Hemantha Amarasinghe

Public awareness of oral cancer, of oral potentially malignant disorders and of their risk factors in some rural populations in Sri Lanka

OBJECTIVE The aim of this study was to investigate the level of public awareness of oral cancer, of oral potentially malignant disorders (OPMD) and of risk factors for developing these diseases in a province of Sri Lanka, a country with one of the highest incidences of these diseases in the world. METHODS A cross-sectional community-based survey was carried out in Sabaragamuwa province by interviewing 1029 subjects above 30 years of age, over a 1-year period from November 2006. RESULTS The level of public awareness of oral cancer was 84%, but only 23% for OPMD. Awareness was especially poor in low socioeconomic groups. The majority of subjects were not aware of the symptoms of oral cancer and of OPMD. Thirty-two percent were unaware that chewing betel quid was a risk factor for these diseases, as were 65% for tobacco smoking and 81% for heavy consumption of alcohol. Overall, 76% were not aware of any of the dangers inherent in the frequent use of areca nut. The majority of smokers, betel quid chewers and alcohol consumers were not aware that their lifestyles were placing their long-term health at serious risk. CONCLUSIONS Knowledge of oral cancer, OPMD and their associated risk factors was poor among this population, indicating an urgent need to implement public health education and promotion strategies.

Derivation and validation of a risk-factor model for detection of oral potentially malignant disorders in populations with high prevalence

Background:Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.Methods:A community-based case–control study (n=1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.Results:A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).Conclusion:This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability.

Oral health of patients on psychotropic medications: a study of outpatients in Queensland

Objective: To describe the oral health of psychiatric patients on psychotropic medication, and compare this to Queensland and national data. Methods: We interviewed and examined 50 patients on medication at two outpatient clinics in South-east Queensland, in 2010. These areas had unfluoridated water till 2009. Results: One-third of the sample had not visited a dentist in the previous 2 years. One-half reported brushing their teeth once a day; 11% stated they never brushed. The mean of decayed, missing and filled teeth (DMFT) was 17.7 (95% confidence interval (CI) = 16.9 – 18.5), significantly higher than the state (13.1) and national (12.8) averages. Almost one-half of dental decay was untreated, compared to the state and national average of one-quarter. Conclusions: The oral health of this subgroup within the community is substantially worse than the general population and there are substantially greater treatment needs. Achieving equity in oral health care for these individuals has substantial resource and management implications.

Epidemiology and Aetiology of Head and Neck Cancers

Malignant neoplasms of the head and neck are among the most common in the world and constitute a major public health problem in most countries. Over 90% of these are squamous cell carcinomas arising in the mucous membranes of the upper aerodigestive tract (UADT). Their epidemiology and aetiology are considered in detail. We separate nasopharyngeal cancer, because it has a specific aetiology related to Epstein-Barr Virus (EBV) infection and dietary carcinogens. We then add those sites with the common major risk factors of alcohol, tobacco (including betel quid/areca nut habits) and diets poor in antioxidants and vitamins, and a minor role for Human Papillomavirus (HPV). Collectively, these UADT sites of oral cavity (including tongue), other pharynx, and larynx have a male incidence/mortality of 15.2/8.1 and for females of 4.6/2.4 cases per 100,000 pa. This ranks UADT cancer as the sixth most common site for men, eighth for women. Adding nasopharynx pushes head and neck cancer higher up the scale. If oesophagus were to be included as another alcohol and tobacco-related cancer, the rates add to 28.6/18.9 and 10.1/6.8 respectively. These cancers – which might be termed cancers of the mouth, throat and gullet – then rank second only to lung cancer in men, and fourth after breast, uterine cervix and large bowel in females, worldwide. Detailed data are presented on geographical, ethnic, gender and time differences. The highest rates in the world are found in Melanesia, South Asia, parts of France, and much of Eastern Europe and the former Soviet republics. Many of these areas are showing rising trends, with a shift to involvement of younger individuals. This, and the fact that survival rates have improved little or not at all in much of the world over several decades, emphasises the need for effective primary and secondary prevention strategies – and for improved public policy to implement these.

Diet and risk of oral potentially malignant disorders in rural Sri Lanka.

BACKGROUND While the protective role of antioxidant nutrients against cancer is well established, data on Asian diets in patients with oral cancer are meagre. METHODS A total of 1029 subjects over 30 years of age were investigated on their dietary practices in the Sabaragamuwa province (Sri Lanka) in 2006-07. Data collection tools were an interviewer-administered questionnaire, a three-day food diary and an examination of the oral cavity. Subjects identified with Oral Potentially Malignant Disorders (OPMD) and disease-free controls were analysed in a case-control fashion. Among the OPMDs, those with leukoplakia were separately considered. A further subgroup analysis was undertaken for β-carotene-rich foods. The analysis was stratified by portions of fruit/vegetables consumed as five or more portions and two or more portions daily. RESULTS A low BMI (<18.5) was a significant independent risk factor for the development of OPMD. More than half of both cases and controls consumed less than two portions of fruit/vegetables per day and only 20 subjects consumed more than five portions per day. Intake of more than two portions per day of β-carotene-containing fruits/vegetables significantly reduced the risk of having an OPMD and leukoplakia (OR = 0.5; 95% CI, 0.3-0.9). The significant differences observed with BMI and fruits/vegetables were attenuated when adjusted for betel quid chewing, smoking and alcohol use. CONCLUSIONS This study discloses prevailing under-nutrition in this rural population with very low daily consumption of fruit/vegetables. Cancer preventive properties in their diets are limited and are swamped by the known carcinogenic agents associated with use of betel quid, tobacco and alcohol.

Epidemiology and Site-Specific Risk Factors for Oral Cancer

To outline the global epidemiology of oral cancer and recent changes in disease prevalence with the emergence of HPV-induced cancers