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

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

Exploring the microbiome of oral epithelial dysplasia as a predictor of malignant progression.

A growing body of research associates the oral microbiome and oral cancer. Well-characterized clinical samples with outcome data are required to establish relevant associations between the microbiota and disease. The objective of this study was to characterize the community variations and the functional implications of the microbiome in low-grade oral epithelial dysplasia (OED) using 16S rRNA gene sequencing from annotated archival swabs in progressing (P) and non-progressing (NP) OED. We characterised the microbial community in 90 OED samples - 30 swabs from low-grade OED that progressed to cancer (cases) and 60 swabs from low-grade OED that did not progress after a minimum of 5 years of follow up (matched control subjects). There were small but significant differences between P and NP samples in terms of alpha diversity as well as beta diversity in conjunction with other clinical factors such as age and smoking status for both taxa and functional predictions. Across all samples, the most abundant genus was Streptococcus, followed by Haemophilus, Rothia, and Neisseria. Taxa and predicted functions were identified that were significantly differentially abundant with progression status (all Ps and NPs), when samples were grouped broadly by the number of years between sampling and progression or in specific time to progression for Ps only. However, these differentially abundant features were typically present only at low abundances. For example, Campylobacter was present in slightly higher abundance in Ps (1.72%) than NPs (1.41%) and this difference was significant when Ps were grouped by time to progression. Furthermore, several of the significantly differentially abundant functions were linked to the Campylobacteraceae family in Ps and may justify further investigation. Larger cohort studies to further explore the microbiome as a potential biomarker of risk in OED are warranted.

Influence of fluorescence on screening decisions for oral mucosal lesions in community dental practices.

BACKGROUND: Quality of oral screening examinations is dependent upon the experience of the clinician and can vary widely. Deciding when a patient needs to be referred is a critical and difficult decision for general practice clinicians. A device to aid in this decision would be beneficial. The objective of this study was to to examine the utility of direct fluorescence visualization (FV) by dental practitioners as an aid in decision-making during screening for cancer and other oral lesions. METHODS: Dentists were trained to use a stepwise protocol for evaluation of the oral mucosa: medical history, head, neck and oral exam, and fluorescent visualization exam. They were asked to use clinical features to categorize lesions as low (LR), intermediate (IR), or high (HR) risk and then to determine FV status of these lesions. Clinicians made the decision of which lesions to reassess in 3 weeks and based on this reassessment, to refer forward. RESULTS: Of 2404 patients screened over 11 months, 357 initially had lesions with 325 (15%) identified as LR, 16 (4.5%) IR, and 16 (4.5%) HR. Lesions assessed initially as IR and HR had a 2.7-fold increased risk of FV loss persisting to the reassessment appointment versus the LR lesions. The most predictive model for lesion persistence included both FV status and lesion risk assessment. CONCLUSION: A protocol for screening (assess risk, reassess, and refer) is recommended for the screening of abnormal intraoral lesions. Integrating FV into a process of assessing and reassessing lesions significantly improved this model.

Controversies regarding oral lichen planus and lichenoid-dysplastic lesions.

Objective: Oral lichen planus (OLP) is an immune-mediated condition featuring chronic inflammation. The World Health Organization classifies OLP as potentially malignant, but it is believed that the malignant transformation of OLP occurs in lesions with both lichenoid and dysplastic features (LD). This review discusses the issues surrounding OLP and LD, including their malignancy, classification, and categorization, and whether lichenoid inflammation causes dysplastic changes in LD or vice versa. Methods: English full-text literature on OLP, LD and/or dysplasia was retrieved from PubMed, CINAHL, and Google Scholar. Results: Thirty-six publications including original research articles, reviews, meta-analyses, books, reports, letters, and editorials were selected for review. Discussion: Research suggests that OLP has malignant potential, although small, and that LD should not be disregarded, as dysplasia presenting with or without lichenoid features may develop into cancer. There is also disagreement over the classification and categorization of LD. Different terms have been used to classify these lesions, including lichenoid dysplasia, OLP with dysplasia, and dysplasia with lichenoid features. Moreover, in LD, it is not clear if dysplasia or lichenoid infiltration appears first, and if inflammation is a response to dysplasia or if dysplasia is a response to the persistent inflammation. The main limitation in the literature is the inconsistency and subjective nature of histological diagnoses, which can lead to interobserver and intraobserver variation, ultimately resulting in the inaccurate diagnosis of OLP and LD. Conclusion: Although further research is required to understand OLP and LD, both lesions should be considered potentially malignant and should not be disregarded.

