Biomedical subjects

G G Giles

Publications and source records attributed to G G Giles.

At least 73 records · Page 4Linked to original sources

PubMed1996

Has mortality from melanoma stopped rising in Australia? Analysis of trends between 1931 and 1994.

OBJECTIVE: To describe recent trends in mortality from melanoma in Australia. DESIGN: An analysis of trends in age standardised and age and sex specific mortalities by year of death and median year of birth (cohort). SETTING: Australia. SUBJECTS: All deaths from melanoma registered in Australia between 1931 and 1994. RESULTS: Melanoma mortality rose steadily from 1931 to 1985. From 1959 the annual rate of increase was 6.3% in men and 2.9% in women, resulting in mortalities of 4.82 and 2.51 per 100,000 person years in 1985 and 1989, respectively. Mortalities for both sexes seem to have plateaued from June 1985 onwards. In 1990-4 the rate rose by 3.7% in men to 5.00 per 100,000 and in women it fell by 5.2% to 2.38 per 100,000. The non-significant increase after 1985 in mortality in men was restricted to those aged over 70 years of age, whereas the fall in rates in women was mostly in those aged under 55 years. This pattern was generally reflected in the state trends, though with some variation: rates for women in Queensland had peaked in the late 1970s; while rates for men in New South Wales continued to rise in 1990-4, placing them above those for Queensland. Examination of mortalities specific for age, period, and cohort for Australia as a whole showed several salient features. Rates in men rose steeply in cohorts born before about 1930; were stable in cohorts born between 1930 and 1950; and fell in more recent cohorts. Rates in women showed similar changes but about five years earlier. CONCLUSION: Melanoma mortality in Australia peaked in about 1985 and has now plateaued. On the basis of trends in cohorts it can be expected to fall in coming years.

Adolescent↗

PubMed1996

Cancer diagnosis after a report of negative cervical cytology.

OBJECTIVES: 1. To determine the annual rate of interval squamous cancer of the cervix after a negative Papanicolaou smear report. 2. To evaluate the proportion of women with cervical cancer who received negative cervical smear reports during the three years before the cancer diagnosis. DESIGN AND SETTING: Objective 1. A prospective study of the incidence of squamous cervical cancer from 1990 to 1993 among women who received negative cervical smear results in Victoria in 1990. Objective 2. A retrospective audit of preceding cervical smear results from 1990 to 1993 in women diagnosed with cervical cancer in Victoria in 1993. RESULTS: The average interval cervical rate was 2.54 squamous cancers per 100000 women per year (95% confidence interval, 1.75-3.67) during the first three years after a negative smear report. The interval cancer rate did not vary by age group nor by the endocervical status of the negative smear report. Of the 233 cases of cervical cancer diagnosed during 1993, 56 women (24%) had negative cervical cytology reported during the preceding three years. The frequency of preceding negative cervical cytology was greater for non-squamous cancer (22 women [33%] from 66 cases) than for squamous cancer (34 women [20%] from 167 cases. CONCLUSION: The rate of interval cancer diagnosis is very low compared with expected rates in the absence of screening, indicating the effectiveness of the cervical screening program in Victoria.

Carcinoma, Squamous Cell↗

PubMed1996

Have increases in solar ultraviolet exposure contributed to the rise in incidence of non-Hodgkin's lymphoma?

The incidence of non-Hodgkin's lymphoma (NHL) has increased substantially in many countries over recent decades. The aetiology of this cancer is poorly understood, and this rise is largely unexplained. The incidence of NHL is known to increase markedly following immune suppression. In the light of evidence that exposure to ultraviolet radiation (UVR) may cause systemic immune suppression, part of the recent increase in NHL incidence may reflect population-based increases in UVR exposure. That such exposure increases have occurred is inferred from the widespread increases in skin cancer incidence in fair-skinned populations, especially malignant melanoma (MM), over recent decades. Epidemiological evidence presented here in support of the proposed UVR-NHL relationship includes the following: in Caucasian populations there is a moderate positive correlation between ambient UVR level, by latitude, and NHL incidence; there is also a positive correlation between time trends in MM incidence and NHL; there is some evidence that migration across latitude gradients induces concordant shifts in risks of NHL and MM. Data from two historical cancer patient registers show that, in individuals, these two cancers concurred a little more often than expected. These findings support recent suggestions that UVR-induced impairment of immune functioning contributes to the aetiology of NHL.

