Epidemiology of cancer
The epidemiology of cancer is the study of the prevalence of disease in human populations and variations in that prevalence resulting from a variety of factors including the environment, life style and genetic characteristics. The Epidemiology Unit at Gustave Roussy is within the Gustave Roussy Biostatistics and Epidemiology Department.
Two indicators are used in the study of cancer prevalence. The first is mortality (the annual death rate) and the second is the incidence (the number of newly diagnosed cases each year). In France, the national mortality data are derived from death certificates and are published annually by INSERM (see the INSERM web site and the INED web site). Calculated national cancer incidence figures appear on the International Agency for Research on Cancer web site.
Cancer overtook cardiovascular disease as the commonest cause of death in men and women in 1988 and 2002 respectively. In 1999 cancer was the cause of death in 32 % of men compared with a figure of 29 % for cardiovascular disease.
Prevention and risk factors
The World Health Organisation (WHO) distinguishes several types of cancer prevention:
- Primary prevention: intervening in cancer causation
- Secondary prevention: treating precancerous conditions. This implies that effective measures are available for diagnosis and therapy.
- Tertiary prevention: using screening for systematic testing of a population to uncover cancer when it is not giving rise to symptoms
To effect primary prevention in the general population, it is necessary to know, amongst other factors, the relative roles of the various identified causes. With this knowledge it is possible to assess preventive measures and limit risk factors. In addition, individuals who understand the risk factors can take care with their lifestyles, in order to reduce the chances of developing the disease.