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

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

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

Evaluation of Usage of Different Diagnostic Aids for Oral Cancer by Oral and Maxillofacial Surgeons: An Original Research

Objective

The purpose of this study was to assess how oral and maxillofacial surgeons used various diagnostic tools for oral cancer.

Materials and Methods

A cross-sectional methodology was used, and a standardized questionnaire was given to oral and maxillofacial surgeons randomly chosen sample. The questionnaire gathered information on demographics and the use of diagnostic tools. Data analysis methods included Chi-square testing and descriptive statistics.

Results

The study included 200 oral and maxillofacial surgeons in total. The most often used diagnostic tool (95%) was visual inspection, followed by toluidine blue staining (48%) and brush biopsy (32%). Less frequently used were newer methods like optical coherence tomography (12.5%) and autofluorescence imaging (15%). No significant correlations between demographic factors and patterns of use of diagnostic tools were found by Chi-square tests.

Conclusion

The results show that oral and maxillofacial surgeons frequently use brush biopsy, toluidine blue staining, and ocular evaluation. However, there is a need for more widespread adoption of cutting-edge technologies. By removing obstacles and offering training opportunities, one can increase the use of diagnostic tools, improving patient outcomes and the diagnosis of oral cancer.

Development of Novel Epigenetic Anti-Cancer Therapy Targeting TET Proteins

Epigenetic dysregulation, particularly alterations in DNA methylation and hydroxymethylation, plays a pivotal role in cancer initiation and progression. Ten-eleven translocation (TET) proteins catalyze the successive oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) and further oxidized methylcytosines in DNA, thereby serving as central modulators of DNA methylation-demethylation dynamics. TET loss of function is causally related to neoplastic transformation across various cell types while its genetic or pharmacological activation exhibits anti-cancer effects, making TET proteins promising targets for epigenetic cancer therapy. Here, we developed a robust cell-based screening system to identify novel TET activators and evaluated their potential as anti-cancer agents. Using a carefully curated library of 4533 compounds provided by the National Cancer Institute, Bethesda, MD, USA, we identified mitoxantrone as a potent TET agonist. Through rigorous validation employing various assays, including immunohistochemistry and dot blot studies, we demonstrated that mitoxantrone significantly elevated 5hmC levels. Notably, this elevation manifested only in wild-type (WT) but not TET-deficient mouse embryonic fibroblasts, primary bone marrow-derived macrophages, and leukemia cell lines. Furthermore, mitoxantrone-induced cell death in leukemia cell lines occurred in a TET-dependent manner, indicating the critical role of TET proteins in mediating its anti-cancer effects. Our findings highlight mitoxantrone's potential to induce tumor cell death via a novel mechanism involving the restoration of TET activity, paving the way for targeted epigenetic therapies in cancer treatment.

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

Background

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

Materials and Methods

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

Results

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

Conclusion

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

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

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

The p38/MKP-1 signaling axis in oral cancer: Impact of tumor-associated macrophages

Oral squamous cell carcinomas (OSCC) constitute over 95% of all head and neck malignancies. As a key component of the tumor microenvironment (TME), chronic inflammation contributes towards the development, progression, and regional metastasis of OSCC. Tumor associated macrophages (TAMs) associated with OSSC promote tumorigenesis through the production of cytokines and pro-inflammatory factors that are critical role in the various steps of malignant transformation, including tumor growth, survival, invasion, angiogenesis, and metastasis. The mitogen-activated protein kinases (MAPKs) can regulate inflammation along with a wide range of cellular processes including cell metabolism, proliferation, motility, apoptosis, survival, differentiation and play a crucial role in cell growth and survival in physiological and pathological processes including innate and adaptive immune responses. Dual specificity MAPK phosphatases (MKPs) deactivates MAPKs. MKPs are considered as an important feedback control mechanism that limits MAPK signaling and subsequent target gene expression. This review outlines the role of MKP-1, the founding member of the MKP family, in OSCC and the TME. Herein, we summarize recent progress in understanding the regulation of p38 MAPK/MKP-1 signaling pathways via TAM-related immune responses in OSCC development, progression and treatment outcomes.

Endogenous Fluorescence Lifetime Imaging (FLIM) Endoscopy For Early Detection Of Oral Cancer And Dysplasia

We have performed a pilot clinical study, in which multispectral endogenous fluorescence (or autofluorescence) lifetime imaging (FLIM) was performed on clinically suspicious oral lesions of 73 patients undergoing tissue biopsy for oral dysplasia and cancer diagnosis. The results from this pilot study indicated that mild-dysplasia and early stage oral cancer could be detected from benign lesions using a computed aided diagnosis system developed based on biochemical and metabolic biomarkers derived from the endogenous FLIM images. The diagnostic performance of this novel FLIM clinical tool was estimated using a leave-onepatient-out cross-validation approach, which reported levels of sensitivity >90%, specificity >85%, and Area Under the Receiving Operating Curve (ROC-AUC) >0.9.