Adult↗

PubMed1996

Validation of questionnaire and bronchial hyperresponsiveness against respiratory physician assessment in the diagnosis of asthma.

BACKGROUND: The Tasmanian Asthma survey (TAS) and the International Study of Asthma and Allergies in Childhood (ISAAC) have used questionnaires to measure the prevalence of asthma in adults and children. We have investigated the validity of these questionnaires by comparing response to questionnaire with a physician assessment of asthma status in the past 12 months. METHODS: Ninety-three adults were given the TAS questionnaire to complete and 361 children were given the ISAAC questionnaire. Ninety-one adults and 168 children completed bronchial challenge with hypertonic saline. A consultation with a respiratory physician blinded to the results of the questionnaire and bronchial challenge was given to all subjects. RESULTS: In both adults and children, questionnaires showed high agreement with respiratory physician diagnosis with respect to asthma symptoms in the past 12 months. For the TAS questionnaire the positive and negative predictive values (95% confidence limits) for physician diagnosis for adults were 0.89 (0.68-0.98) and 0.94 (0. 86-0.98) respectively. The instrument was also sensitive 0.80 (0. 58-0.93) and highly specific 0.97 (0.90-0.99). For the ISAAC questionnaire the positive and negative predictive vales for physician diagnosis of asthma in children were 0.61 (0.50-0.71) and 0.94 (0.88-0.98) respectively. Sensitivity and specificity were 0.85 (0.73-0.93) and 0.81 (0.76-0.86) respectively. Compared to the physician diagnosis, the sensitivity of bronchial hyperresponsiveness (BHR) for asthma was low for adults 0.39 (0.21-0. 61) and children 0.54 (0.48-0.67) as were the positive predictive values: 0.55 (0.31-0.79) for adults and 0.64 (0.449-0.77) for children. A definition of asthma requiring both a positive questionnaire response and BHR was highly specific but not sensitive for adults 0.37 (0.20-0.59) or children 0.47 (0.35-0.60). CONCLUSIONS: Both the TAS and ISAAC questionnaires are valid instruments for the determination of asthma symptoms in the past 12 months.

Adolescent↗

PubMed1996

Incidence trends in oesophageal and proximal gastric carcinoma in Victoria.

BACKGROUND: There is clinical evidence that adenocarcinoma of the lower oesophagus is increasing in the Australian society. The population-based cancer registry of Victoria was used to describe the incidence of adenocarcinoma of the oesophagus and gastric cardia. METHODS: Data were obtained from 1982 to 1991 and were analysed using the Poisson regression techniques. RESULTS: In men, a statistically significant annual increase of 9.5% in oesophageal adenocarcinoma and a non-significant increase of 1.6% in adenocarcinoma of the gastric cardia was observed. These increases were balanced by decreases in other histological types found in the oesophagus in men resulting in little change in the overall rate. No significant trends by age or histological type were observed in women. CONCLUSIONS: There is evidence for a rise in adenocarcinoma in men in Victoria. Possible risk factors include Barrett's oesophagus.

Adenocarcinoma↗

PubMed1996

Blood pressure in the Australian- and Italian-born: a Melbourne suburb revisited after 20 years.

The aim of this study was to investigate changes in the average blood pressure of Australian-born and Italian-born men and women after a 20-year interval, in the same location, the Melbourne suburb of Brunswick, located about five km north of the centre of the city. Data pertaining to blood pressure and its control were obtained from all Australian- and Italian-born residents of Brunswick enrolled in the Melbourne Collaborative Cohort Study between 1990 and 1994. Comparisons were made with published data from a random household survey in Brunswick in 1972. Within the age group 40 to 59 years (in contrast to the earlier study) average blood pressure was significantly higher in Italian-born men and women relative to the Australian-born. Between 1972 and 1990-1994, significant reductions in average systolic and diastolic blood pressure occurred in Australian-born women aged 40 to 59 years. Average systolic and diastolic blood pressures also fell in Australian-born men, although the reduction in systolic blood pressure for those aged 50 to 59 was not statistically significant. Average systolic blood pressure increased in Italian-born men and women. However, the increase was statistically significant only for men aged 50 to 59 years. Average diastolic blood pressure increased in Italian-born men aged 50 to 59 and fell in Italian-born women of the same age. The observed changes in blood pressure could not be attributed directly to changes in the diagnosis and treatment of hypertension, or to changes in the prevalence of overweight and obesity.

