Increased allelic loss in toluidine blue-positive oral premalignant lesions

Adjunctive aids for the detection of oral squamous cell carcinoma and oral potentially malignant disorders: A systematic review of systematic reviews

This study presents the results of systematic reviews on adjunctive tools in screening and diagnosis of oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) and to determine if the current literature supports their use as either an adjunctive tool or replacement of gold standard techniques. Systemic reviews and meta-analysis that evaluated adjunctive tools including chemiluminescence, tissue autofluorescence, tissue fluorescence spectroscopy, vital staining and cytology techniques were systematically examined using AMSTAR II. Twenty-seven systematic reviews were included. Five studies had a low quality of evidence, and nine studies had a critically low quality of evidence. This review found limited evidence to recommend chemiluminescence, tissue autofluorescence tools and vital staining as diagnostic tools, but only serve as clinical adjuncts to conventional oral examination. Cytology techniques and narrow-band imaging may be utilised as a non-invasive diagnostic adjunctive tool for the detection of OSCC and the malignant transformation of OPMD. In conclusion, this paper provides evidence on several types of adjunctive tools and provides recommendations on their use in clinical practice. These tools are considered useful as clinical adjuncts but there is insufficient evidence for their use as a diagnostic tool to replace gold standard conventional oral examination and surgical biopsy.

Diagnostic Accuracy of Toluidine Blue Electrospun in Detecting Oral Potentially Malignant Disorders

OBJECTIVE

Oral potentially malignant disorders (OPMDs) with epithelial dysplasia can progress to oral squamous cell carcinoma (OSCC). Toluidine blue (TB) has been used in oral screening with various methods. This study aimed to evaluate the sensitivity and specificity of TB-containing electrospun fibers in detecting OPMDs with epithelial dysplasia compared to histopathology.

METHODS

The concentrations of polyvinylpyrrolidone (PVP) and TB were optimized for fiber diameter and puncture strength using the design of experiments method with a central composite design. These optimized fibers were tested on 36 suspected OPMD lesions in 30 patients, followed by a biopsy for histopathological examination.

RESULTS

The quadratic and two-factor interaction models described the relationship between TB and PVP concentrations and fiber characteristics. The TB-containing electrospun fibers had 77.3% sensitivity and 35.7% specificity in detecting OPMDs with epithelial dysplasia.

CONCLUSION

The TB-containing electrospun fibers offer advantages such as easy application, cost-effectiveness, and enhanced sensitivity in identifying OPMDs with epithelial dysplasia. However, their diagnostic accuracy is insufficient as a standalone diagnostic method, and they should be considered an adjunctive tool for detecting dysplastic changes in the oral epithelium.

TRIAL REGISTRATION

Thailand Clinical Trials Registry: TCTR20240429002.

Expression of p53 in toluidine blue positive oral squamous cell carcinoma lesions and expression of Ki67 in vinegar positive oral squamous cell carcinoma lesions

The aims of this study were to investigate the sensitivity and specificity of toluidine blue and/or vinegar in oral cancer screening and to examine the correlation between clinical screening using toluidine blue and vinegar and the expression of the tumor marker p53 and proliferation marker Ki67, respectively. The study consisted of 87 patients with suspected oral squamous cell carcinoma lesions. Toluidine blue and/or vinegar were applied to the lesions, followed by biopsies. The tissues were diagnosed histopathologically and underwent immunohistochemical process for p53 or Ki67. The results revealed that the sensitivity and specificity of oral cancer screening using toluidine blue were 93% and 46%, respectively; whereas the sensitivity and specificity using vinegar were 85% and 81%, respectively. A statistically significant correlation between the use of vinegar and the expression of Ki67 (p = 0.019) was observed. Although there was a difference in the expression of p53 between specimens that were positive and negative to toluidine blue, the correlation did not reach a significant level. Based on the results from this study, vinegar has a lower sensitivity than toluidine blue but a higher specificity for oral cancer screening. The results of the clinical screening using vinegar correlated with the expression of Ki67 at the cellular level.

