Observations on the clinical characteristics of oral lesions showing histologic epithelial dysplasia

Proceedings of the North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Oral Cavity Dysplasia: Why Does Histologic Grading Continue to be Contentious?

Head and neck squamous cell carcinoma (HNSCC) is the world's 6th most common malignancy. Oral cavity SCC (OCSCC) represents approximately one third of the HNSCC cases diagnosed annually in the United States. Despite therapeutic advances, OCSCC is frequently lethal, with a modest 5-year survival. Because OCSCC is often preceded by premalignant lesions, it is an ideal disease for screening initiatives. The conventional visual and tactile exam (CVTE), coupled with a tissue biopsy, remains the gold standard. However, CVTE alone cannot reliably differentiate between reactive/inflammatory and dysplastic lesions. Further, the histologic diagnosis of dysplasia is subjective in nature and a highly imperfect predictor of malignant transformation. This prognostic uncertainty creates a significant clinical management dilemma-watchful waiting with increased patient psychological and economic burdens versus unnecessary aggressive treatment. As such, the development and validation of novel diagnostic platforms such as Artificial Intelligence (AI) and prognostic molecular biomarkers may help address these critical unmet clinical needs.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Oral Potentially Malignant Disorders (OPMD): What is the clinical utility of dysplasia grade?

INTRODUCTION

Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to develop invasive cancer. The questions of what process dysplasia grading best represents and what clinical utility dysplasia grading may have are explored.

AREAS COVERED

This narrative review is based on PubMed search with emphasis on papers since 2010. Epithelial dysplasia as a precursor lesion of cancer and dysplasia grading as a risk assessment tool for progression to cancer are discussed. The close clinical association of dysplasia with known carcinogens, alcohol, and tobacco products is presented.

EXPERT OPINION

Oral epithelial dysplasia is often, associated with prolonged exposure to tobacco and alcohol products. With reduction of carcinogen exposure, dysplasia is known to regress in some cases. It is proposed that histologic dysplasia grade together with macroscopic images of dysplastic clinical lesions be used as an educational tool to incentivize patients to reduce their known carcinogen exposure. This strategy has the potential to reduce lesion progression thereby reducing the disease burden of oral cancer.

Current challenges and the diagnostic pitfalls in the grading of epithelial dysplasia in oral potentially malignant disorders: A review

Oral cancer is one of the common cancers in the world causing high morbidity. Development of cancer is preceded by certain asymptomatic clinical lesions and conditions all together known as 'oral potentially malignant disorders'. Histologically they are represented by the term 'oral epithelial dysplasia'. The degree of severity of dysplasia is determined in the form of 'grade'. Despite the existence of several grading systems proposed by various scholars, it is still a challenging task for the Pathologists to grade dysplasia accurately for the proper diagnosis of the disease and to follow preferable treatment plans. This review aims to focus on the current challenges and the diagnostic pitfalls in the grading of oral epithelial dysplasia in various oral potentially malignant disorders.

Long-term follow-up of oral epithelial dysplasia: A hospital based cross-sectional study

Background/purpose

Oral epithelial dysplasia (OED) is characterized histopathologically by cellular and morphological changes that remain the single most important factor predicting risk for subsequent development of invasive neoplasia. Hence the aims of the present study were to determine the rate of malignant change of OED in a group of patients followed-up for a number of years, and hence determine factors likely to influence this malignant change, and to describe the clinical characteristics of patients who developed recurrence of OED and second dysplastic lesions.

Materials and methods

This is hospital based cross-sectional study of all biopsy reports with histologically confirmed OED between 2012 and 2018 were retrospectivelly reviewed.

Results

A total of 359 patients with histologically confirmed OED were reviewed, twenty (5.5%) of the 359 patients developed an invasive squamous cell carcinoma (SCC) of the oral mucosa over a period of 2 to 274 months with mean transformation time of 3.3 years.

Conclusion

The high risk of malignant transformation of OED seems to be related to patients older than 50 years when lesions were on the floor of mouth with severe dysplastic changes.

DNA aneuploidy and tissue architecture in oral potentially malignant disorders with epithelial dysplasia assessed by a 10 locus FISH panel

Subjectivity in oral dysplasia grading has prompted evaluation of molecular-based tests to predict malignant transformation. Aneuploidy detected by DNA image-based cytometry (ICM) is currently the best predictor but fails to detect certain high risk lesions. A novel multiplex fluorescence in situ hybridization (FISH) panel was used to explore possible explanations by detecting aneuploidy at the single cell level. FISH was compared to reference standard DNA ICM in 19 oral lesions with epithelial dysplasia and used to characterize the cellular architecture. Copy number variation at 3q28, 7p11.2, 8q24.3, 11q13.3 and 20q13.12 and matched chromosome specific loci were assessed by dual-color FISH to assess numerical and spatial patterns of copy number increase and gene amplification. FISH revealed wide variation in copy number at different loci. Only low level copy number gain was present and often in only a small proportion of cells, although usually with all or all but one locus (9/12). Four cases showed gene amplification, one at two loci. Some probes revealed an internal presumed clonal structure within lesions not apparent in routine histological examination. Both methods produced similar diagnostic results with concordance in detection of aneuploidy by both methods in 17 out of 19 samples (89%). We have shown that oral dysplastic lesions may contain very few aneuploid cells at a cellular level, high copy number gain is rare and changes appear to arise from large chromosomal fragment duplications. Single stem lines are relatively homogeneous for loci with copy number gain but there is a subclonal structure revealed by gene amplification in some lesions.

