The use of light-based (optical) detection systems as adjuncts in the detection of oral cancer and oral potentially malignant disorders: a systematic review

Development and Evaluation of an Automated Multimodal Mobile Detection of Oral Cancer Imaging System to Aid in Risk-Based Management of Oral Mucosal Lesions

Oral cancer is a major global health problem. It is commonly diagnosed at an advanced stage, although often preceded by clinically visible oral mucosal lesions, termed oral potentially malignant disorders, which are associated with an increased risk of oral cancer development. There is an unmet clinical need for effective screening tools to assist front-line healthcare providers to determine which patients should be referred to an oral cancer specialist for evaluation. This study reports the development and evaluation of the mobile detection of oral cancer (mDOC) imaging system and an automated algorithm that generates a referral recommendation from mDOC images. mDOC is a smartphone-based autofluorescence and white light imaging tool that captures images of the oral cavity. Data were collected using mDOC from a total of 332 oral sites in a study of 29 healthy volunteers and 120 patients seeking care for an oral mucosal lesion. A multimodal image classification algorithm was developed to generate a recommendation of "refer" or "do not refer" from mDOC images using expert clinical referral decision as the ground truth label. A referral algorithm was developed using cross-validation methods on 80% of the dataset and then retrained and evaluated on a separate holdout test set. Referral decisions generated in the holdout test set had a sensitivity of 93.9% and a specificity of 79.3% with respect to expert clinical referral decisions. The mDOC system has the potential to be utilized in community physicians' and dentists' offices to help identify patients who need further evaluation by an oral cancer specialist. Prevention Relevance: Our research focuses on improving the early detection of oral precancers/cancers in primary dental care settings with a novel mobile platform that can be used by front-line providers to aid in assessing whether a patient has an oral mucosal condition that requires further follow-up with an oral cancer specialist.

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.

The Diagnostic Potential of Non-Invasive Tools for Oral Cancer and Precancer: A Systematic Review

OBJECTIVES

This systematic review aimed to analyse the published evidence for the use of non-invasive methods for the early detection of oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs).

METHODS

The literature was systematically searched through several databases: PubMed, Cochrane Library, and Web of Science. Additional exploration was performed through cross-checks on the bibliographies of selected reviews. The inclusion criteria involved studies assessing the application of non-invasive tests on humans in the screening, diagnosis, or surveillance of OSCC or OPMDs and reporting sensitivity (SE) and specificity (SP). The Newcastle-Ottawa scale (NOS) was applied to assess the quality of the studies included.

RESULTS

The search strategy resulted in 8012 preliminary records. After a duplicate check, 116 titles remained. After abstract analysis, 70 papers remained. After full text analysis, only 54 of the 70 papers fit the inclusion criteria (28 were original articles and 26 were reviews). Those 26 reviews were used to manually search for further original articles. From this last search, 33 original articles were found. Thus, a total of 61 original studies were included and investigated. Findings from this systematic review indicate useful information, such as a description of the mechanisms, ease of use, limitations, and SE and SP values, to drive the choice of the optimal minimally invasive method to be utilized as an adjunctive tool to examine the suspicious lesions.

CONCLUSIONS

Each of the analysed tools can be improved or implemented, considering their high SE and low SP. Despite advancements, incisional biopsy continues to be the gold standard for the definitive diagnosis of oral cancer and precancerous lesions. Further research and development are essential to improving the sensitivity, specificity, and reliability of non-invasive tools for widespread clinical application.

Salivary metabolomics in oral potentially malignant disorders and oral cancer patients-a systematic review with meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to assess the diagnostic potential of salivary metabolomics in the detection of oral potentially malignant disorders (OPMDs) and oral cancer (OC).

MATERIALS AND METHODS

A systematic review was performed in accordance with the 3rd edition of the Centre for Reviews and Dissemination (CRD) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Electronic searches for articles were carried out in the PubMed, Web of Science, and Scopus databases. The quality assessment of the included studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale (NOS) and the new version of the QUADOMICS tool. Meta-analysis was conducted whenever possible. The effect size was presented using the Forest plot, whereas the presence of publication bias was examined through Begg's funnel plot.

RESULTS

A total of nine studies were included in the systematic review. The metabolite profiling was heterogeneous across all the studies. The expression of several salivary metabolites was found to be significantly altered in OPMDs and OCs as compared to healthy controls. Meta-analysis was able to be conducted only for N-acetylglucosamine. There was no significant difference (SMD = 0.15; 95% CI - 0.25-0.56) in the level of N-acetylglucosamine between OPMDs, OC, and the control group.

CONCLUSION

Evidence for N-acetylglucosamine as a salivary biomarker for oral cancer is lacking. Although several salivary metabolites show changes between healthy, OPMDs, and OC, their diagnostic potential cannot be assessed in this review due to a lack of data. Therefore, further high-quality studies with detailed analysis and reporting are required to establish the diagnostic potential of the salivary metabolites in OPMDs and OC.

CLINICAL RELEVANCE

While some salivary metabolites exhibit significant changes in oral potentially malignant disorders (OPMDs) and oral cancer (OC) compared to healthy controls, the current evidence, especially for N-acetylglucosamine, is inadequate to confirm their reliability as diagnostic biomarkers. Additional high-quality studies are needed for a more conclusive assessment of salivary metabolites in oral disease diagnosis.

Novel 3D printed probe for bioimpedance spectroscopic measurement of oral mucosa: design and testing with ex vivo porcine oral tissues

Three-dimensional (3D) printing has a high potential in various biomedical applications. We hypothesize that 3D printing could be a viable option to construct novel bioimpedance spectroscopic (BIS) sensors suitable for electrochemical characterization of oral mucosal tissues. Previous BIS studies have relied on hand-made probes possessing significant limitations related to their single patient disposable use, large inter-probe differences, and weak reproducibility of measurement. There is also uncertainty related to the effect of varying loading pressure between the probe and biological tissue. Here, we introduce three differently sized rectangular shaped 3D printed probes and test those using a four-terminal measurement principle on various porcine oral tissue samples. We find that constructing a fully 3D printed probe is a challenging task, prone to issues relating to short-circuiting or electrochemical corrosion. However, our final prototype version, constructed with silver-coated copper electrodes, showed favorable characteristics in BIS experiments. All three differently sized probes were able to differentiate between different tissue types with excellent reproducibility. The effect of loading pressure was found to be almost negligible when using small- and medium-sized probes. However, further studies are needed to measure tissues with uneven surfaces, such as palatinum, and to avoid manual or (electro)chemical surface-finishing steps.

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.

Testing the accuracy of autofluorescence device in diagnosing oral potentially malignant disorders among people with HIV seeking dental care

OBJECTIVES

Although many studies have assessed the diagnostic accuracy of autofluorescence in oral potentially malignant disorders (OPMDs), there has been a paucity of such information in high-risk populations. Our study thereby tested the accuracy of using autofluorescence in the oral examination of suspicious lesions among patients seeking care at an HIV-specialized dental clinic in Houston, Texas.