Adult↗

PubMed1996

Tobacco smoking and alcohol consumption as risk factors for glioma: a case-control study in Melbourne, Australia.

OBJECTIVE: To investigate possible associations between tobacco smoking and alcohol consumption and the risk of adult glioma. DESIGN: This was a population based, case-control study. Relative risks (RR) were estimated using logistic regression analysis. SETTING: Melbourne, Australia. PARTICIPANTS: These comprised 416 case subjects (166 women, 250 men), 66% of those eligible; and 422 control subjects (170 women, 252 men), 43.5% of those potentially eligible. RESULTS: There was no increase in risk of glioma with having ever smoked tobacco (RR 1.29, 95% CI 0.95, 1.75) for all subjects, adjusted for age, a reference date, and gender. There was a slight increase in risk for men (RR 1.64, 95% CI 1.1, 2.45), but not for women (RR 0.99, 95% CI 0.62, 1.62). For men, there was no increase in risk with increasing pack-years of cigarette smoking, but the risk was significantly increased in subjects who had smoked for less than 10 years. There was no increase in risk associated with having ever drunk alcohol for all subjects (RR 0.96, 95% CI 0.67, 1.37), women (RR 0.69, 95% CI 0.4, 1.15) or men (RR 1.40, 95% CI 0.81, 2.43). CONCLUSIONS: This study does not support an association between either tobacco smoking or alcohol consumption and glioma. The pattern of risk associated with tobacco smoking in men appears inconsistent with a causal role, and may be due to chance, response bias, or uncontrolled confounding.

Adult↗

PubMed1995

Vulvar cancer: the Cinderella of gynaecological oncology.

Cancer of the vulva is a rare malignancy that increases progressively with age. The age-standardized incidence averages between 1 and 2 per 100,000 women in Western countries. The majority (80-90%) are squamous cell carcinomas, melanoma and adenocarcinoma each accounting for about 5% of cases. Internationally, the incidence of vulvar cancer varies more than 30-fold, the highest rates being seen in populations of Portuguese South America. In many populations the incidence appears to be stable but there is some evidence that the incidence of in situ carcinoma is increasing in the United States of America. Epidemiological studies have identified sexual factors, particularly human papilloma virus (HPV) infection, as increasing risk. Smoking also increases risk by interacting synergistically with HPV infection and genital warts. The aetiologies of vulvar intraepithelial neoplasia (VIN)3/in situ disease and invasive cancer appear to differ. VIN does not automatically progress to invasive cancer and is strongly associated with HPV infection. Many older women with invasive vulvar cancer do not have evidence of HPV and do not smoke. More research is needed on the cause of vulvar carcinoma in this group. Treatment has become more conservative over the years and this has reduced morbidity and probably mortality. Although FIGO data do not show much by way of improvement in survival, data from population-based cancer registries have shown definite increases in survival (5-year survival proportions in excess of 80%, when age and Stage have been taken into account). Improvement is particularly related to the preponderance of early stage disease.

Age Distribution↗

PubMed1995

Increase in the self-reported prevalence of asthma and hay fever in adults over the last generation: a matched parent-offspring study.