Objectif: Le lichen plan buccal (LPB) est une pathologie auto-immune qui se présente sous la forme d'une inflammation chronique. Selon la classification de l'Organisation mondiale de la santé, le LPB est une pathologie potentiellement maligne. Toutefois, on soupçonne que la transformation maligne du LPB se produit dans des lésions présentant à la fois des caractéristiques lichénoïdes et dysplasiques (LD). Cet examen porte sur les questions relatives au LPB et aux LD, notamment leur malignité, leur classification et leur catégorisation, et pour savoir si l'inflammation du lichénoïde entraîne des changements dysplasiques des LD ou vice versa. Méthodes: On a utilisé le texte intégral de documents rédigés en anglais sur le LPB, les LD et la dysplasie issus de PubMed, de CINAHL et de Google Scholar. Résultats: Trente-six publications, notamment des articles sur des études originales, des revues, des méta-analyses, des livres, des rapports, des lettres et des éditoriaux, ont été sélectionnées aux fins d'examen. Discussion: Des études suggèrent que le LPB est potentiellement malin, bien que ce potentiel soit faible, et que les LD ne doivent pas être ignorés : en effet, une dysplasie peut évoluer en cancer, qu'elle présente des caractéristiques lichénoïdes ou non. On constate également un désaccord quant à la classification et à la catégorisation des LD. Différents termes ont été utilisés pour la classification de ces lésions, notamment « dysplasie lichénoïde ¼, « LPB dysplasique ¼ et « dysplasie à caractéristiques lichénoïdes ¼. De plus, dans le cas des LD, on ne sait pas avec certitude si la dysplasie ou l'infiltration lichénoïde apparaît en premier, ni si l'inflammation découle de la dysplasie ou si la dysplasie est une conséquence de l'inflammation persistante. La principale limite de la littérature est due aux incohérences et à la nature subjective des diagnostics histologiques, qui peut entraîner des variations d'un observateur à l'autre ou même avec un même observateur, ce qui entraîne à terme des diagnostics erronés de LPB et de LD. Conclusion: Bien que d'autres études soient nécessaires pour comprendre le LPB et les LD, les lésions de ces 2 catégories doivent être considérées comme potentiellement malignes et ne doivent pas être ignorées.

Gender- and ethnicity-specific survival trends of oral cavity and oropharyngeal cancers in British Columbia.

INTRODUCTION: A shift in etiology of oral cancers has been associated with a rise in incidence for oropharyngeal cancers (OPC) and decrease for oral cavity cancers (OCC); however, there is limited information about population-based survival trends. We report epidemiological transitions in survival for both OPC and OCC from a population-based cancer registry, focusing upon gender and ethnic differences. METHODS: All primary oral cancers diagnosed between 1980 and 2005 were identified from the British Columbia Cancer Registry and regrouped into OPC and OCC by topographical subsites, time periods (1980-1993 and 1994-2005), stage at diagnosis, and ethnicity. Cases were then followed up to December 2009. Using gender-based analysis, actuarial life tables were used to calculate survival rates, which were compared using Kaplan-Meier curves and log-rank tests. RESULTS: For OPC, survival improved, significant for tonsil and base of tongue in men and marginally significant at base of tongue in women. This improvement occurred in spite of an increase in late-stage diagnosis for OPC in both genders. Interestingly, there was no difference in survival for early- and late-stage disease for OPC in men. For OCC, there was a decrease in survival for floor of mouth cancers in both genders although significant in women only. South Asians had the poorest survival for OCC in both genders. CONCLUSION: Survival for OPC improved, more dramatically in men than women, in spite of late-stage diagnosis and increasing nodal involvement. Given the poor survival rates and need for early detection, targeted OCC screening programs are required for South Asians.

