Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue

Acetic acid versus toluidine blue as screening tools for oral potentially malignant disorders

Background

Diagnostic adjuncts such as toluidine blue have been investigated as screening tools that improve visual examination of potentially malignant disorders (PMD) and oral cancer. Acetic acid has been reported to be of value in the early detection of cervical cancers. This study assessed the utility of 5% acetic acid as a diagnostic adjunct in oral PMD and compared the accuracy of acetic acid with toluidine blue in the detection of dysplastic PMD and high-risk lesions.

Materials and Methods

This cross-sectional study was conducted at a dental hospital in a rural setting. Thirty-one patients with oral PMD formed the study group. Five percent acetic acid was applied to the lesions, followed by toluidine blue application and biopsy. Sensitivity, specificity, and positive and negative predictive values were computed considering true positives as stain uptake in dysplastic and high-risk PMD.

Results

The sensitivity, specificity, and positive and negative predictive values of acetic acid for identifying dysplastic or malignant lesions were 100%, 13.3%, 51.2%, and 100%, respectively, and that for toluidine blue were 75%, 100%, 100%, and 78.9%, respectively. The corresponding values for identifying high-risk PMD (lesions with moderate and severe dysplasia) using acetic acid were 100%, 9.1%, 25.9%, and 100%, respectively, and for toluidine blue were 85.7%, 81.8%, 60%, and 94.7%, respectively.

Conclusion

The utility of acetic acid in detecting dysplasia and high-risk PMD is severely limited due to its poor specificity. Compared with acetic acid, toluidine blue is a superior screening tool.

Current advances in noninvasive methods for the diagnosis of oral squamous cell carcinoma: a review

Oral squamous cell carcinoma (OSCC), one of the most common types of cancers worldwide, is diagnosed mainly through tissue biopsy. However, owing to the tumor heterogeneity and other drawbacks, such as the invasiveness of the biopsy procedure and high cost and limited usefulness of longitudinal surveillance, there has been a focus on adopting more rapid, economical, and noninvasive screening methods. Examples of these include liquid biopsy, optical detection systems, oral brush cytology, microfluidic detection, and artificial intelligence auxiliary diagnosis, which have their own strengths and weaknesses. Extensive research is being performed on various liquid biopsy biomarkers, including novel microbiome components, noncoding RNAs, extracellular vesicles, and circulating tumor DNA. The majority of these elements have demonstrated encouraging clinical outcomes in early OSCC detection. This review summarizes the screening methods for OSCC with a focus on providing new guiding strategies for the diagnosis of the disease.

Autofluorescence Image-Guided Endoscopy in the Management of Upper Aerodigestive Tract Tumors

At this juncture, autofluorescence and narrow-band imaging have resurfaced in the medicine arena in parallel with current technology advancement. The emergence of newly developed optical instrumentation in addition to the discovery of new fluorescence biomolecules have contributed to a refined management of diseases and tumors, especially in the management of upper aerodigestive tract tumors. The advancement in multispectral imaging and micro-endoscopy has also escalated the trends further in the setting of the management of this tumor, in order to gain not only the best treatment outcomes but also facilitate early tumor diagnosis. This includes the usage of autofluorescence endoscopy for screening, diagnosis and treatment of this tumor. This is crucial, as microtumoral deposit at the periphery of the gross tumor can be only assessed via an enhanced endoscopy and even more precisely with autofluorescence endoscopic techniques. Overall, with this new technique, optimum management can be achieved for these patients. Hence, the treatment outcomes can be improved and patients are able to attain better prognosis and survival.

Evaluation of the Role of Toluidine Blue Paint as an Adjunctive Method to Biopsy in Suspicious Oral Lesion: A Hospital Based Study

Early detection is a major step in the success of cancer therapy. Histopathology report is considered as the gold standard in the formulation of management protocol of any malignancy worldwide. But unfortunately, there is a delay in the detection of oral cancer very often due to inconclusive histopathology reports. The main reason behind it is obtaining a biopsy specimen from the non-representative area of the lesion. A hospital-based evaluation of the role of Toluidine Blue dye, used as an adjunctive method prior to biopsy was conducted in a tertiary care hospital on 200 patients presenting with oral lesions persistent for more than 3 weeks. The participants were divided into two equal groups by alternate sampling. In one group biopsy was taken by clinical judgment and in others, Toluidine Blue was used prior to obtaining a biopsy to decide the area to be biopsied. Data was collected using a predesigned proforma and was analyzed with the help of SPSS version 20. Results in two groups were compared with respect to sensitivity, specificity, positive and negative predictive values, false positive and false negative percentages. The Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value of wedge biopsy without staining were 73.68, 58.14, 70.00, and 62.50% respectively. These values were 95.08, 82.05, 89.23, and 91.43% respectively when Toluidine Blue staining was done as an adjunctive before the biopsy procedure. These results indicate the promising role of Toluidine blue staining before the biopsy to diagnose oral malignancy more efficiently than obtaining biopsy specimens on clinical assessment only and in avoiding the delay in initiating the treatment in case of oral malignant lesions.

Comparative study of effectiveness of colposcopic examination versus visual examination for determining the biopsy site of potentially premalignant oral epithelial lesions

Diagnosis of oral malignant and potentially premalignant oral epithelial lesions (PPOELs) cannot be based solely on clinical findings. Tissue biopsy with histopathologic examination remains the gold standard in diagnosis. Selection of a representative biopsy site becomes essential to arrive at an early and precise diagnosis which substantially reduces the incidence of morbidity and mortality from oral cancer. The site for biopsy, however, is always a subjective choice that sometimes raises doubts about its representativeness. Among various techniques developed to complement clinical examination and facilitate early diagnosis, colposcopy can be a simple, reliable diagnostic method available for the selection of the most appropriate biopsy site based on the vascular patterns. Hence, this study has been planned to assess the role of colposcopic examination in the selection of the most representative specimen for histopathologic examination from the oral lesions.

Improving the Diagnostic Performance by Adding Methylation Marker to Conventional Visual Examination in Identifying Oral Cancer

Background: Visual oral examination (VOE) is a conventional oral cancer screening method. This study aimed to evaluate the value of methylation marker to assist VOE in identifying oral epithelial dysplasia and oral squamous cell carcinoma (OED/OSCC) from non-cancerous lesions in a real-world situation. Methods: 201 patients with high-risk personal habits who self-perceived oral anomaly were VOE examined, ZNF582 methylation (ZNF582^m) tested, and histologically diagnosed. Results: Among them, 132 patients (65.7%) were histologically diagnosed OED/OSCC. Using VOE, 56.1% OED/OSCC patients had possible oral cancer, whereas 37.7% non-OED/OSCC patients had leukoplakia. ZNF582^m-positive was detected in 90.2% OED/OSCC patients and 44.9% non-OED/OSCC patients. Various logistic regression models were postulated to evaluate the diagnostic performance of conventional VOE and new strategies using ZNF582^m. ROC analysis and its corresponding C-index demonstrated that either triage or co-testing models of VOE and ZNF582^m could improve diagnostic performance and discriminative abilities compared with the VOE only approach. Conclusions: In conclusion, methylation marker test shows equivalent performance to an experienced judgment by oral maxillofacial surgeons and plays a significantly supplementary role in increasing the efficacy in identifying oral malignant lesions. ZNF582^m may be an especially important tool for family physicians or general dentists to properly diagnose suspicious oral lesions.

