Beauty product-related exposures and childhood brain tumors in seven countries: results from the SEARCH International Brain Tumor Study

Data from 1218 cases of childhood brain tumors (CBT) diagnosed between 1976 and 1994 and 2223 matched controls from the general population were included in an analysis of maternal beauty product exposure and beauty-related employment in 9 centers in 7 countries. A 50% increased odds ratio (OR) [95% confidence interval (CI) = 1.0-2.1] for CBT was observed among children of mothers who were exposed via personal use of and/or possible ambient contact with beauty products during the 5 years preceding the index child's birth compared with children of mothers never exposed to beauty products during this time period. Overall maternal personal use of hair-coloring agents in the month before or during the pregnancy of the index child's birth was not associated with CBT (OR = 1.0, CI = 0.83-1.3) or with astroglial (OR = 1.1, CI = 0.85-1.4), PNET (OR = 1.0, CI = 0.71-1.5) and other glial subtypes (OR = 1.0, CI = 0.62-1.0). Similarly, no statistically increased ORs or discernable pattern of risk estimates were observed for period of use or for number of applications per year for maternal personal use of hair-coloring agents overall or by histologic type. Among children born on or after 1980, increased ORs for CBT were associated with maternal non-work-related exposure to any beauty products (OR = 2.6, CI = 1.2-5.9), hair-dyes (OR = 11, CI = 1.2-90), and hair sprays (OR = 3.4, CI = 1.0-11). No overall increased OR for CBT was observed among children of mothers employed in beauty-related jobs during the 5 years preceding the index child's birth compared with those who reported no beauty-related employment. In general, other specific beauty product-related exposures were not associated with increased ORs for CBT. Data from our study provide little evidence of an increased risk for CBT with mothers' exposures to beauty products.

Parental exposure to polycyclic aromatic hydrocarbons and the risk of childhood brain tumors: The SEARCH International Childhood Brain Tumor Study

Experimental evidence suggests that parental exposure to polycyclic aromatic hydrocarbons (PAH), which occurs primarily through tobacco smoke, occupational exposure, and air pollution, could increase the risk of cancer during childhood. Population-based case-control studies carried out in seven countries as part of the SEARCH Program compared data for 1,218 cases of childhood brain tumors and 2,223 controls (1976-1994). Parental occupational exposure to PAH during the 5-year period before birth was estimated with a job exposure matrix. Risk estimates were adjusted for child's age, sex, and study center. Paternal preconceptional occupational exposure to PAH was associated with increased risks of all childhood brain tumors (odds ratio (OR) = 1.3, 95% confidence interval: 1.1, 1.6) and astroglial tumors (OR = 1.4, 95% confidence interval: 1.1, 1.7). However, there was no trend of increasing risk with predicted level of exposure. Paternal smoking alone (OR = 1.4) was also associated with the risk of astroglial tumors in comparison with nonsmoking, non-occupationally-exposed fathers. Risks for paternal occupational exposure were higher, with (OR = 1.6) or without (OR = 1.7) smoking. Maternal occupational exposure to PAH before conception or during pregnancy was rare, and this exposure was not associated with any type of childhood brain tumor. This large study supports the hypothesis that paternal preconceptional exposure to PAH increases the risk of brain tumors in humans.

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Prevalence of urinary symptoms in urban Australian men aged 40-69

BACKGROUND

This study was devised to determine the prevalence of urinary symptoms among men living in the Australian cities of Melbourne, Sydney or Perth, and to identify factors associated with the presence of moderate-to-severe urinary symptoms.

METHODS

The study comprised a population-based sample of 1,216 men, aged 40-69 years, whose names were obtained through electoral rolls and who participated as controls in a case-control study of risk factors for prostate cancer. As part of a structured face-to-face interview, the men completed the International Prostate Symptom Score (IPSS). Men with moderate (IPSS = 8-19) or severe (IPSS > or = 20) urinary symptoms were compared with those with mild or no symptoms (IPSS < 8) using unconditional logistic regression.

RESULTS

The age-specific prevalence of moderate-to-severe urinary symptoms (IPSS > or = 8) in men aged 40-49, 50-59, 60-69 years was 16%, 23% and 28%, respectively. Compared with men with no or mild urinary symptoms (IPSS < 8), men with moderate-to-severe symptoms were more likely to report not currently living as married [odds ratio (OR) = 1.5; 95% confidence interval (CI) 1.1-2.0] and being circumcised (OR = 1.5; 95% Cl 1.2-2.0). The increased likelihood associated with drinking an average of > 60 g day(-1) of alcohol in the 2 years before interview was of marginal statistical significance (OR = 1.6; 1.0-2.6). There were no significant differences between men with IPSS > or = 8 and those with IPSS < 8 with respect to body mass index, education level, having had a vasectomy, or cigarette smoking.

CONCLUSION

Among Australian men, being circumcised, or not currently living as married, were associated with increased prevalence of urinary symptoms.

Parental occupations and childhood brain tumors: results of an international case-control study

OBJECTIVE

To evaluate the role of parental occupations in the etiology of childhood brain tumors (CBT).

METHODS

Population-based case-control studies were conducted concurrently in seven countries under the coordination of the International Agency for Research on Cancer, gathering 1,218 cases and 2,223 controls. We report here the findings related to parental occupations during the 5-year period before the child's birth. Risk estimates related to a number of paternal and maternal occupations were obtained by unconditional logistic regression adjusted for age, sex, year of birth, and center, for all types of CBT combined and for the subgroups of astroglial, primitive neuroectodermal tumors (PNET), and other glial tumors.

RESULTS

An increased risk in relation with agricultural work was seen for all CBT combined and for other glial tumors. Increased risks for all tumors and PNET were seen for paternal occupation as an electrician; the same pattern held for maternal occupation when children under 5 were selected. Paternal occupation as a driver or mechanic, and maternal work in an environment related to motor-vehicles were associated with an increased risk for all CBT and astroglial tumors. More case mothers compared to control mothers were employed in the textile industry.

CONCLUSION

Our study reinforces previous findings relative to the role of parental work in agriculture, electricity, or motor-vehicle related occupations and maternal work in the textile industry. It does not confirm previous associations with work environments including aerospace, the chemical industry, or the food industry, or with maternal occupation as a hairdresser, a nurse, or a sewing machinist, and paternal occupation as a welder.

Distribution of primary renal diseases leading to end-stage renal failure in the United States, Europe, and Australia/New Zealand: results from an international comparative study

This report notes the differences in the classification of the primary renal disease (PRD) used in different renal dialysis and transplant registries worldwide. The heterogeneity of coding systems complicates the comparative analysis of end-stage renal disease from different regions. Using data collected over two decades in the United States, Europe, and Australia/New Zealand, we present a method for reorganization of the classes of PRD that allows a straightforward comparison of retrospective data from these registries.