Predicting Progression of Low-Grade Oral Dysplasia Using Brushing-Based DNA Ploidy and Chromatin Organization Analysis.

Most oral cancers arise from oral potentially malignant lesions, which show varying grades of dysplasia. Risk of progression increases with increasing grade of dysplasia; however, risk prediction among oral low-grade dysplasia (LGD), that is, mild and moderate dysplasia can be challenging as only 5%-15% transform. Moreover, grading of dysplasia is subjective and varies with the area of the lesion being biopsied. To date, no biomarkers or tools are used clinically to triage oral LGDs. This study uses a combination of DNA ploidy and chromatin organization (CO) scores from cells obtained from lesion brushings to identify oral LGDs at high-risk of progression. A total of 130 lesion brushings from patients with oral LGDs were selected of which 16 (12.3%) lesions progressed to severe dysplasia or cancer. DNA ploidy and CO scores were analyzed from nuclear features measured by our in-house DNA image cytometry (DNA-ICM) system and used to classify brushings into low-risk and high-risk. A total of 57 samples were classified as high-risk of which 13 were progressors. High-risk DNA brushing was significant for progression (P = 0.001) and grade of dysplasia (P = 0.004). Multivariate analysis showed high-risk DNA brushing showed 5.1- to 8-fold increased risk of progression, a stronger predictor than dysplasia grading and lesion clinical features. DNA-ICM can serve as a non-invasive, high-throughput tool to identify high-risk lesions several years before transformation. This will help clinicians focus on such lesions whereas low-risk lesions may be spared from unnecessary biopsies.Prevention Relevance: DNA ploidy and chromatin organization of cells collected from oral potentially malignant lesions (OPMLs) can identify lesions at high-risk of progression several years prior. This non-invasive test would enable clinicians to triage high-risk (OPMLs) for closer follow-up while low-risk lesions can undergo less frequent biopsies reducing burden on healthcare resources.

Basement membrane degeneration is common in lichenoid mucositis with dysplasia.

Background: Two subtypes of lichenoid mucositis (LM) with oral epithelial dysplasia have been proposed, with differing risks of malignant transformation. However, no research has been done to authenticate this hypothesis. The study objective was to determine whether there are 2 subcategories within this entity, one with primary lichenoid and secondary dysplastic features (L1D2), and the other with primary dysplastic and secondary lichenoid features (D1L2), and to compare the proportion of malignant progression in these groups. Methods: Patients with a diagnosis of lichenoid mucositis with low-grade (mild/moderate) oral epithelial dysplasia, no history of head and neck cancer, and who had at least 5 years of follow-up were eligible to participate in this nested case-control study. Cases (n = 10) were defined as lesions that progressed to severe dysplasia, carcinoma in situ or squamous cell carcinoma; controls (n = 32) were defined as those that did not progress. Immunohistochemistry was performed to assess for basement membrane (BM) degeneration using collagen IV-an integral BM protein. Results: Lesions that progressed to cancer exhibited a similar proportion of BM degeneration at baseline (70%) compared to non-progressors (78%), with no statistically significant difference between groups (p = 0.69). Conclusion: BM degeneration is frequently seen in LM with dysplasia and alone does not appear to be a predictor of malignant progression in lesions with both lichenoid and low-grade dysplastic features. Dysplasia should not be discounted in the presence of LM. Lesions that display any degree of dysplasia warrant clinical follow-up and continued monitoring.