Non-invasive imaging of oral potentially malignant and malignant lesions: A systematic review and meta-analysis

Non-invasive (NI) imaging techniques have been developed to overcome the limitations of invasive biopsy procedures, which is the gold standard in diagnosis of oral dysplasia and Oral Squamous Cell Carcinoma (OSCC). This systematic review and meta- analysis was carried out with an aim to investigate the efficacy of the NI-imaging techniques in the detection of dysplastic oral potentially malignant disorders (OPMDs) and OSCC. Records concerned in the detection of OPMDs, Oral Cancer were identified through search in PubMed, Science direct, Cochrane Library electronic database (January 2000 to October 2020) and additional manual searches. Out of 529 articles evaluated for eligibility, 56 satisfied the pre-determined inclusion criteria, including 13 varying NI-imaging techniques. Meta-analysis consisted 44 articles, wherein majority of the studies reported Autofluorescence (AFI-38.6%) followed by Chemiluminescence (CHEM), Narrow Band Imaging (NBI) (CHEM, NBI-15.9%), Fluorescence Spectroscopy (FS), Diffuse Reflectance Spectroscopy (DRS), (FS, DRS-13.6%) and 5aminolevulinic acid induced protoporphyrin IX fluorescence (5ALA induced PPIX- 6.8%). Higher sensitivities (Sen) and specificities (Spe) were obtained using FS (Sen:74%, Spe:96%, SAUC=0.98), DRS (Sen:79%, Spe:86%, SAUC = 0.91) and 5 ALA induced PPIX (Sen:91%, Spe:78%, SAUC = 0.98) in the detection of dysplastic OPMDs from non-dysplastic lesions(NDLs). AFI, FS, DRS, NBI showed higher sensitivities and SAUC (>90%) in differentiating OSCC from NDLs. Analysed NI-imaging techniques suggests the higher accuracy levels in the diagnosis of OSCC when compared to dysplastic OPMDs. 5 ALA induced PPIX, DRS and FS showed evidence of superior accuracy levels in differentiation of dysplastic OPMDs from NDLs, however results need to be validated in a larger number of studies.

Detecting Oral Cancer: The Potential of Artificial Intelligence

BACKGROUND

Physical inspection is a simple way to diagnose oral cancer. Most cases of oral cancer, on the contrary, are diagnosed late, resulting in needless mortality and morbidity. While screening high-risk populations appear to be helpful, these people are often found in areas with minimal access to health care. In this paper, we have reviewed several aspects related to oral cancer such as its cause, the risk factors associated with it, India's oral cancer situation at the moment, various screening methods, and the ability of artificial intelligence in the detection and classification purpose. Oral cancer results can be enhanced by combining imaging and artificial intelligence approaches for better detection and diagnosis.

OBJECTIVE

This paper aims to cover the various oral cancer screening detection techniques that use Artificial Intelligence (AI).

METHODS

In this paper, we have covered the imaging methods that are used in screening oral cancer and after that the potential of AI for the detection of oral cancer.

CONCLUSION

This paper covers some of the main concepts regarding oral cancer and various AI methods used to detect it.

Diagnostic accuracy of conventional oral examination for detecting oral cavity cancer and potentially malignant disorders in patients with clinically evident oral lesions: Systematic review and meta-analysis

This systematic review evaluates the diagnostic accuracy of conventional oral examination (COE) versus incisional or excisional biopsy for the diagnosis of malignant and/or dysplastic lesions in patients with clinically evident lesions. Searches were conducted across five electronic databases from inception to January 2020. Meta‐analyses were undertaken, where appropriate. Among 18 included studies, 14 studies were included in the meta‐analysis, giving summary estimates for COE of 71% sensitivity and 85% specificity for the diagnosis of dysplastic and/or malignant lesions. The pooled diagnostic accuracy of identifying malignant‐only lesions was reported in seven studies, giving a pooled estimate of 88% sensitivity and 81% specificity. Diagnostic accuracy of different types of dental/medical professionals in identifying dysplastic or malignant lesions gave varying estimates of sensitivity and specificity across three studies. Further research is needed to improve the diagnostic accuracy of COE for early detection of dysplastic and malignant oral lesions.

Comparing the efficacy of chemiluminescence with lugol's iodine versus toluidine blue in the diagnosis of dysplasia in tobacco associated oral lesions - A diagnostic study

Background

Chemiluminescence is the production of light as a result of a chemical reaction. Oral potentially malignant disorders (OPMDs) include both precancerous lesions and conditions that carry an increased risk of cancer. There are different etiological and risk factors for OPMDs such as smoking, alcohol consumption, infections such as viral and fungal, sun exposure and certain other genetic factors. The most common etiological factor for OPMDs is tobacco usage. Chemiluminescence is a light-based detection system and is very useful for detecting OPMDs for early intervention. Because it is a non-invasive procedure, it can be used to evaluate dysplastic changes in various OPMDs at their initial stage for timely intervention. Vital staining has also been used as a chair-side marker for delineating normal and dysplastic oral mucosal tissues.

Aim

To compare the efficacy of chemiluminescence with Lugol's iodine to that with toluidine blue in diagnosing dysplastic changes in tobacco associated oral lesions.

Methodology

A total of 84 patients with clinically suspicious oral mucosal lesions and OPMDs with tobacco habit history were included and randomly assigned to either of the diagnostic study groups (Group A: chemiluminescence with Lugol's iodine or Group B: chemiluminescence with toluidine blue). All these patients were subjected to a histopathological examination (reference standard).

Results

The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristics (ROC) were 91.7%, 66.7%, 84.6%, 80%, and 0.792 for chemiluminescence with Lugol's iodine group (P = 0.001) respectively whereas for chemiluminescence with toluidine blue, the sensitivity, specificity, PPV, NPV and ROC were 100%, 60%, 93.3%, 100% and 0.800 (P = 0.002), respectively.

Conclusion

The combination of chemiluminescence with toluidine blue had a better diagnostic efficiency in detecting dysplasia in tobacco-associated oral lesions when compared to the group of chemiluminescence with Lugol's iodine.

Identification of oral precancerous and cancerous tissue by swept source optical coherence tomography

BACKGROUND AND OBJECTIVES

Distinguishing cancer from precancerous lesions is critical and challenging in oral medicine. As a noninvasive method, optical coherence tomography (OCT) has the advantages of real-time, in vivo, and large-depth imaging. Texture information hidden in OCT images can provide an important auxiliary effect for improving diagnostic accuracy. The aim of this study is to explore a reliable and accurate OCT-based method for the screening and diagnosis of human oral diseases, especially oral cancer.

MATERIALS AND METHODS

Fresh ex vivo oral tissues including normal mucosa, leukoplakia with epithelial hyperplasia (LEH), and oral squamous cell carcinoma (OSCC) were imaged intraoperatively by a homemade OCT system, and 58 texture features were extracted to create computational models of these tissues. A principal component analysis algorithm was employed to optimize the combination of texture feature vectors. The identification based on artificial neural network (ANN) was proposed and the sensitivity/specificity was calculated statistically to evaluate the classification performance.

RESULTS

A total of 71 sites of three types of oral tissues were measured, and 5176 OCT images of three types of oral tissues were used in this study. The superior classification result based on ANN was obtained with an average accuracy of 98.17%. The sensitivity and specificity of normal mucosa, LEH, and OSCC are 98.17% / 98.38%, 93.81% / 98.54%, and 98.11% / 99.04%, respectively.

CONCLUSION

It is demonstrated from the high accuracies, sensitivities, and specificities that texture-based analysis can be used to identify oral precancerous and cancerous tissue in OCT images, and it has the potential to help surgeons in diseases screening and diagnosis effectively.

Bimodal multispectral imaging system with cloud-based machine learning algorithm for real-time screening and detection of oral potentially malignant lesions and biopsy guidance

SIGNIFICANCE

Screening and early detection of oral potentially malignant lesions (OPMLs) are of great significance in reducing the mortality rates associated with head and neck malignancies. Intra-oral multispectral optical imaging of tissues in conjunction with cloud-based machine learning (CBML) can be used to detect oral precancers at the point-of-care (POC) and guide the clinician to the most malignant site for biopsy.

AIM

Develop a bimodal multispectral imaging system (BMIS) combining tissue autofluorescence and diffuse reflectance (DR) for mapping changes in oxygenated hemoglobin (HbO2) absorption in the oral mucosa, quantifying tissue abnormalities, and guiding biopsies.

APPROACH

The hand-held widefield BMIS consisting of LEDs emitting at 405, 545, 575, and 610 nm, 5MPx monochrome camera, and proprietary Windows-based software was developed for image capture, processing, and analytics. The DR image ratio (R610/R545) was compared with pathologic classification to develop a CBML algorithm for real-time assessment of tissue status at the POC.

RESULTS

Sensitivity of 97.5% and specificity of 92.5% were achieved for discrimination of OPML from patient normal in 40 sites, whereas 82% sensitivity and 96.6% specificity were obtained for discrimination of abnormal (OPML + SCC) in 89 sites. Site-specific algorithms derived for buccal mucosa (27 sites) showed improved sensitivity and specificity of 96.3% for discrimination of OPML from normal.

