Topical bleomycin for the treatment of dysplastic oral leukoplakia

Chemoprevention of oral cancer: A review and future perspectives

BACKGROUND

Oral cancer causes significant morbidity and mortality. Chemoprevention utilizes medication or natural compounds to reverse oral premalignant lesions and to prevent second primary tumors.

METHODS

A comprehensive PubMed database and Cochrane Library search from 1980 to 2021 was performed using the keywords "leukoplakia," "oral premalignant lesion," and "chemoprevention."

RESULTS

Chemopreventive agents included retinoids, carotenoids, cyclooxygenase inhibitor, herbal extracts, bleomycin, tyrosine kinase inhibitors, metformin, and immune checkpoint inhibitors. Although some agents demonstrated effect in reducing premalignant lesions and preventing second primary tumors, the results among different studies were highly variable.

CONCLUSIONS

The results of different trials, albeit inconsistent, provided substantial information for future studies. In the era of personalized medicine, future studies will focus on identifying specific biomarkers and molecular profile to monitor and to prevent malignant transformation. Larger trials are warranted to validate the effect of chemopreventive agents.

Setting up a Registry for Oral Potentially Malignant Disorders (OPMD)

Background: Oral cancer accounts for 3% of all malignancies. Progression to malignancy occurs with a gradual process. Oral potentially malignant disorders (OPMD) are associated with the development of malignant transformation toward oral cancer. Objectives: This registry aimed at introducing an exact data gathering method for detecting, managing, and monitoring patients with OPMD to decrease the occurrence of oral cancer. Methods: In this registry, all patients with OPMD such as leukoplakia, erythroplakia, and oral lichen planus at Shahid Beheshti Dental School, Tehran, Iran were included. Patients' information including demographics, clinical, and histopathological features, the type of OPMD, treatment measures, and lesion changes in follow-up intervals were recorded in the registry software. In addition, a quality assurance team supervised and guaranteed the quality control of the entire registry process. Results: The following measures have been accomplished so far: development of an ethically-approved proposal, development of a comprehensive data form, development of web-based registration software, development of a manual of operation, signing of a collaborative contract with more than 8 dental schools throughout Iran, identification of 100 eligible patients, signing a contract with the Research Deputy of Shahid Beheshti University of Medical Sciences, and codification of a verified and ethically approved quality assurance proposal. This registry is getting the advantage of being supervised and sponsored by the Disease Registry Center of Shahid Beheshti University of Medical Sciences. Conclusions: The prospect of this registry is to provide patients with OPMD with a nationwide diagnostic service and continuous monitoring protocol through a collaborative network of all dental schools in Iran.

Oral leukoplakia: A review of clinical features and trends in management

Introduction: Oral potentially malignant disorders (OPMD) conisit of the group of diseases of great importance for dentists. Oral leukoplakia (OL) has long been the subject of debate by numerous researchers. A common etiologic factor is tobacco, which is associated with oral cancer. The aim of the study is to indicate the severity of the lesion, the most common clinical characreistics and localization. The prevalence of leukoplakia in the world is 2.6% with a rate of malignant conversion ranging from 0.1% to 17.5%. Literature data about the prevalence and annual rate of malignant transformation, approximately 2%, indicate that these changes should be taken seriously and regularymonitored Conclusion: Occurate diagnosis provides the key to preventing to malignant transformation. Various medical and surgical treatment modalities for this lesion have been described. This article highlights various trends in the diagnosis and treatment of oral leukoplakia.

Difficulties in the Prognostic Study of Oral Leukoplakia: Standardisation Proposal of Follow-Up Parameters

