The aggregation of early-onset melanoma in young Western Australian families.

BACKGROUND: Few studies have examined the familial aggregation of melanoma or its co-aggregation with other cancers using whole-population based designs. This study aimed to investigate aggregation patterns in young Western Australian families, using population-based linked health data to identify individuals born in Western Australia between 1974 and 2007, their known relatives, and all incident cancer diagnoses within the resulting 1,506,961 individuals. METHODS: Cox proportional hazards regression models were used to compare the risk of melanoma for first-degree relatives of melanoma cases to that for first-degree relatives of controls, with bootstrapping used to account for correlations within families. The risk of (i) developing melanoma based on the number of first-degree relatives with other cancers, and (ii) developing non-melanoma cancers based on the number of first-degree relatives diagnosed with melanoma was also investigated. RESULTS: First-degree relatives of melanoma cases had a significantly greater incidence of melanoma than first-degree relatives of individuals not affected with melanoma (Hazard Ratio (HR)=3.58, 95% bootstrap confidence interval (CI): 2.43-5.43). Sensitivity analyses produced a higher hazard ratio estimate when restricted to melanoma cases diagnosed before 40 years of age (HR=3.77, bootstrap 95% CI: 2.49-6.39) and a lower estimate when only later-onset cases (>40 years) were considered (HR=2.45, bootstrap 95% CI: 1.23-4.82). No significant evidence was found for co-aggregation between melanoma and any other cancers. CONCLUSIONS: Results indicated a strong familial basis of melanoma, with the higher than expected hazard ratio observed likely to reflect early-age at onset cases in this young cohort, supported by the results of the sensitivity analyses. Exploratory analyses suggested that the determinants of melanoma causing the observed aggregation within families may be independent of other malignancies, although these analyses were limited by the young age of the sample. Determining familial aggregation patterns will provide valuable knowledge regarding improved clinical risk prediction and the underlying biological mechanisms of melanoma and other cancers.

The association between different night shiftwork factors and breast cancer: a case-control study.

BACKGROUND: Research on the possible association between shiftwork and breast cancer is complicated because there are many different shiftwork factors, which might be involved including: light at night, phase shift, sleep disruption and changes in lifestyle factors while on shiftwork (diet, physical activity, alcohol intake and low sun exposure). METHODS: We conducted a population-based case-control study in Western Australia from 2009 to 2011 with 1205 incident breast cancer cases and 1789 frequency age-matched controls. A self-administered questionnaire was used to collect demographic, reproductive, and lifestyle factors and lifetime occupational history and a telephone interview was used to obtain further details about the shiftwork factors listed above. RESULTS: A small increase in risk was suggested for those ever doing the graveyard shift (work between midnight and 0500 hours) and breast cancer (odds ratio (OR)=1.16, 95% confidence interval (CI)=0.97-1.39). For phase shift, we found a 22% increase in breast cancer risk (OR=1.22, 95% CI=1.01-1.47) with a statistically significant dose-response relationship (P=0.04). For the other shiftwork factors, risks were marginally elevated and not statistically significant. CONCLUSION: We found some evidence that some of the factors involved in shiftwork may be associated with breast cancer but the ORs were low and there were inconsistencies in duration and dose-response relationships.

Association of TGFß1 and clinical factors with scar outcome following melanoma excision.

All patients with primary cutaneous malignant melanoma undergo surgical excision to remove the tumour, resulting in scar formation. There is marked variation in the aesthetic appearance of scars following surgery but limited knowledge about the genetic factors affecting non-keloid, surgical scar outcomes. This study aimed to investigate the role of known clinical factors and genetic polymorphisms in pigmentation and wound repair genes in non-keloid scar outcome, following melanoma excision. Participants were 202 cases who underwent a standardized scar assessment following surgical melanoma excision and provided a DNA sample. Genetic association analyses between single nucleotide polymorphisms (SNPs) from 24 candidate genes and scar outcome data were performed, controlling for relevant clinical factors. Following adjustment for multiple testing, SNP rs8110090 in TGFß1 was significantly associated with both the primary scar outcome (a combination score reflecting vascularity, height and pliability, p = 0.0002, q = 0.01) and the secondary scar outcome (a combination score reflecting vascularity, height, pliability and pigmentation, p = 0.0002, q = 0.006). The minor allele G was associated with a poorer scar outcome. Younger age, time elapsed since excision, absence of kidney failure and eczema, presence of thyroid problems and infection were also associated with poorer scar outcome and were adjusted for in the final model, along with scar site. Results from this study suggest that genes involved in wound healing may play a role in determining scar outcome. Associations observed between scar outcome and clinical factors reinforce current clinical knowledge regarding factors affecting scarring. Replication studies in larger samples are warranted and will improve our understanding of the underlying mechanisms of scarring, potentially help to identify patients at risk of poor scar outcomes.