CONCLUSIONS

Assessment of oral cancer risk is possible by mapping of HbO2 absorption in tissues, and the BMIS system developed appears to be suitable for biopsy guidance and early detection of oral cancers.

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

BACKGROUND

Squamous cell carcinoma is the most common form of malignancy of the oral cavity, and is often proceeded by oral potentially malignant disorders (OPMD). Early detection of oral cavity squamous cell carcinoma (oral cancer) can improve survival rates. The current diagnostic standard of surgical biopsy with histology is painful for patients and involves a delay in order to process the tissue and render a histological diagnosis; other diagnostic tests are available that are less invasive and some are able to provide immediate results. This is an update of a Cochrane Review first published in 2015.

OBJECTIVES

Primary objective: to estimate the diagnostic accuracy of index tests for the detection of oral cancer and OPMD, in people presenting with clinically evident suspicious and innocuous lesions.

SECONDARY OBJECTIVE

to estimate the relative accuracy of the different index tests.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were also searched for ongoing trials to 20 October 2020. No restrictions were placed on the language or date of publication when searching the electronic databases. We conducted citation searches, and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting OPMD or oral cavity squamous cell carcinoma: vital staining (a dye to stain oral mucosa tissues), oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

MAIN RESULTS

This update included 63 studies (79 datasets) published between 1980 and 2020 evaluating 7942 lesions for the quantitative meta-analysis. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (22 datasets), oral cytology (24 datasets), light-based detection or oral spectroscopy (24 datasets). Nine datasets assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis. Two studies were classed as being at low risk of bias across all domains, and 33 studies were at low concern for applicability across the three domains, where patient selection, the index test, and the reference standard used were generalisable across the population attending secondary care. The summary estimates obtained from the meta-analysis were: - vital staining: sensitivity 0.86 (95% confidence interval (CI) 0.79 to 0.90) specificity 0.68 (95% CI 0.58 to 0.77), 20 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; - oral cytology: sensitivity 0.90 (95% CI 0.82 to 0.94) specificity 0.94 (95% CI 0.88 to 0.97), 20 studies, sensitivity moderate-certainty evidence, specificity moderate-certainty evidence; - light-based: sensitivity 0.87 (95% CI 0.78 to 0.93) specificity 0.50 (95% CI 0.32 to 0.68), 23 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; and - combined tests: sensitivity 0.78 (95% CI 0.45 to 0.94) specificity 0.71 (95% CI 0.53 to 0.84), 9 studies, sensitivity very low-certainty evidence, specificity very low-certainty evidence.

AUTHORS' CONCLUSIONS

At present none of the adjunctive tests can be recommended as a replacement for the currently used standard of a surgical biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for oral cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation. Potentially eligible studies of blood and salivary biomarkers were excluded from the review as they were of a case-control design and therefore ineligible. In the absence of substantial improvement in the tests evaluated in this updated review, further research into biomarkers may be warranted.

Validation of a Point-of-Care Optical Coherence Tomography Device with Machine Learning Algorithm for Detection of Oral Potentially Malignant and Malignant Lesions

Non-invasive strategies that can identify oral malignant and dysplastic oral potentially-malignant lesions (OPML) are necessary in cancer screening and long-term surveillance. Optical coherence tomography (OCT) can be a rapid, real time and non-invasive imaging method for frequent patient surveillance. Here, we report the validation of a portable, robust OCT device in 232 patients (lesions: 347) in different clinical settings. The device deployed with algorithm-based automated diagnosis, showed efficacy in delineation of oral benign and normal (n = 151), OPML (n = 121), and malignant lesions (n = 75) in community and tertiary care settings. This study showed that OCT images analyzed by automated image processing algorithm could distinguish the dysplastic-OPML and malignant lesions with a sensitivity of 95% and 93%, respectively. Furthermore, we explored the ability of multiple (n = 14) artificial neural network (ANN) based feature extraction techniques for delineation high grade-OPML (moderate/severe dysplasia). The support vector machine (SVM) model built over ANN, delineated high-grade dysplasia with sensitivity of 83%, which in turn, can be employed to triage patients for tertiary care. The study provides evidence towards the utility of the robust and low-cost OCT instrument as a point-of-care device in resource-constrained settings and the potential clinical application of device in screening and surveillance of oral cancer.

MicroRNAs as Modulators of Oral Tumorigenesis-A Focused Review

Oral cancers constitute the majority of head and neck tumors, with a relatively high incidence and poor survival rate in developing countries. While the five-year survival rates of the oral cancer patients have increased to 65%, the overall survival for advanced stages has been at 27% for the past ten years, emphasizing the necessity for further understanding the etiology of the disease, diagnosis, and formulating possible novel treatment regimens. MicroRNAs (miRNAs), a family of small non-coding RNA, have emerged as master modulators of gene expression in various cellular and biological process. Aberrant expression of these dynamic molecules has been associated with many human diseases, including oral cancers. The deregulated miRNAs have been shown to control various oncogenic processes, including sustaining proliferative signaling, evading growth suppressors, resisting cell death activating invasion and metastasis, and inducing angiogenesis. Hence, the aberrant expression of miRNAs associated with oral cancers, makes them potential candidates for the investigation of functional markers, which will aid in the differential diagnosis, prognosis, and development of novel therapeutic regimens. This review presents a holistic insight into our understanding of the role of miRNAs in regulating various hallmarks of oral tumorigenesis.

Efficacy of non-invasive diagnostic methods in the diagnosis and screening of oral cancer and precancer

INTRODUCTION

Traditional meta-analyses on the diagnostic accuracy of oral lesions have been conducted, but they were inherently limited to direct pairwise comparisons between a single method and a single alternative, while multiple diagnostic options and the ranking thereof were methodologically not possible.

OBJECTIVE

To evaluate the diagnostic values of various methods in patients with oral potential malignant disease by performing a network meta-analysis.

METHODS

Two authors independently searched the databases (MEDLINE, SCOPUS, the Cochrane Register of Controlled Trials, and Google scholar) up to June 2020 for studies comparing the diagnostic accuracy of various tools (autofluorescence, chemiluminescence, cytology, narrow band imaging, and toluidine blue) with visual examination or other tools. The outcomes of interest for this analysis were sensitivity, specificity, negative predictive value, positive predictive value and accuracy. Both a standard pairwise meta-analysis and network meta-analysis were conducted.

RESULTS

Treatment networks consisting of six interventions were defined for the network meta-analysis. The results of traditional meta-analysis showed that, among six methods, narrow band imaging showed higher sensitivity, specificity, negative predictive value, positive predictive value, and accuracy compared to visual examination. The results of network meta-analysis showed that autofluorescence, chemiluminescence, and narrow band imaging had higher sensitivity compared with visual examination, and that chemiluminescence and narrow band imaging had higher negative predictive value compared with visual examination. However, autofluorescence and chemiluminescence had lower specificity compared with visual examination. There were no significant differences in positive predictive value and accuracy among the six interventions.

CONCLUSION

This study demonstrated that narrow banding imaging has superiority in terms of sensitivity and negative predictive value compared with the other five tested agents.

Diagnostic accuracy of clinical visualization and light-based tests in precancerous and cancerous lesions of the oral cavity and oropharynx: a systematic review and meta-analysis

OBJECTIVE

Evaluate and compare the performance of autofluorescence, chemiluminescence, and clinical visual examination in the detection of oral potentially malignant disorders (OPMD), oral cancer (OC), and oropharyngeal cancer (OPC).

MATERIALS AND METHODS

A systematic review with meta-analysis based on diagnostic test studies. A literature search was carried out in the MEDLINE and EMBASE databases through August 30, 2020. For this review, the quality assessment tool of diagnostic precision studies (QUADAS-2) was used. Hierarchical regression models were used to estimate pooled diagnostic precision values in a random effects model.