MATERIALS AND METHODS

We performed a prospective single-arm design in which forty-four (44) HIV-infected individuals seeking dental care at a specialized-HIV dental clinic were recruited. Each subject had their oral cavity examined under conventional lighting and then used a fluorescence light-based handheld device (OralID®). Biopsy was obtained from unresolved suspicious OPMDs at the 15-day follow-up, and histopathological analysis was conducted. The oral lesions, not the patient, were treated as the unit of analysis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated using SPSS.

RESULTS

The results showed that OPMDs could be identified with a sensitivity of 90%, a specificity of 18%, an NPV of 86%, a PPV of 24% using the fluorescence light-based handheld device, with a diagnostic accuracy of 55%.

CONCLUSIONS

Despite the low specificity, fluorescence light can complement clinical oral cancer screening and aid identification of OPMDs during biopsy procedures.

CLINICAL RELEVANCE

Our findings suggest that autofluorescence devices could supplement clinical oral examination and aid the identification of OPMDs during biopsy procedures, potentially improving oral cancer screening among HIV-positive patients seeking care.

Smart Diagnostics: Combining Artificial Intelligence and In Vitro Diagnostics

We are beginning a new era of Smart Diagnostics-integrated biosensors powered by recent innovations in embedded electronics, cloud computing, and artificial intelligence (AI). Universal and AI-based in vitro diagnostics (IVDs) have the potential to exponentially improve healthcare decision making in the coming years. This perspective covers current trends and challenges in translating Smart Diagnostics. We identify essential elements of Smart Diagnostics platforms through the lens of a clinically validated platform for digitizing biology and its ability to learn disease signatures. This platform for biochemical analyses uses a compact instrument to perform multiclass and multiplex measurements using fully integrated microfluidic cartridges compatible with the point of care. Image analysis digitizes biology by transforming fluorescence signals into inputs for learning disease/health signatures. The result is an intuitive Score reported to the patients and/or providers. This AI-linked universal diagnostic system has been validated through a series of large clinical studies and used to identify signatures for early disease detection and disease severity in several applications, including cardiovascular diseases, COVID-19, and oral cancer. The utility of this Smart Diagnostics platform may extend to multiple cell-based oncology tests via cross-reactive biomarkers spanning oral, colorectal, lung, bladder, esophageal, and cervical cancers, and is well-positioned to improve patient care, management, and outcomes through deployment of this resilient and scalable technology. Lastly, we provide a future perspective on the direction and trajectory of Smart Diagnostics and the transformative effects they will have on health care.

Field validation of deep learning based Point-of-Care device for early detection of oral malignant and potentially malignant disorders

Early detection of oral cancer in low-resource settings necessitates a Point-of-Care screening tool that empowers Frontline-Health-Workers (FHW). This study was conducted to validate the accuracy of Convolutional-Neural-Network (CNN) enabled m(mobile)-Health device deployed with FHWs for delineation of suspicious oral lesions (malignant/potentially-malignant disorders). The effectiveness of the device was tested in tertiary-care hospitals and low-resource settings in India. The subjects were screened independently, either by FHWs alone or along with specialists. All the subjects were also remotely evaluated by oral cancer specialist/s. The program screened 5025 subjects (Images: 32,128) with 95% (n = 4728) having telediagnosis. Among the 16% (n = 752) assessed by onsite specialists, 20% (n = 102) underwent biopsy. Simple and complex CNN were integrated into the mobile phone and cloud respectively. The onsite specialist diagnosis showed a high sensitivity (94%), when compared to histology, while telediagnosis showed high accuracy in comparison with onsite specialists (sensitivity: 95%; specificity: 84%). FHWs, however, when compared with telediagnosis, identified suspicious lesions with less sensitivity (60%). Phone integrated, CNN (MobileNet) accurately delineated lesions (n = 1416; sensitivity: 82%) and Cloud-based CNN (VGG19) had higher accuracy (sensitivity: 87%) with tele-diagnosis as reference standard. The results of the study suggest that an automated mHealth-enabled, dual-image system is a useful triaging tool and empowers FHWs for oral cancer screening in low-resource settings.

Photodynamic Diagnosis Using 5-Aminolevulinic Acid with a Novel Compact System and Chromaticity Analysis for the Detection of Oral Cancer and High-Risk Potentially Malignant Oral Disorders

Detecting early-stage oral cancer and precancerous lesions are critical to improving patient prognosis and quality of life after treatment. Photodynamic diagnosis using 5-aminolevulinic acid enables the detection of malignant lesions. This study aimed to improve the diagnostic accuracy of photodynamic diagnosis using an objective chromaticity analysis of fluorescence emitted from oral lesions. Sixty-seven patients with clinically suspicious oral cavity lesions underwent photodynamic diagnosis after topical application of 5-aminolevulinic acid solution, followed by imaging and histological evaluation of the lesions. Chromaticity red and green values were measured from the fluorescence images on the lesion, and the red-to-green ratio was calculated. The photodynamic diagnosis allowed for the visualization of oral cancer and high-risk dysplasia as red fluorescence. Compared to low-risk dysplasia and benign lesions, oral cancer and high-risk dysplasia areas had a significantly higher red value and red-to-green ratio. After setting the cutoff value, sensitivity and specificity were 83.3–88.7% and 83.3–83.9%, respectively, when discriminating between oral cancer or high-risk dysplasia and low-risk dysplasia or benign lesions. Photodynamic diagnosis combined with chromaticity analysis may be a valuable diagnostic tool for detecting oral lesions, with a high likelihood of malignant transformation.

Use of DNA image cytometry in conducting oral cancer screening in rural India

OBJECTIVES

Oral cancer screening can assist in the early detection of oral potentially malignant lesions (OPMLs) and prevention of oral cancers. It can be challenging for clinicians to differentiate OPMLs from benign conditions. Adjunct screening tools such as fluorescence visualization (FV) and DNA image cytometry (DNA-ICM) have shown success in identifying OPMLs in high-risk clinics. For the first time we aimed to assess these technologies into Indian rural settings and evaluate if these tools helped clinicians identify high-risk lesions during screening.

METHODS

Dental students and residents screened participants in five screening camps held in villages outside of Hyderabad, India, using extraoral, intraoral, and FV examinations. Lesion and normal tissue brushings were collected for DNA-ICM analysis and cytology.