Hypotheses for mechanisms linking shiftwork and cancer.

Shift work has been associated with various adverse health outcomes. In particular, there has been a recent flourish in investigating potential cancer risk associated with working night shifts and other shift schedules. Epidemiologic studies have revealed generally weak associations due to several methodological challenges such as lack of standard classifications of shift or night work. The field also has been hindered by a lack of clarity about the possible mechanisms by which shiftwork could have an effect on cancer risk. One possible mechanism is reduced production of melatonin caused by exposure to light at night. Although there is a growing body of evidence that provides some support for this mechanism, several other mechanisms also make sense from a biological point of view. Further, the relatively weak magnitude of the associations between light at night and melatonin level suggests that multiple factors may be operating along the pathway between shift work and adverse health consequences (including cancer risk). Here we propose four additional mechanisms that should be considered for a comprehensive investigation of these potential pathways. These are: phase shift; sleep disruption; lifestyle factors (such as poor quality diets, less physical activity and higher BMI); and lower vitamin D. Consideration of all these mechanisms is necessary in order to design effective preventative workplace strategies. In developed countries, approximately 20% of the population undertake shiftwork and, while we are unlikely to be able to eliminate shiftwork from current work practices, there are aspects of shiftwork that can be modified and there may be facets of individual susceptibility that we may be able to identify and target for prevention.

Meat consumption and cooking practices and the risk of colorectal cancer.

BACKGROUND/OBJECTIVES: The association between meat consumption and the risk of colorectal cancer (CRC) has been controversial. One of the difficulties in determining this association has been measurement of different attributes of meat consumption, including cooking methods and level of doneness. SUBJECTS/METHODS: We investigated the association between meat consumption and cooking practices and the risk of CRC in a population-based case-control study in the Western Australian Bowel Health Study. From July 2005 to February 2007, 567 incident CRC cases and 713 controls, who were frequency matched to cases for age- and sex, completed questionnaires on lifestyle and meat consumption. Estimated odds ratios (ORs) comparing meat consumption quartile groups were obtained from multivariate logistic regression models. RESULTS: The amount of red baked meat consumed had a statistically significant inverse trend of association with CRC (Q4 OR=0.73 95% confidence interval 0.53-1.01). When frequency was multiplied by serving size and by doneness, the association remained protective but was no longer statistically significant. The protective trends for red pan-fried meat were also borderline statistically significant. There were no other statistically significant or meaningful associations with any of the types of meat cooked by any method and the risk of CRC. CONCLUSIONS: Our data do not support the hypothesis that meat consumption is a risk factor for CRC.

Consumption of untreated tank rainwater and gastroenteritis among young children in South Australia.

BACKGROUND: Tank rainwater is a source of untreated drinking water in Australia and elsewhere. The aim of this study was to determine whether the risk of gastroenteritis among children who drank tank rainwater differed from that of children who drank treated public mains water. METHODS: A cohort study of 1,016 4- to 6-year old children who drank rainwater or treated mains water in rural South Australia was undertaken in 1999. Parents kept a daily diary of their child's gastrointestinal symptoms and water consumption for a period of 6 weeks. Data on respiratory illness and other risk factors for gastroenteritis were also collected. RESULTS: The incidence of gastroenteritis among children was 3.8-5.3 episodes per child-year, but most episodes (60%) lasted just 1 day. No increase in odds of gastroenteritis was observed among children who drank rainwater compared with treated mains water. The adjusted odds ratio for gastroenteritis associated with rainwater consumption compared with mains consumption was 0.84 (95% confidence interval 0.63-1.13). CONCLUSIONS: Gastroenteritis was found to be a significant cause of morbidity among young children. Young children, who were regular consumers of tank rainwater, were at no greater odds of gastroenteritis than those who drank treated public mains water.

Does dog or cat ownership lead to increased gastroenteritis in young children in South Australia?

The aim of this study was to investigate the relationship between dog and cat ownership and gastroenteritis in young children. A diary study of 965 children aged 4-6 years living in rural or semi-rural South Australia was undertaken. Data were collected on pet ownership, drinking water and other risk factors for gastroenteritis. Overall 89% of households had pets and dog ownership was more common than cat ownership. The multivariable models for gastroenteritis and pet ownership indicated that living in a household with a dog or cat was associated with a reduced risk of gastroenteritis (adj. OR 0.71, 95% CI 0.55-0.92; OR 0.70, % CI 0.51-0.97 respectively). This paper adds to the evidence that pets are not a major source of gastroenteritis in the home and lends support to the health benefits of pet ownership. However, this must be weighed against the potential negative consequences, such as dog bites, particularly for this age group.

