Oral premalignant lesions: is a biopsy reliable?

Quantitative proteomic analysis of oral brush biopsies identifies secretory leukocyte protease inhibitor as a promising, mechanism-based oral cancer biomarker

A decrease in the almost fifty percent mortality rate from oral cancer is needed urgently. Improvements in early diagnosis and more effective preventive treatments could affect such a decrease. Towards this end, we undertook for the first time an in-depth mass spectrometry-based quantitative shotgun proteomics study of non-invasively collected oral brush biopsies. Proteins isolated from brush biopsies from healthy normal tissue, oral premalignant lesion tissue (OPMLs), oral squamous cell carcinoma (OSCC) and matched control tissue were compared. In replicated proteomic datasets, the secretory leukocyte protease inhibitor (SLPI) protein stood out based on its decrease in abundance in both OPML and OSCC lesion tissues compared to healthy normal tissue. Western blotting in additional brushed biopsy samples confirmed a trend of gradual decreasing SLPI abundance between healthy normal and OPML tissue, with a larger decrease in OSCC lesion tissue. A similar SLPI decrease was observed in-vitro comparing model OPML and OSCC cell lines. In addition, exfoliated oral cells in patients’ whole saliva showed a loss of SLPI correlated with oral cancer progression. These results, combined with proteomics data indicating a decrease in SLPI in matched healthy control tissue from OSCC patients compared to tissue from healthy normal tissue, suggested a systemic decrease of SLPI in oral cells correlated with oral cancer development. Finally, in-vitro experiments showed that treatment with SLPI significantly decreased NF-kB activity in an OPML cell line. The findings indicate anti-inflammatory activity in OPML, supporting a mechanistic role of SLPI in OSCC progression and suggesting its potential for preventative treatment of at-risk oral lesions. Collectively, our results show for the first time the potential for SLPI as a mechanism-based, non-invasive biomarker of oral cancer progression with potential in preventive treatment.

The role of interventional surgery in oral potentially malignant disorders

Oral potentially malignant disorders are mucosal diseases with a significantly increased risk of squamous carcinoma development – a lethal and deforming disease with rising incidence, especially in young people. Despite the ability to recognise pre-cancer disorders in patients, clinicians remain unable to predict individual mucosal lesion behaviour or quantify the risk of malignant transformation. No clear management guidelines exist and the available scientific literature is unable to answer the fundamental question: does early diagnosis and interventional management treat pre-cancer effectively and prevent malignant transformation?

Potentially malignant disorders of the oral cavity: current practice and future directions in the clinic and laboratory

Despite commendable progress in the prevention, detection, and treatment of a wide variety of solid tumor types, oral squamous cell carcinoma (OSCC) remains a significant health burden across the globe. OSCC carcinogenesis involves accumulation of genetic alterations that coincide with the multistep malignant transformation of normal oral epithelium. OSCC is often first diagnosed at late stages of the disease (advanced regional disease and/or metastasis). Delayed diagnosis precludes successful treatment and favorable outcomes. In clinical practice, opportunities exist to identify patients with oral potentially malignant disorders (OPMDs), which precede the development of cancer. This review addresses the current status of laboratory and clinical research on OPMDs, with emphasis on leukoplakia and erythroplakia. OSF is also presented, though there is a paucity of published studies on this disorder. We focus on findings that could translate into earlier diagnosis and more efficacious treatment of those lesions with significant malignant potential. We explore how markers of OPMD malignant transformation might be implemented into current diagnostic practice to help clinicians objectively stratify patients into treatment/follow-up groups according to relative risk. We provide an overview of recently concluded and ongoing OPMD chemoprevention trials. We describe laboratory OPMD models that can be used to not only to reveal the genetic and molecular intricacies of oral cancer but also to develop novel screening methods and therapeutic approaches. Finally, we call for targeted screening programs of at-risk populations in order to facilitate diagnosis and treatment of OPMD and early OSCC.

Between-lesion discrepancies in terms of dysplasia, cell turnover and diagnosis in patients with multiple potentially malignant oral lesions

Objective:

The present study assessed patients with multiple oral lesions to evaluate the mis-estimation rate in terms of diagnosis and risk of malignant transformation when only one biopsy is performed.

Study Design:

Thirty-five patients presenting at least two white and/or red lesions in different oral mucosa sites with a final diagnosis of leuko/erythroplakias or lichenoid lesions were included, for a total of 70 biopsies.

Results:

Nineteen patients (54%) had at least one between-lesion discrepancy considering the presence/absence of dysplasia (10 patients), normal/high cell turnover (13 patients) or diagnosis (5 patients). Discrepancies were not related to clinical aspect or within-patient similarity of lesions.

Conclusions:

Multiple oral lesions in the same patient can significantly differ in terms of dysplasia, high cell turnover and, even diagnosis. Multiple biopsies are imperative and diagnosis as well as risk of malignant transformation should be formulated for each single lesion rather than for each individual patient.

