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.

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.

Intraoral Photography Recommendations for Remote Risk Assessment and Monitoring of Oral Mucosal Lesions.

Oral cancer is a global health issue with substantial morbidity and a high mortality rate mainly because of late-stage diagnosis. Cancerous lesions are often preceded by potentially malignant lesions that may be detected during routine dental examinations. Not only is the oral cavity easily accessible for screening, but the clinical risk factors of the disease are also known. However, patients may not always be able to access screening services or receive follow-up for diagnosed lesions. In these circumstances, intraoral photos are crucial for timely triage, risk assessment, and monitoring of oral lesions. Further, photos form an integral part of a patient's records, facilitate patient education and communication between health care providers, and provide important information during the referral process. To ensure that intraoral photos are of good quality and standardised there is a need to establish recommendations regarding intraoral photography in oral mucosal screening. This article recommends methods to help health professionals and patients obtain interpretable intraoral photographs. Suggestions to achieve ideal lighting, mirror placement, camera angle, and retraction have been discussed. These recommendations are adaptable to easily available smartphone or point-and-shoot cameras and may be further used to develop future teledentistry platforms.

Effect of Fluorescence Visualization-Guided Surgery on Local Recurrence of Oral Squamous Cell Carcinoma: A Randomized Clinical Trial.

Importance: High local recurrence rates with aggressive disease remain the main concern in oral cancer survival. Use of a translational device using fluorescence visualization (FV) approved by the US Food and Drug Administration and Health Canada, has shown a marked reduction in the 3-year local recurrence rate of high-grade oral lesions in a single-center observational study. Objective: To determine whether FV- guided surgery can improve local control rates in the treatment of in situ or T1 to T2 category oral squamous cell carcinoma (OSCC). Design, Setting, and Participants: A multicenter randomized clinical trial was conducted in a surgical setting. A total of 457 patients were enrolled between January 18, 2010, and April 30, 2015. Data analysis of the intention-to-treat population was performed from April 3, 2019, to March 20, 2020. Patients with histologically confirmed high-grade dysplasia/carcinoma in situ or T1 to T2 category OSCC were randomized to receive traditional peroral surgery or FV-guided surgery. Intervention: Fluorescence visualization during surgery. Main Outcomes and Measures: The primary outcome was local recurrence of OSCC. Secondary outcomes were failure of the first-pass margin, defined as a histologically confirmed positive margin for severe dysplasia or greater histologic change of the main specimen (ie, not the margins taken from the resection bed), regional or distant metastasis, and death due to disease. Results: Of the 457 patients enrolled in the study, 443 patients (264 [59.6%] men; mean [SD] age, 61.5 [13.3] years) completed the randomized treatment: 227 FV-guided and 216 non-FV guided surgery. The median follow-up was 52 (range, 0.29-90.8) months. In total, 45 patients (10.2%) experienced local recurrence. The 3-year local recurrence rate was 9.4% in the FV-guided group and 7.2% in the non-FV group (difference, 2.2%; 95% CI, -3.2% to 7.4%). Other similarities between the FV vs non-FV groups included failure of first-pass margin (68/227 [30.0%]) vs 65/216 [30.1%]), regional failure (39/227 [17.2%] vs 37/216 [17.1%]), disease-specific survival (23/227 [10.1%] vs 19/26 [8.8%]), and overall survival (41/227 [18.1%] vs 38/216 [17.6%]) were also similar between groups. No adverse events were judged to be related to the intervention. Conclusions and Relevance: In this randomized clinical trial, FV-guided surgery did not improve local control rates in the treatment of patients with in situ or T1 to T2 category oral cancer. Under a controlled environment, FV-guided surgery did not have an evident effect in reduction of local recurrence for localized OSCC. This result suggests that attention be directed to strategies other than improving definitions of nonapparent disease at clinical margins to identify the sources of local recurrence. Trial Registration: ClinicalTrial.gov Identifier: NCT01039298.

Using quantitative tissue phenotype to assess the margins of surgical samples from a pan-Canadian surgery study.