Oral leukoplakia is the most prevalent potentially malignant disorder of the oral cavity. To evaluate its potential for malignancy, appropriate documentation of the biological parameters is crucial, allowing the patients' progression to be assessed. We hypothesized a lack of standardization in the parameters employed for the prognostic study of oral leukoplakia; our aims were to determine the different parameters used for follow-up according to definition, importance, and frequency of use, and to provide a standardization proposal of follow-up research. We made a scoping review to identify papers with the keywords “leukoplakia,” “oral,” and “follow-up” published until June 2019 in English, Spanish and Portuguese literature through an online search in PUBMED, SCIELO, and SCOPUS databases. In total, 514 articles were initially identified, and fifty-nine publications were selected, of which 37 were retrospective. The reports included a total of 18,660 patients between 13 and 98 years old, with a mean age of 57.6 years. Tobacco and alcohol habits were positive for 77 and 37% of the patients, respectively. Our results showed that reported leukoplakias were predominantly located on buccal mucosa (40.4%), were homogeneous (60.8%), multiple (59.9%), smaller than 2 cm (74.4%) and histopathologically non-dysplastic (71%). The mean follow-up time was 55 months, with a 13% malignant transformation rate. The categorization and definition of multiple variables were notably diverse. Age, sex, habits (tobacco and alcohol), site, size, distribution, morphology, degree of dysplasia, and evolution were the chosen parameters for our proposal. The current study reflected the lack of consensus found in the literature regarding parameters for diagnosis or follow-up, impacting negatively on clinical and research results. standardization comprises an efficient way to facilitate the prognosis assessment of oral leukoplakia, being beneficial for clinical practice, and enabling better quality information to apply in research.

Polymeric drug delivery systems for intraoral site-specific chemoprevention of oral cancer

Oral cancer is among the most prevalent cancers in the world. Moreover, it is one of the major health problems and causes of death in many regions of the world. The traditional treatment modalities include surgical removal, radiation therapy, systemic chemotherapy, or a combination of these methods. In recent decades, there has been significant interest in intraoral site-specific chemoprevention via local drug delivery using polymeric systems. Because of its easy accessibility and clear visibility, the oral mucosa is amenable for local drug delivery. A variety of polymeric systems-such as gels, tablets, films, patches, injectable systems (e.g., millicylindrical implants, microparticles, and in situ-forming depots), and nanosized carriers (e.g., polymeric nanoparticles, nanofibers, polymer-drug conjugates, polymeric micelles, nanoliposomes, nanoemulsions, and polymersomes)-have been developed and evaluated for the local delivery of natural and synthetic chemopreventive agents. The findings of in vitro, ex vivo, and in vivo studies and the positive outcome of clinical trials demonstrate that intraoral site-specific drug delivery is an attractive, highly effective and patient-friendly strategy for the management of oral cancer. Intraoral site-specific drug delivery provides unique therapeutic advantages when compared to systemic chemotherapy. Moreover, intraoral drug delivery systems are self-administrable and can be removed when needed, increasing patient compliance. This article covers important aspects and advances related to the design, development, and efficacy of polymeric systems for intraoral site-specific drug delivery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1383-1413, 2018.

Photodynamic treatment outcomes of potentially-malignant lesions and malignancies of the head and neck region: A systematic review

AIM

The aim of the present study was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral potentially-malignant disorders (PMDS) and head and neck squamous cell carcinoma (HNSCC).

METHODS

From 1985 to 2015, PubMed/Medline, Google Scholar, EMBASE, and ISI Web of Knowledge were searched using different combinations of the following key words: PDT, oral precancer, leukoplakia, erythroplakia, erythroleukoplakia, verrucous hyperplasia, oral submucous fibrosis, and HNSCC. Review articles, experimental studies, case reports, commentaries, letters to the editor, unpublished articles, and articles published in languages other than English were excluded.

RESULTS

Twenty-six studies were included in the present study. The number of patients ranged from 2 to 147, with a mean age of 50-67 years. The reported numbers of PMDS and HNSCC ranged between 5 and 225. Photosensitizers used were aminolevulinic acid, meta-tetrahydroxyphenylchlorin, Foscan, hematoporphyrin derivatives, Photofrin, Photosan, and chlorine-e6. Laser wavelength, power density, irradiation duration were 585-652 nm, 50-500 mW/cm² , and 1-143 minutes, respectively. Complete, partial, and no response to PDT was found in 22.58%-100%, 4%-66%, and 0%-38.70% of PMDS, respectively, and 16%-100% of complete response in HNSCC patients.

CONCLUSION

PDT is effective in the management of PMDS and HNSCC.

Topical agents for oral cancer chemoprevention: A systematic review of the literature

OBJECTIVES/HYPOTHESIS

We review the use of topical chemoprevention agents in patients with oral potentially malignant disorders (PMD).