Contexte: Deux sous-types de mucosites lichénoïdes (ML) avec dysplasie épithéliale buccale ont été proposés, avec des risques différents de transformation maligne. Cependant, aucune recherche n'a été faite pour valider cette hypothèse. L'objectif de l'étude était de déterminer s'il y a 2 sous-catégories au sein de cette entité, la première avec des caractéristiques lichénoïdes primaires et dysplasiques secondaires (L1D2), et l'autre avec des caractéristiques dysplasiques primaires et lichénoïdes secondaires (D1L2), et de comparer la proportion de progression maligne dans ces groupes. Méthodologie: Les patients ayant reçu un diagnostic de mucosite lichénoïde avec une dysplasie épithéliale buccale de faible intensité (faible/modérée), qui n'avaient aucun antécédent de cancer de la tête et du cou, et qui avaient eu au moins 5 ans de suivi, étaient admissible à participer à cette étude de cas-témoins emboîtés. Les cas (n = 10) étaient définis comme des lésions qui ont progressé à la dysplasie sévère, un carcinome in situ ou un carcinome squameux; les contrôles (n = 32) étaient définis comme ceux qui n'ont pas progressé. L'immunohistochimie a été effectuée pour évaluer s'il y avait eu une dégénérescence de la membrane basale (MB) en utilisant du collagène IV, une protéine MB intrinsèque. Résultats: Les lésions qui ont évolué en cancer ont présenté une proportion semblable de dégénérescence de MB au début (70 %) par rapport aux non-progresseurs (78 %), et aucune différence statistiquement significative entre les groupes (p = 0,69). Conclusion: La dégénérescence des MB est fréquemment constatée dans les ML avec dysplasie et seule, ne paraît pas être une variable explicative de l'évolution maligne dans les lésions à caractéristiques à la fois lichénoïdes et dysplasiques de faible intensité. Il ne faut pas sous-estimer la dysplasie en présence de ML. Les lésions qui présentent de la dysplasie, peu importe son étendue, exigent un suivi clinique et une surveillance continue.

Genomic imbalances in precancerous tissues signal oral cancer risk.

Oral cancer develops through a series of histopathological stages: through mild (low grade), moderate, and severe (high grade) dysplasia to carcinoma in situ and then invasive disease. Early detection of those oral premalignant lesions (OPLs) that will develop into invasive tumors is necessary to improve the poor prognosis of oral cancer. Because no tools exist for delineating progression risk in low grade oral lesions, we cannot determine which of these cases require aggressive intervention. We undertook whole genome analysis by tiling-path array comparative genomic hybridization for a rare panel of early and late stage OPLs (n = 62), all of which had extensive longitudinal follow up (>10 years). Genome profiles for oral squamous cell carcinomas (n = 24) were generated for comparison. Parallel analysis of genome alterations and clinical parameters was performed to identify features associated with disease progression. Genome alterations in low grade dysplasias progressing to invasive disease more closely resembled those observed for later stage disease than they did those observed for non-progressing low grade dysplasias. This was despite the histopathological similarity between progressing and non-progressing cases. Strikingly, unbiased computational analysis of genomic alteration data correctly classified nearly all progressing low grade dysplasia cases. Our data demonstrate that high resolution genomic analysis can be used to evaluate progression risk in low grade OPLs, a marked improvement over present histopathological approaches which cannot delineate progression risk. Taken together, our data suggest that whole genome technologies could be used in management strategies for patients presenting with precancerous oral lesions.

Multiple pathways in the FGF signaling network are frequently deregulated by gene amplification in oral dysplasias.

