Short-term breast cancer survival in relation to ethnicity, stage, grade and receptor status: national cohort study in England

Background: In the re-organisation of cancer registration in England in 2012, a high priority was given to the recording of cancer stage and other prognostic clinical data items. Methods: We extracted 86 852 breast cancer records for women resident in England and diagnosed during 2012-2013. Information on age, ethnicity, socio-economic status, comorbidity, tumour stage, grade, morphology and oestrogen, progesterone and HER2 receptor status was included. The two-year cumulative risk of death from any cause was estimated with the Kaplan-Meier method, and univariate and multivariate Cox proportional hazards regressions were used to estimate hazard ratios (HR) and their 95% confidence intervals (95% CI). The follow-up ended on 31 December 2014. Results: The completeness of registration for prognostic variables was generally high (around 80% or higher), but it was low for progesterone receptor status (41%). Women with negative receptor status for each of the oestrogen, progesterone and HER2 receptors (triple-negative cancers) had an adjusted HR for death of 2.00 (95% CI 1.84-2.17). Black women had an age-adjusted HR of 1.77 (1.48-2.13) compared with White women. Conclusions: The excess mortality of Black women with breast cancer has contributions from socio-economic factors, stage distribution and tumour biology. The study illustrates the richness of detail in the national cancer registration data. This allows for analysis of cancer outcomes at a high level of resolution, and may form the basis for risk stratification.