BACKGROUND: The purpose of this study was to use quantitative tissue phenotype (QTP) to assess the surgical margins to examine if a fluorescence visualization-guided surgical approach produces a shift in the surgical field by sparing normal tissue while catching high-risk tissue. METHODS: Using our QTP to calculate the degree of nuclear chromatin abnormalities, Nuclear Phenotypic Score (NPS), we analyzed 1290 biopsy specimens taken from surgical samples of 248 patients enrolled in the Efficacy of Optically-guided Surgery in the Management of Early-staged Oral Cancer (COOLS) trial. Multiple margin specimens were collected from each surgical specimen according to the presence of fluorescence visualization alterations and the distance to the surgical margins. RESULTS: The NPS in fluorescence visualization-altered (fluorescence visualization-positive) samples was significantly higher than that in fluorescence visualization-retained (fluorescence visualization-negative) samples. There was a constant trend of decreasing NPS of margin samples from non-adjacent-fluorescence visualization margins to adjacent-fluorescence visualization margins. CONCLUSION: Our results suggested that using fluorescence visualization to guide surgery has the potential to spare more normal tissue at surgical margins.

Optimizing Fixation Protocols to Improve Molecular Analysis from FFPE Tissues.

Most Departments of Pathology around the world have a considerable archive of formalin-fixed paraffin-embedded (FFPE) tissue suitable for molecular assessment. This article points out the potential DNA damage that may occur if basic steps are not followed during processing and storage of these samples. Furthermore, it hopes to establish parameters to optimize quality and quantity of DNA extracted from FFPE tissues.

Optimizing Fixation Protocols to Improve Molecular Analysis from FFPE Tissues

Abstract Most Departments of Pathology around the world have a considerable archive of formalin-fixed paraffin-embedded (FFPE) tissue suitable for molecular assessment. This article points out the potential DNA damage that may occur if basic steps are not followed during processing and storage of these samples. Furthermore, it hopes to establish parameters to optimize quality and quantity of DNA extracted from FFPE tissues.

Resumo A maioria dos Departamentos de Patologia em todo o mundo têm um considerável acervo de tecidos embebidos em parafina e fixados em formalina, que são passíveis para análises moleculares. Este artigo apresenta os danos ao DNA que podem ocorrer se passos básicos não forem seguidos durante o processamento e armazenamento destas amostras. Além disso, procura estabelecer parâmetros para otimizar a qualidade e quantidade do DNA extraído de tecidos FFPE.

Oral Squamous Cell Carcinomas are Associated with Poorer Outcome with Increasing Ages.

OBJECTIVES: 1.1.Although oral cancers traditionally occur in people between the age of 50 and 70, there are increasing incidences of this disease in younger and very old people. Objectives: to compare the demographics, habits, clinicopathological features, treatment and outcome of oral cancer in three age groups of patients: Young (≤ 45), Traditional (46 to 75), and Old (> 75). SUBJECTS: 1.2.Primary oral cancers (393 patients) in a longitudinal study were used. RESULTS: 1.3.Significant differences were noted in ethnicity (fewer Caucasian patients in Young), tobacco habit (more non-smokers in Young), location of cancer (more at tongue for Young and more at low-risk sites for Old) and treatment (more surgery for Young). Compared to Young (univariate analysis), Traditional and Old showed a 3- and 4.5-fold increase in local recurrences respectively; 1.9- and 2.7-fold increase in regional metastasis; 3.1- and 5.4-fold increase in death due to disease; and a 3.4- and 6.6-fold decrease in overall survival. Compared to Young (multivariate analysis), Traditional and Old showed a 2.4- and 3.3-fold increase in local recurrence; 2.7- and 5.4-fold increase in disease-specific survival; and 2.8- and 6.5-fold decrease in overall survival. CONCLUSION: 1.4.Oral cancer in different age groups showed differing ethnicity, habit, location, treatment and outcome.

Should severe epithelial dysplasia be treated?

