Abstract
Objectives
This study examined whether place and socio-economic status had differential effects on the survival of women diagnosed with breast cancer in Ontario during the 1980s and the 1990s.
Methods
The Ontario Cancer Registry provided 29,934 primary malignant breast cancer cases. Successive historical cohorts (1986–1988 and 1995–1997) were, respectively, followed until 1994 and 2003. Diverse places were compared: the greater metropolitan Toronto area, other cities, ranging in size from 50,000 to a million people, smaller towns and villages, and rural and remote areas. Socio-economic data for each woman’s residence at the time of diagnosis were taken from population censuses.
Results
Very small cities (6%) with populations between 50,000 and 100,000 were the only places where breast cancer survival had advanced less compared to the province as a whole. Income gradients began to appear, however, in larger cities. Urban residents in the lowest income areas were significantly disadvantaged compared to the highest income areas during the 1990s, but not during the 1980s.
Conclusion
This historical analysis of breast cancer survival evidenced remarkably equitable advances across nearly all of Ontario’s diverse places. The most likely explanation for such substantial equity seems to be Canada’s universally accessible, single-payer, health care system.
Keywords: Breast cancer, survival, socioeconomic factors, cancer care, universal access, Ontario, health insurance
Résumé
Objectifs
Déterminer si le lieu et le statut socioéconomique ont eu des effets différents sur la survie des femmes ayant reçu un diagnostic de cancer du sein en Ontario pendant les années 1980 et 1990.
Méthode
Le Registre d’inscription des cas de cancer de l’Ontario a fourni 29 934 cas de cancers malins primaires du sein. Des cohortes historiques successives (1986–1988 et 1995–1997) ont été suivies, respectivement, jusqu’en 1994 et jusqu’en 2003. Divers lieux ont été comparés: la grande agglomération de Toronto, d’autres villes comptant de 50 000 à 1 million d’habitants, de petites villes et de villages, et des régions rurales et éloignées. Les données socioéconomiques sur le lieu de résidence de chaque femme au moment de son diagnostic ont été extraites des recensements.
Résultats
Les toutes petites villes comptant entre 50 000 et 100 000 habitants (6% de l’échantillon) étaient les seuls lieux où les taux de survie au cancer du sein avaient moins progressé que dans l’ensemble de la province. Des gradients selon le revenu commençaient cependant à se dessiner dans les villes plus grandes. En milieu urbain, les résidentes des zones aux revenus les plus faibles étaient significativement défavorisées par rapport à celles des zones aux revenus les plus élevés au cours des années 1990, mais ce n’était pas le cas pendant les années 1980.
Conclusion
Cette analyse historique des taux de survie au cancer du sein a mis au jour une progression remarquablement équitable dans presque tous les lieux de l’Ontario. Cette équité s’explique probablement par la présence au Canada d’un régime de santé universel à payeur unique.
Motsclés: cancer du sein, survie, facteurs socioéconomiques, soins du cancer, accès universel, Ontario, assurance-maladie
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