Summary Following the report from Hawaii (Heilbrun et al., 1986) of relationships between tea consumption and respectively rectal cancer (positive) and prostate cancer (negative), these questions were examined using data from a prospective mortality study of London men initiated in 1967. The small numbers of men who did not usually drink any tea prevented a reliable study of this sub group. Nevertheless no evidence of a dose-response relationship was found for rectal, colon or prostate cancer. Significant relationships were found, however, between tea consumption and deaths from stomach, lung and kidney cancers. In the case of stomach and lung cancer, these were partly due to the effects of social class and smoking, and possible reasons are considered for the residual relations.A prospective study of men of Japanese ancestry in Hawaii reported that, compared with those who seldom or never drank black tea, habitual drinkers showed an increased incidence of rectal cancer, and that there was a doseresponse relationship (Heilbrun et al., 1986). ('Black tea' is the commonest type of tea and that which is mainly drunk in Britain). In addition, prostate cancer showed a weaker, negative association with tea consumption. This has prompted us to investigate the mortality from rectal and other cancers in relation to tea consumption, using data from a prospective study initiated by one of us (JY) in 1967. MethodsA random sample of about 20,000 men aged 45-60 in London was sent questionnaires about diet (including consumption of tea, coffee and other beverages) and smoking habits, by the General Register Office in December 1967. Respondents were 'flagged' in the NHS Central Register so that deaths, and their causes, could be identified as they occurred. Details of causes of death were coded by the Office of Population Censuses and Surveys (OPCS). These details, together with those on diet, were provided by OPCS without disclosure of identities.The questionnaire asked for the average consumption of tea and other beverages before breakfast, at breakfast, midmorning break, midday, tea-time, evening, bed-time, or at any other time. Man-years at risk were calculated by tea consumption category from the end of June 1969 to the end of 1986, or to death or emigration if earlier. Expected numbers of deaths from different causes were calculated by multiplying the age-specific mortality rates for men in England and Wales in the different calendar periods by the corresponding man-years at risk.Statistical modelling of the data was carried out using the computer package GLIM (Baker & Nelder, 1978). For this purpose it was assumed that observed deaths are Poisson variables with means proportional to the corresponding expected numbers (Breslow et al., 1983).Of the approximately 20,000 questionnaires that were sent, replies were received from 14,453 men, and of these the 14,085 (97%) who were traced in the NHS Central Register form the study population.By the end of 1986, a total of 5,732 deaths had been recorded in the study population. An...
The mortality of 1947 Cumbrian iron ore miners has been studied over the period 1939-82 in relation to that among other groups of men in England and Wales: (a) all men, (b) men of similar social class, and (c) men living in similar types of(mainly rural) area. Significant excesses were found for deaths from tuberculosis and respiratory diseases compared with each of the reference populations. Lung cancer showed an excess over that in comparable (mainly rural) areas of England and Wales, as reported in a previous study using a proportionate method of analysis and which covered the period 1948-67 but no appreciable excess after 1967. Reasons for this decline are discussed.Iron ore miners in Cumbria have been found to have a significantly increased mortality from lung cancer, an effect attributed either to the radioactivity in the underground air or to a carcinogenic effect of iron oxide.' In that study it was not possible to obtain adequate details of the population exposed and consequently the mortality data were analysed using a proportionate method. It was considered that a prospective study would be of interest, since this would allow not only a comparison of the findings with those of the previous study but also an examination of mortality from causes not covered previously. Such a study has now been carried out using data held in the National Health Service Central Register (NHSCR) for England and Wales. MethodsDetails were abstracted from the NHSCR by staff of the Office ofPopulation Censuses and Surveys (OPCS) of men resident in September 1939 in Ennerdale RD and Whitehaven UD, Cumberland, and whose occupation as stated included a mention of "iron ore mine"; those described as retired were also covered. In addition to the job description as given the details abstracted included dates of birth and, when relevant, dates of death or emigration.In the case of deaths details of the underlying cause Accepted 6 April 1987 were obtained from the death certificates and coded by the OPCS according to the rules of the 8th revision of the International Classification of Diseases (ICD). In many cases the men were specifically described as "surface" or "underground" workers and the data for these categories have been analysed separately, as has also a third group comprising those in which neither term was mentioned. In a few cases when there could be no doubt about the matter a worker was allocated to one of the first two categories even though the words underground or surface did not appear-for example, "shopfirer" or "clerk in the iron mine". For each work category and for each area of residence in 1939 (Ennerdale RD and Whitehaven MB), man-years at risk by age group and calendar period were calculated for 1939-83. Expected numbers of deaths attributed to particular causes were obtained by multiplying the man-years at risk in each area, age group, and calendar period by the corresponding mortality rates for the following: (1) all men in England and Wales, (2) men in all rural districts (for comparison with...
Summary It has recently been reported that a series of testis cancers shows a temporal cycle in birth dates with a peak in certain months. This observation has been tested by an examination of a larger series covering all testis cancers diagnosed in the years (Registrar General, 1940-60 These tests were also applied to teratomas (combined with chorion epitheliomas) and seminomas separately.It seemed possible that the above analysis, based on total births, might be affected by changes in the sex ratio in different months and calendar years. The data were therefore also analysed using expected numbers derived from estimated numbers of live male births for each month and year. The monthly numbers of live male births were estimated from the total numbers of live male births for each year in the period by applying the monthly proportions of male live births for 1980 (Macfarlane & Mugford, 1984 The observed numbers and observed to expected ratios are summarised in Table I for five calendar periods, 1940-44, 1945-49, 1950-54, 1955-60 Table II, which also shows the corresponding findings in tests for 3-, 4-, 5-and 6-monthly cycles for this period, and also for the other calendar periods mentioned above. The test for a 2-monthly cycle in the period 1945-49 was indeed highly significant (P=0.0002). Also significant (though at a lower level) were the tests for 4-monthly and 6-monthly cycles in the same period, reflecting the effects of the apparent 2-monthly cycle.When the analyses were repeated for teratomas and seminomas separately (Table III)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.