Cancer mortality in migrants from the British Isles and continental Europe to New South Wales, Australia, 1975-1995

Routinely collected data for New South Wales were used to analyse cancer mortality in migrants from the British Isles, southern Europe and eastern Europe according to duration of residence in Australia. A case-control approach compared deaths from cancer at one site with deaths from all other cancers, adjusting for age, sex and calendar period. Compared with the Australia-born, migrants had a significantly lower risk of dying from cancers of the mouth/pharynx and prostate (migrants from each region), colon/rectum (from the British Isles and southern Europe) and lung (female southern European migrants), evident from the time of migration and maintained for 30 years after migration. Whereas a deficit of deaths from colorectal cancer remained in migrants from southern Europe, a clear gradient of increasing risk with duration of stay in Australia was apparent. A similar trend was seen with respect to kidney cancer in southern European migrants. Persistent excess risks of death from stomach cancer were seen in all migrant groups, from lung cancer in British migrants and from liver cancer in southern and eastern European migrants. Although the risk of death from breast cancer increased significantly with duration in Australia in southern European migrants, the increase was not monotonic, as the relative risk in the first 10 years after migration was almost the same as that after more than 30 years. The pattern of risk for cancers of the prostate and mouth/pharynx suggests some protective role for inheritance or maintained cultural factors.

Observations on the effect of abolishing analgesic abuse and reducing smoking on cancers of the kidney and bladder in New South Wales, Australia, 1972-1995

OBJECTIVES

We have assessed the effect on the rates of cancers of the kidney and bladder of measures undertaken by the government in 1979-1983 to limit smoking and analgesic abuse in New South Wales (NSW). Sale of phenacetin-containing analgesics, previously available without restriction and regularly taken by 11-13% of women and 4-9% of men in NSW, was prohibited from 1979. The prevalence of current smokers among adult Australian men had fallen from 72% in 1945 to 43% in 1980 and to 28% in 1992. In women the corresponding figures were 26%, 31% and 24%.

METHODS

Incidence and mortality data from the New South Wales Central Cancer Registry for the period 1972 to 1995 were analyzed, by sex and age, for trends over time. Relative survival was calculated for cases diagnosed in the period 1980-94 and followed until the end of 1996.

RESULTS

Significant trends evident from these data were: throughout the period of review a rising incidence of, and to a lesser extent mortality from, renal parenchymal cancer for which relative survival has steadily improved; falling mortality from bladder cancer throughout the period of review, but more rapid after 1985; a reversal of the earlier increasing incidence of, and mortality from, cancer of the renal pelvis; and relative survival for bladder and renal pelvic cancers which was worse in women than men. Changes in registration practice in 1985 and 1993 introduced artifacts into the trends in incidence of bladder cancer.

CONCLUSIONS

Improvements in the trends of incidence and mortality of cancers of the renal pelvis and bladder in the mid-1980s are interpreted, in the light of registration and clinical practice, to indicate a beneficial effect of regulations which virtually abolished analgesic abuse and, less certainly, a contribution from measures restricting smoking, in New South Wales. However, renal parenchymal cancer continues to increase, although there has been some apparent benefit of earlier detection.

Cancer in patients on dialysis for end-stage renal disease: an international collaborative study

BACKGROUND

Previous studies have suggested that the frequency of cancer is higher in patients with end-stage renal disease (ESRD) than in the general population, but have not established whether this increase is confined to certain cancers or to certain categories of ESRD patients. The aim of this study was to examine the risk of cancer in a large cohort of patients treated by dialysis but not transplantation.

METHODS

We assembled a cohort of 831,804 patients who received dialysis during the period 1980-94 for ESRD in the USA, Europe, Australia, or New Zealand. We compared the observed frequency of cancer among these patients during 2,045,035 person-years of follow-up with the frequency of cancer in the respective background populations.

FINDINGS

During average follow-up of 2.5 years, 25,044 (3%) of 831,804 patients developed cancer compared with an expected number of 21,185 (standardised incidence ratio 1.18 [95% CI 1.17-1.20]). We observed a higher risk of cancer in patients younger than 35 years (3.68 [3.39-3.99]), and the risk gradually decreased with increasing age. High risks were observed for cancer of the kidney (3.60 [3.45-3.76]), bladder (1.50 [1.42-1.57]), and thyroid and other endocrine organs (2.28 [2.03-2.54]). Excess cancers appeared in several organs for which viruses have been suspected as causative agents, whereas cancers of the lung, colorectum, prostate, breast, and stomach were not consistently increased.

INTERPRETATION

The overall risk of cancer is increased in patients with ESRD, and the distribution of tumour types resembles the pattern seen after transplantation (although we have no data to make the comparison with skin cancer). The excess risk can largely be ascribed to effects of underlying renal or urinary-tract disease, or of loss of renal function, on the kidney and bladder, and to increased susceptibility to viral carcinogenesis. The relative risk, which is especially high in younger patients, gradually diminishes with age.

SEARCH international case-control study of childhood brain tumours: role of index pregnancy and birth, and mother's reproductive history

A series of co-ordinated population-based case-control studies of childhood brain tumours (CBT) was undertaken under the auspices of the Surveillance of Environmental Aspects Related to Cancer in Humans (SEARCH) programme of the International Agency for Research on Cancer (IARC) to evaluate, inter alia, the risk in relation to characteristics of the index pregnancy and birth, and maternal reproductive history. Subjects comprised 1218 cases aged 0-19 years and 2223 controls. Risk estimates were calculated by unconditional logistic regression, adjusted for age, sex, centre and mother's years of schooling, for all types of CBT combined as well as for four groups defined by histopathology (astrologlial tumours, primitive neuroectodermal tumours of the brain, 'other glial' tumours and 'other histological types') and for five age groups (0-1, 0-4, 5-9, 10-14, 15-19 years). Use of anaesthetic 'gas' was associated with an increased risk of CBT (OR = 1.5, 95% CI [1.1, 2.0]), apparent in children aged 0-4 years (OR = 2.4, 95% CI [1.4, 4.1]) and for astroglial tumours (OR = 1.6, 95% CI [1.1, 2.2]) with non-significantly increased relative risks for each of the other histological groups. However, not all centre-specific relative risks were elevated. No other aspect of the index pregnancy, delivery and early neonatal period or of the mother's previous reproductive history was associated with risk for CBT.

Breast cancer in New South Wales in 1972-1995: tumor size and the impact of mammographic screening

To examine the use of mammographic screening in women in New South Wales (NSW), we measured uptake of initial mammograms and estimated the proportions of breast cancers that were screen detected. To see if mammographic screening has been associated with reductions in advanced breast cancers and mortality from breast cancer, we analyzed trends in age-specific and age-standardized breast cancer incidence and mortality from 1972 to 1995 and tumor size in 1986, 1989, 1992 and April to September 1995. Between 1984 and the end of 1995, an estimated 72% of NSW women in their 50s and 67% in their 60s had had at least 1 mammogram and, in 1995, an estimated 39% of invasive breast cancers in women in these age groups were detected by mammography. Before 1989, breast cancer incidence increased only slightly (+1.3% annually) but then, from 1990 to 1995, increased more rapidly (+3.1% annually). Between 1986 and 1995, rates of small cancers (< 1 cm) increased steeply by 2.7 times in women 40-49 years of age and 5.6 times in women 50-69 years of age. The incidence of large breast cancers (3+ cm), after little apparent change to 1992, fell by 17% in women 40-49 years of age and 20% in those 50-69 years of age to 1995. Breast cancer mortality increased slightly between 1972 and 1989 (+0.5% annually) but then fell (-2.3% annually) from 1990 to 1995. We concluded that breast cancer rates had been influenced in expected directions by the introduction of mammographic screening in women resident in NSW. We expect that recent falls in incidence of larger breast cancers and breast cancer mortality will become steeper as screening coverage increases in the second half of the 1990s.

