The utility of toluidine blue application as a diagnostic aid in patients previously treated for upper oropharyngeal carcinoma

Chemiluminescence as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions

Chemiluminescence was evaluated as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions (PMELs) by comparing it against 1% tolonium chloride mouth rinse. Forty-six clinically identified lesions [14 primary squamous cell carcinoma (SCC), 26 PMELs and 6 benign lesions] and five cases of normal oral mucosa from 40 subjects (inclusive of 10 previously treated SCC cases) were examined with a commercial chemiluminescent kit (Vizilite) and tolonium chloride. Biopsy and histological verification of 31 lesions disclosed 14 SCC (45.2%), 10 epithelial dysplasias (32.3%), 5 lichen planus (16.1%) and 2 benign lesions (6.4%). For the remaining 15 lesions, a biopsy was not performed owing to patient's lack of consent or ill-health. The five cases of normal oral mucosa which tested negative for both tools were also not biopsied for ethical reasons. Sensitivity for Vizilite and tolonium chloride was 100% and 70.3%, respectively; and specificity was 14.2% for Vizilite and 25% for tolonium chloride. Their accuracy was 80.6% and 64.5%, respectively. Current findings suggest that chemiluminescence is a more reliable diagnostic tool than tolonium chloride in the detection of oral cancer and PMELs, and for follow-up of patients treated for the same.

A systematic review of test performance in screening for oral cancer and precancer

Nine databases were searched for studies on test performance in screening for oral cancer and precancer in primary care. Of 481 papers, full texts of 47 were scrutinised by two reviewers. Only prospective investigations of population screening involving examination of the oral mucosa, with gold standard verification (examination by an expert of subjects screened positive and at least a proportion of negatives), were selected. Seven papers describing eight studies were finally included (kappa=0.83). The weighted pooled value of sensitivity, from random effects meta-analysis, was 0.848 (95% CI 0.730, 0.919). The corresponding value for specificity was 0.965 (95% CI 0.930, 0.982). Main sources of clinical heterogeneity occurred between large house-to-house case finding programmes from SE Asia, utilising primary health workers, and smaller studies from England and Japan. Meta-analysis regression showed no difference (P=0.99) in the generally high level of discriminatory ability of the test between these two groups.

The utility of tolonium chloride rinse in the diagnosis of recurrent or second primary cancers in patients with prior upper aerodigestive tract cancer

BACKGROUND

The clinical utility of tolonium chloride rinse was compared with unaided visual examination alone in the diagnosis of oral carcinoma in patients previously treated for carcinoma of the upper aerodigestive tract.

METHODS

A total of 668 patients were enrolled in this multicenter study. At each site, an oral clinical visual examination was completed by one investigator followed by tolonium chloride rinse and examination by a second investigator blinded to the examination findings of the first investigator. If a lesion was considered suspicious (urgent biopsy required at the first visit), the lesion was biopsied after tolonium chloride rinsing. Patients with lesions characterized at the first visit as not suspicious (biopsy not urgent) or that stained with tolonium chloride were asked to return for a second visit. At the second visit, any residual lesion or lesions that retained tolonium chloride were biopsied.

RESULTS

A total of 96 biopsies was performed in 81 of the 668 patients (12.1%), of which 30 (31.3%) were diagnosed histologically as carcinoma/carcinoma in situ (CIS) and the remainder as inflammation (31.3%), keratosis (26.6%), dysplasia (21.9%), ulcer (2.1%), other (3.1%), or no abnormality (1.0%). Of the 30 lesions with the diagnosis of carcinoma/CIS, 12 (sensitivity 40.0%) were considered to be clinically suspicious (CS+), whereas 29 (sensitivity 96.7%) retained tolonium chloride (p =.0002). The predictive values of a positive test for clinical examination and tolonium chloride staining were similar (36.4% vs 32.6%; p =.5871), indicating that the greater sensitivity of tolonium chloride was not associated with an excessive number of unnecessary biopsies (false positives).

CONCLUSIONS

Tolonium chloride rinse is more sensitive than clinical examination alone in detecting lesions that might be found on biopsy to be carcinoma or CIS. The increased sensitivity is largely attributed to lesions that stain but were not detected clinically on visual examination.