Genetic alteration in oral premalignant lesions (OPLs), the precursors of oral squamous cell carcinomas (OSCCs), may represent key changes in disease initiation and development. We ask if DNA amplification occurs at this early stage of cancer development and which oncogenic pathways are disrupted in OPLs. Here, we evaluated 50 high-grade dysplasias and low-grade dysplasias that later progressed to cancer for gene dosage aberrations using tiling-path DNA microarrays. Early occurrences of DNA amplification and homozygous deletion were frequently detected, with 40% (20/50) of these early lesions exhibiting such features. Expression for 88 genes in 7 recurrent amplicons were evaluated in 5 independent head and neck cancer datasets, with 40 candidates found to be overexpressed relative to normal tissues. These genes were significantly enriched in the canonical ERK/MAPK, FGF, p53, PTEN and PI3K/AKT signaling pathways (p = 8.95 x 10(-3) to 3.18 x 10(-2)). These identified pathways share interactions in one signaling network, and amplification-mediated deregulation of this network was found in 30.0% of these preinvasive lesions. No such alterations were found in 14 low-grade dysplasias that did not progress, whereas 43.5% (10/23) of OSCCs were found to have altered genes within the pathways with DNA amplification. Multitarget FISH showed that amplification of EGFR and CCND1 can coexist in single cells of an oral dysplasia, suggesting the dependence on multiple oncogenes for OPL progression. Taken together, these findings identify a critical biological network that is frequently disrupted in high-risk OPLs, with different specific genes disrupted in different individuals.

Areca nut and betel quid chewing among South Asian immigrants to Western countries and its implications for oral cancer screening.

The South Asian community is the largest and one of the fastest growing minority groups in Canada, according to the 2006 census. These immigrants bring to Canada talents and skills that can promote Canada's economy and cultural diversity, but they also bring lifestyle habits that may lead to serious health issues. Chewing areca nut and betel quid (paan, with and without tobacco) is a known risk factor for oral cancer. This habit is common in the Indo-Canadian population, as evidenced by its sales in local Indian markets and restaurants. In this article, we present an overview of the sociocultural beliefs, knowledge and practices regarding betel quid/areca nut chewing, and discuss its implications for oral cancer screening among this immigrant population.

Primary malignant melanoma of maxillary gingiva--a case report and review of the literature.

Dentists may encounter pigmented lesions in routine clinical practice. In most cases, the lesions are asymptomatic and benign in nature; however, rarely, a pigmented lesion can be a sign of malignancy. We report a case of malignant melanoma of the maxillary gingiva to highlight the importance of biopsy and periodic follow-up of patients with unusual focal pigmented lesions in the oral cavity.

Oral submucous fibrosis, a clinically benign but potentially malignant disease: report of 3 cases and review of the literature.

Oral submucous fibrosis (OSF) is a premalignant condition mainly associated with the practice of chewing betel quid containing areca nut, a habit common among South Asian people. It is characterized by inflammation, increased deposition of submucosal collagen and formation of fibrotic bands in the oral and paraoral tissues, which increasingly limit mouth opening. Recently, OSF has been reported among South Asian immigrants in Canada, the United Kingdom and Germany. Dentists in western countries should enhance their knowledge of this disease as it seems to be increasing with population migration. In this paper, we review the literature on OSF and present 3 cases representing different stages of the disease to help dentists make an early diagnosis and reduce the morbidity and mortality associated with this condition.

Biopsy and histopathologic diagnosis of oral premalignant and malignant lesions.

Accurate diagnosis of premalignant or malignant oral lesions depends on the quality of the biopsy, adequate clinical information and correct interpretation of the biopsy results. The purpose of this paper is to review the procedures for obtaining appropriate biopsy samples, and the criteria for diagnosing and grading dysplasias. The World Health Organization's description of the architectural and cytologic epithelial changes that characterize dysplasia is detailed, and guidelines for following up patients with premalignant and malignant lesions are provided. The benefits of using the centralized services and expertise of the British Columbia Oral Biopsy Service are also reviewed.

New hope for an oral cancer solution: together we can make a difference.

Oral cancer is associated with high mortality and morbidity rates, largely as a result of late diagnosis. Although dental practitioners are trained to identify premalignant and malignant lesions, an organized system is needed to offer guidance and to improve access to experts in diagnosis and management of these lesions. In this article, we describe the many ways in which the British Columbia Oral Cancer Prevention Program (BC OCPP) is addressing this challenge: by linking community dental practices and referral centres, by creating partnerships between scientists and clinicians that already have resulted in new technologies to enhance early diagnosis, by involving a broad range of stakeholders to ensure population-based screening and by engaging in provincial, national and international outreach.