The role of DNA image cytometry in screening oral potentially malignant lesions using brushings: A systematic review

It is believed that the majority of oral cancers develop from oral potentially malignant lesions (OPML). Though they can be easily detected during screening, risk stratification is difficult. During screening clinicians often find it difficult to distinguish OPMLs from benign lesions, and predicting OPML at risk of malignant transformation is particularly challenging. DNA aneuploidy has been known to be a marker of malignancy in a number of sites including the oral cavity. We performed a systematic review to evaluate the effectiveness of DNA-ICM using brushings in differentiating OPMLs from benign/inflammatory lesions during screening and in predicting malignant transformation. MEDLINE, Pubmed, EMBASE electronic databases were systematically searched using a combination of keywords and subject headings. A total of 11 articles satisfied our inclusion criteria. These studies reported a wide range of sensitivity (16-96.4%) and specificity (90-100%) due to the differences in study design, definitions of high risk or low risk lesions and DNA-ICM protocol used. No long-term longitudinal studies were identified to assess the role of DNA-ICM using brushings in predicting malignant transformation. No studies evaluated the role of DNA-ICM in community screening settings. A number of studies combined DNA-ICM with other techniques like cytology or argyrophilic nucleolar organizer region counts leading to improved test results. In spite of DNA aneuploidy being accepted as a marker of malignancy, there is limited evidence of DNA-ICM using brushings being successful as an adjunct oral cancer screening tool. Longitudinal studies and large community screening studies need to be undertaken to draw stronger conclusion.

Late stage diagnosis of oral cancer: components and possible solutions

Stage of disease at the diagnosis of oral cancer is thought to be a significant factor in prognosis and outcome (International Agency for Research on Cancer/World Health Organization, 2014). Unfortunately, we continue to diagnose almost 2/3 of these cancers at advanced stages of disease despite the ongoing research for devices/methods to aid the clinicians in detection and accurate oral mucosal lesion diagnosis. This paper explores both the nature of oral cancer and the adjuncts available for detection, and presents the current issues in diagnostic delays of oral cancer detection.

Diagnostic modalities for squamous cell carcinoma: an extensive review of literature-considering toluidine blue as a useful adjunct

INTRODUCTION

Oral Squamous Cell Carcinomas have been considered as the most prevalent malignancies in the head and neck region and are frequently undiagnosed until symptomatic with an advanced stage of disease. So there is an urgent need to device methods for the detection of oral premalignant lesions and oral cancer at an early stage in order to improve the survival rate for patients. A number of tests have been done for the detection of oral cancer which include oral brush biopsy, the Vizilite, oral autofluorescence including chemiluscence, photodynamic detection, toluidine blue staining, methylene blue staining, incisional biopsy and many more.

MATERIAL

The article reviews various diagnostic modalities available at present for detection of squamous cell carcinomas and oral epithelial dysplasias based on advanced PUBMED search of the English language literature from the year 1972 to present in order to help us select the most suitable among them fulfilling the desired criteria of being non-invasive, highly specific and sensitive, economically viable, having a scope to be used for mass screening, easy to process, having low inter examiner variability and possibly not requiring high expertise to conduct and interpret the results.

CONCLUSION

After reviewing various diagnostic modalities, we conclude that toluidine blue staining emerges as a clear winner among all these and it can act as a valuable adjunct to incisional biopsy in detection of oral cancer and may not substitute it except in certain circumstances when its results are carefully correlated with the patient history and clinical characteristics of the mucosal disorder, considering the fact that incisional biopsy has been reported to cause dissemination of cancer cells in the circulation there by increasing the possibility of metastasis. We must emphasize that toludine blue is a screening modality and not a diagnostic procedure like biopsy and hence cannot replace a confirmatory biopsy as a whole.

Management for premalignant lesions of the oral cavity

Premalignant lesions of the oral cavity present as visibly abnormal areas of mucosa and may be a source of significant anxiety for the patient and the clinician. Suspicious lesions should be biopsied to evaluate for dysplasia. The risk of malignant transformation may relate to patient characteristics, environmental risk factors and genetic alterations. Management of such lesions hinges on risk modification, surveillance, symptom management and directed biopsies. Excision or ablation of dysplastic lesions is indicated. We review the current evidence relating to management of premalignant lesions of the oral mucosa and make recommendations for practice patterns.

The limitations of the clinical oral examination in detecting dysplastic oral lesions and oral squamous cell carcinoma

BACKGROUND

The clinical oral examination (COE) is the criterion standard for the initial detection of oral lesions that harbor dysplasia or oral squamous cell carcinoma (OSCC) at an early stage when they are most treatable. The authors conducted a systematic review to assess the effectiveness of the COE in predicting histologic diagnosis of dysplasia or OSCC.