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

BACKGROUND

The early detection and excision of potentially malignant disorders (PMD) of the lip and oral cavity that require intervention may reduce malignant transformations (though will not totally eliminate malignancy occurring), or if malignancy is detected during surveillance, there is some evidence that appropriate treatment may improve survival rates.

OBJECTIVES

To estimate the diagnostic accuracy of conventional oral examination (COE), vital rinsing, light-based detection, biomarkers and mouth self examination (MSE), used singly or in combination, for the early detection of PMD or cancer of the lip and oral cavity in apparently healthy adults.

SEARCH METHODS

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

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of any of the aforementioned tests in detecting PMD or cancer of the lip or oral cavity. Diagnosis of PMD or cancer was made 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 QUADAS-2. We reported the sensitivity and specificity of the included studies.

MAIN RESULTS

Thirteen studies, recruiting 68,362 participants, were included. These studies evaluated the diagnostic accuracy of COE (10 studies), MSE (two studies). One randomised controlled of test accuracy trial directly evaluated COE and vital rinsing. There were no eligible diagnostic accuracy studies evaluating light-based detection or blood or salivary sample analysis (which tests for the presence of bio-markers of PMD and oral cancer). Given the clinical heterogeneity of the included studies in terms of the participants recruited, setting, prevalence of 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. For COE (10 studies, 25,568 participants), prevalence in the diagnostic test accuracy sample ranged from 1% to 51%. For the eight studies with prevalence of 10% or lower, the sensitivity estimates were highly 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) with uniform specificity estimates around 0.98 (95% CI 0.97 to 1.00). Estimates of sensitivity and specificity were 0.95 (95% CI 0.92 to 0.97) and 0.81 (95% CI 0.79 to 0.83) for one study with prevalence of 22% and 0.97 (95% CI 0.96 to 0.98) and 0.75 (95% CI 0.73 to 0.77) for one study with prevalence of 51%. Three studies were judged to be at low risk of bias overall; two were judged to be at high risk of bias resulting from the flow and timing domain; and for five studies the overall risk of bias was judged as unclear resulting from insufficient information to form a judgement for at least one of the four quality assessment domains. Applicability was of low concern overall for two studies; high concern overall for three studies due to high risk population, and unclear overall applicability for five studies. Estimates of sensitivity for MSE (two studies, 34,819 participants) were 0.18 (95% CI 0.13 to 0.24) and 0.33 (95% CI 0.10 to 0.65); specificity for MSE was 1.00 (95% CI 1.00 to 1.00) and 0.54 (95% CI 0.37 to 0.69). One study (7975 participants) directly compared COE with COE plus vital rinsing in a randomised controlled trial. This study found a higher detection rate for oral cavity cancer in the conventional oral examination plus vital rinsing adjunct trial arm.

AUTHORS' CONCLUSIONS

The prevalence of the target condition both between and within index tests varied considerably. For COE estimates of sensitivity over the range of prevalence levels varied widely. Observed estimates of specificity were more homogeneous. Index tests at a prevalence reported in the population (between 1% and 5%) were better at correctly classifying the absence of PMD or oral cavity cancer in disease-free individuals that classifying the presence in diseased individuals. Incorrectly classifying disease-free individuals as having the disease would have clinical and financial implications following inappropriate referral; incorrectly classifying individuals with the disease as disease-free will mean PMD or oral cavity cancer will only be diagnosed later when the disease will be more severe. General dental practitioners and dental care professionals should remain vigilant for signs of PMD and oral cancer whilst performing routine oral examinations in practice.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Oral cancer is an important global healthcare problem, its incidence is increasing and late-stage presentation is common. Screening programmes have been introduced for a number of major cancers and have proved effective in their early detection. Given the high morbidity and mortality rates associated with oral cancer, there is a need to determine the effectiveness of a screening programme for this disease, either as a targeted, opportunistic or population-based measure. Evidence exists from modelled data that a visual oral examination of high-risk individuals may be a cost-effective screening strategy and the development and use of adjunctive aids and biomarkers is becoming increasingly common.

OBJECTIVES

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

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 22 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6), MEDLINE via OVID (1946 to 22 July 2013), EMBASE via OVID (1980 to 22 July 2013) and CANCERLIT via PubMed (1950 to 22 July 2013). There were no restrictions on language in the search of the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of screening for oral cancer or potentially malignant disorders using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

Two review authors screened the results of the searches against inclusion criteria, extracted data and assessed risk of bias independently and in duplicate. We used mean differences (MDs) and 95% confidence intervals (CIs) for continuous data and risk ratios (RRs) with 95% CIs for dichotomous data. Meta-analyses would have been undertaken using a random-effects model if the number of studies had exceeded a minimum of three. Study authors were contacted where possible and where deemed necessary for missing information.

