Saman Warnakulasuriya

Global epidemiology of oral and oropharyngeal cancer

This review presents data on incidence, mortality, survival and trends in cancers of the lip, oral cavity and oropharynx using available recent data sources around the world. Oral and pharyngeal cancer, grouped together, is the sixth most common cancer in the world. The review focuses primarily on several high-risk countries in an attempt to gain insight into the geographic variations in the incidence of this cancer in the globe and to relate the high incidence in some populations to their life style. With an estimated half a million cases around the globe and the rising trends reported in some populations, particularly in the young, urgent public health measures are needed to reduce the incidence and mortality of oral and oropharyngeal cancer.

Oral epithelial dysplasia classification systems: predictive value, utility, weaknesses and scope for improvement

At a workshop coordinated by the WHO Collaborating Centre for Oral Cancer and Precancer in the United Kingdom issues related to potentially malignant disorders of the oral cavity were discussed by an expert group. The consensus views of the Working Group are presented in a series of papers. In this report, we review the oral epithelial dysplasia classification systems. The three classification schemes [oral epithelial dysplasia scoring system, squamous intraepithelial neoplasia and Ljubljana classification] were presented and the Working Group recommended epithelial dysplasia grading for routine use. Although most oral pathologists possibly recognize and accept the criteria for grading epithelial dysplasia, firstly based on architectural features and then of cytology, there is great variability in their interpretation of the presence, degree and significance of the individual criteria. Several studies have shown great interexaminer and intraexaminer variability in the assessment of the presence or absence and the grade of oral epithelial dysplasia. The Working Group considered the two class classification (no/questionable/ mild - low risk; moderate or severe - implying high risk) and was of the view that reducing the number of choices from 3 to 2 may increase the likelihood of agreement between pathologists. The utility of this need to be tested in future studies. The variables that are likely to affect oral epithelial dysplasia scoring were discussed and are outlined here; these need to be researched in longitudinal studies to explore the biological significance of a low-risk or high-risk dysplasia.

Global epidemiology of areca nut usage

Abstract A substantial proportion of the worlds population is engaged in chewing areca nut and the habit is endemic throughout the Indian subcontinent, large parts of south Asia and Melanesia. A large variety of ingredients, including tobacco, may be used along with areca nut constituting a betel quid. The composition and method of chewing can vary widely from country to country and these population variations are described in this review. Some populations are known to use areca nut without tobacco providing good opportunities to further research the carcinogenecity of areca nut. Some interesting trends on chewing patterns have emerged from recent data, suggesting a decline in the habit in some countries such as Thailand while the prevalence of areca nut use is rising in India and Taiwan.

The oral health consequences of chewing areca nut

Abstract Deleterious effects of areca nut on oral soft tissues are published extensively in the dental literature. Its effects on dental caries and periodontal tissues, two major oral diseases, are less well researched. Areca‐induced lichenoid lesions mainly on buccal mucosa or tongue are reported at quid retained sites. In chronic chewers a condition known as betel chewers mucosa, a discoloured areca nut‐encrusted change, is often found where the quid particles are retained. Areca nut chewing is implicated in oral leukoplakia and submucous fibrosis, both of which are potentially malignant in the oral cavity. Oral cancer often arises from such precancerous changes in Asian populations. In 1985 the International Agency for Research on Cancer concluded that there is limited evidence to conclude that areca chewing may directly lead to oral cancer. There is, however, new information linking oral cancer to pan chewing without tobacco, suggesting a strong cancer risk associated with this habit. Public health measures to quit areca use are recommended to control disabling conditions such as submucous fibrosis and oral cancer among Asian populations.

Living with oral cancer: epidemiology with particular reference to prevalence and life-style changes that influence survival.

This review presents data on incidence, mortality, survival and trends on cancers of the lip, oral cavity and oropharynx using available recent data sources around the world. Oral and pharyngeal cancer, grouped together is the sixth most common cancer in the world. The review focuses primarily on prevalence of people still alive after an oral cancer diagnosis. In the world, there is close to a three quarter of a million people who previously had oral cancer and alive at 5years after diagnosis. The proportion alive at 5years is lower in less developed countries compared to earlier years. Within in Europe highest prevalence at 5years is seen in Western Europe. Our prevention strategies for this high risk group should include offering smoking cessation and other risk reduction measures. Smoking cessation in particular improves prognostic outcomes reducing the risk of secondary disease by approximately 2-3-fold.