RESULTS

A total of 40 studies were identified for this review according to each test evaluated: 5.562 samples for autofluorescence, 1.353 samples for chemiluminescence, and 1.892 samples for clinical examination. The summary measures sensitivity and specificity of the clinical examination were 63% and 78%, respectively, AUC = 0.78 95% CI (0.74-0.81). In the autofluorescence test, these were 86% and 72%, respectively, AUC = 0.86 95% CI (0.83-0.89); and the chemiluminescent test were 67% and 48%, respectively, AUC = 0.59 95% CI (0.54-0.63) CONCLUSIONS: Autofluorescence devices displayed superior accuracy levels in the identification of premalignant lesions and early neoplastic changes compared to clinical examination and chemiluminescent test. Overall, biopsy remains the gold standard for the definitive diagnosis of OPMD, OC, and OPC.

CLINICAL RELEVANCE

Light-based clinical methods such as autofluorescence and chemiluminescence techniques have been used in clinical diagnosis for the differentiation of OPMD and malignant and benign lesions; although detailed visual examination appears to be effective in identifying, previous systematic reviews have not evaluated a relevant number of studies and they did not evaluate the accuracy of the clinical examination.

Toluidine blue versus frozen section for assessment of mucosal tumor margins in oral squamous cell carcinoma

BACKGROUND

When the resected specimen is sent for intraoperative margin assessment, all margins are grossly checked, and selected margins undergo a frozen section (FS) examination. Therefore, there is a possibility of sampling error. This study evaluated the effectiveness of using toluidine blue (TB) as an intraoperative triage screening tool to detect positive mucosal margins of the resected specimens of oral squamous cell carcinoma (OSCC) and serve as a guide for FS sampling.

METHODS

Surgical samples of 30 consecutive patients with biopsy-proven OSCC were included in the study. A total of 140 mucosal margins were analyzed intraoperatively by TB and FS, the results were compared with the final histopathology.

RESULTS

Of the 140 examined mucosal tumor margins, 14 stained positives with TB, six were true-positives, eight were false-positives, and there were no false-negatives, as confirmed by final histopathology of the same margins. The diagnostic performance measures were sensitivity 100.0%; specificity 94.0%; positive predictive value (PPV) 42.9%; negative predictive value (NPV) 100.0%; and accuracy 94.3% (95% CI: 89.0-97.5%). For FS, there were three true-positives, three false-negatives, and no false-positives. The diagnostic performance measures were sensitivity 50.0%; specificity 100.0%; PPV 100.0%; NPV 97.8%; and accuracy 97.9% (95% CI: 93.9-99.6%).

CONCLUSION

TB is less specific but more sensitive than FS for detecting positive mucosal margins of resected OSCC. Screening the tumor mucosal margins with TB before FS sampling may help identify more tumor-bearing margins.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov. Registration number: NCT03554967 . Registration date: June 13, 2018.

Validity of Toluidine Blue test as a diagnostic tool for high risk oral potentially malignant disorders- a multicentre study in Sri Lanka

Introduction

- Early detection plays a major role to reduce the mortality of oral squamous cell carcinoma (OSCC). Many adjunctive techniques have emerged with claims of differentiating high risk oral potentially malignant disorders (OPMDs) from benign lesions. Toluidine blue (TB) test has been established as a diagnostic adjunct in detecting high risk OPMDs and early asymptomatic OSCCs. As majority of OSCC are preceded by OPMDs, recognition of them at an early stage is important in the management of this devastating disease.

Methods

-This study was conducted as a multi-center study prospectively for a period of 2 years. Sixty five patients presented with OPMDs were selected and TB test was performed followed by a biopsy for histopathological confirmation. Criterion validity was assessed with histological diagnosis of the incisional biopsy of the OPMD as a gold standard test verses TB test results.

Results

The sensitivity of the TB test was 68.3% and the specificity 63.1% with a false positive rate of 36.8% and false negative rate of 31.7%. However, the predictive value of the positive test was 80%.

Conclusion

- TB testing might be a potential adjunct diagnostic aid in identifying high risk OPMDs. Further studies with extensive sample size and different demographics are needed to validate our findings.

Efficacy of chemiluminescence in the diagnosis and screening of oral cancer and precancer: a systematic review and meta-analysis

Introduction

Early detection of potentially malignant oral cavity disorders is critical for a good prognosis, and it is unclear whether the use of chemiluminescence as an adjunctive diagnostic screening method improves diagnostic accuracy.

Objective

This systematic review and meta-analysis was performed to assess the accuracy of chemiluminescence for diagnosis of oral cancer and precancerous lesions.

Methods

Sixteen prospective and retrospective studies from PubMed, Cochrane database, SCOPUS, Web of Science, Embase, and Google Scholar were reviewed. Oral mucosal disorder, as detected by chemiluminescence, was compared with oral mucosal disorder detected by toluidine blue or visual examination. True-positive, true-negative, false-positive, and false-negative rates were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies tool (ver. 2).

Results

Sensitivity, specificity, negative predictive value, and diagnostic odds ratio (DOR) of the use of toluidine blue were 0.832 (95% confidence interval [CI] 0.692–0.917), 0.429 (95% CI 0.217–0.672), 0.747 (95% CI 0.607–0.849), and 4.061 (95% CI 1.528–10.796; I² = 9.128%), respectively. The area under the summary receiver operating characteristic (SROC) curve was 0.743. Compared with toluidine blue, as used in 12 studies, chemiluminescence had a higher sensitivity (0.831 vs. 0.694); it had a lower specificity (0.415 vs. 0.734), negative predictive value (0.674 vs. 0.729), and DOR (3.891 vs. 7.705). Compared with clinical examination, as used in three studies, chemiluminescence had lower DOR (4.576 vs. 5.499) and area under the curve (0.818 vs. 0.91).

Conclusion

Although chemiluminescence itself has good sensitivity for diagnostic work-up of oral cancer and precancer, the diagnostic accuracy of chemiluminescence is comparable to or worse than toluidine blue and clinical examination. Diagnostic accuracy was therefore insufficient for reliable use of chemiluminescence alone.

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

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

Prospective evaluation of oral premalignant lesions using a multimodal imaging system: a pilot study

BACKGROUND

Multimodal optical imaging, incorporating reflectance and fluorescence modalities, is a promising tool to detect oral premalignant lesions in real-time.

METHODS

Images were acquired from 171 sites in 66 patient visits for clinical evaluation of oral lesions. An automated algorithm was used to classify lesions as high- or low-risk for neoplasia. Biopsies were acquired at clinically indicated sites and those classified as high-risk by imaging, at the surgeon's discretion.

RESULTS

Twenty sites were biopsied based on clinical examination or imaging. Of these, 12 were indicated clinically and by imaging; 58% were moderate dysplasia or worse. Four biopsies were indicated by imaging evaluation only; 75% were moderate dysplasia or worse. Finally, four biopsies were indicated by clinical evaluation only; 75% were moderate dysplasia or worse.

CONCLUSION

Multimodal imaging identified more cases of high-grade dysplasia than clinical evaluation, and can improve detection of high grade precancer in patients with oral lesions.

Identification of Salivary Biomarkers for Oral Cancer Detection with Untargeted and Targeted Quantitative Proteomics Approaches

Oral cavity squamous cell carcinoma (OSCC) is one of the most common cancers worldwide. In Taiwan, OSCC is the fifth leading cause of cancer-related mortality and leads to 2800 deaths per year. The poor outcome of OSCC patients is principally ascribed to the fact that this disease is often advanced at the time of diagnosis, suggesting that early detection of OSCC is urgently needed. Analysis of cancer-related body fluids is one promising approach to identify biomarker candidates of cancers. To identify OSCC biomarkers, salivary proteomes of OSCC patients, individuals with oral potentially malignant disorders (OPMDs), and healthy volunteers were comparatively profiled with isobaric tags for relative and absolute quantitation (iTRAQ)-based mass spectrometry (MS). The salivary levels of 67 and 18 proteins in the OSCC group are elevated and decreased compared with that in the noncancerous group (OPMD and healthy groups), respectively. The candidate biomarkers were further selected using the multiple reaction monitoring (MRM)-MS and validated with the immunoassays. More importantly, the higher salivary level of three proteins, complement factor H (CFH), fibrinogen alpha chain (FGA), and alpha-1-antitrypsin (SERPINA1) was correlated with advanced stages of OSCC. Our results indicate that analysis of salivary proteome is a feasible strategy for biomarker discovery, and the three proteins are potential salivary markers for OSCC diagnosis.