RESULTS

Of the 1116 participants screened, 184 lesions were observed in 152 participants. Based on white light examination (WLE), 45 lesions were recommended for biopsy. Thirty-five were completed on site; 25(71%) were diagnosed with low-grade dysplasias (17 mild dysplasia, 8 moderate dysplasia) and the remaining 10 showed no signs of dysplasia. FV loss was noted in all but one dysplastic lesion and showed a sensitivity of 96% and specificity of 17%. Cytology combined with DNA-ICM had a 64% sensitivity and 86% specificity in detecting dysplasia.

CONCLUSION

DNA-ICM combined with cytology identified majority of dysplastic lesions and identified additional lesions, which were not considered high-risk during WLE to biopsy on site. Efforts to follow-up with these participants are ongoing. FV identified most high-risk lesions but added limited value over WLE.

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.

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.

Burden of Oral Cancer on the 10 Most Populous Countries from 1990 to 2019: Estimates from the Global Burden of Disease Study 2019

Background: Oral cancer (OC) is a common tumour that poses a threat to human health and imposes a heavy burden on countries. This study assessed the burden imposed by OC on the 10 most populous countries from 1990 to 2019 on the basis of gender, age and socio-demographic index. Methods: Data on incidence, mortality, disability-adjusted life years (DALY) and corresponding age-standardised rates (ASR) for OC in the 10 most populous countries from 1990 to 2019 were derived from the Global Burden of Disease Study 2019. Estimated annual percentage changes were calculated to assess the trends of morbidity, mortality and DALY. The indicator that served as a proxy for survival rate was the supplement of mortality-to-incidence ratio (SMIR) (1 − (M/I)). Results: The number of new cases, deaths and DALY have increased in all 10 countries in the past 30 years. Trends in age-standardised incidence rates (ASIR), age-standardised mortality rate (ASMR) and age-standardised DALY for OC in the 10 most populous countries varied. The SMIR increased in all countries, with most countries having an SMIR between 30% and 50%. In 2019, the United States had the highest SMIR at 76%, whereas Russia had the lowest at 21.7%. Incidence and mortality were close between male and female subjects in Japan, Indonesia, Mexico, India, Bangladesh and Pakistan. The incidence and mortality in male subjects in the United States, Russia, China and Brazil were two or more times those of female subjects. Gender difference was highest among patients aged 40–69 years. Conclusion: Trends and gender differences in ASIR, ASMR and age-standardised DALY for OC vary in the 10 most populous countries. Government cancer programs are often expensive to run, especially in countries with large populations. Policy makers need to take these differences into account when formulating policies.

Clinical assessment for the detection of oral cavity cancer and potentially malignant disorders in apparently healthy adults

BACKGROUND

The early detection of oral cavity squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD), followed by appropriate treatment, may improve survival and reduce the risk for malignant transformation respectively. This is an update of a Cochrane Review first published in 2013.

OBJECTIVES

To estimate the diagnostic test accuracy of conventional oral examination, vital rinsing, light-based detection, mouth self-examination, remote screening, and biomarkers, used singly or in combination, for the early detection of OPMD or OSCC in apparently healthy adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 October 2020), MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. 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 test accuracy of any of the aforementioned tests in detecting OPMD or OSCC during a screening procedure. Diagnosis of OPMD or OSCC was provided by specialist clinicians or pathologists, or alternatively through follow-up.

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). We reported the sensitivity and specificity of the included studies. We provided judgement of the certainty of the evidence using a GRADE assessment.

MAIN RESULTS

We included 18 studies, recruiting 72,202 participants, published between 1986 and 2019. These studies evaluated the diagnostic test accuracy of conventional oral examination (10 studies, none new to this update), mouth self-examination (four studies, two new to this update), and remote screening (three studies, all new to this update). One randomised controlled trial of test accuracy directly evaluated conventional oral examination plus vital rinsing versus conventional oral examination alone. There were no eligible studies evaluating light-based detection or blood or salivary sample analysis (which tests for the presence of biomarkers for OPMD and OSCC). Only one study of conventional oral examination was judged as at overall low risk of bias and overall low concern regarding applicability. Given the clinical heterogeneity of the included studies in terms of the participants recruited, setting, prevalence of the target condition, the application of the index test and reference standard, and the flow and timing of the process, the data could not be pooled within the broader categories of index test. For conventional oral examination (10 studies, 25,568 participants), prevalence in the test accuracy sample ranged from 1% to 51%. For the seven studies with prevalence of 10% or lower, a prevalence more comparable to the general population, the sensitivity estimates were variable, and ranged from 0.50 (95% confidence interval (CI) 0.07 to 0.93) to 0.99 (95% CI 0.97 to 1.00); the specificity estimates were more consistent and ranged from 0.94 (95% CI 0.88 to 0.97) to 0.99 (95% CI 0.98 to 1.00). We judged the overall certainty of the evidence to be low, and downgraded for inconsistency and indirectness. Evidence for mouth self-examination and remote screening was more limited. We judged the overall certainty of the evidence for these index tests to be very low, and downgraded for imprecision, inconsistency, and indirectness. We judged the evidence for vital rinsing (toluidine blue) as an adjunct to conventional oral examination compared to conventional oral examination to be moderate, and downgraded for indirectness as the trial was undertaken in a high-risk population.

AUTHORS' CONCLUSIONS

There is a lack of high-certainty evidence to support the use of screening programmes for oral cavity cancer and OPMD in the general population. Frontline screeners such as general dentists, dental hygienists, other allied professionals, and community healthcare workers should remain vigilant for signs of OPMD and OSCC.

Advancements in diagnostic techniques for oral cancer detection

Oral malignancy is among the highest prevalent malignancies all over the world. In comparison to systemic malignancies such as lung cancer and colon cancer, they are frequently overlooked by the general public. Nevertheless, they can be exceedingly lethal if left ignored, regardless at the early stage of the condition. Dentists are the finest qualified healthcare specialists in this sector and are responsible for detecting benign and potentially malignant oral conditions such as oral cancers. Oral carcinoma's high prevalence and delayed appearance are serious international medical concerns. Early detection and management of oral carcinoma are the key goals of the World Health Organization (WHO). The identification of key clinical manifestations during the preliminary oral examination can enhance the patient's likelihood of living. Unfortunately, the conventional technology's practical value is limited by a number of drawbacks. Current advancements in optical scanning techniques, such as tissue-fluorescence imaging and optical coherence tomography, have proven to be quite effective. In particular, nanoparticle-based immunosensors, genomics, and salivary biomarkers, epigenetics and microarray have all received a lot of attention. Raising awareness about frequent dental examinations and using noninvasive, effective, and cost-effective screening tools would improve initial stage detection of oral carcinoma and improve patients' longevity.

