Case-control study of sun exposure and squamous cell carcinoma of the skin.

We conducted a case-control study of sun exposure and squamous cell carcinoma (SCC) of the skin within a population-based, longitudinal study of skin cancer. Cases had histopathologically confirmed SCC. Subjects were interviewed about their lifetime sun exposure, including exposure to the site of the SCC (sites for controls were assigned randomly). Analysis was restricted to 132 cases and 1,031 controls born in Australia and with no ancestors from southern Europe. The total site-specific exposure was strongly related to risk of SCC; the odds ratio increased to a maximum of 3.3 at 65,000 hr of exposure before falling slightly. Site-specific exposure during childhood and adolescence was more strongly associated with SCC than exposure during adulthood. An intermittent pattern of weekly sun exposure was not associated with SCC and the odds ratios for hours of exposure on vacation were close to unity. The number of blistering sunburns to the site was positively associated with SCC. Use of sunscreens and hats showed inconsistent effects. Sun exposure, especially during childhood and adolescence, increases the risk of SCC. The pattern of exposure appears to be unimportant, despite the association with sunburn, which may simply be an indicator of the skin's sensitivity to sunlight.

Demographic characteristics, pigmentary and cutaneous risk factors for squamous cell carcinoma of the skin: a case-control study.

We conducted a case-control study of squamous cell carcinoma of the skin (SCC) in a cohort of people followed from 1987 to 1994. Subjects were residents of Geraldton, Western Australia, who were between 40 and 64 years of age in 1987. On 2 occasions, in 1987 and 1992, dermatologists examined participants for skin cancers. Subjects were also asked on several occasions about skin cancers that they had had treated. Migrants to Australia had reduced risks of SCC. Furthermore, people who migrated to Australia early in life or, equivalently, lived in Australia for a long time had a higher risk than immigrants who arrived later in life or more recently. People who had southern European ancestry had a much lower risk of SCC than other subjects, most of whom were of British or northern European origin. Among Australian-born subjects of British or northern European ancestry, the skin's sensitivity to sunlight was strongly associated with SCC. The pigmentary traits of hair colour, eye colour and skin colour showed weaker associations. The degree of freckling on the arm was strongly predictive of risk. The risk of SCC increased strongly with increasing evidence of cutaneous solar damage and was most strongly associated with the number of solar keratoses. Our results show that sensitivity to sunlight and high levels of exposure to sunlight are important determinants of the risk of SCC.

Incidence of non-melanocytic skin cancer in Geraldton, Western Australia.

To measure the rate at which non-melanocytic skin cancers develop, we conducted a population-based, longitudinal study in Geraldton, Western Australia. Subjects were residents of Geraldton, Western Australia, who were between 40 and 64 years of age and registered on the electoral roll in 1987. In 1987 and again in 1992, dermatologists examined participants for skin cancers. They examined all skin areas, apart from those covered by underwear or hair. Subjects were asked about skin cancers that they had had treated between the 2 surveys. When all skin cancers were counted, the incidence rates of basal cell carcinoma were 3,379 per 100,000 person-years in women and 7,067 per 100,000 in men; those of squamous cell carcinoma were 501 per 100,000 in women and 775 per 100,000 in men. Sixteen percent of men and 14% of women developed at least one basal cell carcinoma; 2.8% of men and 2.2% of women had at least one squamous cell carcinoma. Most incident skin cancers were diagnosed at the second examination. More than half of the subjects who had a skin cancer at the first examination developed another. Squamous cell carcinomas occurred almost exclusively on parts of the body that are usually exposed. Basal cell carcinomas were common on the head, neck and trunk but not on the forearms and backs of hands. A quarter of people with a skin cancer on an exposed site also had one on the trunk. Our results show that skin cancer is extremely common in this population and frequently undiagnosed. Multiple skin cancers occur commonly, and skin cancers on exposed sites often are associated with skin cancers on less exposed sites.

Meta-analysis of alcohol and all-cause mortality: a validation of NHMRC recommendations.

OBJECTIVE: To compare the National Health and Medical Research Council (NHMRC) recommendations on responsible, hazardous and harmful alcohol intake with their effects on all-cause mortality in men and women and on the occurrence of 10 specific neoplastic, cardiovascular and alimentary diseases. DESIGN: Meta-analyses of relative risks of mortality in relation to usual level of alcohol intake pooled from 16 cohort studies (mostly of adults over 35 years), and alcohol and selected conditions from a further 132 epidemiological studies. Results reported by authors were assigned to sex-specific exposure categories defined by the NHMRC based on median alcohol intakes. Pooled estimates of relative risk were calculated using precision-based weighting. SETTING: The assessment was part of comprehensive meta-analysis of epidemiological research undertaken for the National Drug Strategy. RESULTS: Relative risk of all-cause mortality in male drinkers compared with abstainers fell to 0.84 at 1.0-1.9 standard drinks per day, returned to 1.01 by 3.0-3.9 drinks, and increased to 1.37 at six or more drinks. In female drinkers the lowest relative risk (of 0.88) was at 0-0.9 drinks per day, and by 2.0-2.9 drinks the risk exceeded that in abstainers by 1.13; at six drinks the relative risk was 1.58. Based on NHMRC categories, the relative risks of mortality were 0.93 (0.93-0.94) in responsible drinkers, 1.24 (1.22-1.27) in hazardous drinkers and 1.37 (1.35-1.49) in harmful drinkers. Risk of cancers of the oropharynx, oesophagus, liver, larynx and female breast and of cirrhosis of the liver increased with increasing alcohol intake level. CONCLUSIONS: A pattern of usual alcohol intake consistent with the NHMRC recommendations will confer a mortality risk similar to or less than that observed in abstainers. The biologically effective dose of alcohol on mortality in women is approximately two standard drinks per day less than in men. Our validation is most reliable for drinkers aged 35 years or older.

Mortality and coronary heart disease in diabetes mellitus.

A clinic-based study of 1,063 patients with Type 2 diabetes recruited from 1973 to 1982 identified 533 deaths (attributed to coronary heart disease in 268 cases) by 31 December 1989. When compared to the general population of Australia the overall standardised mortality ratio was 1.42 (95 per cent confidence interval (CI) 1.26 to 1.58) for females and 1.19 (CI 1.03 to 1.35) for males. Cox regression analysis showed that having coronary heart disease or absence of foot pulses at the time of entrance to the study were the major independent risk factors for overall mortality after adjustment for initial age. Elevated cholesterol and blood pressure were found to be major independent risk factors for death from coronary heart disease.