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Biomedical subjects

P Boyle

Publications and source records attributed to P Boyle.

At least 343 records · Page 19Linked to original sources
PubMed1989

Descriptive epidemiology of Hodgkin's disease in Italy.

Death certification data on Hodgkin's disease in Italy over the period 1955-84 were studied in terms of age-standardized and age-specific national trends, and of geographical variation in mortality. There were substantial declines in death rates from the early 1970's onward, which can be largely attributed to therapeutic improvements. These led to avoidance of about 350 deaths, with a total 950 reported, which is probably the major absolute therapeutic advance identified for any cancer site. The declines started earlier in childhood and young adult age, and were restricted to population below age 60. The age distribution of the disease was different in the two sexes, since the age curve for males showed steady rises up to age 75, whereas that for females was clearly bimodal, with a peak around age 30, and another at oldest age. This divergent pattern is consistent with different exposure to (infectious) agent(s) in children of the two sexes, but also to occupational exposures potentially related to the risk of the disease. Examination of rates in various geographical areas showed generally higher rates in the North, and a few provinces with exceedingly high mortality in the central part of Northern Italy, particularly in a chiefly rural province (Mantua). This excess mortality (and, more in general, the observation that rates for Northern Italy are higher than in any other area of the EEC) could not be explained by obvious diagnostic or classification problems, were evident in both sexes, appeared to be consistent over the last decade and are reflected in available Italian cancer registration data.

Adolescent↗
PubMed1989

Relative value of incidence and mortality data in cancer research.

Cancer surveillance has played an important role in programmes of cancer control, ranging from aiding formulation of current hypotheses regarding the nature of the causes of cancer to assessing the effectiveness of cancer treatment regimes and cancer prevention programmes. Central to this has been the contribution from routine data collection schemes, particularly cancer mortality data and cancer registration schemes, the latter providing cancer incidence statistics for a variety of international populations. Criticisms have been made of the quality of cancer incidence data and there have been suggestions that cancer surveillance may be better achieved by use of mortality data. From examination of the reliability and quality of mortality data, it would appear that international variation in the quality of death certification and in the application of internationally agreed rules for selecting the underlying cause of death may in themselves be enough to vitiate the argument that there is significant international variation in cancer levels or to indicate variation where none in reality may exist. Good cancer incidence data are vitally important to descriptive epidemiology as are good cancer mortality data. It is important to recognize that there are limitations to both types of data which vary both temporarily and internationally. Cancer surveillance and the assessment of the impact of cancer control programmes depend on the reliability of descriptive epidemiology and would best be achieved by maintaining current, population-based cancer registration schemes and, if and where possible, extending such schemes to other populations or population groups. Maximum benefit would be achieved by simultaneous improvement in the quality of mortality data.

Cohort Studies↗
PubMed1989

Reproductive factors and breast cancer: an overview.

Despite extensive research, there is still uncertainty on the separate effects of parity and age at first birth on breast cancer risk. Thus, information on these variables from formal epidemiological articles published in English since 1970 is reviewed in the present article. Among 26 studies considered, one found no significant association with either variable, seven showed an association between age at first birth but not parity and breast cancer risk, six an association with parity but not age at first birth, and in twelve studies both variables appeared to be independently related with breast cancer risk. Various reasons for these apparent differences can be considered, including heterogeneity between various populations (for instance, the proportion of multiparous women in studies showing no association with parity tended to be higher than in studies finding an inverse relation with parity), criteria for selection of cases and controls, influence of age and other covariates (among which the interval between pregnancies is of particular interest) and, of course, the role of chance. The data reviewed suggest, from an aetiological viewpoint, that both parity and age at first birth have some independent effect on breast carcinogenesis. From a public health viewpoint, however, it appears that the importance of age at first birth is greater, since the trend is linear across subsequent age levels, while the protection of parity seems to be quantitatively relevant only for women with four or five births or more.

Breast Neoplasms↗
PubMed1989

Epidemiology of pancreas cancer (1988).

This article reviews the epidemiology of cancer of the pancreas, both descriptive and analytical, at all times cognizant of the problems of misdiagnosis, particularly underdiagnosis, of this lethal disease that continue to hinder epidemiological studies. Pancreas cancer is consistently reported to occur more frequently in men than in women, in blacks than in whites, and in urban rather than rural population groups. In some countries, the mortality rates continue to rise, whereas in others, declining levels of disease can be seen among members of younger birth cohorts. Although some of these patterns can be explained by variation in pancreas cancer risk factors, many cannot. Analytical studies consistently demonstrate that cigarette smoking increases the risk of cancer of the pancreas, and this appears, at the present time, to be the only clearly demonstrated risk factor for pancreatic cancer. Although the association with disease risk and coffee consumption, alcohol consumption, occupational exposures, diabetes, pancreatitis, and other factors requires clarification, it appears likely that the most fruitful research area in the coming years may involve exploration of pancreatic cancer risk and nutritional practices.

