Chemiluminescence and Toluidine Blue as Diagnostic Tools for Detecting Early Stages of Oral Cancer: An invivo Study

Cost-effectiveness of population-based screening for oral cancer in India: an economic modelling study

Background

Oral cancer screening reduces mortality associated with oral cancer. The current study evaluated the cost-effectiveness of commonly used screening techniques, namely conventional oral examination (COE), toluidine blue staining (TBS), oral cytology (OC), and light-based detection (LBD) in the Indian scenario.

Methods

The study used a Markov modelling approach to estimate the cost and health outcomes of four different approaches (COE, TBS, OC, and LBD) for screening oral cancer over time from a societal perspective. The discount rate was assumed as 3%. The outcomes estimated were oral cancer incident cases, deaths averted, and quality-adjusted life years (QALYs). To address the high burden of risk factors (tobacco and/or alcohol) in India, two Markov models were developed: Model A adopted a mass-screening strategy, whereas Model B adopted a high-risk screening strategy versus no screening. Probabilistic sensitivity analysis (PSA) was undertaken to address any parameter uncertainty.

Findings

Mass-screening using LBD at three years had the least incident cases (3271.68) and averted the maximum number of oral cancer deaths (459.76). High-risk screening using COE at ten years interval incurred the least lifetime cost of 2,292,816.21 US$ (182,794,468.26 INR). The high-risk strategies (US$/QALY), namely COE 5 years (-29.21), COE 10 years (-90.68), TBS 10 years (-60.54), and LBD 10 years (-13.51), were dominant over no-screening.

Interpretation

The most cost-saving approach was the conventional oral examination at an interval of 10 years for oral screening in high-risk populations above 30 years of age.

Funding

Department of Health Research, Ministry of Health & Family Welfare, Government of India.

Noninvasive Technique for the Screening and Diagnosis of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancy. Squamous cell carcinoma is the second-most prevalent type of cutaneous malignancy after basal cell carcinoma. Biopsy followed by histopathological assessment is the primary basis for assessing squamous cell carcinoma, but nowadays optical non-invasive screening modalities are gaining more importance. There has been an emphasis on implementing relatively quick, affordable, and non-invasive screening methodologies because of various limitations associated with conventional screening techniques, including the encroaching characteristic of the biopsy technique, and the increased price value for treatment. Liquid biopsy, optical detection systems, oral brush cytology, and microfluidic detection, are a few examples of these, each of which has advantages and disadvantages of their own. Dermoscopy is one of the fundamental non-invasive screening techniques used for the examination of cutaneous lesions in clinical practice. Optical coherence tomography and high-frequency ultrasound are considered to be beneficial, particularly for assessing the dimensions of tumors before surgery. The primary site of the lesions, tumor diameter, and the state of the operative borders are some factors that can influence prognosis.

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.

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.

Diagnostic Accuracy of Screening of Lip and Oral Cavity Cancers or Potentially Malignant Disorders (PMD) by Frontline Workers: A Systematic Review and Meta-Analysis

BACKGROUND

Oral cancer screening strategies help reduce associated mortality and could be performed by a trained frontline health worker (FHW). The present review aims to assess the diagnostic accuracy of commonly used screening modalities for oral cancer performed by FHW in apparently healthy individuals.

METHODS

Electronic databases PubMed, Scopus, Embase, Cochrane Library, and Google Scholar, were searched. The review included studies conducted where apparently healthy adult individuals were screened by the FHW for cancer or PMD of the lip and oral cavity by any of the four commonly used techniques - Conventional Oral Examination (COE), toluidine blue staining (TBS), Oral Cytology (OC), and Chemiluminescent Illumination (CLI).

FINDINGS

A total of 2,413 potentially relevant articles were retrieved from the search, among which five studies for COE were included in the review. Four out of those five studies were done before the year 2000. None of the studies fitted the inclusion criteria for TBS, OC, and CLI. Pooled sensitivity of oral screening by COE performed by an FHW (n=5) was 88.8% (95% CI: 71.6-96.1), whereas pooled specificity was 91.9% (95% CI: 78.3-97.3). On subgroup analysis, the pooled sensitivity and specificity of studies where the prevalence of disease was <50% (n=4) was 84.5% (95% CI: 62.6 - 94.7) and 94.1% (95% CI: 82.2 - 98.2), respectively.

INTERPRETATION

COE by trained FHW had high pooled sensitivity and specificity for screening of oral cancer and PMDs. The screening techniques TBS, OC, and CLI, were not studied for mass screening by trained FHW. COE by trained FHW could be utilized for oral screening in limited-resource settings. However, the FHW should be sufficiently trained to get the desired benefits of early detection.

FUNDING

Department of Health Research, Ministry of Health & Family Welfare, Government of India.

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 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.

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.

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.

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.

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.

Diagnostic aids in detection of oral cancer: An update

Oral cancer is the sixth most common malignancy with almost 500000 new cases reported worldwide annually. The diagnosis of oral cancer at an early stage has a good prognosis as the survival rate is high (around 80%). However, the majority of oral cancer cases are diagnosed at a later stage with a considerably poor 5-year survival rate of 50% according to World Health Organization statistics. Thus, an effective management strategy for oral cancer will depend on its early identification and intervention which would pave the way for superior prognosis. Despite the obvious advantage of earlier diagnosis of oral cancer, no approach has yet proven to be a reliably successful in diagnosis of oral cancer at an early stage. Currently; the primary line of screening of oral cancer is performed by visual inspection, which is a subjective examination. Among the screening tests or diagnostic aids now available for oral cancer, few (toluidine blue, brush biopsy, salivary and serum bio-markers) have been utilised and studied for many years while others have recently become commercially available. The authors in the present article review all the modalities of screening aids used in oral cancer detection and provide an update on the latest screening tools used in oral cancer detection.