METHODS

The authors conducted automated searches of PubMed, Web of Knowledge and the Cochrane Library from 1966 through 2010 for randomized controlled trials and observational studies that included the terms "oral mucosal lesion screening" and "oral lesions." They determined the quality (sensitivity, specificity, positive predictive value, negative predictive value and diagnostic odds ratio) of selected studies by using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

The overall diagnostic odds ratio was 6.1 (95 percent confidence interval, 2.1-17.6); therefore, the COE was considered to have poor overall performance as a diagnostic method for predicting dysplasia and OSCC.

CLINICAL IMPLICATIONS

On the basis of the available literature, the authors determined that a COE of mucosal lesions generally is not predictive of histologic diagnosis. The fact that OSCCs often are diagnosed at an advanced stage of disease indicates the need for improving the COE and for developing adjuncts to help detect and diagnose oral mucosal lesions.

Oncoapoptotic signaling and deregulated target genes in cancers: special reference to oral cancer

Cancer is a class of diseases characterized by uncontrolled cell growth. The development of cancer takes place in a multi-step process during which cells acquire a series of mutations that eventually lead to unrestrained cell growth and division, inhibition of cell differentiation, and evasion of cell death. Dysregulation of oncoapoptotic genes, growth factors, receptors and their downstream signaling pathway components represent a central driving force in tumor development. The detailed studies of signal transduction pathways for mechanisms of cell growth and apoptosis have significantly advanced our understanding of human cancers, subsequently leading to more effective treatments. Oral squamous cell carcinoma represents a classic example of multi-stage carcinogenesis. It gradually evolves through transitional precursor lesions from normal epithelium to a full-blown metastatic phenotype. Genetic alterations in many genes encoding crucial proteins, which regulate cell proliferation, differentiation, survival and apoptosis, have been implicated in oral cancer. As like other solid tumors, in oral cancer these genes include the ones coding for cell cycle regulators or oncoproteins (e.g. Ras, Myc, cyclins, CDKs, and CKIs), tumor suppressors (e.g. p53 and pRb), pro-survival proteins (e.g. telomerase, growth factors or their receptors), anti-apoptotic proteins (e.g. Bcl2 family, IAPs, and NF-kB), pro-apoptotic proteins (e.g. Bax and BH-3 family, Fas, TNF-R, and caspases), and the genes encoding key transcription factors or elements for signal transduction leading to cell growth and apoptosis. Here we discuss the current knowledge of oncoapoptotic regulation in human cancers with special reference to oral cancers.

The use of toluidine blue in the detection of pre-malignant and malignant oral lesions

INTRODUCTION

The purpose of this study was to evaluate the efficacy of the toluidine blue (TB) test as a diagnostic tool in the detection of malignant and dysplastic lesions of the oral cavity. This study was carried out because of a lack of consensus among different authors on the utility of TB, as well as to determine useful adjuncts to detect oral pre-cancer and cancer.

MATERIALS AND METHODS

The study included 160 patients with oral mucosal disorders that included suspicious or malignant lesions detected at clinical visual examination, confirmed by histopathological evaluation. All lesions were submitted to TB staining.

RESULTS

The sensitivity and specificity for the detection of malignant or dysplastic lesions by this test were 65.5% and 73.3%, respectively. Overall, the detection rate with TB (sensitivity) was slightly lower compared with those reported by other authors but the specificity was comparable to several reports. Positive predictive value (35.2%) was also lower than previous studies, whereas negative predictive value (90.6%) was similar.

CONCLUSIONS

The simplicity of the test procedure and the validity of derived values suggest TB staining can be a valuable adjunct to the diagnostic process, as long as it is carefully correlated with the clinical characteristics of the mucosal disorder and histopathological diagnosis.