MAIN RESULTS

A total of 3239 citations were identified through the searches. Only one RCT, with 15-year follow-up met the inclusion criteria (n = 13 clusters: 191,873 participants). There was no statistically significant difference in the oral cancer mortality rates for the screened group (15.4/100,000 person-years) and the control group (17.1/100,000 person-years), with a RR of 0.88 (95% CI 0.69 to 1.12). A 24% reduction in mortality was reported between the screening group (30/100,000 person-years) and the control group (39.0/100,000) for high-risk individuals who used tobacco or alcohol or both, which was statistically significant (RR 0.76; 95% CI 0.60 to 0.97). No statistically significant differences were found for incidence rates. A statistically significant reduction in the number of individuals diagnosed with stage III or worse oral cancer was found for those in the screening group (RR 0.81; 95% CI 0.70 to 0.93). No harms were reported. The study was assessed as at high risk of bias.

AUTHORS' CONCLUSIONS

There is evidence that a visual examination as part of a population-based screening programme reduces the mortality rate of oral cancer in high-risk individuals. In addition, there is a stage shift and improvement in survival rates across the population as a whole. However, the evidence is limited to one study, which has a high risk of bias and did not account for the effect of cluster randomisation in the analysis. There was no evidence to support the use of adjunctive technologies like toluidine blue, brush biopsy or fluorescence imaging as a screening tool to reduce oral cancer mortality. Further RCTs are recommended to assess the efficacy and cost-effectiveness of a visual examination as part of a population-based screening programme in low, middle and high-income countries.

Chromosome instability predicts the progression of premalignant oral lesions

OBJECTIVES

One of the main problems in reducing the incidence of oral squamous cell carcinoma (OSCC) is the inability to appropriately deal with leukoplakia. Accurately identifying lesions which will progress to malignancy is currently not possible. The present study aims to establish the value of chromosome instability (CI) detection by DNA image cytometry and FISH analysis for prognosis and monitoring of oral leukoplakia.

MATERIALS AND METHODS

For this purpose, we included from our archives 102 oral leukoplakia cases, which had been diagnosed between 1991 and 2008. Patient follow-up data were collected and the histopathological diagnosis was revised. CI assessment was carried out on paraffin-embedded tissue sections using both DNA image cytometry (ICM) and dual target FISH for chromosomes 1 and 7.

RESULTS

16 of 102 Patients developed carcinoma in situ or OSCC. Both detection methods were found to yield prognostic information independent of the histopathological diagnosis. CI was a strong individual marker of progression, with hazard ratios (HRs) of 7.2 and 6.8 for ICM and FISH respectively. Moreover, this approach seems suitable for monitoring lesions over time (especially ICM). Combining histopathology and CI enables subdivision of patients into three risk groups, with different probabilities of malignant progression.

CONCLUSION

CI detection seems a reliable method for risk assessment of oral premalignancies and its application may contribute to a better risk-counselling and appropriate treatment regimen or watchfull-waiting approach of patients.

The relevance of EGFR overexpression for the prediction of the malignant transformation of oral leukoplakia

The present study evaluated the relevance of EGFR overexpression in prediction of malignant transformation of oral leukoplakia (OLP). The retrospective study comprised paraffin-embedded tissue samples of OLP that transformed into oral squamous cell carcinoma (OSCC) (n=53) and tissue samples of OLP that did not transform into OSCC (n=45) during a follow-up period of 5 years. EGFR overexpression was assessed immunohistochemically. A significantly different expression rate of EGFR was determined between transformed and non-transformed OLP (p=0.017). A statistically significant increase of EGFR expression for low dysplasia lesions in group I compared to group II was proven (D0, p=0.013; D1, p=0.049). By calculation of ROC curve and determination of highest Youden index the optimal threshold value [cut-off point (COP) = 44.96] for distinguishing the transformed from non-transformed lesions was estimated (critical expression rate of EGFR). Using the determined COP the correlation between high-risk lesions and the detection of increased expression rates were significant (p=0.001). In the future, the assessment of EGFR overexpression in OLP may allow identifying OLP lesions with an increased risk of malignant transformation that may have been regarded harmless when only the grade of dysplasia had been taken into account.

Chromosomal instability, aneuploidy and routine high-resolution DNA content analysis in oral cancer risk evaluation

Carcinogen exposure of the oral cavity is thought to create an extensive 'field cancerization'. According to this model, a very early precursor of oral cancer is a patch of normal-appearing mucosa in which stem cells share genetic/genomic aberrations. These precancerous fields then become clinically visible as white and red lesions (leuko- and erythro-plakias), which represent the vast majority of the oral potentially malignant disorders. This review focuses on aneuploidy (where it is from) and on biomarkers associated with DNA aneuploidy in oral mucosa and oral potentially malignant disorders, as detected by DNA image and flow cytometry. Data from the literature strongly support the association of DNA ploidy with dysplasia. However, work is still needed to prove the clinical value of DNA ploidy in large-scale prospective studies. Using high-resolution DNA flow cytometry with fresh/frozen material and the degree of DNA aneuploidy (DNA Index) might improve the prediction of risk of oral cancer development.