Breast cancer in Maori and non-Maori women

BACKGROUND

Breast cancer is more common in Maori than in non-Maori women under the age of 40 years and is equally common in older women, despite Maori being generally of lower socioeconomic status and having had a higher fertility rate than non-Maori.

METHODS

Data from a nationwide population-based case-control study of breast cancer in New Zealand women aged 25-54 years were used to compare the age-adjusted distribution of reproductive and other risk factors for breast cancer in self-identified Maori and non-Maori women from the control group. Separate analyses also were carried out for women aged 25-39 years and for those aged 40-54 years. The risk of breast cancer according to the proportion of Maori ancestry was estimated using multiple logistic regression simultaneously adjusting for several risk factors.

RESULTS

Significant differences were found between self-identified Maori and non-Maori women in the age-adjusted frequencies for education level, socioeconomic status, age at first full-term pregnancy, parity, and duration of breastfeeding; the profile in all instances suggesting a lower risk of breast cancer for Maori than for non-Maori. There were no significant differences with respect to age at menarche, surgery for benign breast disease or a family history of breast cancer. Significantly more Maori than non-Maori were in the highest quartile of recent body mass index. Women self-identified as Maori has an approximately twofold higher risk of breast cancer than non-Maori women.

CONCLUSIONS

Maori have high rates of breast cancer despite having a more favourable profile than non-Maori for most identified risk factors.

Cancer mortality in East and Southeast Asian migrants to New South Wales, Australia, 1975-1995

Routinely collected data for New South Wales were used to analyse cancer mortality in migrants born in East or Southeast Asia according to duration of residence in Australia. A case-control approach compared deaths from cancer at particular sites with deaths from all other cancers, adjusting for age, sex and calendar period. Compared with the Australian-born, these Asian migrants had a 30-fold higher risk of dying from nasopharyngeal cancer in the first 2 decades of residence, falling to ninefold after 30 years, and for deaths from liver cancer, a 12-fold risk in the first 2 decades, falling to threefold after 30 years. The initial lower risk from colorectal, breast or prostate cancers later converged towards the Australian-born level, the change being apparent in the third decade after migration. The relative risk of dying from lung cancer among these Asian migrants was above unity for each category of duration of stay for women, but at or below unity for men, with no trend in risk over time. An environmental or lifestyle influence for nasopharyngeal and liver cancers is suggested as well as for cancers of colon/rectum, breast and prostate.

A case-control study of melanomas of the soles and palms (Australia and Scotland)

OBJECTIVES

Because the factors that influence risk of acral melanomas on the soles and palms in White populations are unknown, we investigated these in a multi-center case-control study.

METHODS

Cases of melanoma of the feet and hands diagnosed from 1987-93 in persons aged over 18 years were ascertained in eastern Australia and western Scotland. There were 275 cases of melanoma on the soles and palms matched to 496 controls (selected from the electoral roll) in Australia, and 36 cases matched to 72 controls (nominated by general practitioners) in Scotland.

RESULTS

Acral melanoma was strongly associated with high total body nevus counts (adjusted relative risk [RR] = 6.3, 95% confidence interval [CI] = 2.5-15.6), and with nevi on the soles (RR = 7.5, CI = 3.0-18.6). There were also significant positive associations with a penetrative injury of the feet or hands (RR = 5.0, CI = 3.0-8.6) and with heavy exposure to agricultural chemicals (RR = 3.6, CI = 1.5-8.3). Sun-sensitive complexions, cumulative sun exposure and a past history of nonmelanoma skin cancer were also associated with increased risk of acral melanoma. Current cigarette smoking was inversely related to acral melanoma (RR = 0.6, CI = 0.4-0.9).

CONCLUSIONS

Melanomas of the soles and palms resemble other cutaneous melanomas in their association with sun exposure, but are distinguished from them by their strong positive associations with nevi on the soles, previous penetrative injury, and exposure to agricultural chemicals, and by their inverse association with smoking.

Carcinomas of the renal pelvis associated with smoking and phenacetin abuse: p53 mutations and polymorphism of carcinogen-metabolising enzymes

Phenacetin abuse and smoking are established risk factors for transitional cell carcinomas of the urinary tract. In the present study, we analysed exposure and the clinical course of patients who underwent nephrectomy for transitional cell carcinoma of the renal pelvis. PCR-SSCP of archival, paraffin-embedded histological sections followed by direct DNA sequencing revealed that 29 of 89 (33%) renal pelvic carcinomas contained a p53 mutation. Double mutations were found in 4 tumours and triple mutations in 1 tumour. The incidence of p53 mutations was significantly higher in tumours with grades 3 and 4 than in those with grades 1 and 2 and higher in invasive than in non-invasive tumours. Furthermore, patients with carcinomas carrying a p53 mutation showed poorer survival than those without mutation. The type of p53 mutation in renal pelvic carcinomas was similar to that reported for bladder cancer, G:C-->A:T transition mutations being most frequent (45%, 33% of these at CpG sites), followed by G:C-->T:A and G:C-->C:G transversions. The incidence and type of p53 mutation did not differ significantly in patients with a history of phenacetin abuse, smoking or neither of these habits. This was also true for G:C-->T:A transversions (17.5% of mutations), which are considered typical of smoking-induced carcinomas at other sites, e.g., lung, oral cavity and oesophagus. Our results indicate that the frequency and pattern of p53 mutations are similar in transitional cell carcinomas of the bladder and the renal pelvis and do not reflect exposure to phenacetin and/or smoking. The frequency of genetic polymorphism in genes coding for carcinogen-metabolising enzymes (CYP1A1, NAT1, GSTT1 and GSTM1) was also independent of exposure. Although the sample size of our study does not allow definite conclusions, these data are compatible with chronic tissue damage as a causative factor in the evolution of urothelial carcinomas rather than pointing to a direct mutagenic effect of phenacetin and tobacco-specific carcinogens.

Reproductive factors and breast cancer in New Zealand

A national population-based case-control study was used to assess the influence on breast cancer risk of reproductive factors and the possibility of an interaction with age at diagnosis. A total of 891 women aged 25 to 54 with a first diagnosis of breast cancer, and 1864 control subjects, randomly selected from the electoral rolls, were interviewed. There was a declining risk of breast cancer with increasing age at menarche (p = 0.06), the strongest effect being seen in women aged less than 40. Parous women had a 27% lower risk of breast cancer than nulliparous women, a reduced risk being evident in all but the youngest age group. A falling risk of breast cancer with rising parity was clear only in women diagnosed when aged at least 45 years. Breast cancer risk tended to fall amongst parous women with increasing duration of breastfeeding (p = 0.14); the association was most apparent in the youngest women, while those over 40 years at diagnosis showed no clear negative trend. There was no association of breast cancer risk with age at first full-term pregnancy, time since last full-term pregnancy, abortion (spontaneous or induced), abortion before first full-term pregnancy, or ability to conceive, and there was no trend in risk with age at natural menopause. Women in the highest category of body mass index at age 20 had the lowest risk of breast cancer in the age group studied. When each reproductive factor was formally tested for effect modification by age at diagnosis, the interaction term in logistic models approached statistical significance only for parity (p = 0.07).