Validation of a water consumption questionnaire for a study of the adverse health outcomes associated with disinfection by-products.

The aim of this study was to assess the validity and reliability of a questionnaire to estimate water exposure through drinking, showering, bathing or swimming. Forty-seven pregnant women were recruited from antenatal or exercise classes and were randomly allocated into three groups. The first group completed the water exposure questionnaire one-week apart. The second group completed a three-day diary and then the questionnaire. The third group completed the questionnaire first followed by the diary. Agreement was assessed by the Intraclass correlation coefficient (ICC) and the Kappa statistic. The questionnaire demonstrated good reliability (ICC 0.93 for water consumption and 0.91 for time spent showering). With regard to validity, average daily water consumption was estimated to be 8.1 glasses/day (2 litres) from the diary compared with 12.2 (3 litres) from the questionnaire. The ICCs comparing the diary and questionnaire responses were 0.31 for water consumption and 0.72 for showering. The water exposure questionnaire overestimated levels of exposure when compared with diary-reporting of consumption. While a water exposure questionnaire may be a less intrusive research instrument than a diary, further development is required to improve the validity of this instrument.

Prevalence of gastroenteritis among 4-year-old children in South Australia.

The aim of this study was to determine the prevalence of gastroenteritis among children aged 4 years in South Australia. A cross-sectional survey of 9543 South Australian children aged 4 years was undertaken. Parents completed a questionnaire on behalf of their child who had attended a pre-school health check in 1998. The questionnaire covered gastrointestinal and respiratory symptoms experienced by the child in the previous 2 weeks and other risk factors for gastroenteritis. The 2-week prevalence of gastroenteritis among 4-year-old children was 14.2%. The major risk factors for gastroenteritis were presence of persons who had gastroenteritis inside the home, contact with persons who had gastroenteritis outside the home, antibiotic use and sore throat. Medical attention was sought for 20% of children who had gastroenteritis. Gastroenteritis is a significant cause of morbidity among young children and presents a considerable burden on the community. A substantial proportion of these occurrences of highly credible gastrointestinal symptoms may be manifestations of respiratory infections.

Port Pirie lead abatement Program, 1992.

The Port Pirie Lead Decontamination Program commenced in 1984 with a ten year mandate. The abatement programme involves identification of children with elevated blood lead levels, house decontamination, soil treatment, general City greening, family education and support and community education. Since 1984 the smelter has also implemented substantial new environmental controls.Blood lead and air monitoring programmes as well as some investigations of recontamination are in place. The blood lead monitoring programme has shown a significant decrease in the mean blood lead levels of the children, with the magnitude of the reduction being greatest in areas remote from the smelter.The results of the air monitoring programme suggest that there has been little change in the general air lead levels in the City over the period of the abatement programme. Analysis of the data suggests that re-entrainment of lead from the contaminated areas within the City is only a small contributor to air-borne lead levels compared with that from the smelter and its environs.Sources and pathways of lead for absorption by the children in Port Pirie are discussed.

Extradural haemorrhage: strategies for management in remote places.

A study of 109 cases of extradural haemorrhage (EDH) treated in South Australia over a period of 7 years showed that 35 cases (32.1 per cent) presented in country areas at considerable distances from a neurosurgical service: the mortality in these country cases was 22.9 per cent, comparing unfavourably with a mortality of 12.2 per cent in metropolitan cases. The country series contained a disproportionately large number of cases with multiple intracranial haemorrhages, which are known to have a poorer outcome; when these cases were excluded, the rural mortality (12.5 per cent) was only a little over the metropolitan mortality (9.7 per cent). These data suggest that it is possible to manage extradural haemorrhages successfully even in places remote from a neurosurgical centre, if communications and air transport are used effectively. However, it was found that emergency operations carried out in country hospitals were sometimes inadequate or done too late. Medical retrieval teams based on city hospitals were sent out on 15 occasions, either to assist a general surgeon to complete an emergency operation, or to provide intensive care during transfer to a neurosurgical unit. Osmotherapy (mannitol and/or frusemide) has been useful in gaining time for transfer; the choice between immediate operation and transfer may be difficult, and decisions should take transfer time, clinical state and rate of deterioration into account.