Studying survival of cancer patients in different populations: its potential and role.
BACKGROUND
Survival figures from a population-based study incorporate the overall practice in diagnosis, cure and clinical follow-up for a specific disease within a given health care system. Being the outcome of a number of individual, social and economical aspects, population-based survival may be thought as index for measuring the level of a country's development.


METHODS
The EUROCARE project, a European Cancer Registries (CR) concerted action, provided reliable information on survival for more than 800,000 cancer patients from 11 European countries. A great deal of epidemiologic information has derived from EUROCARE. Women had a longer survival than men for all studied tumour sites, except for the colon. European survival variability was fairly high for several cancers, but it was lower for cancers with a relatively good prognosis and those sensitive to treatment. The ranking of populations of cancer survival tended to be fairly stable for many cancers: CR of Switzerland and Finland ranked high and Polish CR low. Denmark, Italian and France CR did not substantially differ from the European survival average. For most cancers, prognosis improved during the studied period (years of diagnosis: 1978-1985). Survival figures for colon (r = 0.74, males; r = 0.73, women) and female breast cancer (r = 0.57) well correlated with the national health expenditure of different participating countries. The ITACARE study, a new Italian Cancer Registries collaborative project involving more than 100,000 cancer patients, was set up to study survival differences within the country. Survival of cancer patients was not homogeneous in 7 studied Italian regions (the estimated 5-year relative survival for all malignant neoplasms combined ranked from 37.8% in CR of Sicily to 42.1% in those of Emilia-Romagna). The lowest levels of regional health expenditures were accompanied by the lowest levels of prognosis for overall cancers. However, a relatively low correlation among patient cancer survival and the regional health expenditure (r = 0.21) was found, suggesting that other factors such as different efficiency in managing cancer may play a role in explaining the intracountry differences.


CONCLUSIONS
Population-based survival figures may be used to study epidemiologic aspects, comparing different health systems, and may be interpreted as indexes for discussing inequalities in health in different populations.
Micheli
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Divisione di Epidemiologia, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy. EP14@ICIL64.CILEA.IT
Gatta
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Verdecchia
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D017677:Age Distribution; D005060:Europe / Q000453:epidemiology; D005260:Female; D005102:Health Expenditures; D006304:Health Status; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000191:economics / Q000453:epidemiology / Q000401:mortality*; D012042:Registries; D012306:Risk; D017678:Sex Distribution; D015996:Survival Rate