OBJECTIVE: To identify clinical features associated with progression of primary severe epithelial dysplasia into invasive squamous cell carcinoma (SCC). DESIGN: Longitudinal population-based study. SETTING: Oral dysplasia clinics. PATIENTS: This study involved 118 patients with 118 severe dysplasia who were prospectively enrolled between 1996 and 2014, and the lesions were either completely removed surgically (treated) or actively followed (untreated). MEASUREMENTS: Demographics, habits, clinical information and outcome were compared between the treated and untreated groups. RESULTS: Of the 118 lesions, 77 were treated and 41 were not. The treated lesions showed significantly less progression when compared to the untreated: 5/77 (6%) treated lesions progressed into invasive SCC versus 12/41 (29%) untreated (P=0.004). The 5-year probability (confidence interval) of progression into SCC for the treated was 7.6 (1-14) as compared to 38.6 (16-55) for the untreated. Interestingly the clinical changes at the site of the disease also had strong predictive value for cancer progression. If the site showed no lesion after treatment or after incisional biopsy (40 cases), only 1 (3%) progressed into cancer. If the site showed ever disappearance of the lesion or marked decrease in the size of the lesion to ⩽10mm (29 cases), 4 (15%) progressed. If the site showed lesions with fluctuation in size or persistent in size or marked increase in size (25 cases), 18 (58%) progressed (P<0.001). CONCLUSION: Treatment significantly reduced cancer progression, and phenotypic changes at the site of the disease had significant predictive value for cancer progression.

Fluorescence Visualization-Guided Surgery for Early-Stage Oral Cancer.

IMPORTANCE: The prevalence of genetically altered cells in oral cancers has a negative influence on the locoregional recurrence rate and lowers survival. Fluorescence visualization (FV) can identify clinically occult, high-risk oral lesions by allowing health care professionals and surgeons to visualize and map occult disease. This process may improve overall survival by decreasing rates of locoregional recurrence. OBJECTIVE: To assess the efficacy of FV-guided surgery in reducing locoregional recurrence and improving overall survival. DESIGN, SETTING, AND PARTICIPANTS: A retrospective, case-control observational study was conducted on patients registered at a single oral oncology clinic from September 1, 2004, to August 31, 2009. The study included 246 patients 18 years or older with a diagnosis of a high-grade lesion (severe dysplasia or carcinoma in situ) or squamous cell carcinoma of less than 4 cm who underwent curative surgical treatment with at least 1 follow-up visit. Among these patients, 154 underwent surgery with FV guidance (FV group) and the other 92 underwent conventional surgery (control group). Demographic and lesional characteristics and outcomes were collected, and the key factors for the efficacy of FV-guided surgery were examined. Follow-up was completed on December 31, 2011, and data were analyzed from May 1 to November 30, 2013. MAIN OUTCOMES AND MEASURES: Local recurrence of oral lesions with a histologic grade of severe dysplasia or higher, the presence of regional failure (ie, a metastatic lesion in the cervical lymph nodes), or disease-free survival after surgery. RESULTS: Among the 246 patients included in the study (mean [SD] age, 60 [12] years; 108 women and 138 men), 156 had squamous cell carcinoma and 90 had high-grade lesions. There were no significant differences between the FV (n = 154) and control (n = 92) groups in age, smoking history, anatomical site of the lesion, tumor size, and previous oral cancer. Among the 156 patients with squamous cell carcinoma, the 92 patients in the FV group showed significant reduction in the 3-year local recurrence rate, from 40.6% (26 of 64 patients) to 6.5% (6 of 92 patients) (P < .001). Among the 90 patients with high-grade lesions, the 62 patients in the FV group showed a reduction in local recurrence rate from 11 of 28 patients (39.3%) to 5 of 62 patients (8.1%) (P < .001). The data also indicated that, compared with conventional surgery, the FV-guided approach for squamous cell carcinoma was associated with less regional failure (14 of 92 patients [15.2%] vs 16 of 64 [25.0%]; P = .08) and death (12 of 92 patients [13.0%] vs 13 of 64 [20.3%]; P = .22), although these differences were not statistically significant. CONCLUSIONS AND RELEVANCE: In this study, the use of FV as part of the surgical margin decision process significantly reduced the rate of local recurrence in preinvasive high-grade and early-stage oral cancers. An ongoing multicenter, phase 3, randomized surgical trial has completed accrual, and the data will be used to validate the results of this study.

Characterization of Epithelial Progenitors in Normal Human Palatine Tonsils and Their HPV16 E6/E7-Induced Perturbation.

