastic and neoplastic tissue, with particular emphasis on suprabasal labelling in abnormal tissue. Perhaps of greatest significance was the observation of increased LIs and suprabasal labelling in lesions with poor clinical outcome, such as patients developing recurrent disease or cervical lymph node metastasis. Measurement of cell proliferative activity in individual oral epithelial dysplastic lesions or invasive squamous cell carcinomas may thus provide unique, predictive information on clinical outcome. [ABSTRACT FROM AUTHOR]

This study investigated the immunohistochemical expression of human placental glutathione S-transferase (GST-π) in the epithelium of oral premalignant and malignant lesions. Epithelial lining of normal oral mucosa, hyperplastic lesions and oral epithelium exhibiting mild dysplasia showed weak to moderate GST-π staining. Moderate epithelial dysplasia revealed an increased antibody content while severe dysplasia, carcinoma-in-situ (CIS) and squamous cell carcinoma (SCC) demonstrated markedly increased antibody binding. The GST-π staining was evident mainly in the cytoplasm. Severe dysplasia, CIS and SCC were also characterized by areas by cells with intensive nuclear GST-π staining. These findings support the hypothesis that GST-π plays a role in human oral carcinogenesis and may be used as a tumor marker for human oral premalignant and malignant lesions. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide, and new protocols for routine and early detection are required. Raman spectroscopy is an optical based method that can provide sensitive and non‐invasive real time detailed information on the biochemical content of a sample like saliva, through the unique vibrations of its constituent molecules and this is sensitive to changes associated with disease. A comprehensive systematic review of the available scientific literature related to Raman spectroscopy of human saliva for diagnosis of OSCC was performed. The 785 nm laser line was most applied wavelength along with principal components analysis associated with linear discriminant analysis. The main salivary components possibly associated with the presence of OSCC were proteins and lipids. Measurement in the liquid physical state, and with no addition of nanoparticles for signal enhancement, seemed to best conserve the salivary integrity. However, in terms of sampling protocols, no differentiation was generally made between stimulated and non‐stimulated saliva. Raman spectroscopy of saliva holds a promising future for clinical applications such as early detection of OSCC. However, more systematic analyses are still required for a better elucidation regarding sampling procedure, storage and degradation. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinomas (OSCC) often arise from dysplastic lesions. The role of cancer stem cells in tumour initiation is widely accepted, yet the potential existence of pre-cancerous stem cells in dysplastic tissue has received little attention. Cell lines from oral diseases ranging in severity from dysplasia to malignancy provide opportunity to investigate the involvement of stem cells in malignant progression from dysplasia. Stem cells are functionally defined by their ability to generate hierarchical tissue structures in consortium with spatial regulation. Organotypic cultures readily display tissue hierarchy in vitro; hence, in this study, we compared hierarchical expression of stem cell-associated markers in dermis-based organotypic cultures of oral epithelial cells from normal tissue (OKF6-TERT2), mild dysplasia (DOK), severe dysplasia (POE-9n) and OSCC (PE/CA P J15). Expression of CD44, p75NTR, CD24 and ALDH was studied in monolayers by flow cytometry and in organotypic cultures by immunohistochemistry. Spatial regulation of CD44 and p75NTR was evident for organotypic cultures of normal (OKF6-TERT2) and dysplasia (DOK and POE-9n) but was lacking for OSCC (PE/CA PJ15)-derived cells. Spatial regulation of CD24 was not evident. All monolayer cultures exhibited CD44, p75NTR, CD24 antigens and ALDH activity (ALDEFLUOR® assay), with a trend towards loss of population heterogeneity that mirrored disease severity. In monolayer, increased FOXA1 and decreased FOXA2 expression correlated with disease severity, but OCT3/4, Sox2 and NANOG did not. We conclude that dermis-based organotypic cultures give opportunity to investigate the mechanisms that underlie loss of spatial regulation of stem cell markers seen with OSCC-derived cells. [ABSTRACT FROM AUTHOR]

Background: Human papilloma virus is a risk factor for oropharyngeal cancer. Evidence for a similar aetiological role in the development of oral dysplasia or its transformation to oral cancer is not as clear. Meta-analyses estimate the prevalence of high-risk human papilloma virus (HPV) serotypes to be three times higher in pre-malignant lesions and cancer than in normal oral mucosa. However, this does not imply a causal relationship. Conflicting results are reported from the few studies examining the prognostic significance of HPV positivity in the development of oral cancer. We aimed to examine the ability of p16(INK4a) protein expression, a surrogate marker of HPV infection, to predict malignant progression in a large cohort of oral dysplasia patients., Methods: One hundred forty eight oral dysplasia cases underwent immunohistochemical analysis using a monoclonal antibody against p16(INK4a) . Clinical factors were also collated on each case. Slides were double scored independently by two trained observers. Univariate analyses using both logistic and Cox regression models were performed., Results: Thirty nine of 148 cases progressed to cancer. Ten of 148 cases (7%) were p16(INK4a) positive. High grade of dysplasia (P = 0.0002) and lesion morphology (P = 0.03) were found to be prognostic of malignant progression. p16(INK4a) score was not prognostic in this cohort (P = 0.29). This did not change with a time to event analysis (P = 0.24)., Conclusion: Few studies have assessed the aetiological role of HPV in cancer development from dysplastic lesions. Our study, using one of the largest cohorts of oral dysplasia, demonstrated a low rate of p16(INK4a) positivity and was unable to confirm a prognostic ability for this biomarker., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E-cadherin in oral squamous cell carcinoma (OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E-cadherin proteins in paraffin-embedded specimens of oral leukoplakia (OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double-immunofluorescence analysis of Twist and E-cadherin expression in OSCC cell lines. Significant differences in Twist and E-cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia (r = -0,512; P < 0.001). Western blot and double-immunofluorescence analysis showed differences in Twist and E-cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E-cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E-cadherin in the prediction of risk of oral epithelium malignant transformation., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)