Adjuncts for the evaluation of potentially malignant disorders in the oral cavity: Diagnostic test accuracy systematic review and meta-analysis-a report of the American Dental Association

BACKGROUND

Oral squamous cell carcinoma is the most common manifestation of malignancy in the oral cavity. Adjuncts are available for clinicians to evaluate lesions that seem potentially malignant. In this systematic review, the authors summarized the available evidence on patient-important outcomes, diagnostic test accuracy (DTA), and patients' values and preferences (PVPs) when using adjuncts for the evaluation of clinically evident lesions in the oral cavity.

TYPES OF STUDIES REVIEWED

The authors searched for preexisting systematic reviews and assessed their quality using the Assessing the Methodological Quality of Systematic Reviews tool. The authors updated the selected reviews and searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials and DTA and PVPs studies. Pairs of reviewers independently conducted study selection, data extraction, and assessment of the certainty in the evidence by using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

The authors identified 4 existing reviews. DTA reviews included 37 studies. The authors retrieved 7,534 records, of which 9 DTA and 10 PVPs studies were eligible. Pooled sensitivity and specificity of adjuncts ranged from 0.39 to 0.96 for the evaluation of innocuous lesions and from 0.31 to 0.95 for the evaluation of suspicious lesions. Cytologic testing used in suspicious lesions appears to have the highest accuracy among adjuncts (sensitivity, 0.92; 95% confidence interval, 0.86 to 0.98; specificity, 0.94; 95% confidence interval, 0.88 to 0.99; low-quality evidence).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Cytologic testing appears to be the most accurate adjunct among those included in this review. The main concerns are the high rate of false-positive results and serious issues of risk of bias and indirectness of the evidence. Clinicians should remain skeptical about the potential benefit of any adjunct in clinical practice.

Oral Cancer Knowledge, Attitudes and Practices among Primary Oral Health Care Dentists in Kuwait

Background: Oral cancer signifies a public health concern of international importance. Early detection of oral cancer can improve the prognosis and the 5-year survival rate. Objective: The aim of this study was to assess the level of oral cancer knowledge, opinion, attitudes and practices among dentists working at the primary oral health care centers in Kuwait. Methods: In this cross-sectional study, self-reported questionnaire was distributed to the dentists working at the primary oral health care centers in Kuwait. A total of 289 dentists participated in the present study. The questionnaire included 23- questions on oral cancer knowledge, opinion, attitudes and practices. Results: The mean age of the dentists was 35.2 ± 10.9 years. Approximately, all dentists (99.7%) were aware of the major risk factors that were most likely associated with oral cancer. Overall, majority of the participants knew the most common form of oral cancer (80.6%), most common site (80.3%) and the likely lesions associated with oral cancer occurrence (87.9%). A large number of dental practitioners (81%) would routinely refer a patient with a suspicious lesion to a specialist. Nearly one-third (32%) reviewed their patients’ oral cancer risk factors. Approximately two-thirds (62%) assessed the use of tobacco in their practice. Almost, all (92.4%) were interested in attending continuing education courses on oral cancer. Conclusions: Majority of the participants presented good knowledge about various aspects of oral cancer. More continuing education programs on risk factors and diagnosis of oral cancer should be organized to train the dentists. Oral cancer screening should be a routine procedure for the high risk patients at the primary oral health care centers in Kuwait.

Evaluation of a Lectin-Based Imaging System for the Chairside Detection of Oral Dysplasia and Malignancy

PURPOSE

Currently available oral cancer screening adjuncts have not enhanced clinical screening methods because of high false positives and negatives, highlighting the need for a molecularly specific technique for accurate screening of suspicious oral lesions. The purpose of this study was to evaluate the in vivo screening accuracy of an oral lesion identification system that evaluates aberrant glycosylation patterns using a fluorescently labeled lectin (wheat germ agglutinin and fluorescein isothiocyanate [WGA-FITC]).

MATERIALS AND METHODS

The authors designed and implemented a prospective cohort study at 3 institutions composed of patients with and without suspicious oral lesions. Oral cavities were screened by clinical examination and with the oral lesion identification system according to a stepwise procedure that included the topical application and fluorescence visualization of a fluorescent nuclear stain and WGA-FITC. Tissue samples were obtained from all enrolled patients for histopathological diagnosis and were used to calculate sensitivity and specificity metrics (primary outcome variable) irrespective of the oral lesion identification system result.

RESULTS

The sample was composed of 97 patients; 86 had 100 clinically suspicious lesions and 11 without such lesions were included as a control group. Use of the oral lesion identification system resulted in 100, 100, and 74% sensitivity for cancer, high-grade dysplasia, and low-grade dysplasia, respectively, and a specificity of 80%. Clinical diagnosis yielded similar sensitivity values of 84, 100, and 88% for cancer, high-grade dysplasia, and low-grade dysplasia, respectively, and a specificity of 76%. Use of the oral lesion identification system enhanced the visualization of lesion dimensionality and borders.

CONCLUSIONS

The results of this study suggest the oral lesion identification system was a beneficial adjunct to standard clinical examination, because the system provided sensitivity and specificity values similar to or greater than clinical diagnosis.

Current Practice and Emerging Molecular Imaging Technologies in Oral Cancer Screening

Oral cancer is one of the most common cancers globally. Survival rates for patients are directly correlated with stage of diagnosis; despite this knowledge, 60% of individuals are presenting with late-stage disease. Currently, the initial evaluation of a questionable lesion is performed by a conventional visual examination with white light. If a lesion is deemed suspicious, a biopsy is taken for diagnosis. However, not all lesions present suspicious under visual white light examination, and there is limited specificity in differentiating between benign and malignant transformations. Several vital dyes, light-based detection systems, and cytology evaluation methods have been formulated to aid in the visualization process, but their lack of specific biomarkers resulted in high false-positive rates and thus limits their reliability as screening and guidance tools. In this review, we will analyze the current methodologies and demonstrate the need for specific intraoral imaging agents to aid in screening and diagnosis to identify patients earlier. Several novel molecular imaging agents will be presented as, by result of their molecular targeting, they aim to have high specificity for tumor pathways and can support in identifying dysplastic/cancerous lesions and guiding visualization of biopsy sites. Imaging agents that are easy to use, inexpensive, noninvasive, and specific can be utilized to increase the number of patients who are screened and monitored in a variety of different environments, with the ultimate goal of increasing early detection.

Two-channel autofluorescence analysis for oral cancer

We created a two-channel autofluorescence test to detect oral cancer. The wavelengths 375 and 460 nm, with filters of 479 and 525 nm, were designed to excite and detect reduced-form nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) autofluorescence. Patients with oral cancer or with precancerous lesions, and a control group with healthy oral mucosae, were enrolled. The lesion in the autofluorescent image was the region of interest. The average intensity and heterogeneity of the NADH and FAD were calculated. The redox ratio [(NADH)/(NADH + FAD)] was also computed. A quadratic discriminant analysis (QDA) was used to compute boundaries based on sensitivity and specificity. We analyzed 49 oral cancer lesions, 34 precancerous lesions, and 77 healthy oral mucosae. A boundary (sensitivity: 0.974 and specificity: 0.898) between the oral cancer lesions and healthy oral mucosae was validated. Oral cancer and precancerous lesions were also differentiated from healthy oral mucosae (sensitivity: 0.919 and specificity: 0.755). The two-channel autofluorescence detection device and analyses of the intensity and heterogeneity of NADH, and of FAD, and the redox ratio combined with a QDA classifier can differentiate oral cancer and precancerous lesions from healthy oral mucosae.

An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy, and despite advances in cancer therapies, the overall 5-year survival rate has remained below 50% over the past decades. OSCC is typically preceded by potentially malignant disorders (PMD), but distinguishing high-risk from low-risk PMD is challenging. In the last years, several diagnostic methods as light-based detection systems (LBDS) have been proposed to facilitate the detection of OSCC and PMD. Furthermore, the recent evolution of nanotechnology may provide new opportunities to detect PMD and OSCC at an early stage. Indeed, several preclinical studies showed the potential of nanotechnology to enhance diagnostic accuracy. For these reasons, it is fundamental to conduct studies to evaluate the efficacy of nanotechnology implementation in LBDS. The aim of this article is to review the current literature on LBDS and to provide a summary of the sensitivity and specificity of each technique, and possible future applications of nanotechnologies. The LBDS showed great potential for screening and monitoring oral lesions, but there are several factors that hinder an extensive use of these devices. These devices seem to be useful in assessing lesion margins that must be biopsied. However, to date, conventional oral examination, and tissue biopsy remain the gold standard for OSCC diagnosis. The use of nanotechnologies could be the next step in the evolution of LBDS, thus providing devices that can help clinicians to detect and better monitor oral lesions.