Potentially malignant disorders of the oral cavity and oral dysplasia: A systematic review and meta-analysis of malignant transformation rate by subtype

IMPORTANCE

Potentially malignant disorders of the oral cavity (OPMD) are a heterogeneous group of lesions associated with a variable risk of malignant transformation (MT) to invasive cancer. Leukoplakia (LE), lichen planus (LP), oral lichenoid lesions (OLL), oral erythroplakia (OE), oral submucous fibrosis (OSF), and proliferative verrucous leukoplakia (PVL) are among the most common of these lesions. Oral dysplasia is a mucosal area characterized by cellular and architectural derangement, which may be associated with OPMDs or not.

OBJECTIVE

To define the MT rate of OPMDs and the risk of development into cancer of mild vs moderate/severe oral dysplasia. This in order to implement adequate follow-up strategies and treatment decisions.

STUDY DESIGN

We performed a systematic review and meta-analysis on studies reporting the MT rates of OPMDs and oral dysplasia. Ninety-two studies were included for the analysis. Cumulative rates were reported for OPMDs overall and as a subgroup, a comparison was made of mild vs moderate/severe dysplasia. Meta-regression on OPMD and year of publication was also performed.

MAIN OUTCOME AND MEASURES

Overall MT rates of OPMDs and odds ratio of MT of mild vs moderate/severe dysplasia.

RESULTS

Overall MT rate across all OPMD groups was 7.9% (99% confidence interval [CI] 4.9%-11.5%). MT rates of the specific OPMD subgroups were as follows: LP 1.4% (99% CI 0.9%-1.9%), LE 9.5 (5.9%-14.00%), OLL 3.8% (99% CI 1.6%-7.00%), OSF 5.2% (99% CI 2.9%-8.00%), OE 33.1% (99% CI 13.6%-56.1%), and PVL 49.5% (99% CI 26.7%-72.4%). Regarding the dysplasia grades comparison, the meta-analysis showed that moderate/severe dysplasia is meaningfully associated to a much greater risk of MT compared to mild dysplasia with an odds ratio of 2.4 (95% CI 1.5-3.8) [Correction added on 27 December 2019, after first online publication: CI updated from 99% to 95%.]. Heterogeneity was not significant. Annual MT rates were approximated based on the average follow-up as reported in the various subgroups. Lichen planus had an annual MT of 0.28%, OLL of 0.57%, leukoplakia of 1.56%, PVL of 9.3%, and OSF of 0.98%. Mild dysplasia had an annual MT of 1.7%, while severe dysplasia of 3.57%. Meta-regression showed a significant negative correlation of PVL MT rate and year of the study (P value <.001).

CONCLUSIONS AND RELEVANCE

OPMDs and oral dysplasia are relatively common conditions that general practitioners, head and neck, and oral medicine specialists, face in their everyday practice. Our analysis confirms the significant risk of MT of these lesions, although variable among the subgroups. Moderate/severe dysplasia bears a much higher risk of cancer evolution than mild dysplasia. It is important to raise public health awareness on the MT rates of these conditions, at the same time efficacious communication with the patient is of utmost importance. This, coupled with strict follow-up measures and optimal treatment strategies, would help in reducing the transformation of these oral conditions into invasive cancer.

Oral epithelial dysplasia: Causes, quantification, prognosis, and management challenges

Oral epithelial dysplasia is a spectrum of architectural and cytological epithelial changes caused by accumulation of genetic changes, and is associated with an increased risk of progression to squamous cell carcinoma. It is a microscopic diagnosis of immense clinical importance. The initial reports of oral potentially malignant disorders with oral epithelial dysplasia transforming to oral cancer helped in understanding the nature of oral malignancies. Since then, clinical studies on oral potentially malignant disorders have combined microscopic findings of oral epithelial dysplasia to assess the malignant transformation potential of different grades of epithelial dysplasia. A significant amount of scientific literature has amassed on oral epithelial dysplasia relating to aspects of its diagnosis and management. However, the evidence base is weak as a result of the significant variability of published research. Poorly described study methods, variability in different oral epithelial dysplasia grading systems, inter- and intra-examiner variability causing issues of reliability, inadequate sample size, and inconsistent durations of follow-up are some of the methodological issues contributing to the failure to provide dependable information. Randomized clinical trials on the malignant transformation potential of oral epithelial dysplasia and its treatment outcomes are limited. This comprehensive literature review on oral epithelial dysplasia summarizes the scientific knowledge published in the scientific literature in English since its first description. The historical development, etiological factors, grading systems, diagnostic criteria, assessment of risk factors and prevention of malignant transformation, management principles of different grades of oral epithelial dysplasia (surgical and nonsurgical), recommendations on follow-up, and prognostic indicators are discussed in detail.

A History of Innovations in the Diagnosis and Treatment of Oral and Head and Neck Cancer

Historical records as far back as 3000 BCE show that oral and head and neck cancer was a disease process well known to Egyptian physicians. Luminaries such as Hippocrates, Galen, Pott, and Virchow were instrumental in shaping our understanding of the etiology and pathogenesis of cancer. During the 20th century, evidence-based medicine catalyzed the development of rigorous science-based diagnostic and treatment protocols. The use of surgery, therapeutic radiation, and chemotherapy as single-treatment agents or in combination with one another gradually emerged as the preferred approach to cancer therapy. The recognition of tobacco, alcohol, and human papillomavirus as etiological agents in oral and head and neck cancer prompted the development of new diagnostic aids and treatment strategies to mitigate cancer progression. More in-depth mechanistic insights into the multistep process of oral and head and neck cancer were made possible by the use of the hamster buccal pouch and mouse models. New technologies, such as the sequencing of the human genome, metabolomics, and proteomics, have provided the foundation for what we today call precision medicine. The future success of tailored medical treatment for cancer patients will depend on the discovery of new druggable targets with improved therapeutic efficacy. As the precision and sensitivity of existing tools for prevention and risk assessment improve, greater accuracy will be achieved in predicting health outcomes.