Adjunctive Diagnostic Techniques for Oral and Oropharyngeal Cancer Discovery

The most important prognostic factor in predicting the outcome of oral and oropharyngeal cancer (OPC) is the stage at which it is diagnosed. Only 30% of patients are diagnosed with early-stage disease. The oral health care provider performs an important role in early diagnosis of oral cancer. The conventional oral examination consists of a visual and tactile assessment of accessible oral, and head and neck structures. Any suspicious or equivocal lesion should be reevaluated within 4 weeks. Evidence supporting the use of adjunctive devices to improve the ability to screen for and identify OPCs and oral premalignant lesions remains low.

Toluidine Blue Staining in Identification of a Biopsy Site in Potentially Malignant Lesions: A Case-control Study

Objective:

Oral cancer is a significant threat to public health all over the world, especially in Southeast Asia. At the present time, screening of oral cancer, its premalignant stages as well as its early detection, is still largely based on visual examination of the mouth. Visual examination is highly subjective and hence lacks the specificity and sensitivity. The objective of this study was to determine the usefulness of toluidine blue in marking a biopsy site in potentially malignant disorders.

Methods:

In this study, a total of 500 patients were screened. The study was a case–control study which included 17 lesion cases and 23 normal controls. Toluidine blue staining was taken into consideration to identify clinically doubtful oral potentially malignant lesions and to compare the clinical evaluation with toluidine blue stain followed by a punch biopsy and histological evaluation. SPSS Statistics version 16.0 and Chi-square test were used for statistical analyses.

Results:

The most common site for potentially malignant lesions was found to be the buccal mucosa. The sensitivity of toluidine blue was found to be 88.89%, while specificity was found to be 74.19%. The positive predictive and negative predictive values were 50% and 97.83%, respectively. P = 0.000672 was considered statistically significant.

Conclusions:

The results seem to be promising, but many such studies have to be done at larger scales to exactly help us in identifying the capability of toluidine blue in the long run.

Toluidine blue aids in detection of dysplasia and carcinoma in suspicious oral lesions

OBJECTIVES

Accurate clinical identification of 'higher-risk' oral premalignant lesions or 'higher-risk' areas within lesions is important. Assessment methods that predict their presence have great utility.

SUBJECTS AND METHODS

A cross-sectional, observational study enrolled a consecutive sample of consenting patients diagnosed with oral leukoplakia, erythroleukoplakia, or erythroplakia. Medical history, visual oral examination, ViziLite(®) examination, toluidine blue staining (TBlue(®) ), and finally a biopsy were completed in a single clinic visit. Seventy-seven of 100 examined lesions in 43 patients were biopsied. Sensitivity, specificity, and positive and negative predictive values were computed for visual examination, ViziLite(®) , and TBlue(®) using biopsy results as the gold standard.

RESULTS

The sensitivity of TBlue(®) in detecting high-risk lesions (carcinoma in situ or carcinoma) was 94 (71-100, P < 0.0003) and specificity 45 (32-58, P < 0.53), while for carcinoma, sensitivity was 100 (54-100, P < 0.032) and specificity 39 (28-52, P < 0.097). The results of ViziLite(®) testing either by itself or in combination with the information from toluidine blue testing revealed low sensitivity for the detection of high-risk lesions.

CONCLUSIONS

Clinical examination of leukoplakia, erythroplakia, or erythroleukoplakia lesions combined with toluidine blue staining may aid in the identification of severe dysplasia (carcinoma in situ) or carcinoma. This may help in determining whether, when, and where (the site within a lesion) a biopsy should be taken.

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

Background and objectives

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

Material and Methods

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

Results

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

Conclusions

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

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

Assessment of lipid peroxides in multiple biofluids of leukoplakia and oral squamous cell carcinoma patients-a clinico- biochemical study

BACKGROUND

Oral pre cancer and oral cancer results in lipid peroxidation, and assessment of lipid peroxides in body fluids may give insights into the role of anti oxidants in its management.

AIM

The study was conducted to discern the varying levels of lipid peroxides in saliva, serum and tissue in oral pre cancer and oral cancer and also various forms of tobacco usage with sex as an added parameter.

MATERIALS AND METHODS

The levels of lipid peroxides were measured in saliva, serum and tissue in a total of 50 patients, 20 belonging to control, and 30 study group in which 10 with oral leukoplakia and 20 with histologically proven oral squamous cell carcinoma (OSCC). The mean value of malondialdehyde (MDA) were also recorded in males and females among the patients with oral leukoplakia and OSCC. Among the study group patients, the levels of MDA were also recorded in habits of smoking and chewing tobacco.