Screening diagnostic biomarkers of OSCC via an LCM-based proteomic approach.

The current standard for the diagnosis of oral squamous cell carcinoma (OSCC) is based on the histologic examination of hematoxylin and eosin-stained sections; however, the discrimination among normal tissue, pre­cancerous lesions and cancerous lesions can be difficult. The aim of the present study was to identify proteins with diagnostic significance in differentiating or predicting oral mucosal carcinogenesis. Proteomic profiling based on the laser capture microdissection of formalin-fixed, paraffin-embedded samples was performed, followed by liquid chromatography-tandem mass spectrometry (LC/MS) analysis. Immunohistochemistry (IHC) was used to evaluate the results. IHC of cytokeratins (CKs) was performed in neck dissection treatment cases. The accuracy rate and 95% confidence intervals (CIs) were used to evaluate the value of CKs as biomarkers of OSCC. A lymph node metastasis mouse model was used to validate the selected biomarkers. Among the proteins identified using LC/MS, several CKs exhibited significant differential expression patterns between the cancerous and para-cancerous tissues. The IHC results showed that negative staining of CK4 and CK10/13 distinguished cancerous from para-cancerous tissues with an accuracy of 90% (95% CI, 0.68-0.99) and 75% (95% CI, 0.51-0.91), respectively. Furthermore, the positive staining of CK14 and CK17 clearly distinguished cancerous from para-cancerous lesions with an accuracy of 100% (95% CI, 83-100%) and 90% (95% CI, 0.68-0.99), respectively. There was also CK14-positive staining in micro-metastases of lymph nodes in the clinical samples and in an animal model.

Visualization and other emerging technologies as change makers for oral cancer prevention.

The genomic era has fueled a rapid emergence of new information at the molecular level with a great potential for developing innovative approaches to detection, risk assessment, and management of oral cancers and premalignant disease. As yet, however, little research has been done on complementary approaches that would use different technology in conjunction with molecular approaches to create a rapid and cost-effective strategy for patient assessment and management. In our ongoing 8-year longitudinal study, a set of innovative technologies is being validated alone and in combination to best correlate with patient outcome. The plan is to use these devices in a step-by-step sequence to guide key clinicopathological decisions on patient risk and treatment. The devices include a hand-held visualization device that makes use of tissue autofluorescence to detect and delineate abnormal lesions and fields requiring follow-up, to be used in conjunction with optical contrast agents such as toluidine blue. In addition, two semi-automated high-resolution computer microscopy systems will be used to quantitate the protein expression phenotype of cell nuclei in tissue sections and exfoliated cell brushings. Previously identified risk-associated molecular changes are being used to validate these systems as well as to establish their place in a population-based triage program that will filter out high-risk cases in the community and funnel them to dysplasia clinics where higher-cost molecular tools will guide intervention. A critical development for the translation of this technology into community settings is the establishment of an effective methodology for education and training of health practitioners on the front lines.

Fluorescence visualization detection of field alterations in tumor margins of oral cancer patients.

PURPOSE: Genetically altered cells could become widespread across the epithelium of patients with oral cancer, often in clinically and histologically normal tissue, and contribute to recurrent disease. Molecular approaches have begun to yield information on cancer/risk fields; tissue optics could further extend our understanding of alteration to phenotype as a result of molecular change. EXPERIMENTAL DESIGN: We used a simple hand-held device in the operating room to directly visualize subclinical field changes around oral cancers, documenting alteration to fluorescence. A total of 122 oral mucosa biopsies were obtained from 20 surgical specimens with each biopsy being assessed for location, fluorescence visualization (FV) status, histology, and loss of heterozygosity (LOH; 10 markers on three regions: 3p14, 9p21, and 17p13). RESULTS: All tumors showed FV loss (FVL). For 19 of the 20 tumors, the loss extended in at least one direction beyond the clinically visible tumor, with the extension varying from 4 to 25 mm. Thirty-two of 36 FVL biopsies showed histologic change (including 7 squamous cell carcinoma/carcinomas in situ, 10 severe dysplasias, and 15 mild/moderate dysplasias) compared with 1 of the 66 FV retained (FVR) biopsies. Molecular analysis on margins with low-grade or no dysplasia showed a significant association of LOH in FVL biopsies, with LOH at 3p and/or 9p (previously associated with local tumor recurrence) present in 12 of 19 FVL biopsies compared with 3 of 13 FVR biopsies (P=0.04). CONCLUSIONS: These data have, for the first time, shown that direct FV can identify subclinical high-risk fields with cancerous and precancerous changes in the operating room setting.