Genetics/epigenetics of oral premalignancy: current status and future research

Squamous cell carcinoma (SCC) of the oral and oropharyngeal region is the sixth most common malignancy in the world today. Despite numerous advances in treatment, long-term survival from this disease remains poor. Early detection can decrease both morbidity and mortality associated with this neoplasm. However, screening for potentially malignant disease is typically confounded by difficulty in discriminating between reactive/inflammatory lesions vs those lesions that are premalignant in nature. Furthermore, the histologic diagnosis of dysplasia can be subjective and is thus prone to a considerable range of interpretation. Similarly, no definitive, validated criteria exist for predicting which dysplastic lesions are most likely to progress to cancer over time. Given this state of science, the presence of dysplasia can only be used to indicate that an oral lesion may have an increased risk of malignant transformation. Molecular biomarkers capable of identifying the subset of lesions likely to progress to cancer are required to eliminate this clinical diagnostic dilemma. The purpose of this review is to assess the current state of knowledge regarding genetic/epigenetic alterations observed in oral mucosal premalignancy. In addition, recommendations for future research studies directed at defining the predictive capacity of specific biomarkers in this modeling are presented.

The utility of toluidine blue staining and brush cytology as adjuncts in clinical examination of suspicious oral mucosal lesions

The objective of this study was to investigate the utility of toluidine blue and brush cytology in patients with clinically detected oral mucosal lesions. Clinical examination of 35 patients was completed before toluidine blue application, oral brush cytology and scalpel biopsy. Lesions were photographed before and after stain application; followed by brush cytology. All findings were compared with histopathologic results. Severe dysplasia and carcinoma-in-situ were determined as 'positive'; no dysplasia and mild to moderate dysplasia were defined as 'negative'. The sensitivity, specificity, positive and negative predictive values of clinical examination and toluidine blue were the same: 0.923, 0.433, 0.414, and 0.929, respectively. Those of brush cytology were 0.923, 0.517, 0.462, and 0.938. The concordance of all methods was 30% for benign and 61% for malignant lesions. Adjuncts identified 92% of carcinoma-in-situ and squamous cell carcinoma as confirmed by histopathology, in contrast to clinical findings alone in which 62% of these lesions were identified (p=0.046). In conclusion, adjunct diagnostic methods decreased the level of uncertainty for the diagnosis of oral malignancies and lichenoid dysplasias when applied as adjuncts to clinical examination.

Toluidine blue color perception in identification of oral mucosal lesions

The objective of this study is to examine observer agreement on the rank of the color tones after toluidine blue staining of a mucosal lesion. Cohort study with repeated measures is the design of the study. Twenty observers ranked and scored 8 specified areas on the color images of a lesion before and after toluidine blue application in two sessions. Inter and intra-observer variations were analyzed with Cohen's kappa. The L* (the black-white axis), a* (red-green axis), and b* (yellow-blue axis) values were measured and set as the gold standards. Intra and inter-observer agreements were к = 0.86 and к = 0.854. All color parameters were effective on the color ranking order (pL* = 0.00, pa* = 0.007, pb* = 0.00), although L* and b* were more effective on the ranking of the samples than a*. Areas that appeared pale blue visually had a significant blue component, but the observers were confused with the effect of whiteness of the area in clinical decision making.

Design and statistical analysis of oral medicine studies: common pitfalls

A growing number of articles are emerging in the medical and statistics literature that describe epidemiologic and statistical flaws of research studies. Many examples of these deficiencies are encountered in the oral, craniofacial, and dental literature. However, only a handful of methodologic articles have been published in the oral literature warning investigators of potential errors that may arise early in the study and that can irreparably bias the final results. In this study, we briefly review some of the most common pitfalls that our team of epidemiologists and statisticians has identified during the review of submitted or published manuscripts and research grant applications. We use practical examples from the oral medicine and dental literature to illustrate potential shortcomings in the design and analysis of research studies, and how these deficiencies may affect the results and their interpretation. A good study design is essential, because errors in the analysis can be corrected if the design was sound, but flaws in study design can lead to data that are not salvageable. We recommend consultation with an epidemiologist or a statistician during the planning phase of a research study to optimize study efficiency, minimize potential sources of bias, and document the analytic plan.

The adjunctive role of toluidine blue in detection of oral premalignant and malignant lesions

PURPOSE OF REVIEW

To review the literature on toluidine blue (TBlue) and to discuss the utility of TBlue in assessing and in clinical management of patients with oral mucosal lesions. The literature search was conducted using key word search including oral cancer, oral premalignant lesions, and TBlue and by selecting references from the articles reviewed.