Predicting malignant progression in clinically high-risk lesions by DNA ploidy analysis and dysplasia grading

The value of image cytometry DNA ploidy analysis and dysplasia grading to predict malignant transformation has been determined in oral lesions considered to be at ‘high’ risk on the basis of clinical information and biopsy result. 10-year follow up data for 259 sequential patients with oral lesions clinically at ‘high’ risk of malignant transformation were matched to cancer registry and local pathology database records of malignant outcomes, ploidy result and histological dysplasia grade. In multivariate analysis (n = 228 patients), 24 developed carcinoma and of these, 14 prior biopsy samples were aneuploid. Aneuploidy was a significant predictor (hazard ratio 7.92; 95% CI 3.45, 18.17) compared with diploidy (p < 0.001). The positive predictive value (PPV) for severe dysplasia was 50% (95% CI 31.5, 68.5) and for aneuploid lesions, 33.3% (95% CI 19.0, 47.6). Combined DNA aneuploidy and severe dysplasia increased PPV to 56.3% (95% CI 31.9, 80.6). Diploid-tetraploid and non-dysplastic status had high negative predictive values (NPV) of 94.6% (95% CI 91.4, 97.8) and 99.17% (95% CI 97.4, 100.8) respectively. DNA ploidy predicts malignant transformation well and combining it with dysplasia grading gave the highest predictive value. The predictive values reported here exceed those from other investigations to date.

Quantitative Exfoliative Cytology of Abnormal Oral Mucosal Smears

In this study quantitative techniques have been applied to smears collected from the buccal mucosa and floor of the mouth. The results display an encouraging success rate for identifying premalignant and malignant lesions. ‘Intrapatient’ normal smears provide a satisfactory control for comparison with pathological smears. Early results indicate that quantitative cytology could be of great value for monitoring and follow-up of suspicious lesions and provide an excellent additional diagnostic test for detecting early oral malignancy.

Oral potentially malignant disorders: risk of progression to malignancy

Oral potentially malignant disorders (OPMDs) have a statistically increased risk of progressing to cancer, but the risk varies according to a range of patient- or lesion-related factors. It is difficult to predict the risk of progression in any individual patient, and the clinician must make a judgment based on assessment of each case. The most commonly encountered OPMD is leukoplakia, but others, including lichen planus, oral submucous fibrosis, and erythroplakia, may also be seen. Factors associated with an increased risk of malignant transformation include sex; site and type of lesion; habits, such as smoking and alcohol consumption; and the presence of epithelial dysplasia on histologic examination. In this review, we attempt to identify important risk factors and present a simple algorithm that can be used as a guide for risk assessment at each stage of the clinical evaluation of a patient.

Should severe epithelial dysplasia be treated?

OBJECTIVE

To identify clinical features associated with progression of primary severe epithelial dysplasia into invasive squamous cell carcinoma (SCC).

DESIGN

Longitudinal population-based study.

SETTING

Oral dysplasia clinics.

PATIENTS

This study involved 118 patients with 118 severe dysplasia who were prospectively enrolled between 1996 and 2014, and the lesions were either completely removed surgically (treated) or actively followed (untreated).

MEASUREMENTS

Demographics, habits, clinical information and outcome were compared between the treated and untreated groups.

RESULTS

Of the 118 lesions, 77 were treated and 41 were not. The treated lesions showed significantly less progression when compared to the untreated: 5/77 (6%) treated lesions progressed into invasive SCC versus 12/41 (29%) untreated (P=0.004). The 5-year probability (confidence interval) of progression into SCC for the treated was 7.6 (1-14) as compared to 38.6 (16-55) for the untreated. Interestingly the clinical changes at the site of the disease also had strong predictive value for cancer progression. If the site showed no lesion after treatment or after incisional biopsy (40 cases), only 1 (3%) progressed into cancer. If the site showed ever disappearance of the lesion or marked decrease in the size of the lesion to ⩽10mm (29 cases), 4 (15%) progressed. If the site showed lesions with fluctuation in size or persistent in size or marked increase in size (25 cases), 18 (58%) progressed (P<0.001).

CONCLUSION

Treatment significantly reduced cancer progression, and phenotypic changes at the site of the disease had significant predictive value for cancer progression.

Meta-analysis on clinicopathologic risk factors of leukoplakias undergoing malignant transformation

Context:

Leukoplakia is classified under the term potentially malignant disorder. This term does not suggest the clinician or the patient about the severity of the disease to undergo a malignant transformation. Thus, there arises a need to identify the risk factors associated with malignant transformation (MT) to predict it at the earliest.

Aims:

To generate evidence regarding the clinicopathologic factors affecting MT in oral leukoplakias.

Materials and Methods:

Meta-analysis was done by extracting data from all the previous studies published. Articles were searched in PubMed databases.

Statistical Analysis:

Mixed model by using the PROC MIXED (SAS 9.3) was performed to estimate the effect of different factors such as gender, type of habit (smoking tobacco, gutka, paan (with tobacco) and no habit association), clinical type and histopathology on MT. The lower specific mean for MT was also calculated with respect to the above-mentioned factors.

