Knowledge of oral cancer risk factors amongst high-risk Australians: findings from the LESIONS programme.

BACKGROUND: Patient awareness of risk factors associated with cancer has been shown to increase patient presentation for screening and early detection. This study aimed to identify the level of awareness of oral cancer risk factors in a high risk Australian population. METHODS: Participants were recruited from the LESIONS programme between April 2012 and April 2014. Demographics were collected via semi-structured interview. A self-administered questionnaire was provided, listing a number of possible oral cancer risk factors. Participants were requested to indicate their level of agreement on a three-point scale. Bivariate and multivariable analysis was performed. RESULTS: A total of 1498 participants took part in the LESIONS programme and were invited to complete the questionnaire. The most common risk factors thought to be associated with oral cancer were smoking (87.5%), poor oral hygiene (67.9%) and family history (61.1%). Only 50.2% of respondents were aware of alcohol consumption as a risk factor. CONCLUSIONS: While most participants were aware of the association between smoking and oral cancer, only half were aware of the significant risk alcohol consumption poses. A significant portion of participants also held a number of inaccurate beliefs in relation to oral cancer risk. These findings can benefit both clinicians and public health policy makers in targeting oral cancer education.

Oral cancer in Australia 1982-2008: a growing need for opportunistic screening and prevention.

BACKGROUND: Globally, a decline in the incidence of oral cancer has been noted, while the mortality rates have remained relatively stable. The aim of this study was to provide an update on the incidence and mortality of oral cancer in Australia on a national and state level. METHODS: Data regarding new cases and deaths associated with cancer of the lip, oral cavity and oropharynx were obtained from the Australian Institute of Health and Welfare for the period 1982-2008. Crude- and age-standardized incidence and mortality rates were calculated for all of Australia and for each state and territory. RESULTS: A total of 60 826 cases of lip, oral cavity and oropharyngeal cancer were diagnosed in Australia. Between 1992 and 2008, a decline in the annual percentage change of age-standardized incidence was noted. The lip, followed by the tongue, continue to represent the most common sites of new oral cancer cases. There was no significant change in the rates of mortality for oral cancer over the time period. CONCLUSIONS: These findings show that the oral cancer mortality rate remains high despite a decline in incidence over the past three decades, highlighting a greater need for dental practitioners to undertake preventive strategies and opportunistic screening for patients.

A retrospective analysis of oral and maxillofacial pathology in an Australian adult population.

BACKGROUND: The prevalence of oral and maxillofacial pathology has not previously been reported in the Australian adult population. This study aimed to audit a large pathology service to provide insight into the prevalence of head and neck pathologies. METHODS: Written records of a major Australian oral pathology service were imported into an electronic database. Age, gender and histological diagnosis were assessed. Prevalence of histological diagnoses as a percentage of the major diagnostic categories and of the whole sample were calculated, as well as gender predilections and mean age of presentation of disease. RESULTS: A total of 6344 oral pathology specimens, collected from adults aged 17 years and over were included in the analysis. Mucosal pathology was the most common pathology (37.2%), followed by odontogenic cysts (16.3%) and dental pathology (14.5%). The three most common histological diagnoses were fibrous hyperplasia (15.2%), chronic periapical granuloma (9.6%) and radicular cyst (9.5%). The male:female ratio of the entire sample was 0.74. CONCLUSIONS: This is the first study to describe the prevalence of oral and maxillofacial pathology among adult patients in an Australian population. The trends seen in this study are repeated in studies from other parts of the world, and are of diagnostic importance.

A retrospective analysis of oral and maxillofacial pathology in an Australian paediatric population.

BACKGROUND: The prevalence of oral and maxillofacial pathology has not previously been reported in the Australian paediatric population. This study aimed to audit a large pathology service to provide insight into the prevalence of oral and maxillofacial pathology. METHODS: Written records of a major Australian oral pathology service were imported into an electronic database. Age, gender and histological diagnosis were assessed. Prevalence of histological diagnoses as a percentage of the major diagnostic categories and of the whole sample were calculated, as well as gender predilections and mean age of presentation of disease. RESULTS: A total of 1305 oral pathology specimens, collected from paediatric patients aged 16 and under were included in the analysis. The most common pathology was dental pathology (24.4%), followed by odontogenic cysts (18.5%) and mucosal pathology (17.0%). The most frequently encountered lesion was the dentigerous cyst (9.4%), followed by fibrous hyperplasia (8.3%), radicular cyst (5.2%) and chronic periapical granuloma (5.2%). CONCLUSIONS: In the paediatric population, dental pathology and specifically, the dentigerous cyst is the most common pathology type sent for histopathology, suggesting a high prevalence of pathology of dental origin occurring in Australian children.