The study compared current measures on a population-based cohort of adults with past measures on their parents to determine whether the prevalence of self-reported asthma and hay fever in adults increased between 1968 and the early 1990s. In 1968, 8585 cohort members (99 per cent of eligible Tasmanian 7-year-old school children born in 1961), 16,273 (95 per cent) of their parents (mean age 35 years) and 20,937 siblings completed a questionnaire about asthma and hay fever. In 1991-1993, 1494 members (75 per cent) of a stratified random sample of the cohort (aged 29 to 32 years), 75 per cent resident in Tasmania, were surveyed again. In 1968, the proportion of parents who reported having ever had asthma or attacks of wheezing like asthma was 10.9 per cent, independent of age and sex. In 1991-1993, the estimated adult prevalence of having ever suffered from attacks of asthma or wheezy breathing was 23.2 per cent. The proportion reporting at least one asthma attack within the previous 10 years, 5 years, 2 years, 12 months and 6 months was 17.6 per cent, 16.1 per cent, 14.5 per cent, 13.3 per cent and 10.3 per cent, respectively. For hay fever, the adult prevalence was 19.2 per cent in 1968, and 41.3 per cent in 1991-1993. The self-reported lifetime prevalence of asthma and hay fever among adults in the 1961 birth cohort of Tasmanians was twice as high in 1991-1993 as in their parents 25 years earlier.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Dietary factors and the risk of glioma in adults: results of a case-control study in Melbourne, Australia.

In a population-based case-control study of 416 incident gliomas in adults carried out in Melbourne, Australia, between 1987 and 1991, 409 age-sex-matched case-control pairs (243 male and 166 female) had adequate data available to examine associations between the dietary intake of N-nitroso compounds, N-nitroso precursors, other nutrients including N-nitroso inhibitors, and the risk of glioma. Dietary intakes were based on the reported frequency of consumption of 59 food items. Increased odds ratio (OR) were observed in males who consumed high levels of bacon, corned meats, apples, melons and oil. OR less than unity were observed in men consuming cabbage and cola drinks, and in women who consumed wholegrain bread, pasta, corned meat, bananas, cauliflower, brocoli, cola drinks and nuts. Generally, N-nitroso associations were greater in men and micronutrient associations were greater in women. Elevated OR in men, but not women, were associated with the intake of N-nitroso dimethylamine (NDMA), retinol and vitamin E. The intake of nitrate (largely of vegetable origin) was protective in women but not in men. When analyzed using multiple logistic regression, the association with NDMA intake in males was not modified by dietary micronutrient intakes. In females, beta carotene alone, though not directly associated with risk, modified the effect of NDMA. On balance, this study added only limited support to the N-nitroso hypothesis of glial carcinogenesis.

Australia↗

PubMed1994

Changes in the investigation and management of primary operable breast cancer in Victoria.

OBJECTIVES: To investigate the surgical practice and adjuvant therapies used in the treatment of primary operable breast cancer in Victoria in 1990 and compare them with results of a similar study in 1986. DESIGN: All 856 cases of primary operable breast cancer registered by the Victorian Cancer Registry between 1 April and 30 September 1990 were identified. Each patient's surgeon was sent a standard questionnaire covering diagnosis, investigations, operative procedures, adjuvant therapies and reasons for certain management choices. Data were collected on 89% of the patients from 176 participating surgeons. RESULTS: Most patients (82%) were referred to surgeons by general practitioners. Mammographic screening detected 14% of the cancers. The proportion of women receiving breast-conserving operations rose from 22% in 1986 to 42% in 1990. Surgeons operating on more than 20 breast cancers per annum were most likely to perform breast-conserving operations. The most common reasons given for non-conservative operations were the size of the tumour (37%), its central location (25%) and/or patient concern about the risk of recurrence if the breast was to be conserved (22%). Among these patients, reconstruction was done at the time of primary treatment in 13%, subsequently in 2%, and was planned by another 5%. Of all patients, 33% were referred to a radiation oncologist and 24% actually received radiotherapy (similar to 1986). Medical oncologists saw 33% of the patients and 20% of all patients received chemotherapy (similar to 1986), which was given by a medical oncologist in 83% of the cases. Use of endocrine therapy increased from 20% in 1986 to 40% in 1990. CONCLUSIONS: There has been a strong trend towards more conservative breast surgery in Victoria, with surgeons who are most active in breast cancer surgery most likely to perform breast-conserving operations. Apart from a significant increase in the use of endocrine therapy, use of adjuvant therapies was unchanged from 1986.

Adult↗

PubMed1994

Factors in childhood as predictors of asthma in adult life.