RECENT FINDINGS

The findings of this review show that TBlue has utility as an adjunct in the detection of premalignant and malignant oral mucosal lesions and in identifying high-risk areas of lesions for biopsy in patients at increased risk of cancer when evaluated by experienced healthcare workers.

SUMMARY

TBlue positive lesions, whether histologically benign or with dysplasia, predict molecular change and behavior of oral premalignant lesions. TBlue may provide information regarding lesion margins, accelerate the decision to biopsy, guide biopsy site selection and treatment of oral premalignant and malignant lesions. These findings support the utility of TBlue as a clinical adjunct in assessment of oral mucosal lesions.

Molecular pathology of head and neck cancer: implications for diagnosis, prognosis, and treatment

The prototypic head and neck squamous cell carcinoma (HNSCC) arises from the mucosal lining of the upper aerodigestive tract, demonstrates squamous differentiation microscopically, involves older men with a long history of cigarette smoking and alcohol consumption, and is treated by multimodality therapy. HNSCC has long been regarded as a uniform disease process requiring a methodical and unwavering therapeutic approach. Divergence in epidemiologic trends among HNSCCs arising from different anatomic sites has introduced a view that, morphologic repetition aside, head and neck cancers form a heterogeneous group. This view has been supported at the molecular genetic level. A more complete understanding of the molecular genetics of head and neck cancer is providing new insights into long-held but poorly comprehended concepts such as field cancerization and is introducing various biomarkers with potential application for diagnosing, staging, monitoring, and prognosticating HNSCC.

Adjunctive techniques for oral cancer examination and lesion diagnosis: a systematic review of the literature

BACKGROUND

Adjunctive techniques that may facilitate the early detection of oral premalignant and malignant lesions (OPML) have emerged in the past decades.

METHODS

The authors undertook a systematic review of the English-language literature to evaluate the effectiveness of toluidine blue (TB), ViziLite Plus with TBlue (Zila Pharmaceuticals, Phoenix), ViziLite (Zila Pharmaceuticals), Microlux DL (AdDent, Danbury, Conn.), Orascoptic DK (Orascoptic, a Kerr Company, Middleton, Wis.), VELscope (LED Dental, White Rock, British Columbia, Canada) and OralCDx (Oral CDx Laboratories, Suffern, N.Y.) brush biopsy. They abstracted data relating to study design, sampling and characteristics of the study group, interventions, reported outcomes and diagnostic accuracy of adjunctive aids from 23 articles meeting inclusion and exclusion criteria, including availability of histologic outcomes.

RESULTS

The largest evidence base was for TB. A limited number of studies was available for ViziLite, ViziLite Plus with TBlue and OralCDx. Studies of VELscope have been conducted primarily to assess the margins of lesions in known OPML. The authors identified no studies of Microlux DL or Orascoptic DK. Study designs had various limitations in applicability to the general practice setting, including use of higher-risk populations and expert examiners.

CONCLUSIONS

There is evidence that TB is effective as a diagnostic adjunct for use in high-risk populations and suspicious mucosal lesions. OralCDx is useful in assessment of dysplastic changes in clinically suspicious lesions; however, there are insufficient data meeting the inclusion criteria to assess usefulness in innocuous mucosal lesions. Overall, there is insufficient evidence to support or refute the use of visually based examination adjuncts. Practical Implications. Given the lack of data on the effectiveness of adjunctive cancer detection techniques in general dental practice settings, clinicians must rely on a thorough oral mucosal examination supported by specialty referral and/or tissue biopsy for OPML diagnosis.

Potentially malignant disorders of the oral and oropharyngeal mucosa; terminology, classification and present concepts of management

In a recently held WHO workshop it has been recommended to abandon the distinction between potentially malignant lesions and potentially malignant conditions and to use the term potentially malignant disorders instead. Of these disorders, leukoplakia and erythroplakia are the most common ones. These diagnoses are still defined by exclusion of other known white or red lesions. In spite of tremendous progress in the field of molecular biology there is yet no single marker that reliably enables to predict malignant transformation in an individual patient. The general advice is to excise or laser any oral of oropharyngeal leukoplakia/erythroplakia, if feasible, irrespective of the presence or absence of dysplasia. Nevertheless, it is actually unknown whether such removal truly prevents the possible development of a squamous cell carcinoma. At present, oral lichen planus seems to be accepted in the literature as being a potentially malignant disorder, although the risk of malignant transformation is lower than in leukoplakia. There are no means to prevent such event. The efficacy of follow-up of oral lichen planus is questionable. Finally, brief attention has been paid to oral submucous fibrosis, actinic cheilitis, some inherited cancer syndromes and immunodeficiency in relation to cancer predisposition.

