A comparative analysis of cancer prevalence in cancer registry areas of France, Italy and Spain.

A comparative analysis of cancer prevalence in France, Spain and Italy is presented as part of the EUROPREVAL project. The three countries are culturally and sociologically relatively homogeneous compared with Europe as a whole. However, in all three countries, the cancer registries (CRs) providing the data for prevalence calculation cover only small fractions of the populations, and have been operating for relatively short periods. This leads to problems of representativity and to prevalence underestimates as surviving cases diagnosed before operation of the CR are not recorded. Partial prevalences obtained directly from CR data were therefore corrected using a completeness index obtained by modelling to provide estimates of the complete prevalence. For CRs operating for only 5 years, only approximately half the prevalence was observed. Thus, due to the rather recent start of most of southern European CRs, the role of correction is very important. The prevalence of all cancers was highest in Italy for women and in France for men, while lowest in Spain. Differences in the age structures of the populations were the major cause of these discrepancies and after age adjustment only the prevalence of stomach cancer remained highest in Italy, although differences in incidence also contributed to the prevalence differences. Survival varied little between the three countries and differences in incidence are more important determinants of prevalence. Prevalence of cancer in the elderly represents an increasing load for the community, particularly for France, Italy and Spain due to the ageing population in these countries. Elderly patients with cancer frequently suffer from problems of co-morbidity and disability factors, thus placing a burden on the local medical system where this proportion is high. Prevalent cases diagnosed 1-5 years before the prevalence date formed approximately one-third of the total prevalence, with higher proportions for melanoma, and prostate cancer in males and breast and colorectal cancer in females, and lower proportions for uterine cancer. This subset of the prevalent population consists of those probably on intensive follow-up, or being treated for cancer recurrence or sequelae to primary therapy.