The effectiveness of community-based visual screening and utility of adjunctive diagnostic aids in the early detection of oral cancer

A systematic review of community-based oral cancer screening programmes published between 1966 and March 2002 was undertaken. Data relating to study design, sampling and characteristics of the study group, interventions, and reported outcomes and diagnostic value of visual screening or adjunctive diagnostic aids were abstracted from 36 articles meeting inclusion and exclusion criteria. From these reports, there is insufficient evidence to demonstrate the effectiveness of community-based oral cancer visual screening in enhancing the early detection of oral cancer, due to small effect size. While the evidence is fair to support use of toluidine blue as an aid in diagnosis of oral cancer, there is insufficient evidence to determine whether the use of this or other adjunctive techniques will increase the detection of oral malignancies in community screening programmes. Targeted clinical examination of high-risk individuals may be more effective than mass screening in facilitating early detection of oral cancers.

Autofluorescent diagnostics in laryngeal pathology

Autofluorescent diagnostics are based on the ability of oxidized flavin mononucleotide (FMN) in normal cells to emit green fluorescence when exposed to blue light. Neoplastic cells have significantly lower concentrations of FMN and do not emit green fluorescence. Autofluorescent endoscopy is designed for early, accurate and minimally invasive diagnostics for laryngeal pathology. This procedure has the ability to give information about the nature of laryngeal lesions without the devastation of tissue and has important advantages over standard biopsy. In our investigation we used the System of AutoFluorescent Endoscopy (SAFE 1000) designed by Pentax. We examined 38 patients using the SAFE 1000 system, and then all of the patients underwent laryngomicroscopy (LMS). In LMS, a biopsy was taken, and the diagnostic sensitivity of these two methods was compared according to the pathohistologic diagnosis. For statistical evaluation we used Fisher's exact test. We found that autofluorescent endoscopy has greater sensitivity in the detection of precancerous and malignant conditions in the larynx than standard laryngomicroscopy. We believe that autofluorescent endoscopy in addition to laryngomicroscopy gives a more accurate diagnosis of laryngeal pathology than laryngomicroscopy alone.

Multiple primary tumours following head and neck cancer in southern England during 1961-98

BACKGROUND

Successful initial treatment of oral and oro-phayngeal cancer has led to the emergence of second primary tumours (SPTs). Population data are meagre.

METHODS

Occurrence of multiple primary cancers following a malignancy in a head and neck site was computed using data from a population-based cancer registry covering a population of 14 million.

RESULTS

Among 59,958 subjects reported to the registry, 5.5% males and 3.6% females developed a second primary cancer. At the sites studied, a total of 2771 second primary cancers were found, compared with an expected number of 2341. The standardised incidence ratio (SIR) for contracting a new primary cancer was 1.14 (95% CI=1.09-1.19) for men and 1.34 (95% CI=1.24-1.44) for women. There was a significantly increased risk for a second cancer in most of the upper aerodigestive tract sites that are generally regarded as tobacco associated, with an SIR for subsequent oral cancer of 5.56 in men and 15.31 in women. Subjects first detected with a pharyngeal cancer experienced the highest SIR for a subsequent tumour. Excluding tobacco-associated sites, the risk of a subsequent cancer was not significantly raised in either sex (SIR 0.87 (95% CI 0.81-0.93) for men; SIR 0.99 (95% CI 0.90-1.09) for women).

CONCLUSIONS

The relative risk for multiple primary cancer was higher in younger subjects, those detected with a head and neck cancer during the 1990s as compared with earlier decades of the study, and among patients who received radiotherapy for their first tumour. By 20 years from the time of the first head and neck cancer, we estimate that approximately 30% of male patients and 20% of female patients will have developed an SPT.

The current status of laser applications in dentistry

A range of lasers is now available for use in dentistry. This paper summarizes key current and emerging applications for lasers in clinical practice. A major diagnostic application of low power lasers is the detection of caries, using fluorescence elicited from hydroxyapatite or from bacterial by-products. Laser fluorescence is an effective method for detecting and quantifying incipient occlusal and cervical carious lesions, and with further refinement could be used in the same manner for proximal lesions. Photoactivated dye techniques have been developed which use low power lasers to elicit a photochemical reaction. Photoactivated dye techniques can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis. Using similar principles, more powerful lasers can be used for photodynamic therapy in the treatment of malignancies of the oral mucosa. Laser-driven photochemical reactions can also be used for tooth whitening. In combination with fluoride, laser irradiation can improve the resistance of tooth structure to demineralization, and this application is of particular benefit for susceptible sites in high caries risk patients. Laser technology for caries removal, cavity preparation and soft tissue surgery is at a high state of refinement, having had several decades of development up to the present time. Used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade.