Global Oral Health Inequalities in Incidence and Outcomes for Oral Cancer Causes and Solutions

The mouth and oropharynx are among the ten most common sites affected by cancer worldwide, but global incidence varies widely. Five-year survival rates exceed 50% in only the best treatment centers. Causes are predominantly lifestyle-related: Tobacco, areca nut, alcohol, poor diet, viral infections, and pollution are all important etiological factors. Oral cancer is a disease of the poor and dispossessed, and reducing social inequalities requires national policies co-ordinated with wider health and social initiatives – the common risk factor approach: control of the environment; safe water; adequate food; public and professional education about early signs and symptoms; early diagnosis and intervention; evidence-based treatments appropriate to available resources; and thoughtful rehabilitation and palliative care. Reductions in inequalities, both within and between countries, are more likely to accrue from the application of existing knowledge in a whole-of-society approach. Basic research aimed at determining individual predisposition and acquired genetic determinants of carcinogenesis and tumor progression, thus allowing for targeted therapies, should be pursued opportunistically.

Causes of oral cancer – an appraisal of controversies

Major risk factors for oral cancer are cigarette smoking and alcohol misuse. Among Asian populations, regular use of betel quid (with or without added tobacco) increases oral cancer risks. Dentists should be aware of some emerging risk factors for oral, and particularly oropharyngeal cancer such as the role of the human papillomavirus infection (HPV). Decreases in risk could be achieved by encouraging high fruit and vegetable consumption. Some controversies related to the aetiology of this disease also need clarification. The objective of this paper is to provide an opinion on these debated controversies.

Molecular markers in oral epithelial dysplasia: review

The clinical and histologic features alone cannot accurately predict whether potentially malignant disorders of the oral mucosa remain stable, regress or progress to malignancy. Some of them, with or without epithelial dysplasia, may transform to invasive oral squamous cell carcinomas (OSCC). Identification of molecular markers which can predict disease progression is necessary to improve the management of these disorders. Many genes and signaling pathways have been shown to be involved in the development of OSCC. This review summarizes some molecular markers researched in the detection of pre-cancer. We highlight selected markers that are reported to be significantly associated with progression of potentially malignant disorders to OSCC. These include alterations in genes/pathways which control cellular signaling, cell cycle, apoptosis, genomic stability, cytoskeleton, angiogenesis, etc. However, these genetic tumor markers have so far not gained any use in routine diagnosis and their utility in the prediction of risk of malignant transformation remains unknown. It is, however, clear from the large number of studies, some described in this review, that multiple genes/pathways are involved in the progression from normal to metaplastic/dysplastic, and subsequently to cancer. It is therefore necessary to study those significant alterations in multiple genes simultaneously in biopsy samples from large cohorts of subjects.

Areca nut use: an independent risk factor for oral cancer

Areca nut is the seed of the fruit of the oriental palm, Areca catechu . It is the basic ingredient of a variety of widely used chewed products. Thin slices of the nut, either natural or processed, may be mixed with a variety of substances including slaked lime (calcium hydroxide) and spices such as cardamom, coconut, and saffron. Most significantly, they may be mixed with tobacco products or wrapped in the leaf of the piper betel plant. Hence the more common name betel nut. Areca nut is used by an estimated 200-400 million people, mainly IndoAsians and Chinese.1 It is used by men and women—in some societies the latter predominate. All age groups and social classes use the product. Areca nut has a long history of use and is deeply ingrained in many sociocultural and religious activities.2 Of particular interest in the United Kingdom, and perhaps other developed countries, is that use of areca nut continues and is often enhanced following migration. Thus British Asians have brought the use of areca from India (some via East Africa), Pakistan, Bangladesh, and other countries in the region …

Evaluation of an autofluorescence based imaging system (VELscope™) in the detection of oral potentially malignant disorders and benign keratoses

Early detection of oral cancer is crucial in improving survival rate. Identification and detection of oral potentially malignant disorders (OPMD) allow delivery of interventions to reduce the evolution of these disorders to malignancy. A variety of new and emerging diagnostic aids and adjunctive techniques are currently available to potentially assist in the detection of OPMD. The objective of the present study was to evaluate the accuracy of autofluorescence against conventional oral examination and surgical biopsy. A total of 126 patients, 70 males and 56 females (mean age 58.5±11.9 years) who presented to the Oral Medicine Clinics at Kings and Guys Hospitals, London with oral white and red patches suspicious of OPMD were enrolled. Following a complete visual and autofluorescence examination, all underwent an incisional biopsy for histopathological assessment. Seventy patients had oral leukoplakia/erythroplakia, 32 had oral lichen planus, 9 chronic hyperplastic candidiasis and rest frictional keratosis (13) or oral submucous fibrosis (2). Of 126 lesions, 105 (83%) showed loss of fluorescence. Following biopsy 44 had oral epithelial dysplasia (29 mild, 8 moderate and 7 severe). The sensitivity (se) and specificity (sp) of autofluorescence for the detection of a dysplastic lesion was 84.1% and 15.3% respectively. While VELscope was useful in confirming the presence of oral leukoplakia and erythroplakia and other oral mucosal disorders, the device was unable to discriminate high-risk from low-risk lesions.