Results:

Speckled leukoplakias also known as erythroleukoplakia confirmed to be at the highest risk. Lateral border of the tongue followed by gingiva, buccal mucosa, floor of the mouth, lesions involving tongue and floor of mouth showed increased risk. Smoking tobacco (cigarette and bidi) and idiopathic leukoplakia (without habit) carried almost equal risk. Gender had minimal influence on MT. Histopathologic correlation of grades showed an insignificant bearing on MT.

Conclusion:

The carcinogenic transformation of a preexisting lesion (leukoplakia) is multifactorial and patient specific. The protocol to delineate a high-risk lesion should include the clinical type and site.

Malignant Transformation Rate in Patients Presenting Oral Epithelial Dysplasia: Systematic Review and Meta-Analysis

Objective. To perform a systematic review and meta-analysis on studies that assess malignant transformation rates (MTR) of oral epithelial dysplasia. Materials and Methods. This review was planned and conducted in accordance with the meta-analysis of observational studies in epidemiology (MOOSE) guidelines. PubMed, EMBASE, Google Scholar, and Cochrane databases were screened to identify observational studies. Quality assessments were completed by two reviewers independently using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Pooled-malignant transformation rate (MTR) in person years, subgroup, sensitivity, and publication bias analysis were calculated using STATA 13.0 and Comprehensive Meta-Analysis software. Results. Sixteen observational cohort studies were identified with a total of 3708 participants from Asia, North America, and Europe. Analysis showed a MTR of 10.5% (pooled-MTR: 10.5, 95% CI: 3.7 to 17.3; fixed effect model, I2=0.0%; Q-value = 2.389; p>0.05) among patients with histologically confirmed oral epithelia dysplasia undergoing long-term follow-up. Higher MTR in person year were seen among the sever dysplastic cases (pooled-MTR: 14.4%, 95% CI: 5.3% to 23.5%), studies published in Europe (pooled-MTR: 12.6%, 95% CI: 8.0% to 24.3%), and retrospective studies (pooled-MTR: 11.0%, 95% CI: 2.2% to 19.9%). Conclusion. These studies show that oral epithelial dysplasia has a significant high rate of transformation to cancer.

Clinicopathologic evaluation of lesions associated with tobacco usage

INTRODUCTION

Tobacco usage in different forms is the single most common etiological factor responsible for oral cancers. The aim of the present study was to record various mucosal lesions associated with tobacco usage and to ascertain the prevalence of dysplasia in them by histopathological evaluation and to compare the extent of dysplastic features seen among patients associated with a habit of smoked and smokeless form of tobacco.

MATERIALS AND METHODS

Seventy-six patients with the clinical diagnosis of tobacco related lesions (Leukoplakia, Erythroplakia, Nicotina stomatitis, Tobacco pouch keratosis) were selected. A detailed description of the clinical presentation of the lesion was noted and the patients were subjected to incisional biopsy followed by a histopathological evaluation.

RESULTS

Showed dysplastic changes in 50 cases (65.8%) ranging from mild dysplasia in 27 cases (35.5%), moderate dysplasia in 17 cases (22.4%) and 6 cases (7.9%) showed severe dysplasia. Moderate to severe dysplasia was 1.83 times more likely to occur with smokeless tobacco usage when compared to smoked form. Data obtained from this study reveals that patients with a duration of tobacco usage more than 10 years were 2.17 times more likely to have moderate to severe dysplasia (p = 0.154).

CONCLUSION

Thus, the study highlights the role of oral physicians in detecting oral mucosal lesions and screening high-risk patients on a regular basis and also reaffrms the importance of public education, stressing the risk factors for oral cancers.

Bowman birk inhibitor concentrate and oral leukoplakia: a randomized phase IIb trial

Oral premalignancy serves as an ideal model for study of chemopreventive agents. Although 13-cis-retinoic acid showed reversal of oral premalignancy, toxicity, and reversal of clinical response after cessation of therapy obviated its widespread use. A search for nontoxic agents with cancer preventive activity led us to evaluate Bowman Birk Inhibitor (BBI) formulated as BBI Concentrate (BBIC). We previously reported encouraging results in a phase IIa trial of BBIC in patients with oral leukoplakia with measurable clinical responses and favorable biomarker changes. On the basis of these results, we undertook a randomized, placebo controlled phase IIb trial with patients receiving BBIC or placebo for 6 months, with assessment of clinical response and change in lesion area as primary end point and an intent-to-treat analysis. One hundred and thirty two subjects were randomized; and 89 subjects completed six months on study drug or placebo. Both placebo and BBIC showed a statistically significant decrease in mean lesion area of 17.1% and 20.6%, respectively, and partial or greater clinical responses of 30% and 28% respectively. No significant difference between placebo and study drug arms was observed. Histologic review, review of photographs of lesions, and comparison of serum neu protein and oral mucosal cell protease activity also did not show significant differences between study arms. Probable reasons for these negative results were considered, are discussed, and include a placebo with non-BBIC clinical activity and reduced pharmacokinetic availability of the second batch of BBIC. This experience should be a strong cautionary note to those considering "Green" chemoprevention.