OBJECTIVE: To determine which factors measured in childhood predict asthma in adult life. DESIGN: Prospective study over 25 years of a birth cohort initially studied at the age of 7. SETTING: Tasmania, Australia. SUBJECTS: 1494 men and women surveyed in 1991-3 when aged 29 to 32 (75% of a random stratified sample from the 1968 Tasmanian asthma survey of children born in 1961 and at school in Tasmania). MAIN OUTCOME MEASURES: Self reported asthma or wheezy breathing in the previous 12 months (current asthma). RESULTS: Of the subjects with asthma or wheezy breathing by the age of 7, as reported by their parents 25.6% (190/741) reported current asthma as an adult compared with 10.8% (81/753) of subjects without parent reported childhood asthma (P < 0.001). Factors measured at the age of 7 that independently predicted current asthma as an adult were being female (odds ratio 1.57; 95% confidence interval 1.19 to 2.08); having a history of eczema (1.45; 1.04 to 2.03); having a low mild forced expiratory flow rate (interquartile odds ratio 1.40; 1.15 to 1.71); having a mother or father with a history of asthma (1.74 (1.23 to 2.47) and 1.68 (1.18 to 2.38) respectively); and having childhood asthma (1.59; 1.10 to 2.29) and, if so, having the first attack after the age of 2 (1.66; 1.17 to 2.36) or having had more than 10 attacks (1.70; 1.17 to 2.48). CONCLUSION: Children with asthma reported by their parents in 1968 were more likely than not to be free of symptoms as adults. The subjects who had more severe asthma (especially if it developed after the age of 2 and was associated with reduced expiratory flow), were female, or had parents who had asthma were at an increased risk of having asthma as an adult. These findings have implications for the treatment and prognosis of childhood asthma, targeting preventive and educational strategies and understanding the onset of asthma in adult life.

Adolescent↗

PubMed1994

Colorectal cancer.

International trends in the incidence, mortality and survival for colorectal cancers are heterogeneous, probably because of interpopulation diversity in trends in risk factors and in systems of medical care and screening programmes. Broadly, colorectal cancer rates correlate with the adoption of a western lifestyle, and, depending on each country's stage of transition, colorectal cancer incidence can be increasing (often rapidly), levelling or declining. In high risk countries, although decreases in incidence might be expected in the longer term in response to current dietary trends, some short term increases in incidence may result from the promotion of screening activities. The growing proportion of early stage tumours detected in screened populations will eventually be reflected in lower mortality rates.

Americas↗

PubMed1994

The risk of ano-genital malignancies in dialysis and transplant patients.

The incidence of anogenital malignancies is greatly increased in patients who have received a renal transplant, but this has not been well studied in patients receiving maintenance dialysis. Our aim was to assess the incidence of these malignancies in patients on dialysis and compare these to transplanted patients. The age standardized incidence ratio (SIR) for anogenital malignancies was calculated by comparing the observed number of malignancies to the expected number. The expected number was calculated by multiplying the age specific incidence rates for each malignancy by the person years at risk in 5-year age cohorts. Of 15,820 patients in the Australia and New Zealand data base, 8,215 had received a renal transplant. A total of 39,750 person years at risk were contributed by patients who had received a renal transplant, while 29,276 person years at risk were contributed by dialysis patients who had not received a renal transplant. For dialysis patients, vulval cancer occurred more commonly than expected (2 observed, 0.48 expected) giving a SIR of 4.2 (95% confidence interval = 0.4-11.9). Cervical cancer occurred less commonly with a SIR of 0.74 (95% Cl = 0.07-2.11). No cases of either anal or penile cancer occurred although these are rare tumors, with only 0.13 and 0.23 cases expected respectively. In transplant recipients 44 anogenital malignancies occurred while 4.3 could have been expected. The SIR ranged from 3.3 (95% Cl 1.7-5.8) for cervical cancer to 55.8 (95% Cl 35.8-83.0) for vulval cancer. To investigate the possible effect of chronic uremia before dialysis began, SIR was calculated to include an additional 24 months of observation before dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Trends in non-melanocytic skin cancer treated in Australia: the second national survey.