METHODS

A systematic review of studies on topical chemoprevention agents for oral PMD from 1946 to November 2016 was conducted using the MEDLINE database, Embase, and Cochrane Library. Data were extracted and analyzed from selected studies including study type, sample size, demographics, treatment length, response rate, follow-up time, adverse effects, and recurrence.

RESULTS

Of 108 studies, twenty-four, representing 679 cases met the inclusion criteria. The clinical lesions evaluated included oral leukoplakia, erythroplakia (OEL), verrucous hyperplasia (OVH), oral lichen planus, larynx squamous cell carcinoma, and oral squamous cell carcinoma (OSCC). The mean complete response rate for topical retinoid therapy was 32%. The mean complete response rate for 1% bleomycin therapy and 0.5% bleomycin was 40.2% and 25%, respectively. The complete response rate of OVH, OEL, and OSCC to photodynamic therapy ranged from 66.7% to 100%.

CONCLUSION

There are a paucity of data examining topical treatment of oral PMDs. However, the use of topical agents among patients with oral lesions may be a viable complement or even alternative to traditional surgery, radiation, or systemic chemotherapy, with the advantage of reducing systemic side effects and sparing important anatomic structures. This study of 679 cases represents the largest pooled sample size to date, and the preliminary studies in this systematic review provide support for further inquiry.

Photodynamic therapy: a review and its prospective role in the management of oral potentially malignant disorders

With the unreliability of epithelial dysplasia as a predictor to determine the risk of future malignant development, subjectivity associated in evaluating dysplasia by pathologists and paucity of biomarkers that could accurately predict the progression risks in oral potentially malignant disorders (PMDs), eradication of the lesions appears to be the most desirable approach to minimize the risk of invasive cancer formation. Interventions, such as surgery and chemoprevention, have not shown promising long-term results in the treatment of these lesions, and lack of guidelines and general consensus on their management has incited much anxiety and doubts in both patients and community clinicians. Topical photodynamic therapy (PDT) is a minimally invasive and minimally toxic technique that in recent years has shown great promise in the management of PMDs. In this review, we describe the historical developments in the field of PDT, its basic mechanisms, as well as related clinical studies, and its challenges in the management of oral PMDs. Based on its high efficacy and low side effects, its high patient acceptance/compliance, the simplicity of the procedure and its minimal pretreatment preparation, topical PDT is believed to have potential to play an important role in the management of PMDs, especially of the low-grade dysplasia.

Efficacy of photodynamic therapy in the management of oral premalignant lesions. A systematic review

OBJECTIVE

The aim was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral premalignant lesions.

METHODS

The addressed focused question was "Is PDT effective in the management of oral premalignant lesions?" PubMed/Medline, Google-Scholar, EMBASE and ISI Web of Knowledge databases were searched from 1984 till June 2014 using different combinations of the following keywords: photodynamic therapy; oral premalignant lesions; leukoplakia; erythroplakia; erythro-leukoplakia; verrucous hyperplasia; and submucous fibrosis. Review articles, experimental studies, case-reports, commentaries, letters to the Editor, unpublished articles and articles published in languages other than English were not sought. The pattern of the present study was customized to mainly summarize the relevant information.

RESULTS

Thirteen studies were included. In these studies, the number of patients ranged between 5 patients and 147 individuals with mean ages ranging between 51 years and 62.2 years. Oral premalignant lesions, which were investigated were leukoplakia, erythroplakia, erythro-leukoplakia and verrucous hyperplasia. Reported number of premalignant lesions ranged between 5 and 225. Laser wavelength, duration of irradiation and power density were 585-660nm, 60s to 16.6min and 100-150mW/cm(2), respectively. Aminolevulinic acid, chlorine-e6, meta-tetrahydroxyphenylchlorin and photofrin were used as photosensitizer. The frequency of PDT application ranged between once and 12 times. Complete, partial and no response to PDT was shown by 27-100%, 5-50% and 0-25% of pre-malignant lesions, respectively. The recurrence rate of pre-malignant lesions was up to 36%.

CONCLUSION

PDT is effective in the overall management of oral premalignant lesions.