Role of Chemiluminescence examination as non-invasive diagnostic tool in early detection of Leukoplakia

OBJECTIVES

To assess the efficacy of Chemiluminescent light (Vizilite plus) in enhancing visualization and its ability to highlight Leukoplakia lesion.

MATERIAL AND METHODS

This was a cross-sectional study done on 40 study subjects. Subjects were inducted into the study irrespective of age and sex based on the specific inclusion and exclusion criteria. The lesion parameters like the location of the lesion, the shape of lesion, the size, the extent, borders and the presence or absence of any adjacent satellite lesions were assessed under Incandescent light followed by Toluidine blue and Vizilite plus examinations. Histopathological examination results were considered as the gold standard and TBLU and CHEM outcomes were compared to them.

RESULTS

Vizilite plus examination method was most effective in assessing the size, borders and shape of the lesions followed by Toluidine blue and Incandescent light examinations. Toluidine blue and Vizilite plus examination methods demonstrated the sensitivity of 100% and specificity of 97.3%. They also demonstrated PPV of 100% and NPV of 75% with reliable accuracy of 97.5%.

CONCLUSION

Chemiluminescent light is a stepping stone and has the potential to revolutionize the diagnostic protocol for patients with potentially premalignant lesions. The device can be used as a general oral mucosal examination system and may in particular improve the visualization of potentially premalignant lesions.

Inter-and intra-observer agreement on the judgment of toluidine blue staining for screening of oral potentially malignant disorders and oral cancer

OBJECTIVE

Toluidine blue staining (TBS) is used for screening of oral potentially malignant disorders (OPMDs) and oral cancer. Nevertheless, the judgment of TBS is based on the observer's personal experience and largely considered subjective. The aim of this study was to evaluate the inter- and intra-observer agreement on the judgment of TBS for screening of OPMDs and oral cancer.

MATERIALS AND METHODS

Two hundred randomly ordered TBS images of OPMDs and oral cancer were judged twice independently by four clinicians and four graduated students majored in oral medicine, with an interval of 3 months. Inter- and intra-observer agreement was evaluated by the Cohen's kappa (κ) coefficient. The correlation between κ-value and individual experience was assessed by Spearman's correlation coefficient.

RESULTS

For the two sets of observation, good overall inter-observer agreement was found in the study (κ = 0.620 and 0.667). Sub-group analysis yielded good inter-observer agreement both for clinicians (κ = 0.613 and 0.611) and students (κ = 0.610 and 0.665). Pairwise inter-observer agreement was presented to be moderate to excellent between clinician and clinician (κ = 0.41~0.87, 0.43~0.81), moderate to excellent between student and student (κ = 0.43~0.71, 0.53~0.82), and poor to excellent between clinician and student (κ = 0.25~0.81, 0.35~0.87). Good to excellent intra-observer agreement (κ = 0.69~0.85) was presented for eight observers. However, no correlation was illustrated between years of experience and inter- or intra-observer agreement.

CONCLUSION

Judgment of TBS has a good overall inter-observer agreement and good to excellent intra-observer agreement, which guarantees its utilization and popularity in detecting OPMDs and oral cancer.

CLINICAL RELEVANCE

To our knowledge, this is the first study to investigate the inter- and intra-observer agreement of TBS judgment. The present results revealed a good inter-observer agreement and good to excellent intra-observer agreement, which provide a beneficial supplement to the knowledge of TBS technique.

Diagnostic adjuncts on oral cancer and precancer: an update for practitioners

A variety of devices and techniques are now available to aid the clinician in visualising clinical changes that may be found in the oral cavity. These techniques can now be applied at chairside to characterise these changes and many offer a real time result at the point of care. They may assist in a practitioner referring a case earlier to a specialist to undertake further investigations. The translational value of the research published so far has been limited as these technologies have not been adapted for routine use in primary care. This review aims to examine the utility of these adjunctive aids in clinical practice based on the current available evidence.

A clinicopathologic and epidemiologic study of chronic white lesions in the oral mucosa

Invasive oral squamous cell carcinoma is often preceded by the presence of clinically identifiable premalignant changes of the oral mucosa, including white lesions. We conducted a cross-sectional, observational study to assess the clinicopathologic and epidemiologic aspects of chronic oral mucosal white lesions to determine the necessity of early biopsy in these cases. Our study population was made up of 77 patients-50 males and 27 females, aged 15 to 70 years (mean: 42.9)-who presented with white lesions persisting for at least 4 weeks. All but 3 patients underwent a biopsy; the 3 exceptions were diagnosed with smear-proven candidiasis. Patients with moderate or severe dysplasia underwent an excision biopsy. The buccal mucosa was the single most common site of white lesions, occurring in 15 patients (19.5%), although 21 patients (27.3%) exhibited a diffuse involvement of the oral mucosa. Of the 77 patients, 59 (76.6%) had concerning findings: premalignant lesions in 45 patients (58.4%) and malignant lesions in 14 (18.2%). Also, dysplasia was seen in 8 patients (10.4%), all of whom had premalignant lesions. Tobacco chewing (p = 0.008) and betel quid chewing (p = 0.029) were significantly associated with the development of premalignant and malignant lesions; a longer duration of tobacco chewing (≥10 yr) was significantly associated with a higher risk of malignant but not premalignant lesions (p = 0.031). Finally, illiteracy was a significant risk factor for premalignant and malignant lesions (p = 0.03). Our findings support the necessity of biopsy in every case. Early detection of oral carcinoma by biopsy of all oral white lesions would not only prevent patients from undergoing disfiguring surgery and chemoradiation, but it also would increase the 5-year survival rate.

Characterizing biochemical and morphological variations of clinically relevant anatomical locations of oral tissue in vivo with hybrid Raman spectroscopy and optical coherence tomography technique

This study aims to characterize biochemical and morphological variations of the clinically relevant anatomical locations of in vivo oral tissue (ie, alveolar process, lateral tongue and floor of the mouth) by using hybrid Raman spectroscopy (RS) and optical coherence tomography (OCT) technique. A total of 1049 in vivo fingerprint (FP: 800-1800 cm^-1 ) and high wavenumber (HW: 2800-3600 cm^-1 ) Raman spectra were acquired from different oral tissue (alveolar process = 331, lateral tongue = 339 and floor of mouth = 379) of 26 normal subjects in the oral cavity under the OCT imaging guidance. The total Raman dataset were split into 2 parts: 80% for training and 20% for testing. Tissue optical attenuation coefficients of alveolar process, lateral tongue and the floor of the mouth were derived from OCT images, revealing the inter-anatomical morphological differences; while RS uncovers subtle FP/HW Raman spectral differences among different oral tissues that can be attributed to the differences in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations, enlightening biochemical variability of different oral tissues at the molecular level. Partial least squares-discriminant analysis implemented on the training dataset show that the integrated tissue optical attenuation coefficients and FP/HW Raman spectra provide diagnostic sensitivities of 99.6%, 82.3%, 50.2%, and specificities of 97.0%, 75.1%, 92.1%, respectively, which are superior to using either RS (sensitivities of 90.2%, 77.5%, 48.8%, and specificities of 95.8%, 72.1%, 88.8%) or optical attenuation coefficients derived from OCT (sensitivities of 75.0%, 78.2%, 47.2%, and specificities of 96.2%, 67.7%, 85.0%) for the differentiation among alveolar process, lateral tongue and the floor of the mouth. Furthermore, the diagnostic algorithms applied to the independent testing dataset based on hybrid RS-OCT technique gives predictive diagnostic sensitivities of 100%, 76.5%, 51.3%, and specificities of 95.1%, 77.6%, 89.6%, respectively, for the classifications among alveolar process, lateral tongue and the floor of the mouth, which performs much better than either RS or optical attenuation coefficient derived from OCT imaging. This work suggests that inter-anatomical morphological and biochemical variability are significant which should be considered as an important parameter in the interpretation and rendering of hybrid RS-OCT technique for oral tissue diagnosis and characterization.