STATISTICAL ANALYSIS USED

Student's independent t-test, one way ANOVA, Tukey HSD procedure.

RESULTS

Significantly elevated levels of lipid peroxides were seen in saliva, serum and tissue in oral leukoplakia and OSCC when compared to control patients. Among the study group, there were statistically significant increased levels of MDA in OSCC when compared to oral leukoplakia. There was also increase in MDA level in patients with smoking and chewing, but the variations seen in males and females were not very significant.

CONCLUSION

The results clearly indicate the increase in lipid peroxidation in oral pre cancer and oral cancer with no significant difference between gender groups. The role of saliva as a relatively risk free and reliable, easy to obtain biofuid for diagnostic purposes has been highlighted. Also, since the levels of antioxidants are drastically decreased in carcinogenesis, the importance of anti oxidant supplements in the early stages of the disease has also been elucidated.

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

INTRODUCTION

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

MATERIAL

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

CONCLUSION

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

Management for premalignant lesions of the oral cavity

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

Correlation between histological grading and ploidy status in potentially malignant disorders of the oral mucosa: A flow cytometric analysis

Background:

Histopathological grading of oral dysplastic lesions is the method of choice for evaluating malignant and potentially malignant disorders. Owing to inter- and intra-observer variability, determination of the DNA ploidy status of lesions may serve as an adjunct in the prediction of malignant transformation.

Aim:

To correlate histopathological grading and ploidy status in potentially malignant and malignant disorders of the oral mucosa.

Settings and Design:

A pilot study was done with 30 patients (10 patients with oral potentially malignant disorders predominantly leukoplakia, 10 patients with oral malignant lesions and 10 patients with normal mucosa).

Materials and Methods:

Incisional biopsy was done after isolating the biopsy site with 1% Toluidine blue staining. Two sections of the tissue were removed and sent for histopathological and Flow-cytometric analysis respectively. Histopathological diagnosis was obtained and compared with Flow-cytometric results which were graded as diploid and aneuploid. Further, the S – phase fraction, DNA index were also calculated to evaluate the severity of malignant transformation or malignancy.

Statistical Analysis:

The results were analyzed using Pearson Chi-Square Test.

Results:

There exists a significant correlation between histopathology and ploidy status in both potentially malignant and malignant group. (P = 0.002).

Conclusion:

The data from this study has shown that DNA Ploidy analysis can be used as a valuable tool in assessing the carcinomatous progression of potentially malignant and malignant lesions.

A comparative analysis of toluidine blue with frozen section in oral squamous cell carcinoma

BACKGROUND

Surgical excision of the primary tumor with safe margins remains the mainstay of treatment for oral cavity squamous cell carcinoma (OSCC). The standard of care for assessment of intraoperative margins is frozen section histopathology. Unfortunately the facility is not available at most centers in limited resource countries. Toluidine blue, a metachromatic dye, has been well described in clinical identification of malignant and premalignant lesion in the oral cavity. Considering this we decided to explore intraoperative use of toluidine blue staining, in comparison with frozen sections, for the assessment of tumor-free margins.

METHODS

After obtaining clearance from the in-house ethical review committee, a prospective study was conducted at Aga Khan University Hospital, Karachi, from August 15, 2009 to March 14, 2010. A sample of 56 consenting patients with biopsy-proven OSCC were included in the study, giving us 280 tumor margins. Margins were analyzed using toluidine blue staining and frozen section histopathology. A receiver operator curve (ROC) was then applied to compare assessment of margin status by toluidine blue and frozen section.

RESULTS

Of the 280 examined margins 11 stained positive with toluidine blue, three were positive on frozen section biopsy, and three were positive on final histopathology. Toluidine blue staining had sensitivity and specificity of 100% and 97%, respectively. The diagnostic accuracy of toluidine blue was found to be 97.1% with a positive predictive value (PPV) of 27.2% and a negative predictive value (NPV) of 100%.

CONCLUSIONS

Toluidine blue can be used as an effective screening modality for the assessment of intraoperative margins in resource limited environments and reducing the number of frozen section biopsies performed. Further by providing real-time clinical information within minutes it can reduce indirect costs such as operating room time. It may also be used as an ad hoc for frozen section biopsies where frozen section facilities are available.

Evaluation of chemiluminescence, toluidine blue and histopathology for detection of high risk oral precancerous lesions: A cross-sectional study

Background

Early detection holds the key to an effective control of cancers in general and of oral cancers in particular. However, screening procedures for oral cancer are not straightforward due to procedural requirements as well as feasibility issues, especially in resource-limited countries.