The readiness of dentists to use the autofluorescence method

Background. Head and neck squamous cell carcinoma are the sixth most common cancer in prevalence rate. Early diagnosis significantly reduces morbidity and mortality. Autofluorescence facilitates diagnosis the disease at the early stages, but it depends on the doctor’s skill in interpreting images. The aim of the study: to analyze the results of reading autofluorescence images of the oral mucosa by dentists.Materials and methods. The results of reading 10 autofluorescence images of potentially malignant diseases of the oral mucosa and 10 images of benign lesions and conditions were evaluated. The study involved 308 dentists. The assessment of the ability to recognize autofluorescence images was carried out with respect to gender, age, length of service, qualification category, academic degree, position of the head of the department.Results. On the average, dentists correctly differentiated the results of visualization of potentially malignant diseases of the oral mucosa in 3.85 ± 2.47 cases, benign lesions together with other benign conditions – in 4.56 ± 2.47 cases. Images of benign lesions and conditions were identified by dentists better than images of potentially malignant diseases of the oral mucosa (t = –17.0; p < 0.001). There is a direct correlation between the correct differentiation of visualization of potentially malignant diseases of the oral mucosa with the correct interpretation of benign lesions and conditions (r = 0.956; p < 0.001). The interpretation of potentially malignant diseases of the oral mucosa is not related to gender (t = –1.62; p = 0.306), work experience (r = –0.002; p = 0.977), department head (t = –0.11; p = 0.910), qualification category (t = –0.50; p = 0.574), academic degree (t = –0.34; p = 0.731).Conclusion. Dentists cannot recognize diseases of the oral mucosa well in autofluorescence images. The recognition skill is not related to general professional development.

Accuracy of autofluorescence and chemiluminescence in the diagnosis of oral Dysplasia and Carcinoma: A systematic review and Meta-analysis

OBJECTIVES

To define the accuracy of autofluorescence-based (AF) and chemiluminescence-based (CL) systems in the diagnosis of oral dysplastic and malignant lesions in addition to the Conventional Oral Examination (COE).

MATERIALS AND METHODS

The study was performed according to the PRISMA-DTA guidelines.

RESULTS

A total of 2631 oral cavity lesions (AF, n = 2076; CL, n = 555) from 26 studies (AF = 17; CL = 9) was used for calculation of diagnostic accuracy parameters. The overall pooled sensitivity and specificity of the AF were 81.3% (95% CI: 74.3% - 87.5%) and 52.1% (95% CI: 36.9% - 67.1%), respectively. Cumulative diagnostic odds ratio (DOR) was 5.44 (95% CI: 2.29 - 10.56) with a significant heterogeneity between studies (I² = 80.7%, 95% CI: 70.0% - 86.7%; p < .05). The overall pooled sensitivity and specificity for the CL were 84.9% (95% CI: 66.7% - 96.7%) and 51.8% (95% CI: 37.3% - 65.9%), respectively. The overall pooled DOR was 8.59 (95% CI: 2.11 - 22.38) with a significant heterogeneity between studies (I² = 65.4%, 95% CI: 29.6% - 83.0%; p < .05).

CONCLUSIONS

AF and CL present a high sensitivity in the diagnosis of dysplastic and malignant oral cavity lesions, demonstrating that diagnostic biopsies may be avoided in case of a negative test result. Both tests have a low specificity, and the reduction of the false positive rate compared to the COE alone remains poor.

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.

Identification of Salivary Proteomic Biomarkers for Oral Cancer Screening

BACKGROUND/AIM

The current study aimed to identify biomarkers for differentiating between patients with oral cancer (OC) and healthy controls (HCs) on the basis of the comprehensive proteomic analyses of saliva samples by using liquid chromatography-mass spectrometry (LC-MS/MS).

PATIENTS AND METHODS

Unstimulated saliva samples were collected from 39 patients with OC and from 31 HCs. Proteins in the saliva were comprehensively analyzed using LC-MS/MS. To differentiate between patients with OC and HCs, a multiple logistic regression model was developed for evaluating the discriminatory ability of a combination of multiple markers.

RESULTS

A total of 23 proteins were significantly differentially expressed between the patients with OC and the HCs. Six out of the 23 proteins, namely α-2-macroglobulin-like protein 1, cornulin, hemoglobin subunit β, Ig k chain V-II region Vk167, kininogen-1 and transmembrane protease serine 11D, were selected using the forward-selection method and applied to the multiple logistic regression model. The area under the curve for discriminating between patients with OC and HCs was 0.957 when the combination of the six metabolites was used (95% confidence interval=0.915-0.998; p<0.001). Furthermore, these candidate proteins did not show a stage-specific difference.

CONCLUSION

The results of the current study showed that six salivary proteins are potential non-invasive biomarkers for OC screening.

Management of oral leukoplakia: a position paper of the Society of Oral Medicine, Chinese Stomatological Association

OBJECTIVE

The objective of this study was to develop the first edition of a Chinese evidence-based position paper on the management of oral leukoplakia (OLK).

STUDY DESIGN

The consultant group for drafting the position paper consisted of 31 oral medicine specialists and 2 evidence-based medicine specialists. English studies (searched in PubMed, EMBASE, and the Cochrane Library) and Chinese studies (searched in China National Knowledge Infrastructure and WanFang) published before January 2018 were used. The quality of the study was assessed using the Grading of Recommendations Assessment, Development, and Evaluation grid, and the strength of the recommendations was determined based on the results of 3 rounds of voting among the consultant group members using the Delphi method.

RESULTS

Twenty-two evidence-based guidelines for clinical management and monitoring of OLK were established in this position paper. A clinical path diagram for oral health practitioners was constructed based on the recommendations.

CONCLUSION

Current evidence suggests that management and monitoring of patients with OLK should be performed by experienced clinicians to control the lesion and for early detection of malignant transformation. However, all recommendations are based on evidence of low or extremely low quality and may require further modification as new evidence is produced.

Recent Advances in Nano-Bio-Sensing Fabrication Technology for the Detection of Oral Cancer

Nanotechnology-based miniaturized devices have been a breakthrough in the pre-clinical and clinical research areas, e.g. drug delivery, personalized medicine. They have revolutionized the discovery and development of biomarker-based diagnostic devices for detection of various diseases such as tuberculosis, malaria and cancer. Nanomaterials (NMs) hold tremendous diagnostic potential due to their high surface-to-volume ratio and quantum confinement phenomenon, improving the detection limit of clinically relevant biomolecules in bio-fluids. Thus, they are helpful in the translation of bench-on platform to point-of-care (POC) screening device. The nanomaterial-based biosensor fabrication technology has also simplified and improved oral cancer (OC) or oral squamous cell carcinomas (OSCC) diagnosis. The fabrication of nano-bio sensors involves application specific modifications of NMs. The unique properties functionalized NMs have augmented their application on the nano-biosensing platform for the detection of clinically relevant biomolecules in bio-fluids. Therefore, this article summarizes the recent advancements in the process of fabrication of nano-biosensors for detection of OC.