A survey of the current approaches to diagnosis and management of oral premalignant lesions

BACKGROUND

Early diagnosis of oral premalignant lesions (OPLs) and oral squamous cell carcinoma facilitates treatment with less aggressive approaches and results in a better prognosis. The authors conducted a study to identify current practices in the diagnosis and management of these oral lesions by oral medicine professionals.

METHODS

The authors sent a questionnaire to 176 diplomates of the American Board of Oral Medicine and asked them to complete the questionnaires and return them by mail.

RESULTS

The initial clinical approach taken by most of the responders included visual examination, elimination of possible local causes and two-week follow-up. Adjuvant clinical tests included toluidine blue, oral brush biopsy and exfoliative cytology. If there was no clinical improvement after two weeks, most responders recommended that a biopsy be performed. Induration, red component, nonhomogeneous surface and ulceration were characteristics of lesions that increased the responders' decisions to perform a biopsy. Lesion symptoms and location also contributed to their decisions to perform a biopsy. Follow-up more frequently than twice a year was recommended for red lesions, lesions with histologically confirmed dysplasia or both. Most clinicians recommend a biopsy during follow-up of an OPL whenever the lesion changes in appearance.

CONCLUSIONS

The findings of this survey may provide background for initial guidelines to be used by oral practitioners to diagnose and manage OPL. Clinicians' awareness of the complexity of OPL diagnosis and management is important, and referral to an experienced provider is recommended.

Utility of toluidine blue in oral premalignant lesions and squamous cell carcinoma: Continuing research and implications for clinical practice

Toluidine blue (TB) has been shown to aid in the detection and diagnosis of oropharyngeal squamous cell carcinoma (OSCC) and oral premalignant lesions (OPLs). TB has been shown to enhance visualization of oral lesions and assist in identifying sites of increased risk of dysplastic/malignant change and promote biopsy. TB has been shown to identify lesions with molecular changes associated with risk of progression of OPLs to OSCC. A recent prospective longitudinal study showed TB retention in histologic benign lesions and lesions with mild dysplasia that are at increased risk of progression to cancer. Clinical trials show that TB is useful in identifying asymptomatic OSCC and premalignant lesions at risk of progressing to SCC, which might otherwise be undetected until lesions become more advanced. The data supports TB use in oral examination of patients at risk of OSCC.

Proliferative verrucous leukoplakia and its progression to oral carcinoma: a review of the literature

BACKGROUND

Proliferative verrucous leukoplakia (PVL) is a distinct clinical form of oral leukoplakia defined by its progressive clinical course, changing clinical and histopathological features, and potential to develop into cancer. PVL behaves in a more aggressive and relentless manner than the more innocuous white oral lesions that it can resemble clinically.

METHODS

A PubMed search was conducted which identified studies that examined patients with PVL and reported data meeting inclusion criteria.

RESULTS

PVL is seen much more frequently in females and most often diagnosed after the sixth decade of life. Tobacco use is not strongly linked to the presence of PVL (63% of patients did not use tobacco products). Most (74%) of the patients with PVL progressed to oral carcinoma.

CONCLUSION

PVL is a persistent and progressive oral lesion that requires very close follow-up along with early and aggressive treatment to increase the chances of a favorable outcome.

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.

The efficacy of oral lumenoscopy (ViziLite) in visualizing oral mucosal lesions

Early diagnosis of oral mucosal lesions has been advocated as a means of improving outcomes of cancer therapy. Improved visualization of mucosal lesions may aid in diagnosis by guiding tissue sampling or referral. This multicenter study reports the effect of chemiluminescent light (ViziLite) upon visualization of mucosal lesions. The chemiluminescent light did not appear to improve visualization of red lesions, but white lesions and lesions that were both red and white showed enhanced brightness and sharpness.