Ten-year retrospective study of head and neck carcinoma in situ: incidence, treatment, and clinical outcome

OBJECTIVES

To examine the management and clinical outcome for patients with primary head and neck carcinoma in situ (CIS) and to estimate the incidence in the referral population.

STUDY DESIGN

A retrospective study from 2000-2009 of patients with head and neck CIS referred for treatment at Rigshospitalet. The referral area was East Denmark and Greenland with a population of 2.4 million.

RESULTS

Fifty-five patients with primary CIS were identified: 21 oral cavity, 7 pharynx, 25 larynx, 2 nasal cavity/paranasal sinuses. The median annual incidence was 0.24/100,000. Eleven patients (20%) had T-site recurrence. The 5-year disease-specific survival rate and 5-year recurrence-free survival rate were 98% and 74% respectively.

CONCLUSIONS

The annual incidence of primary head and neck CIS was low and in accordance with previous findings reported in the literature. We recommend that CIS lesions should be treated on T-site and surveilled as T1/T2 head and neck carcinomas.

Podoplanin expression in oral leukoplakia: tumorigenic role

OBJECTIVES

Recent studies have identified podoplanin, a mucin-type transmembrane glycoprotein, as a biomarker for oral cancer risk in patients with oral leukoplakia (OPL). The aim of this study was to investigate the potential association between podoplanin and the risk of malignant transformation of OPL with epithelial dysplasia.

MATERIALS AND METHODS

In this retrospective study, podoplanin immunoexpression was analyzed in 58 patients with oral leukoplakia that showed epithelial dysplasia. Lesions with podoplanin expression in the basal and suprabasal layers of oral epithelium at one area or showing suprabasal expression at two or more areas were considered as positive. Association between podoplanin expression and oral cancer development was analyzed.

RESULTS

Twenty-two of the 58 lesions (38%) were classified as podoplanin-positive, and the remaining 36 (62%) lesions were considered podoplanin-negative. The expression of podoplanin was correlated with the grade of dysplasia (p<0.0005), and with the risk of progression to oral cancer (p<0.0005). In multivariate survival analysis, only premalignant oral lesions displaying positive podoplanin expression showed a significantly increased risk of developing an oral squamous cell carcinoma (hazard ratio=8.738, p=0.007).

CONCLUSION

Podoplanin could be a valuable biomarker for risk assessment of malignant transformation in patients with OPL along with histological assessment.

Expression of the cell cycle regulation proteins p53 and p21WAF1 in different types of non-dysplastic leukoplakias

OBJECTIVES

The aim of this study was to analyze the immunolabeling of two cell cycle protein regulators, p53 and p21WAF1, in non-dysplastic leukoplakias with different epithelial alterations: acanthosis, hyperkeratosis and acanthosis combined with hyperkeratosis, and compare them with dysplastic leukoplakias.

MATERIAL AND METHODS

This was a prospective cohort study involving 36 patients with oral homogeneous leukoplakias. excisional biopsies were performed and the patients remain under clinical follow-up. The leukoplakias were divided into four groups: 6 acanthosis, 9 hyperkeratosis, 10 acanthosis combined with hyperkeratosis, and 11 epithelial dysplasias. Paraffin-embebeded sections were immunostained for p53 and p21WAF1. Five hundred cells from the basal layer and 500 from the parabasal layer were counted to determine the percentage of positive cells. A qualitative analysis was also carried out to determine the presence or absence of immunohistochemical staining in the intermediate and superficial layers. Groups were compared with ANOVA (p<0.05). Pearson's correlation coefficient was used to test for associations between the two markers, p53 and p21WAF1.

RESULTS

No leukoplakia recurred and no malignant transformation was observed whitin a follow-up period of 3-6 years. The mean percentage of p53 staining in the basal and parabasal layers was similar in all groups. p21WAF1 staining differed between layers was as follows: in the basal, only 3 to 4% of cells were stained, while in the parabasal, between 16 and 28% of the epithelial cells were stained in the four different studied groups with no statistically significant difference (p>0.05).

CONCLUSIONS

Our findings failed to differentiate the non-dysplastic lesions by means of p53 and p21WAF1 immunostaining, notwithstanding similar profiles between non-dysplastic and dysplastic leukoplakias were observed.

How should we manage oral leukoplakia?