Methods

We conducted a cross-sectional study to compare the performance of chemiluminescence, toluidine blue and histopathology for detection of high-risk precancerous oral lesions. We evaluated 99 lesions from 55 patients who underwent chemiluminescence and toluidine blue tests along with biopsy and histopathological examination. We studied inter-as well as intra-rater agreement in the histopathological evaluation and then using latent class modeling, we estimated the operating characteristics of these tests in the absence of a reference standard test.

Results

There was a weak inter-rater agreement (kappa < 0.15) as well as a weak intra-rater reproducibility (Pearson's r = 0.28, intra-class correlation rho = 0.03) in the histopathological evaluation of potentially high-risk precancerous lesions. When compared to histopathology, chemiluminescence and toluidine blue retention had a sensitivity of 1.00 and 0.59, respectively and a specificity of 0.01 and 0.79, respectively. However, latent class analysis indicated a low sensitivity (0.37) and high specificity (0.90) of histopathological evaluation. Toluidine blue had a near perfect high sensitivity and specificity for detection of high-risk lesions.

Conclusion

In our study, there was variability in the histopathological evaluation of oral precancerous lesions. Our results indicate that toluidine blue retention test may be better suited than chemiluminescence to detect high-risk oral precancerous lesions in a high-prevalence and low-resource setting like India.

Using toluidine blue as an adjunct to oral visual cancer screening among high-risk individuals may lead to increased detection of oral submucous fibrosis

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

A community-based RCT for oral cancer screening with toluidine blue. Su WW, Yen AM, Chiu SY, Chen TH. J Dent Res 2010;89(9):933-7.

REVIEWER

Mark D. Macek, DDS, DrPH PURPOSE/QUESTION: Does using toluidine blue as an adjunctive tool for oral visual cancer screening lead to higher detection rates of oral premalignant lesions among high-risk populations?

SOURCE OF FUNDING

Information not available

TYPE OF STUDY/DESIGN

Randomized controlled trial

LEVEL OF EVIDENCE

Level 2: Limited-quality, patient-oriented evidence

STRENGTH OF RECOMMENDATION GRADE

Not applicable.

Exciting new advances in oral cancer diagnosis: avenues to early detection

The prognosis for patients with oral squamous cell carcinoma remains poor in spite of advances in therapy of many other malignancies. Early diagnosis and treatment remains the key to improved patient survival. Because the scalpel biopsy for diagnosis is invasive and has potential morbidity, it is reserved for evaluating highly suspicious lesions and not for the majority of oral lesions which are clinically not suspicious. Furthermore, scalpel biopsy has significant interobserver and intraobserver variability in the histologic diagnosis of dysplasia. There is an urgent need to devise critical diagnostic tools for early detection of oral dysplasia and malignancy that are practical, noninvasive and can be easily performed in an out-patient set-up. Diagnostic tests for early detection include brush biopsy, toluidine blue staining, autofluorescence, salivary proteomics, DNA analysis, biomarkers and spectroscopy. This state of the art review critically examines these tests and assesses their value in identifying oral squamous cell carcinoma and its precursor lesions.

Techniques for precancerous lesion diagnosis

The development of the oral squamous cell carcinoma (OSCC) is a multistep process that requires the accumulation of multiple genetic alterations usually preceded by detectable mucosal changes, most often leukoplakias and erythroplakias. The clinical appearance of oral precancerous lesions and their degree of epithelium dysplasia suggests the malignization potential. Several techniques have been developed to improve the clinical and cytological diagnosis of oral precancerous lesions. The present paper reviews the main techniques used to improve premalignant lesion diagnosis.

Diagnostic clinical aids in oral cancer

Conventional oral exploration (visual and palpation examination) constitutes the current gold standard for oral cancer screening, while biopsy and histopathological examination represents the indispensable study for the detection of cases in patients with an identified lesion. Imaging techniques (DPT, CT, and MRI) are frequently used to supplement the clinical evaluation and staging of the primary tumour and regional lymph nodes. There are also a number of techniques that may contribute to the diagnosis of oral cancer: toluidine blue test has been used as a diagnostic aid for the detection of oral cancer over decades. Recently developed light-based detection systems have progressively improved in sensitivity and specificity, but multicentre controlled studies conducted by general dental practitioners must be designed in order to justify their application. The oral brush biopsy appears to overestimate dysplastic lesions and produces a high number of false-positive results. In the near future, immunological and biochemical alterations in the serum (e.g., circulating immune complexes, carcinoembryonic antigen, squamous cell carcinoma associated antigen, inhibitor of apoptosis, cytokeratin fragments, and annexin A1) as well as specific saliva analysis (e.g., cancer related cytokines, metalloproteinases, epithelial tumour markers, DNA promoter hypermethylation, and saliva micro-RNA) may become important tools for the detection of oral cancer.