Adult↗
PubMed1989

Breast cancer and combined oral contraceptives: an Italian case-control study.

The risk of breast cancer in relation to use of oral contraceptives was evaluated using data from a hospital-based case-control study from Northern Italy on 1517 cases below age 60 and 1351 controls admitted for acute diseases unrelated to any of the known or potential risk factors for breast cancer. The multivariate relative risk for ever vs. never users was 1.3 (95% confidence interval = 1.0-1.7). However, the risk was not related to duration of use: indeed the highest risk was observed among short-term users (less than 2 years), and the point estimate was 0.9 among users for 5 years or more. The elevated risk among short-term users, if not due to residual confounding or selection mechanisms, is probably explainable in terms of recall bias (i.e. more careful report of short or very short use by cases). No definite pattern was observed in relation to latency or recency of use, and the point estimates were 0.8 for women who had ever used the pill before age 25 and 0.8 for those who had ever used the pill before first full-term pregnancy. Thus, the study presents further reassuring information on the oral contraceptive/breast cancer debate. Its major limitation lies in the low prevalence of oral contraceptive users in Italy, with a consequently reduced statistical power, although, with the number of cases involved, it was possible to exclude a relative risk of 1.4 for long-term use or for ever use before first birth.

Adult↗
PubMed1989

Alcohol and breast cancer: update from an Italian case-control study.

The analysis of alcohol and breast cancer risk from an Italian case-control study of breast cancer has been updated to include a total of 2402 women with histologically confirmed breast cancer and 2220 controls with acute conditions unrelated to any of the established or potential risk factors for breast cancer, admitted to a network of teaching and general hospitals in the greater Milan area. Compared with non-drinkers, the estimated relative risk for ever drinkers was 1.4 (95% CI = 1.2-1.6). The multivariate risks were 1.3 for less than 1 drink (e.g. 10 g of ethanol) per day, 1.3 for 1 less than 2 drinks, 1.4 for 2-3 and 2.2 for over 3 drinks per day. The positive association between alcohol and breast cancer was consistent across strata of age, socio-demographic variables, smoking, menstrual, reproductive, and hormonal factors, family history of breast cancer, nutrition and diet indicators. In particular, this study indicated that the alcohol-breast cancer relationship is probably not materially different in younger and older women, that alcohol drinking at an early age is not a particularly clear indicator of subsequent risk, nor that the effect of alcohol is enhanced in thin women. Thus, the findings of this study are both internally consistent and in agreement with most previous evidence, since the relative risks of 1.3-1.4 for a consumption of 10-30 g of alcohol per day compare well with the corresponding highest intake levels in most American studies. This study is of particular interest, since it provides data on higher levels of alcohol consumption, on which very little information is available. There are nontheless at least three elements which leave open the question of causality: the absence of duration-risk relationship, the inconsistency with evidence from descriptive epidemiology, and the lack of plausible biological mechanisms.

Adult↗
PubMed1989

An integrative framework for health-related research.

Research on the manifold aspects of health and health-care delivery, economics and administration has expanded rapidly in recent years and now engages a number of disciplines. The array of theories, methods, and analytical strategies derived from such diverse sources frequently impedes effective communication between investigators and sometimes renders it impossible. We propose a conceptual framework that encompasses all health-related research and demonstrates the relationships and interfaces between the various disciplines involved. The framework emerges from a classification of health-related research into studies of health states or health interventions followed by consideration of the level of analysis (e.g. cell, individual, community) employed and the purpose of each study (development, description, explanation, or evaluation).

Delivery of Health Care↗
PubMed1989

The impact of chemotherapy in germ cell tumours.

It is widely appreciated that the application of chemotherapy in the treatment of germ cell tumours exemplifies the best results to be expected from this approach in solid tumours, since the majority of patients treated are now cured. Against a background of steadily rising incidence of testicular cancer, the impact of this highly effective treatment can be measured using national statistics, which for most countries in the developed world indicate a corresponding fall in mortality over the past 15 years. For some countries, however, no such improvement has taken place, presumably reflecting inadequate facilities in those countries for securing appropriate treatment, particularly cisplatin. In most specialist centres, current clinical studies are aimed at reducing the toxicity of treatment for the majority of patients cured of their disease. The other remaining challenge in management is to improve the results of treatment in the small minority of patients for whom chemotherapy is still not curative. More intensive schedules are being tested, and randomized trials to test these approaches are recommended.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Design of the UCH/RNID cochlear implant system.