The aim of this article is to review the management of oral leukoplakia. The topics of interest are clinical diagnosis, methods of management and their outcome, factors associated with malignant transformation, prognosis, and clinical follow-up. Global prevalence is estimated to range from 0.5 to 3.4%. The point prevalence is estimated to be 2.6% (95% CI 1.72-2.74) with a reported rate of malignant transformation ranging from 0.13 to 17.5%. Incisional biopsy with scalpel and histopathological examination of the suspicious tissue is still the gold standard for diagnosis. A number of factors such as age, type of lesion, site and size, dysplasia, and DNA content have been associated with increased risk of malignant transformation, but no single reliable biomarker has been shown to be predictive. Various non-surgical and surgical treatments have been reported, but currently there is no consensus on the most appropriate one. Randomised controlled trials for non-surgical treatment show no evidence of effective prevention of malignant transformation and recurrence. Conventional surgery has its own limitations with respect to the size and site of the lesion but laser surgery has shown some encouraging results. There is no universal consensus on the duration or interval of follow-up of patients with the condition.

Evaluation of MAGE-A expression and grade of dysplasia for predicting malignant progression of oral leukoplakia

The risk of the malignant transformation of oral leukoplakia (OLP) is difficult to predict by histopathology. Melanoma-associated antigen-A (MAGE-A) expression is restricted to malignant cells and may be useful for the more accurate estimation of the potential malignant transformation of pre-malignant lesions. The aim of the present study was to investigate whether the expression of MAGE-A can be used to predict the malignant transformation of OLP. Paraffin-embedded tissue samples of OLP from 74 patients followed-up for at least 5 years were included. A total of 24 progressing and 50 non-progressing OLP, 18 corresponding tumor and 30 healthy mucosa specimens were analysed for MAGE-A 1, 3, 4, 6 10 and 12 expression by nested real‑time RT-PCR and graded for dysplasia. In total, 46% of the progressing lesions expressed at least 1 out of the examined MAGE-A antigens, whereas no expression was detected in any of the non-progressing OLP and normal specimens. The correlation between malignant transformation and MAGE-A expression was statistically significant (p=0.00001). Furthermore, 42% of the progressing OLPs without dysplasia (D0) expressed at least 1 antigen. The correlation between the grade of dysplasia and MAGE-A staining in the malignant transformation group was not significant (p=0.08). The detection of at least 1 MAGE-A antigen may allow the identification of high-risk lesions that may progress into carcinoma with time. Therefore, the investigation of MAGE-A expression should be assessed in order to obtain a more accurate evaluation of the potential cancer risk of OLP.

Detection of MAGE-A expression predicts malignant transformation of oral leukoplakia

The study aimed at checking if MAGE-A expression in oral leukoplakia (OLP) lesions is related to malignant transformation. The 48 samples of OLP that transformed to oral squamous cell carcinoma (OSCC) (group 1) and 50 samples of OLP that did not transform to OSCC (group 2) were included in the study. The expression of MAGE-A was restricted to group 1. The correlation between malignant transformation and MAGE-A occurrence in OLP was statistically significant (p < .0001). Detection of MAGE-A may allow identifying OLP with a high risk of malignant transformation giving a view to a new approach to prevention of oral cancer.

MAPK/ERK-dependent translation factor hyperactivation and dysregulated laminin γ2 expression in oral dysplasia and squamous cell carcinoma

Lesions displaying a variety of dysplastic changes precede invasive oral and epidermal squamous cell carcinoma (SCC); however, there are no histopathological criteria for either confirming or staging premalignancy. SCCs and dysplasias frequently contain cells that abnormally express the γ2 subunit of laminin-332. We developed cell culture models to investigate γ2 dysregulation. Normal human keratinocytes displayed density-dependent repression of γ2, whereas premalignant keratinocytes and SCC cells overexpressed γ2 and secreted laminin assembly intermediates. Neoplastic cells had hyperactive EGFR/MAPK(ERK) signaling coordinate with overexpressed γ2, and EGFR and MEK inhibitors normalized γ2 expression. Keratinocytes engineered to express HPV16 E6 or activated mutant HRAS, cRAF1, or MEK1 lost density repression of γ2 and shared with neoplastic cells signaling abnormalities downstream of ERK, including increased phosphorylation of S6 and eIF4 translation factors. Notably, qPCR results revealed that γ2 overexpression was not accompanied by increased γ2 mRNA levels, consistent with ERK-dependent, eIF4B-mediated translation initiation of the stem-looped, 5'-untranslated region of γ2 mRNA in neoplastic cells. Inhibitors of MEK, but not of TORC1/2, blocked S6 and eIF4B phosphorylation and γ2 overexpression. Immunostaining of oral dysplasias identified γ2 overexpression occurring within fields of basal cells that had elevated p-S6 levels. These results reveal a causal relationship between ERK-dependent translation factor activation and laminin γ2 dysregulation and identify new markers of preinvasive neoplastic change during progression to SCC.

Oral cancer development in patients with leukoplakia--clinicopathological factors affecting outcome

BACKGROUND

Oral leukoplakia (OL) is the best-known potentially malignant disorder. The objective of the current study was to evaluate the clinicopathological factors predictive of outcome in a large cohort of patients with OL, and report our experience in the early detection of malignant events.