Oral lichen planus: progress in understanding its malignant potential and the implications for clinical management

Oral lichen planus (OLP) is an inflammatory lesion that has malignant potential, but few cases of OLP progress to malignancy. A diagnosis of OLP should be confirmed on the basis of historical, clinical, and histologic data. The presence of dysplasia in an OLP-like lesion increases the risk of malignant transformation, mandating management and close follow-up. A molecular assessment of OLP may provide the best evidence of malignant risk and will likely become available for clinical use. In addition, exfoliated cells may be examined for loss of heterozygosity and may become a valuable clinical tool for patient follow-up. The treatment of OLP should include elimination of tissue irritants and recurring exposure to oral carcinogens. If OLP is symptomatic, appropriate treatment with immunosuppressive medications, particularly corticosteroids, should be undertaken. For lesions with dysplastic changes, management may include attention directed to the inflammatory change and follow-up biopsies to assess residual histologic changes that may represent dysplasia. Dysplastic OLP may be best treated as other oral dysplastic conditions; thus, regular, more frequent follow-up is required.

Oral cancer treatment

Oral cancer is the sixth most common cancer in the world, and it continues to represent a serious public health problem. Oral cancer is a preventable disease, related to behavioral and lifestyle factors, including tobacco and alcohol. Prevention and early detection of oral cancer remain the goals of national efforts to reduce the impact of this disease on the public. Surgical treatment is the mainstay of therapy for patients with oral cancer, particularly in advanced stages of cancer. External beam radiation therapy and brachytherapy have been used successfully as the primary modality for treating patients with early stage oral cancer, and they are the standard of care for use as adjuvant therapy in postoperative cases of patients with advanced stage oral cancer. There is an emerging trend for the use of chemotherapy in combination with radiation therapy and surgery for patients with advanced, recurrent, and metastatic head and neck cancer, although evidence is limited regarding survival benefit when used for treating patients with oral cavity carcinoma. Any report on the treatment of oral cancer is incomplete without consideration of functional and aesthetic outcomes, particularly addressing speech, swallowing, masticatory efficiency, and dental rehabilitation. Future generations will continue to fight these dreadful diseases until scientists and clinicians are provided the opportunities to expand efforts to prevent, detect (early), and eradicate oral and other head and neck cancers.

Increased allelic loss in toluidine blue-positive oral premalignant lesions

OBJECTIVE

Recent studies have shown that a loss of chromosome regions (loss of heterozygosity [LOH]) containing known or presumptive tumor suppressor genes is predictive of the cancer risk of oral premalignant lesions. This preliminary study investigated whether the dye toluidine blue (TB) preferentially stains oral premalignant lesions with LOH. This stain has been used by clinicians to delineate dysplasia/carcinoma in the oral cavity.

STUDY DESIGN

The study included 32 patients with oral lesions who underwent biopsy after the assessment of TB dye retention. A total of 39 biopsy specimens were examined (14 hyperplastic, 25 dysplastic). Fourteen of the biopsy specimens were TB-negative. The specimens were analyzed for LOH at 10 microsatellite loci on 3 chromosome arms (3p, 9p, and 17p), and the LOH results of TB-positive samples were compared with those that were negative for the tissue staining.

RESULTS

TB-positive samples had a higher frequency of loss than TB-negative cases for loci on 3p (P = .013) and 17p (P = .049). In addition, more TB-positive cases showed a loss of multiple arms (>2 arms, P = .015), a pattern that has been associated with markedly increased cancer risk.

CONCLUSION

The study results suggest that TB staining may help identify oral premalignant lesions with increased LOH and increased cancer risk.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Although the second half of the last century has generated a rich and complex body of knowledge, the burden of oral cancer is still largely present. As with other cancers, there has been a strong debate whether screening strategies for oral cancer such as visual examination, the use of toluidine blue or newer methods such as brush biopsy or fluorescence imaging are effective in reducing the mortality rate associated with oral cancer.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH STRATEGY

Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to September 2002, The Cochrane Library - Issue 2, 2002), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data.

SELECTION CRITERIA

Randomised controlled trials of screening for oral cancer or potentially premalignant oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

The search found 100 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation have been undertaken by two independent reviewers.

MAIN RESULTS

One ongoing randomised controlled trial has been included (n = 13 clusters: 153,708 eligible subjects, 130,799 included subjects). There was no difference in the age-standardised oral cancer mortality rates for the screened group (21.2/1000,000 person years) and the control group (21.3/100,000 person years). However this study has some methodological weaknesses.

REVIEWER'S CONCLUSIONS

Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness in the included study, it is valid to say that there is no evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Further cost-effective, high quality studies to assess the efficacy and effectiveness of screening are required. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed.