Comparative efficacy of chemiluminescence and toluidine blue in the detection of potentially malignant and malignant disorders of the oral cavity

Context:

Early detection of oral cancer is of paramount importance in determining the prognosis of oral cancer. Literature suggests that several diagnostic modalities have been proposed to aid a clinician in early detection of oral cancer without much conclusive evidence.

Aims:

The present study aims to compare toluidine blue and chemiluminescence screening methods in early detection of carcinoma in North Indian population and also to evaluate these methods with histopathological diagnosis.

Methods:

In this prospective study, 42 patients with clinically visible premalignant lesions were included. Demographic data were collected, and suspicious lesions were examined by chemiluminescence light (Vizilite) and followed by local application of toluidine blue (Mashberg's recommendation). Findings were recorded for each lesion under standard incandescent light as positive or negative. Biopsy and histopathological analysis of the tissues were performed.

Statistical Analysis:

Sensitivity, specificity and positive and negative predictive values for the chemiluminescence technique and toluidine blue were calculated for diagnostic tests.

Results and Conclusions:

In the present study, toluidine blue test was found to be moderately sensitive (63.33%) whereas chemiluminescence test (Vizilite) was found to be highly sensitive (90%); however, the test has limited specificity (50%). Thus, the study concluded that both toluidine blue and Vizilite can be used as an adjunct to simple, conventional visual examination and in screening procedure for oral potentially malignant disorders.

Novel quantitative analysis of autofluorescence images for oral cancer screening

OBJECTIVES

VELscope® was developed to inspect oral mucosa autofluorescence. However, its accuracy is heavily dependent on the examining physician's experience. This study was aimed toward the development of a novel quantitative analysis of autofluorescence images for oral cancer screening.

MATERIALS AND METHODS

Patients with either oral cancer or precancerous lesions and a control group with normal oral mucosa were enrolled in this study. White light images and VELscope® autofluorescence images of the lesions were taken with a digital camera. The lesion in the image was chosen as the region of interest (ROI). The average intensity and heterogeneity of the ROI were calculated. A quadratic discriminant analysis (QDA) was utilized to compute boundaries based on sensitivity and specificity.

RESULTS

47 oral cancer lesions, 54 precancerous lesions, and 39 normal oral mucosae controls were analyzed. A boundary of specificity of 0.923 and a sensitivity of 0.979 between the oral cancer lesions and normal oral mucosae were validated. The oral cancer and precancerous lesions could also be differentiated from normal oral mucosae with a specificity of 0.923 and a sensitivity of 0.970.

CONCLUSION

The novel quantitative analysis of the intensity and heterogeneity of VELscope® autofluorescence images used in this study in combination with a QDA classifier can be used to differentiate oral cancer and precancerous lesions from normal oral mucosae.

Adjunctive aids for the detection of oral premalignancy

Early detection of cancer greatly decreases the morbidity and mortality rates and thereby increases the 5-year survival rates. In developing countries like India where the disease is highly prevalent focus is mainly on decreasing the mortality rates which can be easily achieved by detection at an asymptomatic stage. Visual examination has been the standard screening method for screening oral cancer through several decades, and it is well known that conventional visual examination is limited to subjective interpretation and cannot be easily achieved in certain anatomical sites. As a solution to all these adjunctive techniques have emerged, and it has been widely used. An effort is made through this paper to review the most commonly used adjunctive aids for the detection of premalignancy and cancer.

The diagnostic performance parameters of Narrow Band Imaging: A preclinical and clinical study

OBJECTIVES

The oral carcinoma is a widespread pathology and still presents poor prognosis. Among the available procedures for its early detection, Narrow Band Imaging technique allows to assess potential vascular network abnormalities. The reliability of this technique in the detection of dysplastic and neoplastic oral lesions was evaluated in a preclinical and clinical study.

MATERIALS AND METHODS

In the preclinical study, a chemical oral carcinogen was administered to 50 mice to induct both dysplastic and neoplastic oral lesions. In the clinical study 91 patients, bearing suspicious premalignant and malignant oral lesions, have been included. Images of animals' and patients' lesions were acquired under white and Narrow Band Imaging light prior to biopsy. Two expert raters examined the images and classified lesions, which were eventually compared to the histological diagnosis. The diagnostic performance included sensitivity, specificity, positive likelihood ratio, positive and negative predictive values, accuracy, percentages and degree of agreement between raters' evaluation and the histological report.

RESULTS

In the preclinical study sensitivity ranged from 0.57 to 1, specificity from 0.85 to 0.99, positive likelihood ratio from 6.54 to 65.04, positive predictive values from 0.32 to 0.96, negative predictive values from 0.91 to 1 and accuracy from 0.86 to 0.98. In the clinical study sensitivity ranged from 0.63 to 0.99, specificity from 0.89 to 1, positive likelihood ratio from 8.45 to 61.47, positive predictive values from 0.59 to 0.96, negative predictive values from 0.78 to 1 and accuracy from 0.82 to 0.99.

CONCLUSION

Narrow Band Imaging is an accurate technique, which holds a great potential for tumour angiogenesis evaluation and for the subsequent early detection of suspicious premalignant and malignant oral lesions.

Efficacy of light based detection systems for early detection of oral cancer and oral potentially malignant disorders: Systematic review

Background

Earlier detection of oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) is essential for dental professionals to improve patient survival rates. The aim of this systematic review is to to evaluate the effectiveness of devices that utilise the principles of chemiluminescence and tissue autofluorescence as adjuncts in the detection of OSCC and OPMD.

Material and Methods

The electronic retrieval systems and databases searched for relevant articles were PubMed [MEDLINE] and Science direct. The search was for limited articles published in English or with an English abstract and articles published during the period from January 2005 to April 2014. Clinical trials utilized ViziLite, Microlux TM/DL and Visual Enhanced Light scope (VELscope) for early detection of OPMD and OSCC.

Results

Twenty primary studies published satisfied our criteria for selection - 10 utilised chemiluminescence and 10 tissue autofluorescence. Senstivity of Vizilite for detecting OSCC nad OPMD ranged from 77.1 % to 100% and specificity was low that ranged from 0% to 27.8%.Most have shown that chemiluminescence increases the brightness and margins of oral mucosal white lesions and thus assist in identification of mucosal lesions not considered under Conventional visual examination. However, it preferentially detects leukoplakia and may fail to spot red patches. Clinical trials demonstrated that sensitivity of VELscope in detecting malignancy and OPMD ranged from 22 % to 100 % and specificity ranged from 16 % to 100%. Most studies concluded that VELscope can help the experienced clinician to find oral precursor malignant lesions. But it couldnot differentiate between dysplasia and benign inflammatory conditions.

Conclusions

Both devices are simple, non-invasive test of the oral mucosa but are suited for clinicians with sufficient experience and training. More clinical trials in future should be conducted to establish optical imaging as an efficacious adjunct tool in early diagnosis of OSCC and OPMD.

Key words:Oral cancer, early diagnosis, potentially malignant disorders, chemiluminescence, tissue autofluorescence, VELscope, ViziLite plus.

Non-invasive visual tools for diagnosis of oral cancer and dysplasia: A systematic review

Background

Gold standard for the diagnosis of oral dysplasia (OD) oral squamous cell carcinoma (OSCC) and malignant lesions is the histological examination. Several adjunctive diagnostic techniques have been proposed in order to increase the sensitivity (SE) and specificity (SP) of conventional oral examination and to improve the diagnostic first level accuracy. The aim of this study is to perform a systematic review on non-invasive tools for diagnosis of OD and early OSCC.

Material and Methods

Medline, Scopus, Web of Knowledge databases were searched, using as entry terms “oral dysplasia AND diagnosis” / ”oral cancer AND diagnosis”. Data extracted from each study included number of lesions evaluated, histopathological diagnosis, SE, SP, positive and negative predictive values (PPV and NPV), diagnostic accuracy (DA) and the main conclusions.

