• avoidable deaths;
  • excess mortality models;
  • relative survival;
  • socioeconomic differences

Socioeconomic differences in cancer patient survival exist in many countries and across cancer sites. In our article, we estimated the number of deaths in women with breast cancer that could be avoided within 5 years from diagnosis if it were possible to eliminate socioeconomic differences in stage at diagnosis. We analysed data on East of England women with breast cancer (2006–2010). We estimated survival for different stage-age-deprivation strata using both the observed and a hypothetical stage distribution (assuming all women acquired the stage distribution of the most affluent women). Data were analysed on 20,738 women with complete stage information (92%). Affluent women were less likely to be diagnosed in advanced stage. Relative survival decreased with increasing level of deprivation. Eliminating differences in stage at diagnosis could be expected to nearly eliminate differences in relative survival for women in deprivation groups 3 and 4, but would only approximately halve the difference in relative survival for women in the most deprived group (5). This means, for a typical cohort of women diagnosed in a calendar year with breast cancer, eliminating deprivation differences in stage at diagnosis would prevent ∼40 deaths in the East of England from occurring within 5 years from diagnosis. Using appropriate weighting we estimated the respective number of avoidable deaths for the whole of England to be ∼450. The findings suggest that policies aimed at reducing inequalities in stage at diagnosis between women with breast cancer are important to reduce inequalities in breast cancer survival.