An Australia-wide survey in 1985 recorded the highest rates of medically treated non-melanocytic skin cancer (NMSC) ever reported. We report the findings of a repeat survey conducted in 1990. This second survey confirmed the differences, by age, sex, body site, latitude, country of birth and skin reaction to strong sunlight, that were observed in 1985. Over the 5-year period certain changes were noted: the incidence of NMSCs increased by 19%, of basal-cell carcinomas (BCC) by 11% and of squamous-cell carcinomas (SCC) by 51%. With advancing age, men and women differed in their incidence, and this difference was greater for SCC than for BCC. Log-linear modelling, however, failed to detect either a cohort or a survey effect between the 2 surveys. The proportional distribution of BCCs and SCCs by body site indicated an increase in BCCs on the trunk in both men and women, and half the proportion of SCCs on the head and neck in women as compared with men. The latitudinal gradients observed in 1985 were even stronger in 1990; the population living north of 37 degrees S experienced a 30% increase in the incidence of treated NMSC between 1985 and 1990, while the population living south of 37 degrees S had a 25% decrease. The implications of these findings for cancer-control initiatives are discussed.

Adult↗

PubMed1993

The incidence of colon, breast and prostate cancer in Italian migrants to Victoria, Australia.

The incidence of cancers of the colon, breast and prostate in Australian and Italian born residents of Victoria, Australia were compared with the incidence of these cancers in Italy. Italian migrants' rates were between those of the Australian born and those from Italian cancer registries. Italian migrants' rates for colon cancer (males 23.1 and females 15.8 per 100,000) differed from rates in Ragusa (males 12.1 and females 10.4 per 100,000) but not from rates in Parma or Varese. The migrants' breast cancer rate was similar to the rate in Ragusans (48.7 vs 46.7) and their prostate cancer rate of 27.3 was higher than all Italian registries. Modelling identified that Italian migrants' rates by age were intermediate to Australian and Italian rates, but indistinguishable from cancer rates in Ragusa, except for colon cancer which demonstrated an interaction with age.

Adult↗

PubMed1993

The associations between childhood asthma and atopy, and parental asthma, hay fever and smoking.

The aim of this analysis was to examine the degree to which a life time prevalence of asthma in a 7-year-old child is statistically associated with atopic conditions of the child, and with parental asthma, hay fever and smoking. In 1968, 8585 children who were born in 1961 and who were attending school in Tasmania were surveyed. This comprised 99% of the eligible population. The prevalence of a history of asthma in the 7-year-olds was 16.2% (males 19.0%, females 13.2%). Multiple logistic regression analysis showed that a history of asthma in a 7-year-old was associated with the child being male (odds ratio [OR] 1.56; 99% confidence interval 1.30-1.86), having a history of hay fever (3.86; 3.12-4.78), eczema (2.04; 1.63-2.55), hives (1.34; 1.09-1.65) or allergy to foods or medicines (1.70; 1.26-2.30), the child's mother or father having a history of asthma (2.63; 2.08-3.31 or 2.52; 1.99-3.19, respectively), and the mother being a smoker (1.26; 1.05-1.51). Parental hay fever and paternal smoking were not independently associated with childhood asthma. The strength of association between childhood asthma and parental asthma was independent of the sex of either the parent or the child, and of atopic conditions in the child. In the 133 children for whom both parents were asthmatic, 65 (49%) had a history of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗

PubMed1993

Primary central nervous system tumours in Australia: a profile of clinical practice from the Australian Brain Tumour Register.

An epidemiological survey of all primary central nervous system tumours in Australia was commenced in 1986. Cases was reported by the treating physician to the Australian Brain Tumour Register, located at the Victorian Cancer Registry. Ninety-three per cent of tumours were histologically confirmed and 69% were reviewed by an independent pathology panel. During the initial 3 years of the survey a total of 4577 brain tumours and 266 primary spinal cord tumours were reported to the Register. The age standardized rates for malignant tumours of the central nervous system, sum to 5.0/100,000 males and 3.4/100,000 females. Twenty-eight per cent of gliomas were biopsied only. Radiotherapy was administered to 57% of cerebral gliomas and 2% of these tumours were treated with adjuvant chemotherapy. Forty per cent of meningiomas were considered to have had a complete tumour resection.

Age Factors↗