Contrast agents for confocal microscopy: how simple chemicals affect confocal images of normal and cancer cells in suspension

Normal and malignant human cervical cancer cells were imaged in vivo with confocal, phase contrast, and brightfield microscopies. Results were compared between cells in growth medium before and after addition of acetic acid, hypertonic saline solution, toluidine blue, and Lugol's iodine. The exogenous agents changed the backscattering characteristics of the cells when measured with confocal microscopy at 808 nm. A tendency toward higher scattering was observed in treated cells. Acetic acid and toluidine blue increased the brightness of the nucleus with respect to the cytoplasm in normal and cancer cells. Hypertonic saline solution made the cytoplasm brighter than the nucleus in both types of cells. The results indicate that simple chemicals can be used to enhance confocal microscopy's ability to differentiate intracellular components, such as nuclear size and shape. This can further confocal microscopy's ability to assess disease in cells and tissues.

The use of diagnostic data in clinical dental practice

This article has briefly introduced the dental clinician to the principles and practical application of diagnostic decision analysis. There are trade-offs and uncertainties in the process of arriving at a diagnosis, but they can be understood and controlled. First, the clinician must understand the significance of disease prevalence and assign to the patient an initial probability of disease being present. The clinician must then determine if further diagnostic measurements or tests are warranted. If so, the appropriate test must be selected, based on the ability of the test to revise the initial pretest probability. When a diagnostic test is positive, the clinician must know the probability that disease is actually present. The clinician must also know the probability that disease is actually present if the test result is negative. The astute clinician will calculate the posttest probabilities before proceeding with a test and will base treatment decisions on test results in accordance with predetermined test and test-treatment thresholds.

Reliability of toluidine blue application in the detection of oral epithelial dysplasia and in situ and invasive squamous cell carcinomas

OBJECTIVE

The objective of this study was to evaluate the reliability of in vivo staining with toluidine blue in the detection of oral epithelial dysplasia, in situ carcinoma, and invasive squamous cell carcinomas in potentially malignant epithelial lesions (PMELs) and superficial oral ulcerations suggesting malignancy.

STUDY DESIGN

Fifty patients with PMELs and superficial oral ulcerations suggestive of malignancy were selected from those treated at the Oral Medicine Service, Faculty of Dentistry, Araraquara, Brazil. All lesions were submitted to staining with an aqueous solution of 1% toluidine blue, followed by biopsy and histologic analysis. The sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

Histologic diagnosis revealed that 14% of the lesions analyzed were in situ carcinoma and invasive squamous cell carcinomas, 12% were epithelial dysplasias, 13% were keratosis, 40% were lichen planus, and 8% were other benign lesions. The sensitivity of the staining was 77%, the specificity 67%, and the positive and negative predictive values 43.5% and 88.9%, respectively.

CONCLUSIONS

Staining with toluidine blue was demonstrated to be highly reliable in the detection of in situ carcinoma and invasive squamous cell carcinoma, because false-negative results for the lesions did not occur. Toluidine blue staining is an adjunct to clinical judgment and not a substitute for either judgment or biopsy.

Direct oral microscopy and its value in diagnosing mucosal lesions: a pilot study

OBJECTIVE

Clinical examination of the oral mucosa often leads to an uncertain diagnosis, and a supplementary biopsy with a histopathologic examination of the lesion is necessary to establish a definite diagnosis. However, the site for the biopsy is a subjective choice that sometimes raises doubts about its representativeness. So far, no simple and reliable method is available for selecting the most appropriate area for biopsy.

STUDY DESIGN

In a prospective study, we performed direct oral microscopy (oral application of the colposcopy technique used in gynecology) in 35 patients with various clinical diagnoses, such as leukoplakia, oral lichenoid lesions, or suspected malignancy. First, the oral mucosa was examined with direct microscopy, and the most representative site, according to colposcopic criteria, was selected. Then, the mucosa was clinically inspected by an independent examiner. The best site for biopsy according to clinical criteria was noted, and any difference in biopsy sites was recorded. Biopsy specimens were taken from 2 of these sites.

RESULTS

Twenty-nine patients (83%) showed changes in the vascular picture on microscopy, according to the colposcopy criteria. In 14 patients (40%), the biopsy sites identified by direct oral microscopy showed more advanced histologic signs than those selected by routine clinical examination (0.01 < P </=.05). Four patients (11%) had more advanced histologic signs in the biopsy samples, as identified during routine clinical examination. In 17 patients (49%), we found no differences between the biopsy specimens.

CONCLUSION

Direct oral microscopy of mucosal lesions seems to offer advantages in selecting more representative sites for biopsy than routine clinical examination alone.