Cancer epidemiology in migrant populations

Migrant studies have taken advantage of the wide geographical variation in cancer risk. Cancer rates in migrants, obtained from routinely collected incidence or mortality statistics, are compared with those in the host country and in the country of origin; the rate of change with time since migration (or age at migration) and in subsequent generations is assessed; and the results are interpreted in the light of differences in socio-economic status and the degree of cultural assimilation. Rapid changes in cancer risk following migration imply that life-style or environmental factors are of overriding importance in aetiology. The susceptibility of fair-skinned races to ultraviolet (UV)-associated skin cancers is an example of racial differences based on inherited factors, but the long-term excess or deficit of other cancers in migrants has not yet been attributed definitively to genetic rather than persisting life-style factors. Are there racial differences in metabolism, DNA repair mechanisms or altered expression of oncogenes or tumour suppressor genes? Several genetic polymorphisms affecting the metabolism of known occupational carcinogens or hormonal factors do vary by race. While classical epidemiology has shown that the environment predominates in determining cancer incidence, molecular epidemiology has identified several examples of genetically determined differences between races.

Family history and risk of breast cancer in New Zealand

A national population-based case-control study was used to assess the influence on breast cancer risk of a family history of the disease and the possibility of an interaction with reproductive risk factors. A total of 891 women aged 25-54 years with a first diagnosis of breast cancer and 1,864 control subjects randomly selected from the electoral rolls were interviewed. Age-adjusted relative risks (RR) of breast cancer were similar for mothers (RR = 2.3) and sisters (RR = 2.7) but somewhat higher for first-degree (RR = 2.6) than for second-degree (RR = 1.7) relatives. Cases reporting a first- or second-degree relative with breast cancer were no more likely to be diagnosed at an early age than those with no family history. With regard to the age at diagnosis of the relative, the RR was higher if breast cancer had been diagnosed before the age of 45 years than later; this was true for first-degree as well as for second-degree relatives. In women with no family history, the falling RRs with increasing age at menarche reflected the usual pattern, but no such trend was apparent in those reporting a mother or sister with breast cancer. For age at first full-term pregnancy, parity, breast-feeding, menopausal status, infertility, history of benign breast disease and body mass index, no evidence was seen of effect modification by a family history of breast cancer. Mothers of cases had about twice the cumulative rate of breast cancer as mothers of controls, a similar difference being seen between sisters of cases and sisters of controls.

Second primary cancers after cancers of the colon and rectum in New South Wales, Australia, 1972-1991

Data from the New South Wales Central Cancer Registry for the period 1972-1991 were examined to determine the risk of second primary cancers after an initial invasive cancer of the colon (ICD-9 153) or rectum (ICD-9 154). The expected numbers of cancers were obtained by assuming that subjects experienced the same cancer incidence as prevailed in the corresponding general population and by applying sex-, age-, and calendar-specific rates to the appropriate person-years at risk. The relative risk (RR) of a second primary cancer was taken to be the ratio of observed:expected numbers of second cancers. After colon cancer, there was an excess of cancers of the small intestine in both sexes (RRs of 4.5 and 4.4); prostate (RR = 1.4) and kidney (RR = 1.8) in men; and breast (RR = 1.3), body of uterus (RR = 1.9), ovary (RR = 2.8), and thyroid (RR = 2.7) in women. Lung cancer occurred less frequently in men than expected (RR = 0.7). After rectal cancer, men had increased risks of cancers of the colon (RR = 1.5) and prostate (RR = 1.3) and a reduced risk of pancreatic cancer (RR = 0.3). A reciprocal relationship of increased risk was seen between cancers of the proximal (but not the distal) colon and rectum. Shared luminal risk factors for proximal colon cancer and rectal cancer and three syndromes of hereditary predisposition to colon cancer seem to be the major contributors to second primary cancers in patients with an initial colon cancer. Sources of bias have been considered.

Trends in colorectal cancer incidence and mortality in New South Wales, 1973-1992

OBJECTIVE

To assess changes in incidence and mortality rates of colorectal cancer in different age groups in New South Wales (NSW) between 1973 and 1992.

DESIGN

Descriptive analysis of data on incidence and mortality from the population-based NSW Central Cancer Registry and on colorectal cancer diagnostic tests from the Health Insurance Commission.

MAIN OUTCOME MEASURES

Age-standardised incidence and mortality rates for colon and rectal cancer (defined by codes 153 and 154 in the International classification of diseases, 9th revision) by sex and age group (15-44, 45-59, 60-74 or > or = 75 years) and incidence by cancer spread at diagnosis; age-standardised rates for faecal occult blood tests, sigmoidoscopy and colonoscopy.

RESULTS

From 1973 to 1992, colorectal cancer incidence increased significantly in NSW by an average of 2.0% per year in males (95% confidence interval [CI], 1.8 to 2.3) and 0.9% in females (95% CI, 0.7 to 1.1). Mortality rates remained nearly constant in males, but fell significantly in females by an average of -1.0% per year (95% CI, -1.3 to -0.7). In the youngest age group (15-44 years) both incidence and mortality rates fell significantly, while rates were stable or rose in older age groups, except for a significant fall in mortality in women aged > or = 75 years. Use of colonoscopy (an early detection method) increased, but a corresponding shift to detection of earlier-stage cancers was not seen.

CONCLUSIONS

A reduction in risk factors and better treatment leading to longer survival may have contributed to the falls in incidence in younger people and in mortality in females.

Differences in patterns of care of prostate cancer, New South Wales, 1991

BACKGROUND

In this time of uncertainty about the benefits of earlier diagnosis for prostate cancer and the optimal choice of treatment in various clinical scenarios, we addressed the hypothesis that two groups in the population, namely country dwellers and migrants from non-English-speaking countries, were less likely to be offered new methods of diagnosis and treatment for prostate cancer.

METHODS

Incident cases of prostate cancer in 1991 were identified through the population-based New South Wales Central Cancer Registry. For 73% of eligible cases information relating to diagnosis, staging and treatment was abstracted onto a checklist from clinical records in urologists' consulting rooms and in public hospitals.

RESULTS

Transrectal ultrasound and prostatic biopsy were used for diagnosis significantly more often in urban than in rural cases while the reverse was true for transurethral resection of the prostate. Intravenous pyelography, ultrasound (other than transrectal) and bone scans were performed for staging more frequently in urban than rural cases. Rural cases were more likely to be treated with anti-androgens than urban cases and less likely to be given luteinizing-hormone releasing hormone (LH-RH) agonists. The pattern of use of various diagnostic and staging procedures for 1991 rural cases resembled that for urban men diagnosed with prostate cancer in 1986 rather than that for 1991 urban cases.

CONCLUSIONS

At least in part, these urban-rural differences could be explained by the fact that some patients in the country would have been treated by general surgeons rather than urologists. The patterns of care for non-English-speaking migrants resembled those for the Australian-born and for English-speaking migrants.