Proliferative verrucous leukoplakia: recognition and differentiation from conventional leukoplakia and mimics

The majority of conventional leukoplakia remains constant and only a subset progress to high-grade dysplasia or invasive carcinoma. A less recognized form known as proliferative verrucous leukoplakia (PVL) represents a unique progressive and elusive variant. Identifying patients with this form can only be achieved through the keen clinical observation of the temporal gross and histologic progression in individual patients with squamous cell carcinoma. The difficulty in the early diagnosis of PVL stems from the overlapping clinical and pathologic features with conventional multifocal leukoplakia with dysplasia. We present the current view on the clinicopathologic and biological characteristics of PVL and discuss their diagnosis, differential diagnosis, and management.

Current evidence in diagnosis and treatment of proliferative verrucous leukoplakia

Proliferative verrucous leukoplakia is multifocal and progressive lesion with a high rate of malignant transformation. This short review highlights the diagnosis, traditional treatment and the current management of the disease. A MEDLINE search for the specific English word including proliferative verrucous leukoplakia in the last two years (2009-2010). This study indicates the current evidence for the diagnosis and the management of proliferative verrucous leukoplakia to help the specialist in this domain for early diagnosis of proliferative verrucous leukoplakia according to the new criteria of diagnosis to prevent the recurrence and any malignant transformation.

Clinical appraisal of endoscopy with narrow-band imaging system in the evaluation and management of homogeneous oral leukoplakia

PURPOSE

To evaluate the clinical usefulness of endoscopy with a narrow-band imaging (NBI) system for the evaluation and management of homogeneous oral leukoplakia.

METHODS

The chart records, morphology of vascular architecture of NBI, and histopathology of patients with homogeneous leukoplakia were retrospectively reviewed and analyzed.

RESULTS

A total of 160 patients, with an average age of 50.96 ± 10.25 years, were enrolled. In 35 cases of thin leukoplakia, only intraepithelium papillary capillary loop (IPCL) type I was shown by NBI, and only squamous hyperplasia was revealed pathologically. In 125 cases of thick leukoplakia, IPCL type I was found in 94, IPCL type II in 29, and IPCL type III in 2. The Kendall rank correlation between pathology and NBI images was significant (p < 0.0001).

CONCLUSIONS

The dichotomous classification of homogeneous leukoplakia by NBI is meaningful, and endoscopy with the NBI system is a promising tool for the evaluation and management of homogeneous oral leukoplakia.

Optimizing therapeutic efficacy of chemopreventive agents: A critical review of delivery strategies in oral cancer chemoprevention clinical trials

Due to its characterized progression from recognized premalignant oral epithelial changes (i.e., oral epithelial dysplasia) to invasive cancer, oral squamous cell carcinoma represents an optimal disease for chemopreventive intervention prior to malignant transformation. The primary goal of oral cancer chemoprevention is to reverse, suppress, or inhibit the progression of premalignant lesions to cancer. Over the last several decades, numerous oral cancer chemoprevention clinical trials have assessed the therapeutic efficacy of diverse chemopreventive agents. The standard of care for more advanced oral dysplastic lesions entails surgical excision and close clinical follow-up due to the potential (~33%) for local recurrence at a similar or more advanced histological stage. The purpose of this review was to identify prominent oral cancer chemoprevention clinical trials, assess their overall therapeutic efficacy, and delineate effects of local versus systemic drug administration. In addition, these compiled clinical trial data present concepts for consideration in the design and conduction of future clinical trials.

Local drug delivery for oral mucosal diseases: challenges and opportunities

There are few topical formulations used for oral medicine applications most of which have been developed for the management of dermatological conditions. As such, numerous obstacles are faced when utilizing these preparations in the oral cavity, namely enzymatic degradation, taste, limited surface area, poor tissue penetration and accidental swallowing. In this review, we discuss common mucosal diseases such as oral cancer, mucositis, vesiculo-erosive conditions, infections, neuropathic pain and salivary dysfunction, which could benefit from topical delivery systems designed specifically for the oral mucosa, which are capable of sustained release. Each condition requires distinct penetration and drug retention profiles in order to optimize treatment and minimize side effects. Local drug delivery may provide a more targeted and efficient drug-delivery option than systemic delivery for diseases of the oral mucosa. We identify those mucosal diseases currently being treated, the challenges that must be overcome and the potential of novel therapies. Novel biological therapies such as macromolecular biological drugs, peptides and gene therapy may be of value in the treatment of many chronic oral conditions and thus in oral medicine if their delivery can be optimized.

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.