Urban legends series: oral leukoplakia

To date, the term oral leukoplakia (OL) should be used to recognize 'predominantly white plaques of questionable risk, having excluded (other) known diseases or disorders that carry no increased risk of cancer'. In this review, we addressed four controversial topics regarding oral leukoplakias (OLs): (i) Do tobacco and alcohol cause OLs?, (ii) What percentage of OLs transform into oral squamous cell carcinoma (OSCC)?, (iii) Can we distinguish between premalignant and innocent OLs?, and (iv) Is proliferative verrucous leukoplakia (PVL) a specific entity or just a form of multifocal leukoplakia? Results of extensive literature search suggest that (i) no definitive evidence for direct causal relationship between smoked tobacco and alcohol as causative factors of OLs, (ii and iii) the vast majority of OLs follow a benign course and do not progress into a cancer, and no widely accepted and/or validated clinical and/or biological factors can predict malignant transformation, and (iv) the distinction between multifocal/multiple leukoplakias and PVL in their early presentation is impossible; the temporal clinical progression and the high rate of recurrences and development of cancer of PVL are the most reliable features for diagnosis.

An Insight to Oral Epithelial Dysplasia

Oral dysplasia is a potentially precancerous lesion diagnosed histologically. While the risk of progression is associated with histological grade, it is currently impossible to predict accurately which lesions will progress. Although most oral pathologists recognize and accept the criteria for grading epithelial dysplasia based on architectural and cytological changes, there can be considerable interexaminer and intraexaminer variation in the assessment of the presence or absence and the grade of oral epithelial dysplasia. This article reviews the alterations, criteria, different grading systems and the markers used for assessing the malignant transformation of epithelial dysplasia.

How to cite this article

Rastogi V, Puri N, Mishra S, Arora S, Kaur G, Yadav L. An Insight to Oral Epithelial Dysplasia. Int J Head Neck Surg 2013;4(2):74-82.

Relevance of tumor angiogenesis patterns as a diagnostic value and prognostic indicator in oral precancer and cancer

Tumor angiogenesis occurs by recruitment of endothelial cell precursors or by sprouting of existing capillaries, which differ from the normal vasculature by having an altered morphology that can be exploited for diagnosis and as a prognostic indicator. Improved technologies have propelled diagnosis into a new era. These technologies have to be used with great precision. The diagnosis of a dysplastic premalignant lesion of the oral mucosa cannot be based solely on clinical findings. Therefore histologic evaluation of a representative biopsy specimen is necessary. Accurate judgment of the proper site for biopsy is essential for reaching a correct diagnosis. The aim of this report is to analyze the vascular patterns with the help of direct oral microscopy and the technique of stereo-optical microscopy in the oral cavity to select biopsy sites, and compare the outcome of a directed biopsy with that of biopsy specimens obtained from sites selected solely on the basis of clinical criteria. The study sample comprised 50 oral mucosal lesions. A statistically significant difference was noted between samples judged to be microscopically representative sites. We conclude that this method would aid in early and better diagnosis and treatment planning of oral premalignant and malignant lesions by assessing the various vascular patterns in the mucosa.

Oral premalignant lesions: from a clinical perspective

In this review article, the clinical and histopathological characteristics of oral premalignant lesions, and primarily oral leukoplakia, are noted and the risk factors for malignant transformation of oral leukoplakia are discussed. Malignant transformation rates of oral leukoplakia range from 0.13 to 17.5%. The risk factors of malignant transformation in the buccal mucosa and labial commissure are male gender with chewing tobacco or smoking in some countries such as India, or older age and/or being a non-smoking female in other countries. Some authors have reported that leukoplakia on the tongue or the floor of the mouth showed a high risk of malignant transformation, although others have found no oral subsites at high risk. In concurrence with some authors, the authors of this review view epithelial dysplasia as an important risk factor in malignant transformation; however, there are conflicting reports in the literature. Many authors believe that nonhomogeneous leukoplakia is a high risk factor without exception, although different terms have been used to describe those conditions. The large size of lesions and widespread leukoplakia are also reported risk factors. According to some studies, surgical treatment decreased the rate of malignant transformation; however, many review articles state that no definitive treatment including surgery can decrease the malignant transformation rate of oral leukoplakia because of the lack of randomized control trials of treatment. Tobacco chewing and smoking may be causative agents for cancerization of oral leukoplakia in some groups, and evidence for a role of human papilloma virus in the malignant transformation of oral leukoplakia is inconsistent. Further research to clarify its role in malignant transformation is warranted.

Treatment of oral leukoplakia with carbon dioxide and potassium-titanyl-phosphate lasers: a comparison

PURPOSE

To determine whether the treatment of oral leukoplakia with potassium-titanyl-phosphate (KTP) lasers versus CO(2) lasers results in lower recurrence rates.

MATERIALS AND METHODS

Retrospective data were collected from the records of 30 patients (mean age 75.6 years) with 35 primary oral leukoplakia who had their lesions ablated by KTP laser, and 45 patients (mean age 59.9 years) with 59 primary oral leukoplakia who had CO(2) laser treatment. The recurrence rates of lesions between these 2 groups was then compared.

RESULTS

A statistically significant (P = .049) reduction in recurrence rates for those patients treated with KTP lasers versus CO(2) lasers was found.

CONCLUSION

The use of KTP lasers for the treatment of oral leukoplakia may result in lower recurrence rates than when using CO(2) lasers.