Oral mucosal lesions: findings from the Australian National Survey of Adult Oral Health.

BACKGROUND: The prevalence of oral mucosal lesions (OMLs) and factors associated with these has not previously been reported in the Australian population. This study aimed to report on the prevalence of OMLs in Australian adults and to evaluate their association with socio-demographic factors. METHODS: This study utilized data from the Australian National Survey of Adult Oral Health 2004-06, which employs a multi-stage, stratified random sample selection procedure. Information on socio-demographics, smoking and presence of OMLs were collected using telephone interview, self-reported questionnaires and comprehensive oral examination. A multivariate regression model was generated to estimate effect of factors on the prevalence of non-ulcerated OMLs. RESULTS: A total of 3551 dentate adult Australians had complete data for this analysis. Over 20% of study participants presented with an OML on the day of examination. The prevalence of suspected malignancy was less than 1% and over 17% for non-ulcerated OMLs. Prevalence of non-ulcerated OMLs was associated with age, gender, residential location, household income and smoking. CONCLUSIONS: The study reported that epidemiological survey can provide useful information on OMLs. Certain population groups had a higher risk of having the condition. Preventing smoking uptake and smoking cessation can reduce the prevalence of OMLs in the population.

Malignant transformation of oral epithelial dysplasia: a real-world evaluation of histopathologic grading.

OBJECTIVE: This study describes the predictive value of oral epithelial dysplasia (OED) grading as an indicator for malignant transformation and progression. STUDY DESIGN: The records of an Australian-based pathology laboratory were searched for oral mucosal biopsies with a dysplastic or malignant diagnosis. Examination for an association with progression and malignant transformation without reinterpretation was performed. Analysis was undertaken using hazard ratios and the Fisher exact test. RESULTS: A total of 368 patients with a diagnosis of OED were included. Twenty-six patients (7.1%) underwent progression or malignant transformation; the annual malignant transformation rate was 1%. No other characteristics were associated with a heightened risk of progression or transformation. CONCLUSIONS: The severity of OED was not associated with risk of malignant transformation, suggesting that the current OED grading system is not useful for predicting patient outcomes or for determining management strategies. Definitive treatment of all OED is recommended, until a more reliable progression/transformation system is developed.

Stimulating the discussion on saliva substitutes: a clinical perspective.

Xerostomia is a significant problem commonly faced by patients and oral health practitioners. There is no cure for this condition, which commonly manifests as a side effect of medications, head and neck irradiation and other systemic conditions, such as Sjögren's syndrome and type 2 diabetes. It may also arise idiopathically. Therefore, treatment is palliative and takes the form of oral lubricants and saliva substitutes which aim to reduce symptoms associated with xerostomia as well as prevent oral disease secondary to it. Recently there has been an expansion of the number and range of products available in Australia for the palliative management of xerostomia. It is imperative then that oral health professionals have a sound understanding of the advantages and disadvantages of using such products as patients tend to be well informed about new products which are commercially available. This article discusses some of the most commonly available products used for the symptomatic relief and preventive management of xerostomia. Amongst the plethora of products available to the patient suffering from xerostomia, no single product or product range adequately reproduces the properties of natural saliva and therefore consideration of patients' concerns, needs and oral health state should be taken into account when formulating a home care regime. With Australia's ageing population and its heavier reliance on medications and treatments which may induce xerostomia, oral health professionals are likely to encounter this condition more than ever before and therefore an understanding of xerostomia and its management is essential to patient care.

Weight of the evidence on the human carcinogenicity of 2,4-D.

The phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used to control the growth of weeds and broadleaf plants. We convened a panel of 13 scientists to weigh the evidence on the human carcinogenicity of 2,4-D. The panel based its findings on a review of the toxicological and epidemiological literature on 2,4-D and related phenoxy herbicides. The toxicological data do not provide a strong basis for predicting that 2,4-D is a human carcinogen. Although a cause-effect relationship is far from being established, the epidemiological evidence for an association between exposure to 2,4-D and non-Hodgkin's lymphoma is suggestive and requires further investigation. There is little evidence of an association between use of 2,4-D and soft-tissue sarcoma or Hodgkin's disease, and no evidence of an association between 2,4-D use and any other form of cancer. Scientists on the panel were asked to categorize 2,4-D as a "known," "probable," "possible," or "unlikely" carcinogen or as a noncarcinogen in humans. The predominant opinion among the panel members was that the weight of the evidence indicates that it is possible that exposure to 2,4-D can cause cancer in humans, although not all of the panelists believed the possibility was equally likely: one thought the possibility was strong, leaning toward probable, and five thought the possibility was remote, leaning toward unlikely. Two panelists believed it unlikely that 2,4-D can cause cancer in humans.

Acute toxicology of components of vegetation smoke.

Only in recent times, systematic attention has been paid to the occupational health of forest firefighters and workers who manage prescribed fire. Two parts of the effort to learn the impact on worker health are medical observation of those workers, and study of occupational hygiene. It is also necessary to learn what components of smoke are most likely to affect firefighters, and to learn something of the manner in which those substances might compromise health; this review is a step toward that end. The number of possible products of vegetation combustion is almost limitless, and every fuel and condition of burning produces a unique pattern. Nonetheless, it is possible and practical to select a limited number of products that are most likely to be involved in the acute toxicity of smoke. Two products that are almost certainly important are formaldehyde and acrolein. Both appear to occur in all smoke. The toxicology of both is well studied; in particular both are powerful mucosal irritants. Estimates of exposure suggest strongly that concentrations are high enough in smoke to contribute some or all of the irritant activity. There seems to be a reasonable prospect that free radical precursors with half-lives in the tens of minutes are produced when cellulosic materials burn. If so, they will reach the respiratory tract, and liberate free radicals that react immediately on or in pulmonary cells. Ozone is not produced in the fire, but the various hydrocarbons of smoke are substrates for reactions that eventually produce ozone, and that production may continue for miles down-plume. Some measured plume concentrations approach the threshold for human health effects. The effects of the best known component, the particulate material, are unknown in isolation from all of the other substances in smoke. In spite of that ignorance, particulate loading is the principal index of smoke pollution for regulatory purposes, and sometimes is incorrectly used to represent smoke emissions regardless of source. The need to understand health impacts of these components of smoke seems obvious. Perhaps less obvious is the need to use such knowledge in management of both prescribed burning and wildfire. To some extent, it is possible to either manage fire itself to alter emission patterns, or control exposures in certain situations. Whether that should be done to protect worker health can only be judged if enough is known about health effects to direct the management decisions.

Isolation and measurement of 15N2 from respiratory gases of animals administered 15N-labeled substances.

A method is described for collection of metabolic 15N2 from in vitro preparations or intact rats administered 15N-containing compounds. The methods enables routine collection and mass spectrometric measurement of as little as 10 mumol 15N2 respired by a rat over a 24-h period. A device is described that includes either an animal chamber or a tissue reaction vessel in a closed recycling atmosphere, with automatic O2 replenishment and removal of CO2 and water. It is capable of sustaining moderate vacuum and is coupled to a high-vacuum manifold designed to process the contained atmosphere and respiratory gases. The starting atmosphere is an 80:20 mix of sulfur hexafluoride and O2. Recovery of 15N2 gas from the system without an animal present was 101.3 +/- 5.75%. When 15N2 gas was very slowly infused iv into an animal, recovery was 89.1 +/- 5.38%. Use of the method in studies of the fate of [15N]hydrazine in rats indicated that about 15% of the administered hydrazine is rapidly converted to 15N2, followed by slower conversion of an additional 7-10% over the next several hours.

Metabolic fate of hydrazine.

Studies of the disposition of hydrazine administered to mammals have not succeeded in accounting for more than a modest fraction of the dose, nor have the excretory products been completely identified. We have utilized 15N-labeled hydrazine and conventional methods to account for about 75% of single doses of about 0.5 LD50 (1 mmol/kg). In 48 h, about 30% appeared in urine as hydrazine and about 20% emerged as a derivative that is acid-hydrolyzable to hydrazine. About 25% was converted to N2 gas, most of which appeared less than 30 min after administration. The percentage converted to N2 at 4 h increased only slightly with dose between 0.5 and 2.0 mmol/kg. Disappearance of hydrazine from blood was biphasic with half-times of 0.74 and 26.9 h.