METHODS

A total of 320 patients with biopsy-proven OL were retrospectively reviewed from the study institution who had a mean follow-up of 5.1 years. Data on patient and lesion at initial diagnosis and patient underwent sequential biopsies were reviewed. Multiple biopsies indicates > = 3 times sequential biopsies. Oral cancer-free survival rate (OCFS) was determined by the Kaplan-Meier method and significant factors were identified by Cox regression analysis.

RESULTS

The 3-year and 5-year OCFS was 86.6% and 82.0%, respectively. A new binary system of grading oral dysplasia was performed and Kaplan-Meier analysis indicated that high-grade dysplasia had significantly higher malignant incidence than low-grade dysplasia (5-year OCFS, 90.5% vs 59.0%; P<0.001), especially during the first 2-3 years of follow-up. Multivariate analysis revealed that the 4 factors including patient aged >60 years, lesion located at lateral/ventral tongue, non-homogenous lesion, high-grade dysplasia were independent significant indicators for OL malignant transformation. In addition, significant positive correlation between the multiple biopsies and these 4 factors and malignant outcome was established.

CONCLUSIONS

Elderly patients with OL located at lateral/ventral tongue and who had non-homogenous lesion with high-grade dysplasia correlated much higher risk of transformation. This high-risk subpopulation was suggested to undergo sequential biopsies and histologic examination contributing to early detection of malignant event.

Oral Leukoplakia as It Relates to HPV Infection: A Review

Leukoplakia is the most common potentially malignant lesion of the oral cavity and can be categorised according to its clinical appearance as homogeneous or nonhomogenous. Tobacco and areca nut use, either alone or in combination are the most common risk factors for oral leukoplakia, but some oral leukoplakias are idiopathic. Some leukoplakias arise within fields of precancerized oral epithelium in which the keratinocytes may be at different stages of cytogenetic transformation. Leukoplakias may unpredictably regress, may remain stable, or may progress to carcinoma. There is a greater risk of carcinomatous transformation of idiopathic leukoplakia, of non-homogenous leukoplakia, of leukoplakia affecting the floor of the mouth; the ventrolateral surface of the tongue and the maxillary retromolar and adjoining soft palate (collectively called high-risk sites), of leukoplakia with high-grade epithelial dysplasia, and of leukoplakia in which the keratinocytes carry cytogenetic alterations associated with carcinomatous transformation. Although there appears to be some link between human papillomavirus (HPV) and oral leukoplakia, there is little evidence to support a causal relationship either between HPV infection and oral leukoplakia or between HPV-infected leukoplakic keratinocytes and their carcinomatous transformation.

The efficacy of oral brush biopsy with computer-assisted analysis in identifying precancerous and cancerous lesions

Background

Cancer of the oral cavity is the sixth most common malignancy reported worldwide and one with the highest mortality rate among all malignancies. There is a paucity of reliable diagnostic methods to detect early malignancies. This study was performed to evaluate the sensitivity and specificity of brush biopsy in identifying oral premalignant and malignant lesions.

Methods

Oral brush and scalpel biopsies were performed on 85 consecutive patients presenting with an oral lesion deemed to be minimally suspicious by clinical examination and the results were compared.

Results

Of 79 patients with adequate brush biopsy samples with matching scalpel biopsies, 27 revealed histopathologic evidence of dysplasia or carcinoma, 26 of which were independently identified with the oral brush biopsy (sensitivity: 96.3% - 95% CI, 87%-100%). 52 oral lesions did not reveal any histopathologic evidence of dysplasia or carcinoma and of these, brush biopsy reported 47 as "negative" and 5 as "atypical"(specificity of "positive" brush biopsy result is 100%- 95% CI, 93%-100%; specificity for "atypical" brush biopsy result is 90.4%- 95% CI, 82%-97%. The positive predictive value of an abnormal oral brush biopsy was 84% and the negative predictive value was 98%.

Conclusion

Our study demonstrated that the oral brush biopsy is an accurate test in identifying oral premalignant and malignant lesions, even if minimally suspicious.

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.

A brief review of common oral premalignant lesions with emphasis on their management and cancer prevention

Long-term outcomes associated with oral cancer and its management over the past several decades has caused concern and the value of mass oral cancer screenings has come under scrutiny. Though not all oral carcinomas are preceded by premalignant lesions as clinically visible morphological alterations occur secondary to the cellular or molecular changes, certain high risk lesions have been identified. Their management remains controversially polarized between surgical excision to prevent malignant change and conservative medical or surveillance techniques. Though oral cancer is one of the "major killers" of modern times, there seem to be no widely accepted criteria for decision making in clinical practice, the evidence base is scanty and uncertainty persists throughout investigation, diagnosis, and treatment. In this article, we have briefly discussed the common premalignant lesions, with an emphasis on their evidence based management and prevention.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s12262-011-0286-6) contains supplementary material, which is available to authorized users.