Occurrence of melanomas on the upper and lower limbs in eastern Australia

In view of the changing trends in the incidence of melanoma at different body sites and in particular on the limbs, the detailed distributions of over 10,000 invasive melanomas diagnosed on the upper and lower limbs in residents of mainland eastern Australia between 1987 and 1993 were examined. Cancer notifications and histopathology reports from the cancer registries of Queensland, New South Wales and Victoria were searched manually, and subsites when specified were recorded as shoulder, upper arm, forearm, elbow, wrist or hand, and thigh, leg, knee, ankle or foot. On the upper limbs relative tumour densities were highest on the shoulder, approximately equal on the upper arm and forearm and least on the hand in both men and women; on the lower limbs melanomas occurred more than twice as often on the leg than on the thigh or the foot, taking account of surface area. There was a clear inverse gradient of incidence of melanoma with latitude in the three eastern Australian states studied, but little difference between the states or between sexes in distribution of histological type: the majority specified being specified as superficial spreading melanomas. In contrast to predictions based on apparent frequency of sun exposure at subsites on the upper limbs, the relative concentration of melanomas on the shoulder suggests that wearing sleeveless garments outdoors in the sun should be avoided whenever possible. Also, the similar densities of leg and forearm melanomas seems inconsistent with the relative degree of exposure of each and further suggests that women's adoption of ankle-length skirts or trousers, in preference to knee-length skirts would be a worthwhile modern control measure.

International renal-cell-cancer study. VI. the role of medical and family history

A number of medical conditions have been linked with renal-cell cancer, although the evidence is not consistent in every case. In a large international case-control study of renal-cell cancer, we examined, among other hypotheses, associations with a personal history of certain medical conditions and a family history of cancer of the kidney or thyroid. Relative risks (RR), adjusted for the effects of age, gender, body-mass index, tobacco smoking and study centre, were significantly increased by a history of kidney stones or thyroid or kidney disease. The RR were not altered by additional adjustment for hypertension, or when diagnoses were restricted to those made at least 5 or 10 years before 1987 (the usual "cut-off" date). The link with kidney injury is particularly likely to be affected by recall bias. Increased RR of borderline significance were found for kidney infection (RR, 1.2) and diabetes (RR, 1.4). Having one first-degree relative with kidney cancer was associated with a significantly increased risk of renal-cell cancer (RR, 1.6; 95% Cl, 1.1-2.4). Seven cases reported 2 first-degree relatives with kidney cancer. No controls had first-degree relatives with kidney cancer. None of our participants reported having von Hippel-Lindau disease. The data suggests that a few conditions of the kidney are strongly associated with renal-cell cancer and that heredity plays a role in a small proportion of cases.

International renal-cell-cancer study. VI. the role of medical and family history

A number of medical conditions have been linked with renal-cell cancer, although the evidence is not consistent in every case. In a large international case-control study of renal-cell cancer, we examined, among other hypotheses, associations with a personal history of certain medical conditions and a family history of cancer of the kidney or thyroid. Relative risks (RR), adjusted for the effects of age, gender, body-mass index, tobacco smoking and study centre, were significantly increased by a history of kidney stones or thyroid or kidney disease. The RR were not altered by additional adjustment for hypertension, or when diagnoses were restricted to those made at least 5 or 10 years before 1987 (the usual "cut-off" date). The link with kidney injury is particularly likely to be affected by recall bias. Increased RR of borderline significance were found for kidney infection (RR, 1.2) and diabetes (RR, 1.4). Having one first-degree relative with kidney cancer was associated with a significantly increased risk of renal-cell cancer (RR, 1.6; 95% Cl, 1.1-2.4). Seven cases reported 2 first-degree relatives with kidney cancer. No controls had first-degree relatives with kidney cancer. None of our participants reported having von Hippel-Lindau disease. The data suggests that a few conditions of the kidney are strongly associated with renal-cell cancer and that heredity plays a role in a small proportion of cases.

Second primary cancers following cancers of the kidney and prostate in New South Wales (Australia), 1972-91

Data from the New South Wales (NSW) (Australia) Central Cancer Registry for the period 1972-91 were examined to determine the risk of second primary cancers following an initial invasive cancer of the renal parenchyma (ICD-9 code 189.0), renal pelvis (code 189.1), or prostate (code 185). Eligible cases were restricted to those who had survived for at least two months after diagnosis of the first primary cancer. Expected numbers of cancers were obtained by assuming that subjects experienced the same cancer incidence as prevailed in the corresponding general population and applying gender-, age-, and calendar-specific rates to the appropriate person-years at risk. The relative risk (RR) of a second primary cancer was taken to be the ratio of observed to expected numbers of second cancers. Following prostatic cancer, there was an overall deficit of cancers at all sites combined (RR = 0.79, 95 percent confidence interval [CI] = 0.75-0.84), and no site had a significantly raised RR. Taking this into consideration, there appeared to be a reciprocal relationship of increased risk of prostatic cancer (RR = 1.7, CI = 1.2-2.3) following an initial cancer of the renal parenchyma and of renal parenchymal cancer (RR = 1.2, CI = 0.8-1.7) after cancer of the prostate. An increased risk of bladder cancer occurred following renal parenchymal (RR = 3.4, CI = 1.1-8.0, for women only) as well as after renal pelvic cancer (men: RR = 8.7, CI = 5.4-13; women: RR = 39, CI = 26-56). A tobacco-related pattern of excess risk was seen after renal pelvic cancer but not after cancer of the renal parenchyma. These data illustrate that an excess of second primary cancers may reflect shared etiologic factors or increased medical surveillance.

Activated clotting time differential is a superior method of monitoring anticoagulation following coronary angioplasty

The standard high-range activated clotting time (sHR ACT) is used to monitor anticoagulation postangioplasty (PTCA), but may be unreliable. We assessed the accuracy of a new method we termed the ACT differential (ACT Diff), obtained by measuring the difference between an sHR ACT and a heparinase ACT from the same sample. Heparinase removes heparin from its sample and provides a current heparin-free baseline. For phase 1 of the study, the sHR ACT, ACT Diff, and laboratory APTT were measured in 250 samples from 75 PTCA patients. In 125 samples with an APTT prolonged but within measurement range, linear regression against the APTT was performed. The correlation coefficient was 0.74 for the ACT Diff and 0.24 for the sHR ACT. An ACT Diff of 15-25 sec was found to equal an APTT of 2.5-3.5 x control. In 50 samples with a normal activated partial thromboplastin time (APT), there was good differentiation by the ACT Diff of results from those adequately heparinized, with a value of 0.9 +/- 4.4 sec. The sHR ACT was 114 +/- 15.5 sec, and could not reliably distinguish between anticoagulated and nonanticoagulated samples. In 75 samples obtained with a high APTT (above measurement range), the ACT Diff was > 30 sec in 95% of samples, and again this allowed differentiation from therapeutic samples. The equivalent sHR ACT was 148 sec, and could not reliably distinguish between anticoagulated and overanticoagulated samples as the ACT Diff could. In phase 2, to examine the clinical usefulness of the ACT Diff, 286 patients were managed post-PTCA by starting heparin when ACT Diff fell to < 50 sec, maintaining ACT Diff at 15-25 sec during heparin infusions, and following cessation of heparin, by removing sheaths when the ACT Diff was < 7 sec. These patients were compared to a control group of 250 patients. Major bleeding (5% vs. 0.5%, P < 0.005) and minor bleeding (30% vs. 13%, P < 0.001) were significantly reduced in the group managed using the ACT Diff. The reduction in bleeding was thought to be due to the rapid availability of reliable results. Abrupt closure was low in both groups (0% with ACT Diff vs. 0.8%). No other thrombotic events occurred. Following phases 1 and 2, the ACT Diff replaced the APTT in all PTCA patients at this institution. In the 18 mo from July 1993, 1,104 patients were managed this way. Incidence of major bleeding (0.2%), transfusion requirement (0.1%), false anneurysm (0.6%), and abrupt closure during heparin infusion (0.1%) remained low. In conclusion, the ACT Diff is more accurate than an sHR ACT, and its clinical use in PTCA patients is associated with a very low incidence of complications from anticoagulation. Its routine use should be considered by units unable to obtain rapid APTT results.

