An international comparison of cancer survival: relatively poor areas of Toronto, Ontario and three US metropolitan areas

Background This study of cancer survival compared adults in Toronto, Ontari o and three US metropolitan areas: Seattle, Washington; San Francisco, Cali fornia; and Hartford, Connecticut. It examined whether socioeconomic status has a differential effect on cancer survival in Canada and the United Stat es. Methods The Ontario Cancer Registry and the National Cancer institute's Sur veillance, Epidemiology and End Results (SEER) programme provided a total o f 23 437 and 37 329 population-based primary malignant cancer cases for the Toronto and VS samples, respectively (1986-1988, followed until 1994). Cen sus-based measures of socioeconomic status were used to ecologically contro l absolute income status. Results Among residents of low-income areas, persons in Toronto experienced a 5 year survival advantage for 13 of 15 cancer sites [minimally one gende r significant at 95 per cent confidence interval (CI)]. An aggregate 35 per cent survival advantage among the Canadian cohort was demonstrated (surviv al rate ratio (SRR) = 1.35, 95 per cent CI = 1.30-1.40), and this effect wa s even larger among younger patients not yet eligible for Medicare coverage in the United States (SRR = 1.46, 95 per cent CI = 1.40-1.52). Conclusion Systematically replicating a previous Toronto-Detroit comparison , this study's observed consistent pattern of Canadian survival advantage a cross various cancer sites suggests that their more equitable access to pre ventive and therapeutic health care services may be responsible for the dif ference.