Potential use of quantitative tissue phenotype to predict malignant risk for oral premalignant lesions

The importance of early diagnosis in improving mortality and morbidity rates of oral squamous cell carcinoma (SCC) has long been recognized. However, a major challenge for early diagnosis is our limited ability to differentiate oral premalignant lesions (OPL) at high risk of progressing into invasive SCC from those at low risk. We investigated the potential of quantitative tissue phenotype (QTP), measured by high-resolution image analysis, to identify severe dysplasia/carcinoma in situ (CIS; known to have an increased risk of progression) and to predict progression to cancer within hyperplasia or mild/moderate dysplasia. We generated a nuclear phenotype score (NPS), a combination of five nuclear morphometric features that best discriminate 4,027 "normal" nuclei (selected from 29 normal oral biopsies) from 4,298 "abnormal" nuclei (selected from 30 SCC biopsies). This NPS was then determined for a set of 69 OPLs. Severe dysplasia/CIS showed a significant increase in NPS compared with hyperplasia or mild/moderate dysplasia. However, within the latter group, elevated NPS was strongly associated with the presence of high-risk loss of heterozygosity (LOH) patterns. There was a statistical difference between NPS of hyperplasia or mild/moderate dysplasia that progressed to cancer and those that did not. Individuals with a high NPS had a 10-fold increase in relative risk of progression. In the multivariate Cox model, LOH and NPS together were the strongest predictors for cancer development. These data suggest that QTP could be used to identify lesions that require molecular evaluation and should be integrated with such approaches to facilitate the identification of hyperplasia or mild/moderate dysplasia OPLs at high risk of progression.

Upregulation of heme oxygenase-1 in oral epithelial dysplasias

The expression of heme oxygenase-1 (HO-1), stress-related enzyme, is induced in leukaemia and some cancer tissues, but relatively little is known about the differential pattern of HO-1 expression and proliferation in premalignant lesions of the epithelial oral mucosa. The purpose of this study was to evaluate whether HO-1 expression and proliferation were increased in preneoplastic lesions compared to normal and oral cancer tissues. Immunohistochemical staining was used to examine the expression patterns of HO-1 and proliferating cell nuclear antigen (PCNA) in a series of normal mucosa and mild-to-severe cases of oral epithelial dysplasia (OED) and oral squamous cell carcinoma. Both HO-1 and PCNA are expressed in the basal cells of normal oral mucosa. In patients with OED and carcinoma in situ, immunostaining for PCNA and HO-1 was more intense, and gradually extended into the superficial layers of the mucosa. HO-1 and PCNA expression was correlated with the degree of epithelial dysplasia. Oral squamous cell carcinoma also showed elevated expression of HO-1, but this level was not higher than in severe OED or carcinoma in situ. These results suggest that the up-regulation of HO-1 in premalignant oral lesions is part of an early cytoprotection mechanism against carcinogenesis in the oral mucosa.

Three-year follow-up of oral leukoplakia after neodymium:yttrium aluminum garnet (Nd:YAG) laser surgery

Oral leukoplakia is a relatively common lesion with a significant proportion of cases changing into cancer. Since most leukoplakias are asymptomatic, the primary objective of treatment must aim at the prevention of such malignant transformation. The main objectives of the study are to observe (1) the efficacy, safety and acceptability of the neodymium:yttrium aluminum garnet (Nd:YAG) laser in the management of oral leukoplakia; (2) the nature of postoperative complications, if any, associated with laser ablation, and (3) the 3-year prognosis of oral leukoplakia treated with laser. Twenty-eight patients with histologically proven leukoplakia were treated with Nd:YAG laser. From this study, we observed that the patients treated with Nd:YAG laser had only mild to moderate pain, swelling and restricted mouth opening, which peaked between 72 h and 1 week. In a majority of the patients the healing was prolonged, to a maximum of 5 weeks, and there was no clinical evidence of scarring in 26 out of 28 cases. In this study we achieved a cure rate of 92.86% in a 6-month period. Further follow-up after 3 years yielded almost the same result, except that one patient was not available for follow-up. We concluded that Nd:YAG laser is an effective device in the management of oral leukoplakia, which is one of the major pre-cancerous lesions in our country.

Oral premalignant lesions: is a biopsy reliable?

PURPOSE

The purpose of the present retrospective study was to learn whether a biopsy of oral premalignant lesions, leukoplakia and erythroplakia, shows histopathological findings representative of the whole surgically removed lesion. Moreover, to see whether histopathological characteristics of the whole lesion are significant for future malignant development after surgery.

MATERIALS AND METHODS

A total of 101 lesions in 96 patients were included, 42 lesions (41%) being homogenous and 50 (50%) non-homogenous leukoplakias, whereas nine (9%) were erythroplakias. The lesions were biopsied and subsequently surgically removed on the average of 10.4 months after biopsy. Surgical specimens were examined in two or more step sections distributed throughout the specimen. The histological findings of the biopsies were compared with those of the whole lesions. After surgical intervention the patients were followed (mean 6.8 years, range: 1.5-18.6), and new biopsies taken in case of recurrences. Smokers (73%) were encouraged to quit smoking and candidal infections were treated. The possible influence of different variables on the risk of malignant development was estimated by means of logistic regression analysis.

RESULTS

Histological examination of the whole lesions showed that seven lesions (7%) harboured a carcinoma and 70 lesions (69%) showed a degree of epithelial dysplasia or carcinoma in situ. Eleven lesions (12%) developed carcinoma after a mean follow-up period of 7.5 years. A comparison of the degree of dysplasia in the biopsies with that of the whole lesion demonstrated variation with concurrent diagnosis in 49% of the lesions and in 79% after inclusion of lesions with one degree up or down the scale of epithelial dysplasia.

CONCLUSION

The estimated odds ratio showed that none of the associated variables including presence of any degree of epithelial dysplasia in the whole lesion, site, demarcation and smoking had influence on the risk of malignant development.