International renal cell cancer study. VII. Role of diet

We investigated the role of diet in the etiology of renal cell cancer (RCC) in a multi-center, population-based case-control study conducted in Australia, Denmark, Sweden and the United States, using a shared protocol. A total of 1,185 incident histopathologically confirmed cases (698 men, 487 women) and 1,526 controls (915 men, 611 women) frequency-matched to cases by sex and age were included in the analyses. The association between RCC and diet was estimated by relative risks (RR) and 95% confidence intervals (CI) adjusted for age, sex, study center, body mass index and smoking. A statistically significant positive association was observed for total energy intake (RR = 1.7, 95% CI = 1.4-2.2 for the highest vs. lowest quartile, p value for trend < 0.00001), while the hypothesis that protein and fat are risk factors independent of energy was not supported. Fried meats were associated with increased RCC risk, while vegetables and fruits were protective, with the strongest effect observed for the highest quartile of consumption of orange/dark green vegetables but not vitamin C or beta carotene. Increased risk was associated with low intake (lowest decile) of vitamin E and magnesium. We observed an apparent protective effect of alcohol confined to women and probably due to chance. Our findings indicate an important role of nutrition in the development of RCC. The apparent positive association of energy intake with risk of RCC needs further investigation in a prospective cohort study to exclude the possible impact of differences in recall between cases and controls.

Multiple primary melanomas: an analysis of cancer registry data from Victoria and New South Wales

All primary invasive cutaneous malignant melanomas (CMM) diagnosed in Victoria and New South Wales from 1985 to 1989 were obtained from the population-based cancer registries. Altogether 14,590 people with first CMMs were followed for at least 2 years, during which time 496 multiple primary CMMs were identified. Of the study population, 3.4% developed a second primary CMM and 0.3% developed three or more. It was estimated that 4.5% of people would develop a second CMM within 5 years of the first and that the risk was higher in males, particularly in men aged over 70 years. With regard to metachronous primaries, only age and thickness of the first primary were significant predictors of the thickness of the second: older people tended to have thicker CMMs and second CMMs were generally thinner than the first. Body site concordance was higher than expected by chance, particularly for synchronous diagnoses. The high degree of site concordance of metachronous primaries lent support to the hypothesis that skin adjacent to the first CMM might have undergone a 'field effect', rendering it at increased susceptibility to malignancy.

Changes in cancer incidence and mortality in New South Wales

OBJECTIVE

To assess changes in cancer incidence and mortality in New South Wales (NSW) between 1973-1977 and 1988-1992.

DESIGN

Descriptive analysis of statutory cancer notifications to the NSW Central Cancer Registry.

OUTCOME MEASURES

Age-standardised incidence and mortality rates calculated with the "world" standard population.

RESULTS

Overall cancer incidence rose markedly, from 251 to 318 per 100,000 in men and from 202 to 241 per 100,000 in women. The rise was greatest in the 60-and-over age group. Cancer mortality fell marginally in men (from 166 to 162 per 100,000) and did not change in women (100 per 100,000 in both periods). It fell in the under-60 age group, and remained stable or rose in older people. Prostate and breast cancers and melanoma of the skin accounted for about half the increase in incidence. Both incidence and mortality increased significantly (P < 0.01) for melanoma and non-Hodgkin's lymphomas in men and lung cancer in women, and fell substantially for stomach cancer in both sexes, lung cancer in men and cervical cancer in women. Despite increasing incidence, mortality, also fell for testicular cancer in men and rectal cancer in women and for leukaemias in children.

CONCLUSIONS

The major factor causing the increased incidence of overall cancer was earlier detection. Altered exposure to risk factors could be identified for only a minority of the changes.

Risk factors and preventive strategies for breast cancer

Several risk factors for breast cancer are readily identifiable, but most are not preventable. Hence the importance of screening, as early diagnosis and treatment offer the best hope of saving lives.

International renal-cell cancer study. VIII. Role of diuretics, other anti-hypertensive medications and hypertension

Risk of renal-cell cancer in relation to use of diuretics, other anti-hypertensive medications and hypertension was assessed in a multi-center, population-based, case-control study conducted in Australia, Denmark, Germany, Sweden and the United States, using a shared protocol and questionnaire. A total of 1,732 histologically confirmed cases and 2,309 controls, frequency-matched to cases by age and sex, were interviewed. The association between renal-cell cancer and the drugs was estimated by relative risks (RRs) and 95% confidence intervals (CIs). Risks were increased among users of diuretics and other anti-hypertensive medications. After adjustment for hypertension, risk for diuretics was reduced to unity, except among long-term (15+ years) users. Risk for use of non-diuretic anti-hypertensive drugs remained significantly elevated and increased further with duration of use. Overall risk was not enhanced when both classes of medications were used. Excess risk was not restricted to any specific type of diuretic or anti-hypertensive drug and no trend was observed with estimated lifetime consumption of any particular type of product. The RR for hypertension after adjustment for diuretics and other anti-hypertensive medications was 1.4 (95% CI = 1.2-1.7), although among non-users of any anti-hypertensive medications, there was little excess risk associated with a history of hypertension. Exclusion of drug use that first occurred within 5 years of cancer diagnosis or interview did not alter the associations. Our findings suggest small effects on renal-cell cancer risk associated with hypertension and use of diuretics and other anti-hypertensive medications. However, because of potential misclassifications of these highly correlated variables, it is difficult to distinguish the effect of treatment from its indication, hypertension.

Adequacy of histopathology reports for breast cancer in New South Wales

To assess the adequacy of diagnostic histopathology reports for breast cancer in New South Wales (NSW) and the Australian Capital Territory (ACT), a cross-sectional survey of diagnostic histopathology reports was carried out on a random sample (n = 1000) of NSW and ACT women diagnosed with breast cancer in 1992 and notified to the NSW Central Cancer Registry. A single pathologist with expertise in breast cancer reviewed the reports, from laboratories in public and private sectors, against a checklist enumerating basic features considered useful for decision making by surgeons and/or medical and radiation oncologists. While information was provided by almost all reports on histological classification (94%), size of tumor (93%) and involvement of lymph nodes (99.8%), this was not so for tumor resection/biopsy margin (77%), histological grade (69%), nuclear grade (23%), mitotic rate (11%) and the presence or absence of lymphatic (34%) or vascular (24%) invasion. Pathologists from teaching hospitals and those who reported on more than 10 cases in the sample were more likely to provide relevant information. Many diagnostic histopathology reports for breast cancer did not fulfil the requirements for a satisfactory report, established prognostic and predictive features frequently being omitted. The uniform use by pathologists of a carefully designed checklist could ensure that standard information is provided for every breast cancer, thereby facilitating choice of therapy for all patients.

