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Biomedical subjects

P Boyle

Publications and source records attributed to P Boyle.

At least 361 records · Page 20Linked to original sources
PubMed1988

Cigarette smoking and male lung cancer in an area of very high incidence. I. Report of a case-control study in the West of Scotland.

Altogether 656 male lung cancer cases and 1312 age and sex matched controls were interviewed between 1976 and 1981 in a case-control study of cigarette smoking habits and lung cancer in Glasgow and the West of Scotland, an area with the highest recorded incidence in the world. The relative risk of lung cancer increased significantly for smokers whose consumption was below 20 cigarettes per day but did not rise significantly in those who smoked more than 20 cigarettes per day. Other smoking characteristics such as inhalation and tar yields of brands smoked did not explain this finding. Additionally, the relative risks observed at all levels of cigarette consumption were low in comparison with those in the published literature. By constructing an index of cigarette exposure which included the tar yields of brands smoked, an assessment of the risk of lung cancer in relation to tar exposure independent of amount smoked was derived. Only in smokers of less than 15 cigarettes per day was there a statistically significant reduction in risk of lung cancer associated with lower levels of tar yield.

Age Factors↗
PubMed1987

Carcinoma of the larynx.

Six hundred sixty-eight patients with tumours of the larynx were treated by radiotherapy. The patients had stage T1 N0 M0 to T4 N3 M0 disease. Patients with T1 N0 M0 disease (273) had an excellent long-term survival (90%) as did those with T2 N0 M0 disease (142), whose 5-year survival was 70%. Patients with more advanced disease but no nodal spread did not respond as readily to radiotherapy; the 5-year survival was 40%. All patients were treated using a parallel pair set-up 6 X 6 cm lateral neck fields. A more aggressive radiotherapy regime to a larger tissue volume to include microscopic spread to lymph nodes may improve survival of locally advanced disease.

Adult↗
PubMed1987

Changes in testicular cancer in Scotland.

There are two purposes to this paper. Firstly to describe the temporal pattern of germ-cell testicular cancers in Scotland, both as a single entity and as the histological sub-types (pure) seminoma and teratoma. Incidence rates rose by over 50% between 1959 and 1984, with the rates of seminoma increasing only marginally and the majority of the overall increase accounted for by the substantial increase observed among the sub-type teratoma. Secondly, to investigate the impact of new therapies on the mortality rate from germ-cell testicular cancer in Scotland in the light of improvements in survival rate reported during the last 25 years from clinical trials and clinical series. Noticeable changes have occurred in the temporal pattern of mortality which cannot be explained by changes in incidence. The ever-widening gap between the increasing incidence rate and the declining mortality rate, particularly apparent in the high-risk age group 15-44, indicates an improving prognosis for patients with this malignancy in Scotland.

Adolescent↗
PubMed1987

Pilot study of the prevalence of head lice infestation in a population of Saudi Arabian children.

The prevalence of infestation with the head louse, Pediculus capitis, was assessed among the child population, from birth to 10 years old inclusive, of the rapidly expanding Saudi Arabian city of Jeddah. Over a period of two months, 300 consecutive children attending the general practitioner for any reason were examined specifically to identify those infested with head lice: 37 cases of active infestation were found, which is an overall prevalence of 12%. An interesting distribution, however, was noted in respect of age, ranging from less than 2% in the first year of life, rising rapidly to around 30% in ages six to eight years, thereafter declining steadily to about 16% by age 10 years. The distribution of infestation among males and females was broadly similar. These results show a high head lice infestation, particularly in the early school years, where presumably interpersonal contacts are most frequent, facilitating contagious spread. As the head lice is known to spread several viral and rickettsial diseases, such as relapsing fever and typhus, greater efforts should be made towards patient education in hygiene, and towards identifying and treating the disease when found.

Child↗
PubMed1987

Statistical modelling of lung cancer and laryngeal cancer incidence in Scotland, 1960-1979.

The ratio of cancer occurrence among smokers compared to nonsmokers has been generally reported to be greatest for carcinomas arising in the lung and larynx. This report presents the results of an investigation into mechanisms underlying the temporal trends in the incidence of these two forms of cancer in Scotland over the 20-year period, 1960-1979. The purpose of the study was to establish the independent effects of age, calendar time, and birth cohort on the observed pattern of incidence by adopting an alternative approach to this classical problem which can be employed when data are available as individual records. The most economic model found to explain the data involved the independent effects of site, sex, and age and different cohort effects in each sex. The cohort effect was more pronounced in men than women in older cohorts but, conversely, stronger in women than in men in younger cohorts, i.e., among those born most recently. This observation accords with the observed increase in the use of cigarettes in young women relative to young men. There appeared to be a small effect of calendar time which was the same in both sexes and both sites, although this main effect, it must be emphasized, could be eliminated from the model on statistical grounds. The effect can be interpreted to indicate the increase in the coverage of cancer registration in Scotland which has taken place since 1960. These results indicate that lung cancer risk in Scottish males will continue to fall, with the risk in women lagging 20 years behind, although the levels in women will probably not reach those attained by men.

Adult↗
PubMed1987

Morphological and cell kinetic effects of dietary manipulation during colorectal carcinogenesis.