Human palatine tonsils are oropharyngeal lymphoid tissues containing multiple invaginations (crypts) in which the continuity of the outer surface epithelium is disrupted and the isolated epithelial cells intermingle with other cell types. We now show that primitive epithelial cells detectable in vitro in 2D colony assays and in a 3D culture system are CD44(+)NGFR(+) and present in both surface and crypt regions. Transcriptome analysis indicated a high similarity between CD44(+)NGFR(+) cells in both regions, although those isolated from the crypt contained a higher proportion of the most primitive (holo)clonogenic cells. Lentiviral transduction of CD44(+)NGFR(+) cells from both regions with human papillomavirus 16-encoded E6/E7 prolonged their growth in 2D cultures and caused aberrant differentiation in 3D cultures. Our findings therefore reveal a shared, site-independent, hierarchical organization, differentiation potential, and transcriptional profile of normal human tonsillar epithelial progenitor cells. They also introduce a new model for investigating the mechanisms of their transformation.

Targeting of chemoprevention to high-risk potentially malignant oral lesions: challenges and opportunities.

Worldwide, oral cancer is responsible for 170,000 deaths per year. Intervention to prevent this disease is a long sought after goal. Chemoprevention studies have focused on clinicopathological features of potentially malignant lesions (PML) in an effort to prevent their progression to cancer. However, prediction of future behavior for such lesions is difficult and remains a major challenge to such intervention. Different approaches to this problem have been tested in the past 20years. Early genetic progression models identified critical regions of allelic imbalance at 3p and 9p, and provided the basis for molecular markers to identify progressing PMLs. Subsequently, technological advances, such as genome-wide high-throughput array platforms, computer imaging, visualization technology and next generation sequencing, have broadened the scope for marker development and have the potential of further improving our ability to identify high-risk lesions in the near future either alone or in combination. In this article, we examine the milestones in the development of markers for PML progression. We emphasize the critical importance of networks among scientists, health professionals and community to facilitate the validation and application of putative markers into clinical practice. With a growing number of new agents to validate, it is necessary to coordinate the design and implementation of strategies for patient recruitment, integration of marker assessment, and the final translation of such approaches into clinical use.

Decision making on detection and triage of oral mucosa lesions in community dental practices: screening decisions and referral.

UNLABELLED: Oral cancer is a substantial, often unrecognized issue globally, with close to 300 000 new cases reported annually. It is a management conundrum: a cancer site that is easily examined; yet more than 40% of oral cancers are diagnosed at a late stage when prognosis is poor and treatment can be devastating. Opportunistic screening within the dental office could lead to earlier diagnosis and intervention with improved survival. OBJECTIVE: To describe how clinicians make decisions about referral based on the risk classification of the lesion. METHODS: Eighteen dentists from 15 dental offices participated in a 1-day workshop on oral cancer screening. Participants then screened patients (medical history, conventional oral exam, fluorescent visualization examination) in-office for 11 months, triaging patients by apparent clinical risk: low risk (common benign conditions, geographic tongue, candidiasis, trauma), intermediate risk (lichenoid lesions) and high risk (white or red lesions or ulcers without apparent cause). Clinicians made the decision on which lesions to reassess in 3 weeks based on risk assessment and clinical judgment. Lesions of concern were seen by a community facilitator or referred to an oral medicine specialist. RESULTS: Of 2542 patients were screened, and 389 lesions were identified (15% of patients). 350 were determined to be low risk (90%), 19 intermediate risk (IR) (5%), and 20 high risk (HR) (5%). One hundred and sixty-six (43%) patients were recalled for 3-week reassessment: 90% of HR lesions, 63% of IR lesions (63%), and 39% of low-risk lesions. Compliance to recall was high (92% of cases). Reassessment eliminated the referral of 99/166 (60%) of lesions that had resolved. six lesions were biopsied with three low-grade dysplasias identified. CONCLUSIONS: Three key decision points were tested: risk assessment, need for reassessment, and need for referral. A 3-week reassessment appointment was invaluable to prevent the unnecessary referral due to confounders. There is a need for a well-defined triage pathway to facilitate oral cancer screening and a methodical and consistent approach to opportunistic screening in the dental office.

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.

High throughput image cytometry for detection of suspicious lesions in the oral cavity.