Second cancers occurring after cancers of the mouth and pharynx: data from three population-based registries in Australia, Scotland and Slovenia

Data over at least 20 years from three large population-based registries in Europe and Australasia have been used to assess the risk of second primary tumours occurring after a cancer of the mouth or pharynx. These patients have previously been shown in clinical series to be at a particularly high risk of subsequent tumours, while data from cancer registries have shown conflicting results on the magnitude of the risk. In this study, patients were found to have between a 2-fold (Scotland and New South Wales) and 4-fold (Slovenia) increase in risk of a subsequent tumour over that in the population, although the actual risk in each centre was similar (between 2.8 and 3.1 per 100 person years). The risk remained for 10 years after diagnosis of the original tumour and was primarily in the upper aerodigestive tract. The most elevated risks (approximately 10-fold) were for tumours in the oral cavity and oesophagus. These data provide higher estimates of risk than previously reported from European cancer registries for second primary tumours and emphasize the need for close follow-up of patients who may represent an appropriate population in which to assess possible new chemopreventive agents.

Breast cancer in NSW women: a shift in tumour size

OBJECTIVE

To determine whether there has been an increase in the proportion of small (< 1 cm in size) and localised breast cancers in women aged 50-69 (the group actively recruited to mammographic screening) compared with women aged 40-49.

DESIGN

Cases of invasive breast cancer in women aged 40-69 notified to the NSW Central Cancer Registry in 1986, 1989 and 1992 were included. Tumour sizes were determined from histopathology reports.

RESULTS

A higher percentage of breast cancers were under 1 cm in size in 1992 (10%) than in 1986 and 1989 (7%). The increase in the percentage of small breast cancers was statistically significant in women aged 50-69 (chi 2 for linear trend, 7.9; P = 0.005) but not in those aged 40-49 (chi 2 for linear trend, 2.5; P = 0.12). Slightly more than half the breast cancers (53%) in 1992 were localised to the breast, representing an increase from 49% in both 1986 and 1989. This increase was also statistically significant in women aged 50-69 (chi 2 for linear trend, 3.9; P = 0.05) but not in those aged 40-49 (chi 2 for linear trend, 1.4; P = 0.24).

CONCLUSIONS

Breast cancers in 1986, 1989 and 1992 showed a moderately strong shift to smaller tumours and localised disease in women aged 50-69. As women of this age group were targeted by mammographic screening, the widespread availability of mammography may explain this shift.

International renal-cell cancer study. IV. Occupation

The relationship between renal-cell cancer (RCC) and occupation was investigated in an international multicenter population-based case-control study. Study centers in Australia, Denmark, Germany, Sweden and the United States interviewed 1732 incident RCC cases and 2309 controls. Significant associations were found with employment in the blast-furnace or the coke-oven industry [relative risk (RR), 1.7; 95% confidence interval (CI), 1.1-2.7], the iron and steel industry (RR, 1.6; 95% CI, 1.2-2.2) and exposure to asbestos (RR, 1.4; 95% CI, 1.1-1.8), cadmium (RR, 2.0; 95% CI, 1.0-3.9), dry-cleaning solvents (RR, 1.4; 95% CI, 1.1-1.7), gasoline (RR, 1.6; 95% CI, 1.2-2.0) and other petroleum products (RR, 1.6; 95% CI, 1.3-2.1). Asbestos, petroleum products and dry-cleaning solvents appear to merit further investigation, in view of the relationship between risk and duration of employment or exposure and after adjustment for confounding. There was a negative association between RCC and education, but it was not consistent across all centers. Overall, the results of our multicenter case-control study suggest that occupation may be more important in the etiology of RCC than indicated by earlier studies.

International renal-cell cancer study. V. Reproductive factors, gynecologic operations and exogenous hormones

The relationships between reproductive factors, exogenous hormones and renal-cell cancer were examined in an international, multicenter, population-based, case-control study undertaken in 1989-1991. Data from 5 centers situated in Australia, Denmark, Germany, Sweden and the United States included for analysis 608 women with renal-cell cancer and 766 female controls. A significant trend in risk (p = 0.002) was associated with number of births, with an 80% excess risk for 6 or more births [RR = 1.8, 95% confidence interval (CI) = 1.1 to 2.9] compared with one birth. A decreasing risk was seen for increasing age at first birth, although this was confounded by body-mass index and number of births. A suggestive reduction of risk was also seen for increasing age at menarche. Age at menopause was unrelated to risk of renal-cell cancer. An increased risk was observed for women having had both a hysterectomy and an oophorectomy. Use of oral contraceptives in non-smoking women reduced the risk of renal-cell cancer (RR = 0.5, 95% CI = 0.4 to 0.8); this reduction increased with longer duration of use. No association was observed for estrogen replacement therapy. Our results indicate that certain hormonal and reproductive variables may be related to risk of renal-cell cancer and deserve further investigation, both epidemiologically and experimentally.

Cancer incidence in Asian migrants to New South Wales, Australia

Cancer incidence during 1972-90 in Asian migrants to New South Wales, Australia, is described. Overall cancer incidence was lower than in the Australia born in most migrant groups, and this reached significance in migrants born in China/Taiwan, the Philippines, Vietnam and India/Sri Lanka, and in male migrants born in Indonesia. For the majority of cancers, rates were more similar to those in the Australia born than to those in the countries of birth. For cancers of the breast, colorectum and prostate, rates were relatively low in the countries of birth, but migrants generally exhibited rates nearer those of the Australia born. For cancers of the liver and cervix and, in India/Sri Lanka-born migrants, of the oral cavity, incidence was relatively high in the countries of birth but tended to be lower, nearer Australia-born rates, in the migrants. For these cancers, environmental factors related to the migrant's adopted country, and migrant selection, appeared to have a major effect on the risk of cancer. For certain other cancers, incidence was more similar to that in the countries of birth. Nasopharyngeal cancer, and lung cancer in females, had high rates in both the countries of birth and in migrants to Australia. Nasopharyngeal cancer rates were highest in China/Taiwan and Hong Kong-born migrants, and were also significantly high in migrants from Malaysia/Singapore, Vietnam and the Philippines. Rates of lung cancer were significantly high in women born in China/Taiwan, and the excess was greater for adenocarcinoma than for squamous cell carcinoma. Melanoma had low rates in both the migrants and in the countries of birth. For these cancers, it was probable that genetic factors, or environmental factors acting prior to migration, were important in causation.

Incidence of cancer among New South Wales adolescents: which classification scheme describes adolescent cancers better?