An improved algorithm using a Health Canada-approved DNA-image cytometry system for non-invasive screening of high-grade oral lesions

BACKGROUND

DNA-image cytometry (DNA-ICM) is able to detect gross alterations of cellular DNA-content representing aneuploidy, a biomarker of malignancy. A Health Canada-approved DNA-ICM system, ClearCyte^® in combination with a cytopathologist's review, has demonstrated high sensitivity (89%) and specificity (97%) in identifying high-grade oral lesions. The study objective was to create an improved automated algorithm (iClearcyte) and test its robustness in differentiating high grade from benign reactive oral lesions without a cytopathologist's input.

METHODS

A set of 214 oral brushing samples of oral cancer (n = 92), severe dysplasia (n = 20), reactive lesions (n = 52), and normal samples (n = 50) were spun down onto slides and stained using Feulgen-Thionin reaction. Following ClearCyte^® scan, nuclear features were calculated, and nuclei categorized into "diploid," "hyperdiploid," "tetraploid," and "aneuploid" DNA ploidy groups by the ClearCyte^® software. The samples were randomized into training and test sets (70:30) based on patient's age, sex, tobacco use, and lesion site risk. The training set was used to create a new algorithm which was then validated using the remaining samples in the test set, where sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

The proposed iClearCyte algorithm (>1 "aneuploid" cell or ≥ 1.7% combined "hyperdiploid" and "tetraploid" nuclei frequency) identified high-grade samples with sensitivity, specificity, PPV, and NPV of 100.0%, 86.7%, 89.7%, and 100.0%, respectively, in the test set.

CONCLUSION

The iClearCyte test has potential to serve as a robust non-invasive automated oral cancer screening tool promoting early oral cancer detection and decreasing the number of unnecessary invasive biopsies.

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.

Clinicopathological Features Associated with Fluorescence Alteration: Analysis of 108 Oral Malignant and Potentially Malignant Lesions

Background: Several noninvasive diagnostic tools have been developed to aid the early detection of oral cancer and for evaluation before definitive biopsy. Among these, devices evaluating a tissues autofluorescence (AF) are emerging. In particular, the most well known of these is the VELscope^® system (LED Medical Diagnostics, Inc., Barnaby, Canada), which emits a light of 400-460 nm. This study has been developed to describe the most relevant clinicopathological features associated with AF alterations in a set of patients with oral squamous cell carcinoma and potentially malignant disorders (PMDs). Materials and methods: Overall, 108 lesions from 60 patients with clinical diagnoses of potentially malignant oral disorders and carcinomas were included in the study. For each case, the following variables were recorded and compared with the AF pattern: (1) clinical appearance (white, red, and white/red); (2) histological diagnosis (no dysplasia, mild/moderate dysplasia, severe dysplasia/in situ carcinoma, invasive carcinoma, and verrucous carcinoma); and (3) clinicopathological diagnosis. Binomial logistic regression was performed to investigate whether clinical appearance and/or histological diagnosis were significant in determining the degree of AF. Results: Among the white lesions, 66% resulted in hyper-fluorescence, whereas the red lesions appeared hypo-fluorescent in 95.2% of cases. The AF was altered (both hypo-fluorescent and hyper-fluorescent) in 36% of lesions without dysplasia; in 75.9% of lesions with mild or moderate dysplasia and in the totality of the in situ, invasive, and verrucous carcinomas (p < 0.0001). With regard to the binomial logistic regression, variables were separately considered and both were extremely significant in determining the degree of AF. Conclusions: Promising evidence for the use of AF as an adjunctive tool to conventional oral examinations (COEs) has been demonstrated. However, although the sensitivity of AF examination associated with COE is very high, both the literature and this study agree to indicate a low specificity.

Nuclear F-actin Cytology in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Oral cavity cancer has a low 5-y survival rate, but outcomes improve when the disease is detected early. Cytology is a less invasive method to assess oral potentially malignant disorders relative to the gold-standard scalpel biopsy and histopathology. In this report, we aimed to determine the utility of cytological signatures, including nuclear F-actin cell phenotypes, for classifying the entire spectrum of oral epithelial dysplasia and oral squamous cell carcinoma. We enrolled subjects with oral potentially malignant disorders, subjects with previously diagnosed malignant lesions, and healthy volunteers without lesions and obtained brush cytology specimens and matched scalpel biopsies from 486 subjects. Histopathological assessment of the scalpel biopsy specimens classified lesions into 6 categories. Brush cytology specimens were analyzed by machine learning classifiers trained to identify relevant cytological features. Multimodal diagnostic models were developed using cytology results, lesion characteristics, and risk factors. Squamous cells with nuclear F-actin staining were associated with early disease (i.e., lower proportions in benign lesions than in more severe lesions), whereas small round parabasal-like cells and leukocytes were associated with late disease (i.e., higher proportions in severe dysplasia and carcinoma than in less severe lesions). Lesions with the impression of oral lichen planus were unlikely to be either dysplastic or malignant. Cytological features substantially improved upon lesion appearance and risk factors in predicting squamous cell carcinoma. Diagnostic models accurately discriminated early and late disease with AUCs (95% CI) of 0.82 (0.77 to 0.87) and 0.93 (0.88 to 0.97), respectively. The cytological features identified here have the potential to improve screening and surveillance of the entire spectrum of oral potentially malignant disorders in multiple care settings.

Oral potentially malignant disorders: A consensus report from an international seminar on nomenclature and classification, convened by the WHO Collaborating Centre for Oral Cancer

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening period was considered to make essential changes to the 2007 classification. In the current update, most entities were retained with minor changes to their definition. There is sufficient evidence for an increased risk of oral cancer among patients diagnosed with "oral lichenoid lesions" and among those diagnosed with oral manifestations of 'chronic graft-versus-host disease'. These have now been added to the list of OPMDs. There is, to date, insufficient evidence concerning the malignant potential of chronic hyperplastic candidosis and of oral exophytic verrucous hyperplasia to consider these conditions as OPMDs. Furthermore, due to lack of clear evidence of an OPMD in epidermolysis bullosa this was moved to the category with limited evidence. We recommend the establishment of a global research consortium to further study the natural history of OPMDs based on the classification and nomenclature proposed here. This will require multi-center longitudinal studies with uniform diagnostic criteria to improve the identification and cancer risk stratification of patients with OPMDs, link them to evidence-based interventions, with a goal to facilitate the prevention and management of lip and oral cavity cancer.

Non-Invasive Diagnostic System Based on Light for Detecting Early-Stage Oral Cancer and High-Risk Precancerous Lesions-Potential for Dentistry

Simple Summary

The early detection of oral cancer and oral potentially malignant disorders can facilitate minimum intervention and subsequent improvements in prognosis and quality of life after treatment. Recently, several non-invasive adjunctive fluorescence-based detection systems have improved the accuracy of detection and diagnosis of oral cancer and oral potentially malignant disorders. This article summarizes current knowledge about fluorescence-based diagnostic methods and discusses their benefits and drawbacks from a clinical viewpoint.