Malignant transformation in 1458 patients with potentially malignant oral mucosal disorders: a follow-up study based in a Taiwanese hospital

BACKGROUND

It is generally accepted that the development of cancer in the oral mucosa is preceded by an identifiable non-invasive precursor lesion. The aim of this follow-up study was to estimate the rate and the time to transformation in a group of patients from southern Taiwan with potentially malignant oral epithelial lesions.

METHODS

The follow-up time is defined as the duration between the onset of the initial diagnosis and the occurrence of confirmed oral cancer. A total of 1458 patients with histological diagnoses of various pre-malignant oral lesions were followed up between 1991 and 2001. The average age at initial diagnosis was 47.5 years. The histological diagnoses were divided into six categories: epithelial dysplasia with hyperkeratosis/epithelial hyperplasia (8.85%); epithelial dysplasia with submucous fibrosis (2.54%); submucous fibrosis (27.57%); hyperkeratosis/epithelial hyperplasia (29.01%); lichen planus (9.80%) and verrucous hyperplasia (22.22%).

RESULTS

Within the cohort of 1458 patients, 44 patients progressed to oral cancer in the same site as the initial lesions with an overall transformation rate of 3.02% and a mean follow-up time of 42.64 months. Eight of the 166 patients with dysplastic lesions and 15 of 423 patients with hyperkeratosis/epithelial hyperplasia progressed to malignancy. The other patients with malignant transformation originated from various pre-cancerous oral lesions and conditions (submucous fibrosis, eight of 402; lichen planus, three of 143; verrucous hyperplasia, 10 of 324).

CONCLUSION

These results indicate that patients with pre-malignant oral lesions need long-term follow up.

Tobacco harm reduction: an alternative cessation strategy for inveterate smokers

According to the Centers for Disease Control and Prevention, about 45 million Americans continue to smoke, even after one of the most intense public health campaigns in history, now over 40 years old. Each year some 438,000 smokers die from smoking-related diseases, including lung and other cancers, cardiovascular disorders and pulmonary diseases. Many smokers are unable--or at least unwilling--to achieve cessation through complete nicotine and tobacco abstinence; they continue smoking despite the very real and obvious adverse health consequences. Conventional smoking cessation policies and programs generally present smokers with two unpleasant alternatives: quit, or die. A third approach to smoking cessation, tobacco harm reduction, involves the use of alternative sources of nicotine, including modern smokeless tobacco products. A substantial body of research, much of it produced over the past decade, establishes the scientific and medical foundation for tobacco harm reduction using smokeless tobacco products. This report provides a description of traditional and modern smokeless tobacco products, and of the prevalence of their use in the United States and Sweden. It reviews the epidemiologic evidence for low health risks associated with smokeless use, both in absolute terms and in comparison to the much higher risks of smoking. The report also describes evidence that smokeless tobacco has served as an effective substitute for cigarettes among Swedish men, who consequently have among the lowest smoking-related mortality rates in the developed world. The report documents the fact that extensive misinformation about ST products is widely available from ostensibly reputable sources, including governmental health agencies and major health organizations. The American Council on Science and Health believes that strong support of tobacco harm reduction is fully consistent with its mission to promote sound science in regulation and in public policy, and to assist consumers in distinguishing real health threats from spurious health claims. As this report documents, there is a strong scientific and medical foundation for tobacco harm reduction, and it shows great potential as a public health strategy to help millions of smokers.

Long-term treatment outcome of oral premalignant lesions

The purpose of the present retrospective study was to learn the long-term outcome of oral premalignant lesions, leukoplakia and erythroplakia, with or without surgical intervention and to relate the outcome to factors supposed to be significant for malignant development including clinical type, demarcation, size, site, presence of epithelial dysplasia, smoking and surgery. A total of 269 lesions in 236 patients were included. Ninety-four lesions were surgically removed, 39 lesions (41%) being homogenous and 46 (49%) non-homogenous leukoplakias whereas nine (5%) were erythroplakias. Seventy-three percent of the lesions were associated with tobacco habits. The mean size of the lesions was 486 mm(2), and 71% of the lesions showed a degree of epithelial dysplasia. After excision the defects were closed primarily by transposition of mucosal flaps or they were covered by free mucosal or skin grafts. A few defects were left for secondary healing. After surgical treatment the patients were followed (mean 6.8 yrs, range 1.5-18.6 yrs), and new biopsies taken in case of recurrences. One hundred and seventy five lesions had no surgical intervention, 149 lesions (85%) being homogenous and 20 (11%) non-homogenous leukoplakias, and 6 (3%) erythroplakias. Eighty-one percent of the lesions were associated with smoking. The mean size of the lesions was 503 mm(2) and 21 of the lesions (12%) exhibited epithelial dysplasia. Sixty-five lesions were not biopsied. These patients were also followed (mean 5.5 yrs, range 1.1-20.2 yrs), and biopsies taken in case of changes indicative of malignant development. All patients were encouraged to quit smoking and candidal infections were treated. The possible role of different variables for malignant development was estimated by means of logistic regression analysis. Following surgical treatment 11 lesions (12%) developed carcinoma after a mean follow-up period of 7.5 yrs. Non-homogenous leukoplakia accounted for the highest frequency of malignant development, i.e. 20%, whereas 3% of the homogenous leukoplakias developed carcinomas. Surgically treated lesions with slight, moderate, severe and no epithelial dysplasia developed carcinoma with similar frequencies, i.e. 9-11%. Without surgical intervention 16% of the 175 lesions disappeared whereas seven lesions (4%) developed carcinoma after a mean observation period of 6.6 yrs. The highest frequency of malignant development (15%) was seen for non-homogenous leukoplakias, this figure being 3% for homogenous leukoplakias. Fourteen percent of lesions with slight epithelial dysplasia developed malignancy and 2% of lesions with no dysplasia showed malignant transformation. Logistic regression analysis showed a seven times increased risk (OR = 7.0) of non-homogenous leukoplakia for malignant development as compared with homogenous leukoplakia and a 5.4 times increased risk for malignant development for lesions with a size exceeding 200 mm(2). No other examined variables including presence of any degree of epithelial dysplasia, site, demarcation, smoking and surgical intervention were statistically significant factors for malignant development.