Results

After title and abstract scanning of 11.080 records, we selected 35 articles for full text evaluation. Most evaluated tools were autofluorescence (AF), chemiluminescence (CL), toluidine blu (TL) and chemiluminescence associated with toluidine blue (CLTB).

Conclusions

There is a great inhomogeneity of the reported values and there is no significant evidence of superiority of one tool over the other. Further clinical trials with a higher level of evidence are necessary in order to assess the real usefulness visual diagnostic tools.

Key words:Oral dysplasia, oral cancer, diagnosis, visual diagnostic tool, systematic review.

Acetic acid as an adjunct vital stain in diagnosis of tobacco-associated oral lesions: A pilot study

Background:

One of the most important risk factors for oral precancer and cancer in India is the use of tobacco. In chronic tobacco users, the mucosa may appear clinically healthy, however, changes are observed histologically. Screening of such tobacco users for an early diagnosis is, therefore, of paramount importance. Several adjunctive diagnostic modalities have been used in the past, but none has been conclusively validated as confirmative and cost-effective screening methodology. The aim of this study was to evaluate the use of 5% acetic acid as a vital staining agent in tobacco-associated oral lesions.

Materials and Methods:

The study subjects were divided into two groups. Group I (n = 40) subjects with a history of chronic tobacco use and clinically apparent normal mucosa. Group II (n = 40) subjects suspected of having oral cancer, 5% acetic acid was applied to the mucosa/lesions, followed by incisional biopsy for confirmatory diagnosis.

Results:

The sensitivity and specificity for Groups I and II were 97%, 50% and 95%, 60%, respectively. Positive predictive value (PPV) and negative predictive value (NPV) of Group I were 0.95 and 0.66. Group II showed PPV and NPV of 0.95 and 0.60.

Conclusion:

The results of this study suggest that acetic acid holds promise for future. Hence, further studies are needed to be undertaken on a large scale to assess its potential as a screening tool for high-risk individuals and oral cancer.

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

BACKGROUND

Oral squamous cell carcinoma is the most common form of malignancy of the lip and oral cavity, often being proceeded by potentially malignant disorders (PMD). Early detection can reduce the malignant transformation of PMD and can improve the survival rate for oral cancer. The current standard of scalpel biopsy with histology is painful for patients and involves a delay whilst histology is completed; other tests are available that are unobtrusive and provide immediate results.

OBJECTIVES

PRIMARY OBJECTIVE

To estimate the diagnostic accuracy of index tests for the detection of oral cancer and PMD of the lip and oral cavity, in people presenting with clinically evident lesions.

SECONDARY OBJECTIVE

To estimate the relative accuracy of the different index tests.

SEARCH METHODS

The electronic databases were searched on 30 April 2013. We searched MEDLINE (OVID) (1946 to April 2013) and four other electronic databases (the Cochrane Diagnostic Test Accuracy Studies Register, the Cochrane Oral Health Group's Trials Register, EMBASE (OVID) and MEDION (Ovid)). There were no restrictions on language in the searches of the electronic databases. We conducted citation searches and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting PMD or oral squamous cell carcinoma of the lip or oral cavity: vital staining, oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using QUADAS-2. Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

MAIN RESULTS

We included 41 studies, recruiting 4002 participants, in this review. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (14 studies), oral cytology (13 studies), light-based detection or oral spectroscopy (13 studies). Six studies assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis.The summary estimates for vital staining obtained from the meta-analysis were sensitivity of 0.84 (95% CI 0.74 to 0.90) with specificity of 0.70 (0.59 to 0.79), with 14 studies were included in the meta-analysis. For cytology, sensitivity was 0.91 (0.81 to 0.96) and specificity was 0.91 (0.81 to 0.95) with 12 studies included in the meta-analysis. For light-based detection, sensitivity was 0.91 (0.77 to 0.97) and specificity was 0.58 (0.22 to 0.87) with 11 studies included in the meta-analysis. The relative test accuracy was assessed by adding covariates to the bivariate analysis, no difference in model fit was observed.

AUTHORS' CONCLUSIONS

The overall quality of the included studies was poor. None of the adjunctive tests can be recommended as a replacement for the currently used standard of a scalpel biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation.

Techniques for early diagnosis of oral squamous cell carcinoma: Systematic review

Background and objectives

The diagnosis of early oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) is of paramount clinical importance given the mortality rate of late stage disease. The aim of this study is to review the literature to assess the current situation and progress in this area.

Material and Methods

A search in Cochrane and PubMed (January 2006 to December 2013) has been used with the key words “squamous cell carcinoma”, “early diagnosis” “oral cavity”, “Potentially Malignant Disorders” y “premalignant lesions”. The inclusion criteria were the use of techniques for early diagnosis of OSCC and OPMD, 7 years aged articles and publications written in English, French or Spanish. The exclusion criteria were case reports and studies in other languages.

Results

Out of the 89 studies obtained initially from the search 60 articles were selected to be included in the systematic review: 1 metaanalysis, 17 systematic reviews, 35 prospective studies, 5 retrospective studies, 1 consensus and 1 semi-structured interviews.

Conclusions

The best diagnostic technique is that which we have sufficient experience and training. Definitely tissue biopsy and histopathological examination should remain the gold standard for oral cancer diagnose. In this systematic review it has not been found sufficient scientific evidence on the majority of proposed techniques for early diagnosis of OSCC, therefore more extensive and exhaustive studies are needed.

Key words: Squamous cell carcinoma, early diagnosis, oral cavity, potentially malignant disorders, premalignant lesions.

Light-emitting diode-assisted narrow band imaging video endoscopy system in head and neck cancer

Background/Aims

To validate the effectiveness of a newly developed light-emitting diode (LED)-narrow band imaging (NBI) system for detecting early malignant tumors in the oral cavity.

Methods

Six men (mean age, 51.5 years) with early oral mucosa lesions were screened using both the conventional white light and LED-NBI systems.

Results

Small elevated or ulcerative lesions were found under the white light view, and typical scattered brown spots were identified after shifting to the LED-NBI view for all six patients. Histopathological examination confirmed squamous cell carcinoma. The clinical stage was early malignant lesions (T1), and the patients underwent wide excision for primary cancer. This is the pilot study documenting the utility of a new LED-NBI system as an adjunctive technique to detect early oral cancer using the diagnostic criterion of the presence of typical scattered brown spots in six high-risk patients.

Conclusions

Although large-scale screening programs should be established to further verify the accuracy of this technology, its lower power consumption, lower heat emission, and higher luminous efficiency appear promising for future clinical applications.

Assessing the accuracy of autofluorescence, chemiluminescence and toluidine blue as diagnostic tools for oral potentially malignant disorders--a clinicopathological evaluation

OBJECTIVES

Early detection of oral cancer and their precursors is the key to reducing the high mortality rate attributable to oral cancer. A variety of new chair-side diagnostic tools are currently available that may enhance oral mucosal examination and facilitate the detection of benign and malignant disorders. The aim of this study was to investigate the accuracy of autofluorescence, chemiluminescence and toluidine blue (TBlue) when used in combination against conventional oral examination and surgical biopsy for the detection and assessing risk status of oral potentially malignant disorders.

MATERIALS AND METHODS

A total of 126 patients, with white, red and mixed white and red patches were included. Following a comprehensive oral examination, all patients underwent a standard protocol of autofluorescence, chemiluminescence and TBlue examination. A surgical biopsy was performed to assess oral epithelial dysplasia.

RESULTS

Seventy patients had leukoplakia/erythroplakia and 44 had epithelial dysplasia. In relation to leukoplakia/erythroplakia, autofluorescence, chemiluminescence and TBlue showed a sensitivity of 87.1, 77.1 and 52.9 % and a specificity of 21.4, 26.8 and 67.9 %, respectively. For dysplasia cases, autofluorescence, chemiluminescence and TBlue showed sensitivity and specificity of 84.1, 77.3 and 56.8 % and 15.3, 27.8 and 65.8 %, respectively.

CONCLUSION

While all the three tests were useful in detecting oral mucosal changes, their accuracy in identifying oral potentially malignant disorders (OPMD) is questionable. However, in combination, the tests yielded better results, with improved specificity.

CLINICAL RELEVANCE

These research tools are helpful in specialist clinics but further studies are necessary to examine their role in screening in primary care settings.