A review of the nonsurgical treatment of oral leukoplakia

The aim of this paper was to assess the nonsurgical treatment of oral leukoplakia (OL). A medline search from 1983 to 2009 was conducted. The topical or systemic nonsurgical treatments or combination of both was reviewed. The primary outcomes of interest were clinical resolution, malignant transformation, follow-up, and recurrence of OL. Studies showed a rate higher than 50% of clinical resolution with photodynamic therapy, beta-carotene, lycopene, or vitamin A. Few studies reported rates of recurrence from 5 to 67% and of malignant transformation from 8 to 23%. There is a lack of randomized clinical trials that assess the effectiveness of nonsurgical treatment of OL. At this time, randomized controlled trials for nonsurgical treatment of OL demonstrate no evidence of effective treatment in preventing malignant transformation and recurrence. It reinforces that even after clinical resolution, OL should be regularly followed.

A survey of the current approaches to diagnosis and management of oral premalignant lesions

BACKGROUND

Early diagnosis of oral premalignant lesions (OPLs) and oral squamous cell carcinoma facilitates treatment with less aggressive approaches and results in a better prognosis. The authors conducted a study to identify current practices in the diagnosis and management of these oral lesions by oral medicine professionals.

METHODS

The authors sent a questionnaire to 176 diplomates of the American Board of Oral Medicine and asked them to complete the questionnaires and return them by mail.

RESULTS

The initial clinical approach taken by most of the responders included visual examination, elimination of possible local causes and two-week follow-up. Adjuvant clinical tests included toluidine blue, oral brush biopsy and exfoliative cytology. If there was no clinical improvement after two weeks, most responders recommended that a biopsy be performed. Induration, red component, nonhomogeneous surface and ulceration were characteristics of lesions that increased the responders' decisions to perform a biopsy. Lesion symptoms and location also contributed to their decisions to perform a biopsy. Follow-up more frequently than twice a year was recommended for red lesions, lesions with histologically confirmed dysplasia or both. Most clinicians recommend a biopsy during follow-up of an OPL whenever the lesion changes in appearance.

CONCLUSIONS

The findings of this survey may provide background for initial guidelines to be used by oral practitioners to diagnose and manage OPL. Clinicians' awareness of the complexity of OPL diagnosis and management is important, and referral to an experienced provider is recommended.

Factors associated with underdiagnosis from incisional biopsy of oral leukoplakic lesions

OBJECTIVES

Incisional biopsy is accepted by most clinicians as a dependable way of assessing the nature of oral leukoplakia (OL). The aim of the present study was to investigate its reliability and analyze risk factors associated with underdiagnosis from incisional biopsy.

STUDY DESIGN

A cross-sectional retrospective study was conducted in 242 patients with a clinical diagnosis of OL. The discrepancy between provisional diagnosis (from incisional biopsy) and definitive diagnosis (from resection specimen) was analyzed and correlated with clinical variables. Patients who had incisional biopsy taken from a single location and those who received multiple-site biopsies were analyzed separately.

RESULTS

In the 200 cases receiving single-site biopsy, the agreement rate between provisional and definitive diagnoses was only 56%, and underdiagnosis from incisional biopsy was noted in 29.5% of patients. Underdiagnosis rate in the 42 patients receiving multiple-site biopsies was significantly lower (11.9%; P < .05). The rate of unexpected carcinoma in resection specimen was also significantly lower in the multiple-biopsy patients than in the single-biopsy patients (2.4% vs. 12.0%; P < .05). For the single-biopsy group, multivariate analysis revealed that clinical appearance significantly influenced the risk of underdiagnosis and unexpected carcinoma (both P < .05). Compared with homogeneous lesions, nonhomogeneous OL were more prone to be underdiagnosed (adjusted odds ratio [AOR] 2.36, 95% confidence interval [CI] 1.16-4.82) and have carcinoma undetected by incisional specimen (AOR 15.94, 95% CI 2.09-121.72).

CONCLUSIONS

Incisional biopsy was found to have limitations in the assessment of OL, especially for nonhomogeneous lesions. Clinicians should be conscious of the possible underdiagnosis from incisional biopsy, and multiple biopsies should be taken whenever they think that it is necessary.