Dysplasia/neoplasia surveillance in oral lichen planus patients: A description of clinical criteria adopted at a single centre and their impact on prognosis

The concept of dysplasia/neoplasia surveillance has been applied to long-standing conditions associated with an increased risk of cancer. Although still controversial, periodic direct clinical examination as well as endoscopic techniques are currently performed in patients with inflammatory bowel diseases, Barrett's esophagus, and melanocytic skin lesions in order to detect and treat dysplastic or early malignant changes and therefore improve the patients' prognosis. It is not known if patients with oral lichen planus (OLP), a chronic inflammatory condition associated with an increased risk of cancer development, might benefit from such surveillance as well, nor how this should be performed. Here we present the clinical criteria we have adopted over a 12-year period to detect early malignant transformation of OLP, and report on their impact on the management and prognosis of patients. Overall data from 45 patients affected by 117 neoplastic events arising from OLP have been evaluated. Our dysplasia/neoplasia surveillance has led us to diagnose most episodes (94.9%; n.: 111) of OLP malignant transformation in early intraepithelial and microinvasive phases, namely stage 0 and I oral cancers (T(is) N0M0 or T1N0M0). The 5-year survival rate, where applicable, has been 96.7%. Advanced stage oral cancers have been diagnosed in six patients, three of whom have died. We suggest that the application of strict and rigorous clinical criteria in dysplasia/neoplasia surveillance could help clinicians to detect and treat early OLP malignant transformation and therefore improve long-term survival rates. Nevertheless, a small subgroup of patients has been shown not to benefit from such surveillance and to be characterized by a rapid development of advanced-stage oral carcinomas, with consequent poor prognosis.

Toluidine blue uptake in potentially malignant oral lesions in vivo: clinical and histological assessment

To assess the histological features of in vivo toluidine blue (TB) uptake in potentially malignant oral lesions (PML) and to determine whether any were related to clinical Dark versus Pale Royal Blue stain and/or to the malignant/dysplastic nature of the lesions. Frozen sections were used to evaluate TB extra- and intra-epithelial distribution, depth of penetration and nuclear or extra-nuclear uptake. Eighteen lesions were studied. The clinical appearance of a Dark Royal Blue stain was significantly related to the nuclear uptake of the dye. Conversely Pale Royal Blue staining was unrelated to any histological feature. Dark Royal Blue-malignant lesions had more nuclear uptake than benign lesions. The results suggest that Dark Royal Blue staining is the true positive outcome of a TB test and showed that Dark Royal Blue-malignant and Dark Royal Blue-benign lesions have a different histological pattern of uptake.

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.

Biophotonic and Other Physical Methods for Characterizing Oral Mucosa

This article discusses biophotonic and other physical methods for characterizing oral mucosa.

Oral cancer prevention and the evolution of molecular-targeted drug development

The multifaceted rationale for molecular-targeted prevention of oral cancer is strong. Oral cancer is a major global threat to public health, causing great morbidity and mortality rates that have not improved in decades. Oral cancer development is a tobacco-related multistep and multifocal process involving field carcinogenesis and intraepithelial clonal spread. Biomarkers of genomic instability, such as aneuploidy and allelic imbalance, can accurately measure the cancer risk of oral premalignant lesions, or intraepithelial neoplasia (IEN). Retinoid-oral IEN studies (eg, of retinoic acid receptor-beta, p53, genetic instability, loss of heterozygosity, and cyclin D1) have advanced the overall understanding of the biology of intraepithelial carcinogenesis and of preventive agent molecular mechanisms and targets-important advances for monitoring preventive interventions and assessing cancer risk and pharmacogenomics. Clinical management of oral IEN varies from watchful waiting to complete resection, although complete resection does not prevent oral cancer in high-risk patients. New approaches, such as interventions with molecular-targeted agents and agent combinations in molecularly defined high-risk oral IEN patients, are urgently needed to reduce the devastating worldwide consequences of oral cancer.