This report has the dual purpose of describing patterns of cancer incidence among adolescents in New South Wales (NSW), Australia, and comparing adult and childhood cancer classification schemes. All cases of cancer incident between 1972 and 1991 in NSW residents aged 10-19 years were obtained from the population-based NSW Central Cancer Registry and coded according to Birch and Marsden (1987) in addition to routine coding by the Ninth Revision of the International Classification of Diseases. The average incidence rate for all cancers combined was 158 and 140 per million in males and females respectively. The Birch and Marsden category of "carcinomas and other epithelial neoplasms" comprised 22% of all cancers in male adolescents and 37% in females. Melanoma alone accounted for 16% of all cancers in males and 26% in females. Rates of leukaemias and central nervous system tumours were similar in the age groups 10-14 years and 15-19 years. By contrast, lymphomas, bone tumours (males only), soft tissue (males only), "germ-cell, trophoblastic and other gonadal tumours" and "carcinomas and other epithelial neoplasms" were more common in the older age group. The Birch and Marsden classification with its emphasis on morphology provided a clearer picture of some types of cancer which occurred frequently among teenagers. Cancers common in adults did occur in older adolescents but were less well described by the childhood scheme. Cancers of colon and lung were often of unusual histological type compared to adult tumours. It would appear appropriate to use the childhood classification scheme to describe cancer incidence in adolescent age groups, perhaps with minor modification.

International renal-cell cancer study. II. Analgesics

There has been concern about the role of analgesics in the development of renal-cell cancer, although a few studies have reported moderately elevated risks with regular or long-term use. In a large international case-control study of renal-cell cancer we examined, among other hypotheses, the effect of phenacetin-containing and of other types of analgesics: paracetamol (acetaminophen), salicylates (mainly aspirin) and pyrazolones (e.g., antipyrine or phenazone). Relative risks, adjusted for the effects of age, sex, body-mass index, tobacco smoking and study centre, were not significantly increased with intake of phenacetin, either when lifetime consumption was categorized at the level of > or = 0.1 kg or when subjects were subdivided further by amount. Nor were paracetamol, salicylates or pyrazolones linked with renal-cell cancer. No consistently increasing risks with consumption level was found. The lack of association was not altered by restricting analgesic use to that which occurred 5 or 10 years before the defined "cut-off" date or when analysis was restricted to exclusive users of a particular type of analgesic. Neither was the risk influenced by the rate of consumption or whether the consumption had occurred at a young age. Our study provides clear evidence that aspirin is unrelated to renal-cell cancer risk, and our findings do not support the hypothesis that analgesics containing phenacetin or paracetamol increase the risk, although the number of "regular" users and the amount of these types of analgesic consumed were too small to confidently rule out a minor carcinogenic effect of phenacetin and paracetamol.

International renal-cell cancer study. III. Role of weight, height, physical activity, and use of amphetamines

Although numerous studies have identified obesity or high relative weight as a risk factor for renal-cell cancer in women, the degree to which this effect is present in men remains unclear. A multicenter population-based case-control study concerning incident cases of histologically verified renal-cell cancer (n = 1,732) and age- and sex-matched controls (n = 2,309) was conducted in Australia, Denmark, Germany (2 centers), Sweden and the United States. Relative weight was estimated by the body mass index, and the association between this factor and other factors, such as height, physical activity and use of amphetamines, was measured by the relative risk estimated in logistic regression models. Body mass index was found to be a risk factor among women and, to a lesser extent, among men. A 3-fold increased risk (RR = 3.6, 95% CI = 2.3-5.7) was observed for women with a relative weight in the top 5% compared with those in the lowest quartile. Rate of weight change (estimated as weight change per annum in kilograms) appeared to be an independent risk factor among women but not among men. Physical activity and height were unrelated to risk of renal-cell cancer regardless of level of BMI, while use of amphetamines was associated with an increased risk among men, although no dose or duration effect was seen. Our findings verify the link between high relative weight and risk of renal-cell cancer, particularly among women. The mechanism that underlies this association is, however, still unclear, although the rate of weight change may play a role.

International renal-cell cancer study. I. Tobacco use

The relationship between renal-cell cancer (RCC) and tobacco use was investigated in an international, multicenter, population-based case-control study. Coordinated studies were conducted in Australia, Denmark, Germany, Sweden and the United States using a shared protocol and questionnaire. A total of 1,732 cases (1,050 men, 682 women) and 2,309 controls (1,429 men, 880 women) were interviewed for the study. No association was observed between risk and use of cigars, pipes or smokeless tobacco. A statistically significant association was observed for cigarette smoking, with current smokers having a 40% increase in risk [relative risk (RR) = 1.4, 95% confidence interval (CI) 1.2-1.7]. Risk increased with intensity (number of cigarettes) and duration (years smoked). Among current smokers the RR for pack-years rose from 1.1 (95% CI 0.8-1.5) for < 15.9 pack years to 2.0 (95% CI 1.6-2.7) for > 42 pack years (p for trend < 0.001). Long-term quitters (> 15 years) experienced a reduction in risk of about 15-25% relative to current smokers. Those who started smoking late (> 24 years of age) had about two-thirds the risk of those who started young (< or = 12 years of age). Overall, the findings of this pooled analysis confirm that cigarette smoking is a causal factor in the etiology of RCC.

Modifying fluoroscopic views reduces operator radiation exposure during coronary angioplasty

OBJECTIVES

This three-part study examined the feasibility of reducing operator radiation exposure during coronary angioplasty.

BACKGROUND

As case loads and complexity increase, some cardiologists are receiving increasing radiation scatter doses. Techniques to reduce this are therefore becoming more important.

METHODS

First, the determinants of the operator dose were assessed by measuring the differences in scatter dose with different camera views. The relative contribution of fluoroscopy as opposed to cine was then quantified. Finally, operators were provided with these data, and subsequent changes in technique were evaluated.

RESULTS

Left anterior oblique views resulted in 2.6 to 6.1 times the operator dose of equivalently angled right anterior oblique views. Increasing steepness of the left anterior oblique view also resulted in a progressive increase in operator dose, with left anterior oblique 90 degrees causing eight times the dose of left anterior oblique 30 degrees and three times that of left anterior oblique 60 degrees. In the 45 coronary angioplasty cases prospectively analyzed, fluoroscopy was found to be a greater source of total radiation than cine by a 6.3:1 ratio (range 1.1 to 15.8). Once operators were made aware of the importance of left anterior oblique fluoroscopy, there was a marked reduction in its use. When this was not feasible, there was a reduction in the steepness of the angulation. Left anterior oblique fluoroscopy during angioplasty of the left anterior descending and circumflex coronary arteries was reduced from 40% of total screening time to approximately 5%, and left anterior oblique angulation for fluoroscopy during angioplasty of the right coronary artery decreased from 43.6 degrees (+/- 9.1 degrees) to 29.4 degrees (+/- 2.2 degrees). Success rates (90% vs. 89%) and screening times (19.5 vs. 20.7 min) remained unchanged in 200 coronary angioplasties performed after the study. Average operator radiation dose (measured by radiation badges worn under lead at waist level) was reduced from 32.6 to 14.3 microSv/operator per week despite a slight increase in case load.

CONCLUSIONS

Fluoroscopy is the major source of total radiation exposure during coronary angioplasty, with left anterior oblique views providing the highest dose. Modification of views is feasible and will result in significant reduction of operator radiation dose.