Abstract

Oral health promotion and examinations have contributed to the early detection of oral cancer and oral potentially malignant disorders, leading to the adaptation of minimally invasive therapies and subsequent improvements in the prognosis/maintenance of the quality of life after treatments. However, the accurate detection of early-stage oral cancer and oral epithelial dysplasia is particularly difficult for conventional oral examinations because these lesions sometimes resemble benign lesions or healthy oral mucosa tissues. Although oral biopsy has been considered the gold standard for accurate diagnosis, it is deemed invasive for patients. For this reason, most clinicians are looking forward to the development of non-invasive diagnostic technologies to detect and distinguish between cancerous and benign lesions. To date, several non-invasive adjunctive fluorescence-based detection systems have improved the accuracy of the detection and diagnosis of oral mucosal lesions. Autofluorescence-based systems can detect lesions as a loss of autofluorescence through irradiation with blue-violet lights. Photodynamic diagnosis using 5-aminolevulinic acid (ALA-PDD) shows the presence of very early oral cancers and oral epithelial dysplasia as a red fluorescent area. In this article, currently used fluorescence-based diagnostic methods are introduced and discussed from a clinical point of view.

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.

Strategies to improve diagnosis and risk assessment for oral cancer patients

To realise the benefits of new diagnostic techniques for the prediction of oral cancer, further validation and multicentre analyses are needed to determine their clinical impact in contemporary practice.

Minimally invasive procedures for the recognition and diagnosis of oral precancer and cancer

Oral cancer represents a blend of genetic and epigenetic instability. Many a times, oral cancer occurs in the background of oral potentially malignant disorders (OPMDs), which could be easily detected and diagnosed. Various diagnostic aids have been explored for early detection of oral cancer. Some of the minimally invasive (chair-side diagnostic) procedures such as vital staining and light-based systems are used widely in the clinical practice as well as in the hospital setting owing to their simple and easy operability. In addition, these chair-side diagnostic procedures offer relatively good sensitivity and specificity despite some of their limitations. These diagnostic tools could complement good clinical history and thorough examination of patients for early detection of oral precancer and cancer.

May VelScope Be Deemed an Opportunistic Oral Cancer Screening by General Dentists? A Pilot Study

Early diagnosis of oral cancer through visual inspection followed by histopathological confirmation is a pivotal step for reducing rates of morbidity and mortality. There are several auxiliary devices used to improve oral examination. The purpose of this cross-sectional pilot study is to evaluate the sensitivity and specificity of the Visually Enhance Lesion Scope (VelScope) system when it is used by the general dentist after a yearly oral medicine training. Thirty-five patients with oral lesions were evaluated with clinical and VelScope examination by two general dentists, one of which trained with a specific course. A comparison of the histopathological results, clinical examination, and VelScope made by both dentists was performed through statistical analysis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detecting oral potentially malignant disorders (OPMDs) are 53.3%, 65%, 53.3%, 76.5% for unskilled dentist, 73.3%, 65%, 61.1%, 76.5% for skilled clinician. When both examiners use VelScope the values are 53.3%, 70%, 57.1%, 66.7% for unskilled general dentist (u-GD), 86.7%, 90%, 86.7%, 90% for skilled general dentist (s-GD). Improvement of a skilled general dentist for detecting malignancies is higher than inexperienced examiner when using VelScope. VelScope alone is unable to improve the general dentist’s ability to detect malignancies, but it could be a useful adjunctive device for clinicians when a focused training program is performed.

NOVEL USE OF FLUORESCEIN DYE IN DETECTION OF ORAL DYSPLASIA AND ORAL CANCER

BACKGROUND

India is now regarded as the country with one of the highest incidence of oral cancer in the world. Considering poor survival in cases with late diagnosis, early detection can reduce morbidity and mortality of cancer patients and may impede malignant transformation in cases of oral potentially malignant disorders (OPMD). Most of the diagnostic aids are expensive and not available for mass screenings in developing countries. There is a need to develop a sensitive and affordable technique for screening of oral cancer, which can be accurate even in hands of health care workers with limited experience. Fluorescein dye has been used for tumour detection in colon, stomach, breast and brain. However, its utility in the diagnosis of oral cancer and OPMD has not yet been explored.

METHODS

This is the first study to report the role of fluorescein in the detection of oral cancer and OPMD. The present cross sectional study was conducted at a tertiary care dental centre. It included 100 individuals presenting with 42 OPMDs, 40 oral squamous cell carcinoma (OSCC) and 18 controls.

RESULTS

The sensitivity and specificity for the fluorescein detection method for OPMDs and OSCC was found to be 96.6% and 52.4% respectively. The positive predictive value was 73.7% and the negative predictive value was 91.7% for the fluorescein method. The likelihood ratios stood at 2.03 for a positive test and 0.066 for a negative test.

CONCLUSION

We conclude that fluorescein staining along with blue light is likely to improve detection of early oral cancers and dysplasia and can play a vital role in mass screening programmes of oral cancer.

The use of Velscope to assess cellular changes occuring in oral premalignancy

Objectives

To improve visualization of suspicious lesions of the oral mucosa and to assess the accuracy of Velscope in assessing cellular changes occurring in oral premalignancy for early diagnosis.

Materials and methods

In this prospective, randomized in-vivo clinical study a total of 250 patients who gave history of chewing tobacco were screened. The selection of the site of biopsy was taken based on the area of loss of fluorescence identified by the Velscope within the lesion. Routine blood investigations were done. A biopsy was performed to confirm the findings of clinical examination. The data was collected and analysed.

Results

Among 200 patients only 110 underwent incisional biopsy. Of these only 89 patients showed neoplastic changes. Of the control biopsies, none of them showed any dysplastic changes. Out of 106 who exhibited speckling under autofluorescence, only 89 showed dysplastic changes whereas only 17 showed no dysplastic changes. Out of these 17 specimens, the histopathological diagnosis of 5 was coated tongue, 3 were pigmented lesions, 3 were geographic tongue and 2 were mucositis. Of the remaining 4, the histopathological diagnosis of 1 was oral submucous fibrosis, 1 was lichen planus and 2 were frictional keratosis.

Conclusion

False positive findings are possible in presence of highly inflamed tissues, and it is possible that use of Velscope alone may result in failure to detect regions of dysplasia, but it has its use definitely to improve clinical decision making about the nature of oral lesions and aids in decisions to biopsy regions of concern. Use of the scope has allowed practitioners to identify the best region for biopsy. It is much better to occasionally sample tissue that turns out to be benign than to fail to diagnose dysplastic or malignant lesions. However, poor specificity is a major limitation for using it as a screening tool.