Proliferative verrucous leukoplakia and its progression to oral carcinoma: a review of the literature

BACKGROUND

Proliferative verrucous leukoplakia (PVL) is a distinct clinical form of oral leukoplakia defined by its progressive clinical course, changing clinical and histopathological features, and potential to develop into cancer. PVL behaves in a more aggressive and relentless manner than the more innocuous white oral lesions that it can resemble clinically.

METHODS

A PubMed search was conducted which identified studies that examined patients with PVL and reported data meeting inclusion criteria.

RESULTS

PVL is seen much more frequently in females and most often diagnosed after the sixth decade of life. Tobacco use is not strongly linked to the presence of PVL (63% of patients did not use tobacco products). Most (74%) of the patients with PVL progressed to oral carcinoma.

CONCLUSION

PVL is a persistent and progressive oral lesion that requires very close follow-up along with early and aggressive treatment to increase the chances of a favorable outcome.

Cytologic and DNA-cytometric follow-up of oral leukoplakia after CO2- and Er:YAG-laser assisted ablation: A pilot study

BACKGROUND AND OBJECTIVES

The aim of the present pilot study was to determine therapeutic responses to Er:YAG- and CO(2)-laser ablation in patients with oral leukoplakia as evaluated by means of exfoliative cytology (EC) and DNA-image-cytometry (DNA-I).

STUDY DESIGN/MATERIALS AND METHODS

Ten patients exhibiting a total of 16 lesions affecting a variety of intraoral sites were randomly treated with either (1) an Er:YAG laser (300 mJ/pulse, 10 Hz, defocused mode) (ERL), or (2) an CO(2) laser (4-6 W, 20-50 Hz, focused mode) (CO). Brush (B) and incisional (I) biopsies were obtained from the respective lesions immediately before treatment (B, I) as well as 24-96 weeks postoperatively (B). In cases, in which EC revealed suspicious cells, nuclear DNA-contents were measured using a TV image analysis system.

RESULTS

Both treatment approaches resulted in a complete (C) or partial (P) remission of all investigated lesions. In particular, ERL exhibited C(3), P(5), and CO C(5), P(3). However, in the CO group, two of eight lesions showed a recurrence 32-48 weeks following treatment. Among all investigated lesions, both histological and EC/DNA-I diagnosis revealed no sign of malignancy or dysplasia before or following laser assisted ablation.

CONCLUSIONS

Within the limits of the present study, it may be concluded that both treatment approaches seem to have limitations to achieve predictable eradication of oral leukoplakia.

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

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

Progress and perspectives in chemoprevention of head and neck cancer

Head and neck squamous cell carcinoma is ideally suited for chemoprevention efforts. Elucidation of molecular events underlying head and neck cancer has facilitated the development of preventive strategies. Landmark trials of 13-cis retinoic acid demonstrated that chemoprevention of head and neck cancer is indeed possible. New agents targeting specific molecular abnormalities contributing to the multifocal and multistep process of carcinogenesis have been identified. Innovative approaches to the study of chemoprevention, such as the use of biomarker intermediate end points, can select agents with particular promise for more definitive trials. However, barriers to progress in chemoprevention remain, including the validation of surrogate end point biomarkers and identification of safe and well-tolerated agents with the ability to delay carcinogenesis.

The Ljubljana classification - its application to grading oral epithelial hyperplasia

INTRODUCTION

The diagnosis, prognosis and treatment of particular pathologic entities of the oral mucosa depend almost exclusively on the histologic changes in the epithelium. The basis for the classification of oral epithelial hyperplastic lesions should be their propensity to progress to invasive cancer.

MATERIAL AND METHODS

In a retrospective study, 135 biopsies of oral epithelial hyperplastic lesions from 115 patients were classified according to the Ljubljana classification, which has recently been introduced for the grading of laryngeal hyperplastic epithelial lesions.

RESULTS

Seventy nine cases (59%) showed simple, 42 (31%) abnormal and 11 (8%) atypical hyperplasia; carcinoma in situ was found in three cases (2%). During the follow-up, ranging from 3 months to 6 years (median 1 year), two cases of atypical hyperplasia progressed to invasive cancer, whereas none of the cases classified as simple or abnormal hyperplasia showed progression.

CONCLUSION

The present study suggests that the Ljubljana classification can be reliably applied for classifying oral epithelial hyperplastic lesions into different risk groups, which is essential for prognosis in order to plan therapy.