Oral cancer screening in a high-risk underserved community--Vancouver Downtown Eastside.

The objective of this study was to evaluate a clinic-centered oral cancer screening initiative in one of the poorest communities in Canada, assessing the need for screening and the acceptance of screening and identifying hindrances to both screening and follow-up. The study group included 204 people in the Vancouver Downtown Eastside (DTES). This was shown to be a high-risk community based on risk factors, lack of access to care, and the high frequency of oral mucosal anomalies. Acceptance of screening was high (98%); however, acceptance of biopsy for abnormal findings and follow-up was low. Among the 12 patients with clinical leukoplakia who were biopsied, 10 showed cancer or precancer. In summary, these data show a need for screening in this population and an ability to recruit patients to screening. They support a future expansion of this initiative to create a more comprehensive strategy for outreach to this underserved community that extends to screening, diagnostic work-up, and treatment.

Multiple microalterations detected at high frequency in oral cancer.

The development of array comparative genomic hybridization (array CGH) at tiling-path resolution has enabled the detection of gene-sized segmental DNA copy number gains and losses. Here, we present the first application of whole genome tiling-path array CGH to archival clinical specimens for the detailed analysis of oral squamous cell carcinomas (OSCC). We describe the genomes of 20 OSCCs as well as a selection of matched normal DNA in unprecedented detail. Examination of their whole genome profiles enabled the identification of alterations ranging in size from whole-arm, segmental, to gene size alterations. Tiling-path resolution enabled the detection of many more alterations within each tumor than previously reported, many of which include narrow alterations found to be frequent events among the 20 OSCCs. We report the presence of several novel frequent submegabase alterations, such as the 0.58 Mb gain at 5p15.2 containing triple functional domain (TRIO), detected in 45% of cases. We also report the first coamplification of two gene clusters, by fine-mapping the precise base pair boundaries of the high-level amplification at 11q22.2-22.3 containing both matrix metalloproteinase and baculoviral IAP repeat-containing protein 2 (BIRC) gene clusters. These results show the large improvement in detection sensitivity and resolution compared with genome interval marker arrays and the utility of tiling resolution array CGH for the detection of both submegabase and single copy gains and losses in cancer gene discovery.

Toluidine blue staining identifies high-risk primary oral premalignant lesions with poor outcome.

There is a pressing need for the development of visual aids that will facilitate the detection of oral premalignant lesions (OPLs) with a high-risk of progression. Preliminary data suggest that toluidine blue stain may be preferentially retained by OPLs with high-risk molecular clones. In this study, we monitored OPLs from 100 patients without any history of oral cancer for an average of 44 months in order to evaluate the association of toluidine blue status with clinicopathologic risk factors, molecular patterns (microsatellite analysis on seven chromosome arms: 3p, 9p, 4q, 8p, 11q, 13q, and 17p) and outcome. Toluidine blue-positive staining correlated with clinicopathologic risk factors and high-risk molecular risk patterns. Significantly, a >6-fold elevation in cancer risk was observed for toluidine blue-positive lesions, with positive retention of the dye present in 12 of the 15 lesions that later progressed to cancer (P = 0.0008). This association of toluidine blue status with risk factors and outcome was evident even when the analysis was restricted to OPLs with low-grade or no dysplasia. Our results suggest the potential use of toluidine blue in identifying high-risk OPLs.