Mortality from selected malignant neoplasms in the British Isles: The spatial perspective

Data for mortality from lung-bronchus cancer, gastric cancer and cancer of the large intestine and rectum, respectively, in males and for breast cancer in females, age group 15–64 years for both sexes, for the years 1970–1972 inclusive, and data on age-structure of local populations (1971 census) are used to calculate standardized mortality ratios (SMR) for the selected causes for 320 administrative areas in the British Isles. The SMRs indicate mortality experience after allowance is made for variations in the age structure of populations throughout the country. The SMRs are portrayed on a demographic map, which shows the distribution of mortality experience relative to the populations at risk in the different parts of the country. Marked spatial variations in mortality experience of each of the selected malignant neoplasms are revealed. The unequivocal quantitative relationship which epidemiologists have demonstrated between lung cancer experience and cigarette smoking does not explain the spatial disparities and urban affinities of mortality from that disease. In the case of gastric cancer, high risk areas are present in both urban and rural areas; the spatial pattern provides no support for the reported statistical association between gastric carcinoma and people of blood group A. The geographical pattern of elevated mortality from cancer of the large intestine and rectum does not lend support for the hypothesis that the carbohydrate rich diet of people living in less affluent parts of the country predisposes to tumours of this site. The marked spatial heterogeneity of female mortality from cancer of the breast suggests a variety of life-style and environmental associations. Geographical variations in mortality experience from the selected malignant neoplasms within the British Isles support the view that environmental factors—physical, biological, socio-cultural—are involved in their multifactorial aetiology.