Point-of-care oral cytology tool for the screening and assessment of potentially malignant oral lesions

BACKGROUND

The effective detection and monitoring of potentially malignant oral lesions (PMOL) are critical to identifying early-stage cancer and improving outcomes. In the current study, the authors described cytopathology tools, including machine learning algorithms, clinical algorithms, and test reports developed to assist pathologists and clinicians with PMOL evaluation.

METHODS

Data were acquired from a multisite clinical validation study of 999 subjects with PMOLs and oral squamous cell carcinoma (OSCC) using a cytology-on-a-chip approach. A machine learning model was trained to recognize and quantify the distributions of 4 cell phenotypes. A least absolute shrinkage and selection operator (lasso) logistic regression model was trained to distinguish PMOLs and cancer across a spectrum of histopathologic diagnoses ranging from benign, to increasing grades of oral epithelial dysplasia (OED), to OSCC using demographics, lesion characteristics, and cell phenotypes. Cytopathology software was developed to assist pathologists in reviewing brush cytology test results, including high-content cell analyses, data visualization tools, and results reporting.

RESULTS

Cell phenotypes were determined accurately through an automated cytological assay and machine learning approach (99.3% accuracy). Significant differences in cell phenotype distributions across diagnostic categories were found in 3 phenotypes (type 1 ["mature squamous"], type 2 ["small round"], and type 3 ["leukocytes"]). The clinical algorithms resulted in acceptable performance characteristics (area under the curve of 0.81 for benign vs mild dysplasia and 0.95 for benign vs malignancy).

CONCLUSIONS

These new cytopathology tools represent a practical solution for rapid PMOL assessment, with the potential to facilitate screening and longitudinal monitoring in primary, secondary, and tertiary clinical care settings.

Oral potentially malignant disorders: A comprehensive review on clinical aspects and management

Oral potentially malignant disorders (OPMDs) include a group of conditions that affect the oral mucosa with an increased risk of malignancy. During their evolution visible changes may be found in the colour or in the thickness of the oral mucosa and these changes can be detected during an oral examination. Their clinical presentations are diverse and their natural history is not well described. Oral leukoplakia is the most commonly encountered OPMD in clinical practice. Use of optical fluorescence imaging or staining with toluidine blue may increase the number of lesions detected compared to oral visual examination alone and may increase border distinction at a subjective level. When stratifying their risk consideration is given to the presence of red areas, size exceeding 200 mm², presence of lichenoid features and a higher grade of dysplasia in the pathology report. Up to a third of OPMDs may transform to squamous cell carcinomas.

A personalized computational model predicts cancer risk level of oral potentially malignant disorders and its web application for promotion of non-invasive screening

BACKGROUND

Despite their high accuracy to recognize oral potentially malignant disorders (OPMDs) with cancer risk, non-invasive oral assays are poor in discerning whether the risk is high or low. However, it is critical to identify the risk levels, since high-risk patients need active intervention, while low-risk ones simply need to be follow-up. This study aimed at developing a personalized computational model to predict cancer risk level of OPMDs and explore its potential web application in OPMDs screening.

METHODS

Each enrolled patient was subjected to the following procedure: personal information collection, non-invasive oral examination, oral tissue biopsy and histopathological analysis, treatment, and follow-up. Patients were randomly divided into a training set (N = 159) and a test set (N = 107). Random forest was used to establish classification models. A baseline model (model-B) and a personalized model (model-P) were created. The former used the non-invasive scores only, while the latter was incremented with appropriate personal features.

RESULTS

We compared the respective performance of cancer risk level prediction by model-B, model-P, and clinical experts. Our data suggested that all three have a similar level of specificity around 90%. In contrast, the sensitivity of model-P is beyond 80% and superior to the other two. The improvement of sensitivity by model-P reduced the misclassification of high-risk patients as low-risk ones. We deployed model-P in web.opmd-risk.com, which can be freely and conveniently accessed.

CONCLUSION

We have proposed a novel machine-learning model for precise and cost-effective OPMDs screening, which integrates clinical examinations, machine learning, and information technology.

Discrimination of oral squamous cell carcinoma from oral lichen planus by salivary metabolomics

OBJECTIVE

This study was conducted to distinguish salivary metabolites in oral squamous cell carcinoma (OSCC) from those in oral lichen planus (OLP) to identify practical biomarkers for the discrimination of OSCC from OLP.

SUBJECTS AND METHODS

Whole unstimulated saliva samples were collected from patients with OSCC (n = 34) and OLP (n = 26). Hydrophilic metabolites in the saliva samples were comprehensively analysed by capillary electrophoresis mass spectrometry. To evaluate the discrimination ability of a combination of multiple markers, a multiple logistic regression (MLR) model was developed to differentiate OSCC from OLP.

RESULTS

Fourteen metabolites were found to be significantly different between the OSCC and OLP groups. Among them, indole-3-acetate and ethanolamine phosphate were used to develop the MLR model. The combination of these two metabolites showed a high area under the receiver operating characteristic curve (0.856, 95% confidential interval: 0.762-0.950; p < .001) for discriminating OSCC from OLP.

CONCLUSIONS

We identified salivary metabolites for discerning between OSCC and OLP, which is clinically important for detecting the malignant transformation of OLP by both dentists and oral surgery specialists. Our candidate salivary metabolites show potential for non-invasive screening of OSCC versus OLP.

Early Diagnosis on Oral and Potentially Oral Malignant Lesions: A Systematic Review on the VELscope® Fluorescence Method

The fluorescence method is an innovative technique used by pathologists for examining body mucosa, and for the abnormalities tissue screening, potentially leading to the earlier discovery of pre-cancer, cancer or other disease processes. The early detection is one of the best mechanisms for enabling treatment success, increasing survival rates and maintaining a high quality of life. The purpose of this review is to evaluate the clinical efficiency of this diagnostic tool applied to the oral cavity (VELscope^®). A literature systematic review has been performed. The initial research provided 53 results after applying the inclusion and exclusion criteria, and after a manual screening of the abstracts by the authors, only 25 results were eligible for review. The results and data contained in all the researches, no older than 10 years, were manually evaluated, and provided useful information on this diagnostic method. The VELscope^® mean value about sensitivity and specificity resulted of 70.19% and 65.95%, respectively, by results analysis, but despite this some studies disagree about its clinical effectiveness, and this diagnostic method is still much debated in scientific and clinical medical literature. Surely being able to have efficient and effective tools from this point of view could help the clinician in the diagnosis, and also make timelier the pharmacological or surgical therapy, improving the quality of life of the patient, and in some cases guaranteeing a longer survival term.

Identification of salivary metabolites for oral squamous cell carcinoma and oral epithelial dysplasia screening from persistent suspicious oral mucosal lesions

OBJECTIVE

To identify salivary metabolite biomarkers to differentiate patients with oral squamous cell carcinoma and oral epithelial dysplasia (OSCC/OED) from those with persistent suspicious oral mucosal lesions (PSOML).

