Inequalities in Female Breast Cancer Survival: A Study Using the Population-Based Cancer Registry of São Paulo, Brazil

Inequalities in cancer mortality rates reflect differences in incidence, mortality and prevalence of the disease among different populations. It has been observed in many developed countries an increase in survival rates that can be explained both by improvements in early detection of new cases and by progress of therapies used in treatment. The literature shows that cancer survival may be influenced by socioeconomic factors. Some studies suggest that the coverage by private health plans is a mediator in the correlation between socioeconomic status, late diagnosis and survival, and may be a cause of inequalities in incidence, mortality and survival of breast cancer. But the results are controversial and some studies found no differences in survival rates even when the stage is controlled. This is a retrospective longitudinal study, with analysis of the 5-year survival of women diagnosed with breast cancer, living in São Paulo city, Brazil. The research used vital statistics data from the Mortality Information System (SIM-SP), the Population-Based Cancer Registry of São Paulo (RCBP/FSP/USP) and the administrative data from the National Information System of Private Health Plans (SIB/ANS/MS). Kaplan-Meier method was used for data analysis and the results pointed out significant associations survival rates and socioeconomic factors. The comparison of survival curves between women covered and not covered by private health insurance have shown that patients without insurance coverage presented a survival rate of 89.1% while among patients with health insurance the estimated survival was 80,6%. These findings highlight the need for additional studies to assess new variables in the analyses.