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Background: Melanoma risk is related to sun exposure; we have investigated risk variation by tumour site and latitude., Methods: We performed a pooled analysis of 15 case-control studies (5700 melanoma cases and 7216 controls), correlating patterns of sun exposure, sunburn and solar keratoses (three studies) with melanoma risk. Pooled odds ratios (pORs) and 95% Bayesian confidence intervals (CIs) were estimated using Bayesian unconditional polytomous logistic random-coefficients models., Results: Recreational sun exposure was a risk factor for melanoma on the trunk (pOR = 1.7; 95% CI: 1.4-2.2) and limbs (pOR = 1.4; 95% CI: 1.1-1.7), but not head and neck (pOR = 1.1; 95% CI: 0.8-1.4), across latitudes. Occupational sun exposure was associated with risk of melanoma on the head and neck at low latitudes (pOR = 1.7; 95% CI: 1.0-3.0). Total sun exposure was associated with increased risk of melanoma on the limbs at low latitudes (pOR = 1.5; 95% CI: 1.0-2.2), but not at other body sites or other latitudes. The pORs for sunburn in childhood were 1.5 (95% CI: 1.3-1.7), 1.5 (95% CI: 1.3-1.7) and 1.4 (95% CI: 1.1-1.7) for melanoma on the trunk, limbs, and head and neck, respectively, showing little variation across latitudes. The presence of head and neck solar keratoses was associated with increased risk of melanoma on the head and neck (pOR = 4.0; 95% CI: 1.7-9.1) and limbs (pOR = 4.0; 95% CI: 1.9-8.4)., Conclusion: Melanoma risk at different body sites is associated with different amounts and patterns of sun exposure. Recreational sun exposure and sunburn are strong predictors of melanoma at all latitudes, whereas measures of occupational and total sun exposure appear to predict melanoma predominately at low latitudes.

Background: This study aimed to explore the meaning and potential use of women's self-reported difficulties in conceiving as a measure of infertility in epidemiological studies, and to compare women's stated reasons for infertility with information in their medical records., Methods: Data were available from a population-based case-control study of ovarian cancer involving 1638 women. The sensitivity and specificity of women's self-reported infertility were calculated against their estimated fertility status based on detailed reproductive histories. Self-reported reasons for infertility were compared with diagnoses documented in women's medical records., Results: The sensitivity of women's self-reported difficulty in conceiving was 66 and 69% respectively when compared with calendar-derived and self-reported times taken trying to conceive; its specificity was 95%. Forty-one (23%) of the 179 women for whom medical records were available had their self-reported fertility problem confirmed. Self-reported infertility causes could be compared with diagnoses in medical records for only 22 of these women., Conclusions: Self-reported difficulty conceiving is a useful measure of infertility for quantifying the burden of fertility problems experienced in the community. Validation of reasons for infertility is unlikely to be feasible through examination of medical records. Improved education of the public regarding the availability and success rates of infertility treatments is proposed.

The proposition that mucinous ovarian cancer has an etiology distinct from that of other histologic types has been evaluated using data from a population-based case-control study of epithelial ovarian cancer conducted in 1990--1993 among Australian women aged 18--79 years. The protective effects of parity and oral contraceptive use were greater in nonmucinous than in mucinous ovarian tumors. However, these differences appeared to be driven largely by the effect of ovulatory life, which was positively associated with nonmucinous tumors only. An association with family history of breast and/or ovarian cancer also appeared to be restricted to nonmucinous cancers. These results lend support to the hypothesis that mucinous and nonmucinous ovarian tumors develop via different causal mechanisms.

Melanocytic naevi on the face and neck of 110 Brisbane secondary school students aged 16-17 years were mapped according to specified regions to investigate the dose-response relationship between ultraviolet (UV) radiation and melanocytic naevi. Highest naevus density occurred in regions receiving a mean UV dose of 0.2-0.4 relative to the vertex while densities were low in minimally and maximally exposed regions. This pattern of naevus distribution was unaffected by sex or phenotypic features such as skin colour or degree of freckling. These findings suggest that there is a narrow dose range over which UV radiation can effectively promote the proliferation of melanocytes. A comparison of the regional distribution of naevi on the face and neck with that of solar keratoses appearing over 1 year on the heads of residents of a neighbouring town has shown them to differ significantly. This study may shed some light on the unknown, yet expectedly complex, relation of UV radiation to melanocytic naevi.