Direct visualization of oral-cavity tissue fluorescence as novel aid for early oral cancer diagnosis and potentially malignant disorders monitoring

Direct visualization of the oral tissue autofluorescence has been recently reviewed in several studies as a possible adjunctive tool for early recognition and diagnosis of potentially malignant and malignant oral disorders. The aims of this study were to assess: a) the value of a simple handheld device for tissue auto-fluorescence visualization of potentially malignant oral lesions; and b) the sensitivity, specificity and diagnostic accuracy of tested device, using histological examination as the gold standard. 175 consecutive patients, with at least one clinical oral lesion, were enrolled in the study. Clinical conventional inspections were performed for each patient by two blind operators. Then, oral biopsy and histological examination were performed. Pathologist was blind with respect to the autofluorescence results. The 175 histological assessments revealed no dysplasia, mild dysplasia, moderate/severe dysplasia and OSCC, in the 67.4%, 8.6%, 8%, 16% of cases, respectively. Oral lesions diagnosed as OSCC were found as positive under fluorescent light in the 96.4% of cases. Statistically significant correlation was observed between oral dysplastic lesions and the loss of tissue fluorescence (p-value=0.001). Low sensitivity values (60% and 71%) were recorded about the ability of the device in differentiating mild dysplasia vs. lack of dysplasia and moderate/severe dysplasia vs absence of dysplasia, respectively. The device tested in our study was found to not replace the histopathology procedure. However, we assessed its usefulness for oral tissue examination, especially within an oral medicine secondary care facility, before performing a biopsy and in monitoring oral lesions.

Excisional biopsy with margin control for oral cancers

BACKGROUND

This study was undertaken to show how an excisional biopsy procedure can be used to remove the entire specimen for oral lesions with difficult diagnoses.

METHODS

We retrospectively reviewed 52 cases with 56 oral lesions either suspected to be malignant or with a preliminary controversial diagnosis. These were treated by excisional biopsy with frozen section intraoperatively between January 2003 and June 2008.

RESULTS

Twenty-eight of 56 lesions were diagnosed with malignancy. We found a high underdiagnosis rate (7 of 12) in patients who had a preliminary controversial diagnosis. Twenty-one patients without preoperative biopsy were diagnosed to have malignancies. Of the 28 malignant cases, all surgical margins were negative. Neck ultrasound scans with fine-needle aspiration cytology was carried out and no patient demonstrated simultaneous neck metastasis. One patient died of locoregional recurrence. Two patients died of a second primary cancer.

CONCLUSION

Excisional biopsy with margin control is useful both in diagnosis and treatment of oral cancers.

Evaluation of high-performance liquid chromatography laser-induced fluorescence for serum protein profiling for early diagnosis of oral cancer

The present work deals with the evaluation of a high-performance liquid chromatography laser-induced fluorescence (HPLC-LIF) technique developed in our laboratory for early detection of oral cancer from protein profiles of body fluids. The results show that protein profiles of serum samples from a given class of samples, say, normal, premalignant, or malignant, are statistically very close to each other, while profiles of members of any class are significantly different from other classes. The performance of the technique is evaluated by the use of sensitivity and specificity pairs, receiver operating characteristic (ROC) analysis, and Youden's Index. The technique uses protein profile differences in serum samples, registered by the HPLC-LIF technique. The study is carried out using serum samples from volunteers diagnosed as normal or premalignant clinically, and as malignant by histopathology. The specificities and sensitivities of the HPLC-LIF method at an ideal threshold (M-distance = 2) for normal, malignant, and premalignant classes are 100, 69.5, and 61.5%, and 86.5, 87.5, and 87.5% respectively.

[Screening and diagnosis of precancerous oral mucosa lesions]

The screening and early diagnosis of cancerous oral mucosa lesions are still key elements for a better prognosis. Therefore, it is of tremendous importance to try to determine how and when to diagnose precancerous oral mucosa lesions. Usually, clinical examination data must be completed by a pathological examination. This study, based on an exhaustive literature review, has for purpose to determine the sensitivity and specificity of complementary diagnostic tools currently available.

Evaluation of COX-2, EGFR, and p53 as biomarkers of non-dysplastic oral leukoplakias

OBJECTIVE

Identify candidate SEBs (surrogate endpoint biomarkers) for premalignant trends in head and neck mucosa.

STUDY DESIGN

Study, by qPCR (quantitative real-time polymerase chain reaction), the expression of COX-2, EGFR and p53 in 24 biopsies of non-dysplastic oral leukoplakia and contra-lateral normal-appearing mucosa.

RESULTS

COX-2 was up-regulated in leukoplakia (79.2%); whereas EGFR and p53 were up-regulated (p>0.05) in oral contra-lateral normal-appearing mucosa (60% and 46% respectively). Also, p53 expression was correlated with tobacco smoke habits and Spearman's rank correlation coefficient showed a positive linear correlation between p53 and EGFR mRNA expression levels.