SUBJECTS AND METHODS

Whole unstimulated saliva samples were collected from age-, sex-, and race-matched patients who had a lesion in the oral cavity and for whom open biopsies were performed. The patients included OSCC (n = 6), OED (n = 10), and PSOML (n = 32). Hydrophilic metabolites in saliva samples were comprehensively analyzed using capillary electrophoresis mass spectrometry. To evaluate the discrimination ability of a combination of multiple markers, a multiple logistic regression (MLR) model was developed to differentiate OSCC/OED from PSOML.

RESULTS

Six metabolites were significantly different in OSCC/OED compared with PSOML. From these six metabolites, ornithine, o-hydroxybenzoate, and ribose 5-phosphate (R5P) were used to develop the MLR model, which resulted in a high value for the area under receiver operating characteristic curve (AUC 0.871, 95% confidential interval (CI) 0.760-0.982; p < 0.001) to discriminate OSCC/OED from PSOML.

CONCLUSIONS

This is the first study to identify salivary metabolites that discriminate OSCC/OED from PSOML rather than from healthy controls. The profiles of salivary metabolites were significantly different between OSCC/OED and PSOML. The ability to discriminate OSCC/OED from PSOML is important for dentists who are not oral surgery specialists. These salivary metabolites showed potential for non-invasive screening to discriminate OSCC/OED from PSOML.

CLINICAL RELEVANCE

Salivary metabolites in this study showed potential for non-invasive screening to discriminate OSCC/OED from PSOML.

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.

Potential role of autofluorescence imaging in determining biopsy of oral potentially malignant disorders: A large prospective diagnostic study

Autofluorescence examination of oral tissues using the VELscope has been suggested as an adjunctive tool for cancer detection and diagnosis. This study aimed to determine the diagnostic value of VELscope in a large prospective study of 517 patients with oral potentially malignant disorders (OPMD). For the outcome assessments of discrimination of carcinoma form general OPMD and distinguishing high-risk lesions (moderate/severe dysplasia and carcinoma) from low-risk lesions (no/mild dysplasia), high sensitivity (100% and 95.9% respectively) and negative predictive value (100% and 98.2% respectively) were observed. All the carcinoma and showed loss of autofluorescence (LAF) and only 3 (0.6%) moderate/severe dysplasia were observed without LAF. These data indicate that the cases without LAF using VELscope substantially rule out the presence of high-risk lesions including cancer. This may prove to be useful specially to alleviate patient anxiety regarding a clinically suspicious oral lesion without the LAF, and to avoid a unnecessary biopsy for these cases. Collectively, a perspective to highlight was that a no biopsy strategy may be appropriate for OPMD without LAF using VELscope after conventional oral examination.

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.

Assessment of the cancerization risk for oral potentially malignant disorders by clinical risk model combined with autofluorescence and brush biopsy with DNA-image cytometry

PURPOSE

To explore the feasibility of assessing the cancerization risk of oral potentially malignant disorders (OPMD) through a clinical risk model combined with autofluorescence and brush biopsy with DNA-image cytometry.

METHODS

We collected the baseline clinical data of 269 patients; then, performed autofluorescence, brush biopsy with DNA-image cytometry and histopathological examination. Then, we obtained the significant factors by univariate logistic analysis, constructed the clinical risk model by multiple logistic regression and selected the optimal cutoff value according to the maximum Youden index. Finally, we calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the clinical risk score ≥ cutoff value, autofluorescence and brush biopsy with DNA-image cytometry, and plotted the receiver-operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

The clinical risk model is represented by the formula: 1 × gender + 1.6 × age group + 1 × lesion site + 1.4 × local stimulus + 1.5 × drink. The area under the curve (AUC) was 0.83, and the optimal cutoff score was 3. The AUC indicated that the clinical risk score ≥ 3 (0.74) and autofluorescence (0.77) had a certain diagnostic values, while brush biopsy with DNA-image cytometry (0.92) displayed a good value. Besides, the DCA showed that all three tests had clinical significance.

CONCLUSIONS

The cancerization risk of patients can be assessed by the clinical risk model combined with sequence application of autofluorescence and brush biopsy with DNA-image cytometry, to decide whether histopathological examination or other intervention measures should be selected.

Feasibility of a Video-Mosaicking Approach to Extend the Field-of-View For Reflectance Confocal Microscopy in the Oral Cavity In Vivo

BACKGROUND

Reflectance confocal microscopy (RCM) is a developing approach for noninvasive detection of oral lesions with label-free contrast and cellular-level resolution. For access into the oral cavity, confocal microscopes are being configured with small-diameter telescopic probes and small objective lenses. However, a small probe and objective lens allows for a rather small field-of-view relative to the large areas of tissue that must be examined for diagnosis. To extend the field-of-view for intraoral RCM imaging, we are investigating a video-mosaicking approach.

METHODS

A relay telescope and objective lens were adapted to an existing confocal microscope for access into the oral cavity. Imaging was performed using metal three-dimensional-printed objective lens front-end caps with coverslip windows to contact and stabilize the tissue and set depth. Four healthy volunteers (normal oral mucosa), one patient (with an amalgam tattoo) in a clinical setting, and 20 anesthetized patients (with oral squamous cell carcinoma [OSCC]) in a surgical setting were imaged. Instead of the usual still RCM images, videos were recorded and then processed into video-mosaics. Thirty video-mosaics were read and qualitatively assessed by an expert reader of RCM images of the oral mucosa.

RESULTS

Whereas the objective lens' native field-of-view is 0.75 mm × 0.75 mm, the video-mosaics display larger areas, ranging from 2 mm × 2 mm to 4 mm × 2 mm, with resolution, morphologic detail, and image quality that is preserved relative to that observed in the original videos (individual images). Video-mosaics in healthy volunteers' and the patients' images showed cellular morphologic patterns in the lower epithelium and at the epithelial junction, and connective tissue along with capillary loops and blood flow in the deeper lamina propria. In OSCC, tumor nests could be observed along with normal looking mucosa in margin areas.

CONCLUSIONS

Video-mosaicking is a reasonably quick and efficient approach for extending the field-of-view of RCM imaging, which can, to some extent, overcome the inherent limitation of an intraoral probe's small field-of-view. Reading video-mosaics can mimic the procedure for examining pathology: initial visualization of the spatial cellular and morphologic patterns of the tumor and the spread of tumor margins over larger areas of the lesion, followed by digitally zooming (magnifying) for closer inspection of suspicious areas. However, faster processing of videos into video-mosaics will be necessary, to allow examination of video-mosaics in real-time at the bedside. Lasers Surg. Med. 51:439-451, 2019. © 2019 Wiley Periodicals, Inc.