M.J. Gardner

Analysis of trends in cancer mortality in England and Wales during 1951-80 separating changes associated with period of birth and period of death.

Cancer mortality rates in England and Wales were analysed so to describe simultaneously changes affecting successive generations--that is, associated with period of birth--as well as changes associated with the period of which the deaths took place. When mortality from all cancers was considered the analysis implied that, contrary to a widely held view, the rate of death from cancer had been declining in each sex in successive generations. For men the decline had occurred in generations born since 1900, whereas for women the peak came in the 1925 birth group. On the other hand, there had been little decline in the rates associated with period of death. Five examples of cancers of specific organs for which the trends contrasted are shown.

MESOTHELIOMA IN A FACTORY USING AMOSITE AND CHRYSOTILE ASBESTOS

Abstract 5 deaths have been certified as due to mesothelioma (4 pleural and 1 peritoneal) in men who worked at a London factory where insulation board has been manufactured since 1946 from a mixture of amosite and chrysotile asbestos. It seems reasonable to relate 4 of these cases to work at the factory. Amosite has been the fibre predominantly in use and seems likely to be the cause of the tumours.

Variations in cancer mortality among local authority areas in England and Wales: relations with environmental factors and search for causes.

Geographical variations in specific causes of mortality among the 1366 local authority areas of England and Wales as defined at 1971 were studied by examining extracts from death certificates held on computer tape. Five items of information on each death--year of death, age at death, sex, local authority area of residence, and the underlying cause of death, during the 11 years 1968-78--permitted a more detailed investigation than had been possible before. Analysis of some early results of the study--including maps of mortality for pleural mesothelioma, nasal cancer and bladder cancer--suggested that, despite the known limitations of death certification, systematic study of the mortality of small areas may give clues to aetiological factors in the environment. Analyses relating mortality to the distribution of environmental factors and examining disease profiles of each area may also provide clues. These will be followed up by other methods of study, such as case-control techniques.

Interpretation of disease time trends: is cancer on the increase? A simple cohort technique and its relationship to more advanced models.

Analysis of trends in mortality from respiratory cancer among women shows that, contrary to previous interpretation, there is no suggestion of any increase over time which might be due to recent increases in exposures to carcinogens. Although there are upward trends in the number of deaths, the crude death rate, and the age standardised rate, these are shown to be related to the aging of earlier cohorts of women who have experienced high mortality rates. More recent cohorts, born since the middle 1920s, show a decline. A simple technique to identify trends in different cohorts is described, and it is shown to be linked to the age-period-cohort modelling approach to investigating time trends. Dangers inherent in ignoring either period or cohort effects when describing one of these factors are discussed.

Mapping cancer mortality.

complicating factor. The effect of opiates on respiration in healthy cats (references 5 and 6 in Dr Woodcocks letter) is hardly comparable to responses in an ill man with chronic lung disease. But the observation reinforces our point that when this man was well after his discharge from hospital he, indeed, showed no response to naloxone. He responded only when he was severely ill, and the greatest response in terms of ventilation was with the bolus study on the day before the infusion study. Since our paper was accepted for publication, we have given naloxone to more patients in respiratory failure and have found one further patient with a convincing response in rate and depth of ventilation and in blood gases while severely ill but no response after recovery. Dr Webbs point about the use of a cuirass was one that we discussed. Because of his palsied diaphragms he was provided with a rocking bed, which greatly helped him subjectively both at home and in hospital, where it was also shown to improve his night-time desaturation. He had no evidence of upper airways obstruction. The role of naloxone is not irrelevant as the response in oxygen saturation occurred only during naloxone infusion. We are not suggesting that naloxone is the treatment of choice in acute respiratory failure, but we do believe that our conclusion that endorphins may play a part in some patients with acute respiratory failure is valid, and that this case report should act as the basis for a formal study of this response both in the investigation of the mechanism involved and therapeutically.