Molecular markers for diagnosis and prognosis

A plethora of aberrations are associated with progress and outcome for head and neck cancer patients and some have been shown to provide prognostic information independent of the TNM staging system. These findings justify future studies that will harness recent advances in technologies to refine the range of molecular markers available. Important lessons have been learnt during the last two decades, particularly the need to perform multivariate analysis and to combine information derived from several molecular markers. At present the overall evidence is insufficient to alter clinical practice or to consider restricting clinical trials of new adjuvant to subsets of patients, identified on the basis of the use of molecular markers. However, a number of key prospective clinical studies are in progress and we can be optimistic that in the near future clinical research incorporating specific markers may provide new criteria for defining risk of relapse or of developing a new primary tumour, and guide the choice of optimal adjuvant treatment after surgery. The only way to truly validate a marker is to incorporate it into large clinical trials, and it is anticipated that the new treatment options that are on the horizon, that are likely to be an improvement on radiotherapy alone, will provide opportunities to help translate this laboratory research into clinical practice.

Photo-Activated Disinfection Of The Root Canal: A New Role For Lasers In Endodontics

Because micro-organisms play a crucial role in the development of pulpal and periapical disease, the prognosis of endodontic therapy is intimately related to the presence of bacteria within the root canal system. Micro-organisms may persist in the apical region of the root canal system despite chemomechanical preparation. The usefulness of Class IV lasers (such as Nd:YAG, diode, KTP and Er:YAG) for photo-thermal disinfection of the root canal has been demonstrated in numerous studies. An alternative approach to microbial killing in the root canal system by laser light involves the use of low-power lasers to drive a photochemical reaction that produces reactive oxygen species, a technique termed photo-activated disinfection (PAD). By using exogenous photosensitisers such as tolonium chloride, killing of all types of bacteria can be achieved. In vitro studies of PAD have demonstrated its ability to kill photosensitised oral bacteria (such as E. faecalis), and more recently microbial killing in vivo in the root canal system has been demonstrated. While PAD can be undertaken as part of the routine disinfection of the root canal system, it also has potential use for eradicating persistent endodontic infections for which conventional methods have been unsuccessful.

An audit of the efficacy of the oral brush biopsy technique in a specialist Oral Medicine unit

The diagnosis of oral epithelial dysplasia has traditionally been based upon histopathological evaluation of a full thickness biopsy specimen from lesional tissue. It has recently been proposed that cytological examination of "brush biopsy" samples is a non-invasive method of determining the presence of cellular atypia, and hence the likelihood of oral epithelial dysplasia. The present audit determined, retrospectively the sensitivity, specificity and positive and negative predictive values of the oral brush biopsy technique in the diagnosis of potentially malignant disease in a group of 112 patients attending a specialist Oral Medicine unit. The sensitivity of detection of oral epithelial dysplasia or squamous cell carcinoma of the oral brush biopsy system was 71.4% while the specificity was 32%. The positive predictive value of an abnormal brush biopsy result (positive or atypical) was 44.1%, while the negative predictive value was 60%. It is concluded that not all potentially malignant disease is detected with this non-invasive investigative procedure.

Oral white lesions associated with chewing khat

Introduction

Khat is a cultivated plant whose leaves when chewed elevate mood. Unlike the chewing of betel nut, no association between the white oral mucosal lesions in khat users and oral malignancies has been reported. Chewing of khat has been documented in many countries and has increased with worldwide migration. The impact of chewing khat upon the oral mucosa is essentially unknown.

Purpose

The purpose of this study was to assess the occurrence of oral white changes in chronic khat chewers. Oral mucosal changes in a group of 47 Yemenite Israeli men over 30 years of age, who had chewed khat more than 3 years, were compared to those of 55 Yemenite men who did not chew.

Results

White lesions were significantly more prevalent in the khat chewers (83%) compared to the non chewing individuals (16%) (P < 0.001). White oral lesions were identified primarily on the lower buccal attached gingival mucosa, the alveolar mucosa and the lower mucobuccal fold on the chewing side (p < 0.001). There was no significant association between the occurrence of the white lesions and smoking. Even though the majority of the white lesions (85.4%) were homogenous, 71.4% of the non homogenous lesions were identified in khat chewers. Vital staining with toluidine blue and exfoliative cytology was conducted on a subset of patients with homogenous and non-homogenous oral lesions, and there were no findings suspicious for pre-malignant or malignant changes.

Discussion

This study demonstrated a relationship between khat chewing and oral white lesions, which we attribute to chronic local mechanical and chemical irritation of the mucosa. Our findings also suggest that mucosal changes associated with khat are benign, however, this initial study requires further studies including follow-up of khat users to confirm the current findings, including the likely benign changes associated with chronic use and histologic findings of clinical lesions.