The successful management of oral cancer depends upon early detection, which relies heavily on the clinician's ability to discriminate sometimes subtle alterations of the infrequent premalignant lesions from the more common reactive and inflammatory conditions in the oral mucosa. Even among experienced oral specialists this can be challenging, particularly when using new wide field-of-view direct fluorescence visualization devices clinically introduced for the recognition of at-risk tissue. The objective of this study is to examine if quantitative cytometric analysis of oral brushing samples could facilitate the assessment of the risk of visually ambiguous lesions. About 369 cytological samples were collected and analyzed: (1) 148 samples from pathology-proven sites of SCC, carcinoma in situ or severe dysplasia; (2) 77 samples from sites with inflammation, infection, or trauma, and (3) 144 samples from normal sites. These were randomly separated into training and test sets. The best algorithm correctly recognized 92.5% of the normal samples, 89.4% of the abnormal samples, 86.2% of the confounders in the training set as well as 100% of the normal samples, and 94.4% of the abnormal samples in the test set. These data suggest that quantitative cytology could reduce by more than 85% the number of visually suspect lesions requiring further assessment by biopsy.

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.

Loss of heterozygosity (LOH) profiles--validated risk predictors for progression to oral cancer.

A major barrier to oral cancer prevention has been the lack of validated risk predictors for oral premalignant lesions (OPL). In 2000, we proposed a loss of heterozygosity (LOH) risk model in a retrospective study. This paper validated the previously reported LOH profiles as risk predictors and developed refined models via the largest longitudinal study to date of low-grade OPLs from a population-based patient group. Analysis involved a prospective cohort of 296 patients with primary mild/moderate oral dysplasia enrolled in the Oral Cancer Prediction Longitudinal Study. LOH status was determined in these OPLs. Patients were classified into high-risk or low-risk profiles to validate the 2000 model. Risk models were refined using recursive partitioning and Cox regression analyses. The prospective cohort validated that the high-risk lesions (3p and/or 9p LOH) had a 22.6-fold increase in risk (P = 0.002) compared with low-risk lesions (3p and 9p retention). Addition of another 2 markers (loci on 4q/17p) further improved the risk prediction, with five-year progression rates of 3.1%, 16.3%, and 63.1% for the low-, intermediate-, and high-risk lesions, respectively. Compared with the low-risk group, intermediate- and high-risk groups had 11.6-fold and 52.1-fold increase in risk (P < 0.001). LOH profiles as risk predictors in the refined model were validated in the retrospective cohort. Multicovariate analysis with clinical features showed LOH models to be the most significant predictors of progression. LOH profiles can reliably differentiate progression risk for OPLs. Potential uses include increasing surveillance for patients with elevated risk, improving target intervention for high-risk patients while sparing a large number of low-risk patients from needless screening and treatment.

Canadian Optically-guided approach for Oral Lesions Surgical (COOLS) trial: study protocol for a randomized controlled trial.

BACKGROUND: Oral cancer is a major health problem worldwide. The 5-year survival rate ranges from 30-60%, and has remained unchanged in the past few decades. This is mainly due to late diagnosis and high recurrence of the disease. Of the patients who receive treatment, up to one third suffer from a recurrence or a second primary tumor. It is apparent that one major cause of disease recurrence is clinically unrecognized field changes which extend beyond the visible tumor boundary. We have previously developed an approach using fluorescence visualization (FV) technology to improve the recognition of the field at risk surrounding a visible oral cancer that needs to be removed and preliminary results have shown a significant reduction in recurrence rates. METHOD/DESIGN: This paper describes the study design of a randomized, multi-centre, double blind, controlled surgical trial, the COOLS trial. Nine institutions across Canada will recruit a total of 400 patients with oral severe dysplasia or carcinoma in situ (N = 160) and invasive squamous cell carcinoma (N = 240). Patients will be stratified by participating institution and histology grade and randomized equally into FV-guided surgery (experimental arm) or white light-guided surgery (control arm). The primary endpoint is a composite of recurrence at or 1 cm within the previous surgery site with 1) the same or higher grade histology compared to the initial diagnosis (i.e., the diagnosis used for randomization); or 2) further treatment due to the presence of severe dysplasia or higher degree of change at follow-up. This is the first randomized, multi-centre trial to validate the effectiveness of the FV-guided surgery. DISCUSSION: In this paper we described the strategies, novelty, and challenges of this unique trial involving a surgical approach guided by the FV technology. The success of the trial requires training, coordination, and quality assurance across multiple sites within Canada. The COOLS trial, an example of translational research, may result in reduced recurrence rates following surgical treatment of early-stage oral cancer with significant impacts on survival, morbidity, patients' quality of life and the cost to the health care system. TRIAL REGISTRATION: Clinicaltrials.gov NCT01039298.