Objectives: We describe the attitude and views of general practitioners towards the menopause and hormone replacement therapy (HRT) in metropolitan Brisbane, Australia., Methods: A total of 216 general practitioners were nominated by a random sample of urband-welling women aged 45-54 years who formed the Brisbane Women's health study. A 20-30 minute face-to-face questionnaire with the general practitioners was administered and analysed by demographic characteristics., Results: There was a 93% response rate. Management of the menopause and HRT was routinely undertaken by general practitioners for their own patients. After deciding to initiate HRT, > 60% of general practitioners ordered five investigations or more. They may have confused the risk of thrombo-embolism from oestrogens used in the post-menopause with that for contraception. There were differences between male and female practitioners in some areas. Male general practitioners, in particular, reported more difficulty with tailoring and adjusting regimes., Conclusions: Specific areas for further education are explored to meet the educational needs of general practitioners.

Background: There has been a major decline in mortality from coronary heart disease (CHD) in Australia from about 1967 through to 1989, occurring across all age groups simultaneously. We have analysed data up until 1992 to examine for trends within age cohorts., Methods: Death registrations for acute myocardial infarction and CHD were used to construct male and female 5-year age- and cohort-specific mortality rates starting at 1900-1904 for cohorts and 25-29 years for age. Trends within age group and within cohort were compared across time., Results: Across all female and most male birth cohorts there was a decrease in CHD mortality across the time period. In the youngest male cohorts there was a significant flattening in the rate of decline in the most recent periods. Comparison of age-specific mortality across cohorts showed the mortality at any period to be lower in the most recent cohort., Conclusions: This analysis demonstrates a continuing decline in mortality from CHD among females of all ages in Australia although the rate of decline appears to have slowed or even ceased in younger males.

Much of the evidence that supports a relation between a positive family history of and increased risk for colorectal cancer is based on information obtained exclusively from patients. There have been few assessments of the accuracy of such data. The validity of self-reported family history of colorectal cancer was assessed in the course of a case-control study of colorectal adenomas conducted among patients aged 20-75 years who underwent colonoscopy in Brisbane, Australia between 1980 and 1985. Family histories reported by a subsample of 237 colonoscopy patients (74 cases and 163 controls) were compared with relatives' medical records and death certificates. Patients' reports of colorectal cancer in 90 relatives were confirmed for 70 (77.8%; 95% confidence interval (CI) 67.8-85.9). Among 124 reports by patients of relatives who had other abdominal cancer or bowel conditions, 114 (91.9%; 95% CI 85.7-96.1) were confirmed to be correct, while 10 (8.1%) were found to be colorectal cancer. Finally, 105 (99.1%; 95% CI 94.9-100.0) of a random sample of 106 completely negative reports by patients were confirmed to be correct. Overall, 77% of positive family histories (any positive relatives) were confirmed, and it was estimated that 98% of negative family histories (no positive relatives) were correct. Cases were slightly more accurate than controls in reporting both positive and negative histories among their relatives. By extrapolation of these results to the total sample of 1,244 patients in the larger case-control study, sensitivity of self-reported positive family history was estimated to be 0.87 among cases and 0.82 among controls, and specificity was estimated to be 0.97 in both groups.

To test the hypothesis that children living in subtropical and tropical environments have more naevi than those of similar ethnicity living in temperature countries, a comparative study of melanocytic naevi in 111 schoolchildren from Brisbane, Australia, and 222 from Glasgow, Scotland, was carried out. All children were aged 13-15 years, of European ancestry, and had spent most of their lives at latitudes of less than 30 degrees S (Australia) or greater than 30 degrees N (Scotland). Using an identical protocol, all naevi of 2 mm or more in diameter occurring on the right arm were counted by either a highly experienced research nurse in Brisbane, or a dermatologist in Glasgow. Hair and eye colour, and facial freckling, were assessed by the examiner, and axillary skin colour of children in both cities was measured using the same reflectance spectrophotometer. Children in Brisbane had significantly more naevi than those in Glasgow (P < 0.05), after adjusting for complexion variables. The difference in the geometric mean number of naevi on the arm was much greater among boys (7.7 vs. 4.4, in Brisbane and Glasgow, respectively) than among girls (7.3 vs. 6.7). This has parallels with the sex differences in melanoma at later ages in the two countries. Besides country of residence, freckles and innate skin colour were the most significant predictors of large numbers of naevi, whereas red hair had a significant protective effect. Overall, these data on prevalence of naevi in children from contrasting environments provide some evidence in support of the theory that naevus development is related to the level of sun exposure in childhood and adolescence.