This paper describes the design of the UCH/RNID single channel, extracochlear, auditory prosthesis. The system employs a body-worn analogue sound processor whose output is transmitted to a pair of implanted Platinum/Iridium stimulating electrodes via a transcutaneous inductively coupled link. The stimulating current is passed between a 1 mm diameter ball electrode, resting in the round window, and a 5 mm square foil electrode placed under the temporalis muscle. The implanted amplitude modulation receiver circuit is fabricated from hermetically sealed electronic components which are mounted on a ceramic substrate. The implanted circuit is encapsulated in silicone rubber. The primary design objective was to produce a reliable and effective auditory prosthesis costing less than 1,000 pounds.

Cochlear Implants↗
PubMed1989

Risk factors and prognosis in primary biliary cirrhosis.

The relationship between survival and 25 clinical and histologic variables was studied in 195 patients (171 women, 24 men) who satisfied stringent criteria for the diagnosis of primary biliary cirrhosis. The mean duration of follow-up was 6 yr (range 0-17). One hundred and sixteen patients died, 84% as the result of liver disease and 16% from nonhepatic causes. Using the Kaplan-Meier estimate, we calculated the mortality from liver disease to be 40% after 5 yr and 60% after 10 yr. Ascites, serum bilirubin level, variceal hemorrhage, and age were identified as independent clinical risk factors, and extent of hepatic fibrosis, bilirubinostasis, and Mallory's hyalin were identified as independent histologic risk factors correlating with reduced survival.

Adult↗
PubMed1988

Risk of breast cancer among Greek women in relation to nutrient intake.

A case-control study of the role of diet in the cause of breast cancer was conducted in Athens, Greece. The case series consisted of 120 consecutive patients with histologically confirmed breast cancer admitted to either of two teaching hospitals over a 12-month period. The controls were 120 patients admitted to a teaching hospital for trauma and orthopedic conditions during the same period. Dietary histories concerning the frequency of consumption of 120 foods and drinks were obtained by interview. Nutrient intakes for individuals were estimated by multiplying the nutrient content of a selected typical portion size for each specified food item by the frequency that the food was used per month and summing these estimates for all food items. Cases reported significantly less frequent consumption of vitamin A after controlling for total caloric intake, potential external confounding variables and other nutrients associated with breast cancer risk. The odds ratio estimated for consumption of vitamin A equal to the value of the 90th centile versus consumption equal to the value of the 10th centile was 0.46 with 90% confidence limits 0.26-0.82. There was no evidence that high intake of dietary fat increases the risk of breast cancer.

Breast Neoplasms↗
PubMed1988

Progress in understanding breast cancer: epidemiological and biological interactions.

Little progress has been made recently in our understanding of the epidemiology of breast cancer. While results from epidemiologic studies regarding reproductive factors remain fairly reproducible from one study to another, other associations such as that between breast cancer risk and dietary fat intake, although biologically plausible, are not consistently found in direct study of humans, while yet other associations, which appear less plausible biologically, become stronger (such as the increased risk associated with modest levels of alcohol consumption). In this paper we attempt to review the epidemiology and biology of breast cancer jointly and describe possible mechanisms of breast cancer induction, the cellular composition of the breast, the epidemiology of breast cancer, and salient biological features, and attempt to reconcile the biology and epidemiology. It becomes obvious that future progress depends on better biological thinking by epidemiologists, and vice-versa. Areas of further research are suggested and discussed, concluding that the ability to measure diet with greater precision could have an important role to play in clarifying our understanding of breast cancer.

Breast Neoplasms↗
PubMed1988

Improving prognosis of Hodgkin's disease in Scotland.

Time trends in mortality from Hodgkin's disease have been studied in Great Britain for the 70-year period, 1911-1980, and incidence in Scotland since 1959. In both Scotland and England and Wales, in each sex, mortality from Hodgkin's disease rose steadily from 1911 until 1970 and thereafter dropped substantially; the greatest fall was apparent in Scottish males. While mortality rates continue to decline in Scotland the incidence has remained fairly constant over the last 25 years suggesting a major change in prognosis for this disease. The introduction of effective chemotherapy and improved techniques of radiotherapy appear to have improved prognosis sufficiently, and to have been made adequately widely available, as to influence overall mortality rates at a national level as well as at the level of the clinical trial. No such improvement in prognosis, however, explains the declines observed in mortality rates among children of each sex in both areas which have taken place since the 1930s. In view of the current knowledge of the aetiology of Hodgkin's disease this fall may have been brought about by changes in socioeconomic factors.

Age Factors↗