The effect of dietary manipulation of fat and fibre on the structural and cell kinetic characteristics of colonic mucosa was studied before and during experimental carcinogenesis in 232 male Albino Swiss rats. Carcinogen treated animals were given 12 weekly injections of azoxymethane (10 mg/kg/week). The animals were divided between four dietary groups (1) high fat, high fibre, (2) low fat, high fibre, (3) high fat, low fibre and (4) low fat, low fibre. Pathological and cell kinetic information together with details of certain faecal characteristics was collected when the animals were killed 4, 20, and 28 weeks after starting their experimental diet. Tumour induction was significantly influenced by diet. The highest risk of colorectal tumour development was found in groups fed diet 3: high fat, low fibre (p less than 0.03). In contrast, diet 2: low fat, high fibre was associated with the lowest risk. The proportion of histologically proven colonic tumours occurring in each dietary group was: diet 1-10.9%, diet 2-3.6%, diet 3-63.7%, diet 4-21.8%. Scanning electron microscopic (SEM) studies done on selected samples indicated both dietary and azoxymethane related alterations in crypt unit integrity. The most marked surface architectural changes were seen in carcinogen treated animals maintained on diet 3 (high fat, low fibre). Stathmokinetic analysis revealed considerable intergroup variability. Both fat and fibre produced significant effects, principally during the preneoplastic phase of carcinogenesis. Faster proliferative activity tended to be found in animals at low risk of tumour induction (diet 2), slower proliferation being more characteristic of animals at high risk (p less than 0.05). The findings suggest that both topographical and cell kinetic parameters have an important relationship with promoting and protecting dietary factors during the development of colorectal cancer.

Animals↗
PubMed1987

Breast cancer and colon cancer incidence in females in Scotland, 1960-84.

In view of the suggested similarity in risk factors for breast cancer and colon cancer in women, an analysis was undertaken to investigate age, period, and cohort influences on the risk of these diseases by use of incidence data for Scotland. Statistical modeling of data for the period 1960-84 revealed that both the age effects and the cohort effects were different for each site. While younger cohorts apparently had signs of reduced risk of both diseases, reduced risk was only apparent among the very youngest cohorts in the case of breast cancer, whereas there has been a gradual reduction in the risk of colon cancer among successive cohorts born since the beginning of the century. Clemmesen's hook was demonstrated in the age-incidence curve of breast cancer, which was clearly shown to have two different slopes: among premenopausal and among postmenopausal women. The declining risk of breast cancer in younger cohorts appeared contradictory to their apparently "high-risk" profile (in terms of present knowledge of etiologic factors) and suggested the possible existence of a factor that protects against breast cancer, at least at younger ages, but that remains, as yet, unidentified.

Adult↗
PubMed1986

Diet and breast cancer: a case-control study in Greece.

A case-control study of the role of diet in the etiology of breast cancer was conducted in Athens, Greece. There are reasons to believe that the diet of the Greek population is characterized by greater heterogeneity than that in most countries where such studies have been undertaken. 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. Cases reported significantly less frequent consumption of vegetables as a group and, within that group, specifically of cucumber, lettuce and raw carrot. After adjustment for potential external confounding variables and for confounding between food categories, the odds ratio for persons in the highest quintile of vegetable consumers, relative to those in the lowest quintile, was 0.09 with 95% confidence limits 0.03-0.30. That is to say, the lowest quintile of vegetable consumers had about 10 times the breast cancer risk of the highest quintile. For a score based on consumption of only the 3 specified salad items the odds ratio over the extreme quartiles was 0.12 (0.05-0.32). There was no association with consumption of fats and oils, alcohol or coffee, and no significant association with any other major food category (including alcohol and coffee) after adjustment for confounding variables.

Breast Neoplasms↗
PubMed1986

Experimental colorectal cancer: the relationship of diet and faecal bile acid concentration to tumour induction.

Epidemiological studies have consistently suggested an aetiological relationship between certain dietary constituents, faecal bile acid (FBA) concentration and colorectal cancer. This study was designed to examine the effect of the dietary manipulation of fat and fibre on tumour induction and on various faecal characteristics in Albino Swiss rats. A total of 232 animals were maintained on one of four different diets for 4, 20 and 28 weeks respectively. The diets were classified as high fat high fibre, low fat high fibre, high fat low fibre and low fat low fibre. The groups were further sub-divided according to the administration of systemic azoxymethane (10 mg/kg per week) or saline over 12 consecutive weeks. The high fat low fibre diet was associated with the highest risk for tumour production and the low fat high fibre diet with the lowest risk. Statistically significant differences between all the diets were noted with the exception of a comparison between the high fat high fibre and low fat high fibre diets. The highest total concentration of free FBA was found in the faeces from animals fed low fibre containing diets. The results show a clear influence of both fat and fibre on tumour induction while, in this model, fibre was the principle determinant of faecal bile acid concentration.

Animals↗
PubMed1986

Post-operative radiotherapy in the management of advanced intra-oral cancers.

Advanced tumours of the tongue and floor of the mouth have a poor prognosis when treated by surgery or radiotherapy alone. The results reported here suggest that combined surgery and radical post-operative radiotherapy greatly improve the outlook for such patients. When the oral cavity is irradiated, both parotids usually receive a radical dose resulting in xerostomia. In this study, shaped fields are used to spare the contralateral parotid, thus minimising the reduction in saliva production. Previously, radical surgery of oral tumours left the patient deformed. Plastic surgery techniques of reconstruction using radial free flaps give excellent cosmetic results. Radial free flaps have their own blood supply and tolerate a radical dose of radiotherapy.

Adult↗
PubMed1986

Prognostic factors in thyroid tumours.

Using Cox's Proportional Hazard Model, we have demonstrated the influence of age, sex, microscopic tumour type, extent of primary tumour, nodal status and the presence of metastases on prognosis, in our population of 441 patients with thyroid carcinoma. The TNM classification contributes significantly to survival, but does not include other contributory prognostic variables, whereas the prognostic index developed by the EORTC thyroid study group, which takes account of age and histology, proved a reliable predictor of survival for our patient group.

Age Factors↗