Associations between various anthropometric indicators and breast cancer were investigated in a community-based case-control study conducted among 456 premenopausal women (135 cases) and 656 women who were at least 10 years past menopause (185 cases) in Brisbane, Australia, from 1981 to 1985. Among postmenopausal women, increased risk was associated with greater weight at age 25 years (p trend = 0.002) and with a heavier maximum weight (p trend = 0.003), but not with recent weight. Results were similar for relative weight (weight (kg)/height (m)1.5). Overall, weight gain was unrelated to the occurrence of breast cancer, although risks were elevated among postmenopausal women who weighed less at age 25 (< 54 kg) and subsequently experienced a large weight gain (> 13 kg). Among premenopausal women, there was little indication that body size or change in weight was related to breast cancer. These results suggest that both heaviness in early adulthood and a large maximum weight at any time are associated with elevated risks for postmenopausal breast cancer.

Routine data on mortality and hospital activity were used to estimate changes in coronary heart disease mortality, case fatality, and hospitalizations in the Australian state of Queensland over the decade 1971-1980. Acute myocardial infarction (International Classification of Diseases (ICD) 410) and other ischemic heart disease (ICD 411-414) were considered separately. For acute myocardial infarction, age-adjusted total mortality declined by about one fourth in both men and women; in-hospital mortality decreased somewhat more and deaths out of hospital correspondingly less. The age-adjusted case fatality ratio fell by the same amount (29%), in both sexes. Similar trends occurred at all ages. Admission rates decreased 11% in men and 18% in women. Similar patterns were evident for other ischemic heart disease except for admissions, which rose 23% among men and remained at the same level in women. These findings suggest that both declining incidence, particularly in the form of fewer deaths out of hospital, and improvements in care may have contributed to the general decline in coronary heart disease mortality in this community. Without direct measures of incidence or changing disease severity, the relative contributions of each factor cannot be examined.

The risk of hepatocellular carcinoma (HCC) and other internal malignancies was examined in patients with genetic hemochromatosis (GH) by following 208 patients from the time of diagnosis to June 1983 and by comparing the numbers of cancers they developed with expected values constructed from cancer registry incidence data by means of actuarial methods. In addition, cancers occurring in a comparison group of 148 subjects with other chronic nonalcoholic liver diseases (CLD) were determined. Among the GH group, 16 new cases of HCC occurred subsequent to the diagnosis of GH, together with 8 other malignancies. The 16 cases of HCC reflect a 200-fold excess risk, which from all indications represents the first quantitation of the risk of this tumor in GH. There appears to be no increased risk of other malignancies in this disease. Among the CLD group only 1 HCC and 1 other malignancy occurred.

A case-control study of breast cancer, diet, and lactational history was carried out in Brisbane, Australia, between 1981 and 1985. Cases were recruited from both the private and the public health care sectors. The breastfeeding histories of 459 cases and 1,091 controls selected from the electoral roll were analyzed. An odds ratio of 0.85 (95% confidence interval 0.55-1.30) for any lactation versus no lactation was observed, with no suggestion of a monotonic trend with increasing duration. This estimate was only slightly altered by multiple logistic regression analysis. A statistically significant nonlinear association was noted for breastfeeding of the first liveborn child (chi 2 = 14.8, df = 6; p less than 0.05), with a slightly elevated odds ratio for lactations of less than one month, a lowered odds ratio for lactations of one month to three months, and a weakly elevated odds ratio in women breastfeeding for more than nine months. Results for premenopausal women were very similar to those for postmenopausal women. Taken together with other recent studies, these results suggest that lactation may play a modest direct or indirect part in reducing the risk of breast cancer.

Plastic adherent and non-adherent mononuclear cells derived from synovial fluid were found to stimulate peripheral blood mononuclear cells of patients with rheumatoid arthritis (RA) in an autologous mixed lymphocyte reaction (AMLR). Stimulation produced by adherent cells was consistently greater than that produced by non-adherent mononuclear cells. CD11 enriched cells were not significant stimulators in the AMLR, however their presence was required for a significant reaction to occur. Limiting dilution studies revealed that the most plausible model involved two or more cells of the same type in each of the stimulator and responder populations for the AMLR to occur.