The effect of retinoids on premalignant oral lesions: focus on topical therapy

BACKGROUND

Retinoids have been studied as chemopreventive treatment for patients with oropharyngeal carcinoma. Vitamin A modulates growth and differentiation of cells, and its deficiency enhances susceptibility to carcinogenesis. The chemopreventive mechanism of action of vitamin A is discussed, and a review of clinical results and side effects of the systemic use of vitamin A is included. The objective of the current report was to review the possible role of topical vitamin A and vitamin A derivatives in the management of patients with oral lesions with a risk of transformation to carcinoma.

METHODS

A Medline search was conducted and references identified within the identified papers were also reviewed.

RESULTS

Only four studies using topical vitamin A for patients with oral leukoplakia have been reported. A complete response was achieved in 10-27% of patients, and a partial response was achieved in 54-90% of patients; however, recurrence of leukoplakia was reported after withdrawing the medication in approximately 50% of patients. The side effects of the topical use were minimal.

CONCLUSIONS

Although the direct application of higher concentrations of retinoic acid results in suppression of oral leukoplakias only, its use in the treatment of patients with recurrent and persistent lesions may be justified for controlling lesions that otherwise may progress. Further controlled clinical studies are needed.

Interventional laser surgery: an effective surgical and diagnostic tool in oral precancer management

Invasive oral squamous cell carcinomas (OSCCs) are often preceded by precancerous lesions, the management of which remains controversial, polarized between active surgical excision to try to prevent malignant change or more conservative, medical or observational techniques. In order to determine the efficacy of interventional CO2 laser surgery in oral precancer management, the records of 57 consecutive laser-treated patients presenting over a 4-year period, with histologically confirmed dysplastic lesions, were reviewed. Leukoplakias were the commonest clinical lesions (69%), whilst the floor of the mouth was the most frequent anatomical site (42%). Laser surgery successfully excised 55 precancerous lesions, 11 of which exhibited more severe dysplasia or neoplasia compared with initial biopsy. Postoperative scarring and morbidity were minimal. After surgery, patients were followed for between 1 and 44 months (mean 18 months). Of these patients, 76% remained disease-free, whilst 24% developed new dysplastic lesions at distinct or multiple sites, often exhibiting increased dysplasia. Of the patients experiencing recurrence, 7% developed OSCC, whilst a further 3.5% presented with other aerodigestive tract cancers. Neither initial lesion appearance nor histological diagnosis predicted clinical behaviour. Interventional laser surgery is thus advised, in contradistinction to conservative management of oral precancers, to facilitate efficacious, low-morbidity treatment and to establish definitive histological diagnosis. As a consequence of field change carcinogenesis, regular follow up of treated precancer patients is mandatory for effective tertiary prevention.

Topical application of vitamin A to oral leukoplakia: A clinical case series

BACKGROUND

Due to the possibility of malignant transformation of oral leukoplakia, these lesions must be assessed and managed closely and, if not resolved, must be reassessed on a regular basis.

METHODS

This study evaluated the use of topical 0.05% vitamin A (tretinoin) acid gel for the treatment of oral leukoplakia. Tretinoin was applied topically 4 times a day for the management of nonmalignant oral white lesions in 26 patients. The clinical response was evaluated in all patients and posttreatment biopsies were performed in ten patients.

RESULTS

The mean age of the patients at the time of diagnosis was 62 years. Of the 26 patients, 50% were tobacco users. Patients were followed for a mean of 23 months. Approximately 27% of the patients had a complete clinical remission. Recurrence of leukoplakia was observed in approximately 40% of patients in whom complete clinical remission occurred if topical applications were discontinued. A 50% reduction in the clinical grade of leukoplakia from a mean of 2.8 to 1.4 on a scale ranging from 0 (no leukoplakia) to 4 (speckled leukoplakia) was observed. When the pretreatment and posttreatment biopsies from 10 patients were evaluated, no change in the mean histologic grade (between mild and moderate dysplasia) was noted; however, some reduction in the histologic grade was noted in 3 of these patients (30%).

CONCLUSIONS

The use of topical vitamin A acid showed a limited effect in controlling oral leukoplakia. Further studies are needed to establish the appropriate indication, efficacy, and best choice for chemoprevention agents. Close follow-up of all patients with oral leukoplakia is required.