Papillary Squamous Cell Carcinoma Presenting on the Gingiva

BACKGROUND

Papillary squamous cell carcinoma (PSCC) is a rare variant of squamous cell carcinoma. PSCC can occur as either an in situ or invasive tumor. The sites of occurrence in order of the most to least prevalent are the larynx, oropharynx, and nasopharynx. We present an unusual case of PSCC occurring on the gingiva.

METHODS

A 72-year-old white female presented with a chief complaint of tooth mobility in the right posterior mandible. Clinical examination revealed a Miller's Class 2 mobility of tooth #28 along with an erythematous, papillary appearance of the lingual gingiva on teeth #27, #28, and #29. Her dental history revealed treatment of tooth #28 with locally delivered antibiotics. Her medical history revealed a diagnosis of breast cancer 8 years prior to examination that was treated with partial mastectomy and radiation therapy. An initial differential clinical diagnosis of verrucous carcinoma or metastatic carcinoma was made.

RESULTS

Surgical therapy included extraction of tooth #28 and an excisional biopsy of the lesion on the lingual gingiva. Microscopic evaluation of the gingival specimen revealed a neoplastic papillary proliferation of the surface epithelium with a thick layer of parakeratin, deep parakeratin-lined crypts, and a thickened spinous cell layer along with islands and strands of malignant epithelium. The microscopic appearance of the lesion was characteristic for PSSC. The patient's tumor was removed via a block resection that included teeth #27 through #31 and a radical neck dissection.

CONCLUSIONS

This is a case report of PSCC occurring on the gingiva. This report demonstrates that, even though oral cancers involving the periodontium are a relatively rare occurrence, periodontists cannot be complacent about the diagnosis of periodontal bone loss. It also highlights the importance of utilizing a histopathologic examination to confirm the clinical diagnosis for any suspicious lesion.

Frequent allelic imbalances at 8p and 11q22 in oral and oropharyngeal epithelial dysplastic lesions

Allelic imbalance is characteristic of oral squamous cell carcinoma (SCC) and contributes to the tumorigenesis of this disease. Our previous studies suggest that chromosome regions 8p and 11q22.2 approximately q22.3 are frequent sites of loss of heterozygosity (LOH) in head and neck SCC. Here, we explored the allelic imbalance pattern of these regions in 27 cases of oral epithelial dysplastic lesions. A previously reported frequent LOH (9p21) in head and neck dysplasia was also examined. Laser capture microdissection (LCM) technology was utilized to harvest homogenous cell populations from archived clinical tissues and thus greatly enhancing the sensitivity, accuracy and reliability of genetic assessment. The allelic imbalance (LOH and microsatellite instability) on 8p, 11q22.2 approximately q22.3, and 9p21 were observed at one or more loci in 66.7%, 63.0%, and 63.0% of cases, respectively. Our results demonstrate that 8p, 11q22.2 approximately q22.3, and 9p21 are frequent allelic imbalance regions in oral premalignant dysplasia and suggest the presence of tumor suppressor genes in these regions.

Oral erythroplakia--a review

Oral erythroplakia (OE) is considered a rare potentially malignant lesion of the oral mucosa. Reports entirely devoted to OE are very few, and only two reviews none of which are of recent date have been published. Only the true, velvety, red homogeneous OE has been clearly defined while the terminology for mixed red and white lesions is complex, ill-defined and confusing. A recent case control study of OE from India reported a prevalence of 0.2%. A range of prevalences between 0.02% and 0.83% from different geographical areas has been documented. OE is predominantly seen in the middle aged and elderly. One study from India showed a female:male ratio of 1:1.04. The soft palate, the floor of the mouth and the buccal mucosa is commonly affected. A specific type of OE occurs in chutta smokers in India. Lesions of OE are typically less than 1.5 cm in diameter. The etiology of OE reveals a strong association with tobacco consumption and the use of alcohol. Histopathologically, it has been documented that in OE of the homogenous type, 51% showed invasive carcinoma, 40% carcinoma in situ and 9% mild or moderate dysplasia. Recently, genomic aberrations with DNA aneuploidy has been demonstrated. p53 mutations with different degrees of dysplasia may play a role in some cases of OE. Transformation rates are considered to be the highest among all precancerous oral lesions and conditions. Surgical excision is the treatment of choice. Data on laser excision are not available. Recurrence rates seem to be high, reliable data are, however, missing. More studies on OE are strongly needed to evaluate a number of so far unanswered questions. The natural history of OE is unknown. Do OEs develop de novo or are they developing from oral leukoplakia through several intermediate stages of white/red lesions? The possible role of fungal infection (Candida micro-organisms) is not clear as is the possible role of HPV co-infection in the development of OE. More data on incidence and prevalence, biological behaviour and adequate treatment are urgently needed.