CONCLUSIONS

COX-2 would serve as SEB of oral leukoplakia. The results suggest that p53 appears to be one of the molecular targets of tobacco-related carcinogens in leukoplakia and that the co-expression of p53 and EGFR may play a role in this kind of oral pre-cancerous lesion. More detailed studies of EGFR and p53 should be continued in the future.

Oral cancer screening: what have we learnt and what is there still to achieve?

Oral cancer is an important global healthcare problem. In the UK, the incidence is increasing and late-stage presentation is common. Determining the feasibility of a national screening program for oral cancer is therefore an important step in the prevention of the disease. Evidence exists to suggest that an oral examination of high-risk individuals may be a cost-effective screening strategy. However, questions remain over which primary care environment would be the most suitable and the criteria for a positive screen and referral. Further research is needed in the form of clinical trials or demonstration studies in primary care. The impact on secondary care, the role of auxiliaries and training needs also need to be determined. In addition, the assessment of adjunctive aids and evaluation of potential biomarkers are considered important.

Overview of cancer for the healthcare team: aetiopathogenesis and early diagnosis

Much cancer presents late, at a stage when not only is more radical treatment necessary, but the prognosis is also less favourable. This paper attempts to provide an overview of the aetiopathogenesis of cancer (carcinoma) for the healthcare team, a broad understanding of which is crucial for coping with issues related to prevention, diagnosis and management. Prevention of cancer involves lifestyle decisions which afford protection not only against cancers in many sites, but also against a wide range of other conditions, many of which are equally life-threatening. The paper also highlights areas of controversy in the early diagnosis of oral cancer. Earlier diagnosis is likely to be achieved reliably only with the introduction of molecular studies.

MAGE-A as a novel approach in the diagnostic accuracy of oral squamous cell cancer: a case report

Background

The aim of this case report is to introduce the combined use of brush biopsy and measurement of MAGE-A expression in the diagnosis of oral squamous cell carcinoma (OSCC).

Case report

We report of a 49-year old male patient who was referred to our department with a persistent-suspicious looking leukoplakia. Brush biopsy and an incisional biopsy were performed following clinical diagnosis. Histopathological examination revealed no malignancy. Expression analysis of melanoma-associated antigens A (MAGE-A) using real time RT-PCR was applied to brush biopsy materials because of the high prevalence of MAGE-A determined previously in OSCC's. Results indicated significant MAGE-A3 and A4 expression pattern. Therefore, the lesion was excised completely and an early invasive carcinoma was identified.

Conclusion

These results emphasize the role of brush biopsy using a tumor marker with a high expression frequency combined with a high sensitive and high specific detection system in the early diagnosis of OSCC, particularly in widespread leukoplakias.

[Squamous cell carcinoma and potentially malignant disorders of the oral mucosa]

Squamous cell carcinoma is the most frequent malignant tumor of the oral mucosa. Various endogenous and exogenous factors promote its development. Therapy and prognosis depend mainly on tumor stage. Early detection is therefore of utmost importance. In most cases cancer develops from "leukoplakia". Both homogeneous leukoplakias as well as "erythroleukoplakias" should be biopsied. The"brush-biopsy", imaging techniques, molecular biologic or DNA tests are not reliable enough at present, often technically demanding and not applicable in daily practice. In extensive lesions "field cancerization" has to be considered. Further important precursor lesions are proliferative verrucous leukoplakia and erosive lichen planus. The management of oral precancerous lesions should be individually tailored: Low-grade dysplasia can be observed. If indicated, patients at risk should be biopsied in intervals. High-grade dysplasia ("carcinoma in situ") should be surgically removed.

DNA aneuploidy and dysplasia in oral potentially malignant disorders: association with cigarette smoking and site

To date there are still no reliable biomarkers for oral potentially malignant disorders (PMDs) to predict the risk of progression to squamous cell carcinoma (SCC). Within a prospective clinical trial of patients with PMDs, DNA content flow cytometry (DNA FCM) was evaluated for 60 PMDs using fresh samples obtained by a dermatological curette. There were 6/42 PMDs without dysplasia, but with DNA aneuploidy, versus 8/18 with both dysplasia and aneuploidy (p=0.02). When the tongue and the buccal mucosa, the two most common sites in the present series of cases were compared, dysplastic PMDs were mainly located on the tongue (p=0.01). Tobacco smokers, who preferentially developed PMDs in the buccal mucosa at a younger age than non-smokers (p=0.002), had fewer dysplastic PMDs than did non-smokers (p=0.01). Dysplasia was significantly linked to DNA aneuploidy (p=0.03) in smokers. The present data suggest that aneuploidy is an early event in oral carcinogenesis and that the influence of tobacco varies according to subsite and patient age. When DNA FCM of PMD samples are obtained by curette scraping, extensive areas can be covered with a minimally invasive, rapid, inexpensive procedure. Moreover DNA FCM of these samples appears easy amenable to routine analysis. Further research on larger numbers of PMDs should be carried out to determine whether DNA FCM plays a role in the prediction of risk of PMD transformation.