The impact of ethnicity on breast cancer surgery decisions and mortality in England: a population-based cohort study
Session type: E-poster/poster
In the UK, Black breast cancer patients have a higher cancer-specific and all-cause mortality compared to White and South Asian (SA) women. In the US, Black-White differences in the receipt of breast-conserving surgery (BCS) compared to mastectomy are evident. This study aims to estimate UK ethnic differences in BCS/mastectomy rates and its impact on mortality.
The National Cancer Registry provided data on breast cancer cases diagnosed between 01/01/2009 and 31/12/2012 (follow up 31/12/2014) on the following variables: patient characteristics (age, deprivation, ethnicity, comorbidities), tumour characteristics (morphology, grade), system characteristics (route to diagnosis), breast surgery (dichotomised into 'mastectomy' and 'BCS'), vital status and date of death. Complete-case analysis was performed. The odds of mastectomy by ethnicity was estimated using a logistic regression, adjusting for patient, tumour and system factors. Overall mortality was estimated using classical Cox regression.
77940 White (96.3%), Black (1.4%) and SA (2.3%) women had undergone mastectomy (64.5%) or BCS (38.5%). Black and SA women were more deprived, younger and diagnosed with a higher tumour grade. 27.6% of ethnicity information was missing and 67.5% of these cases underwent BCS. SA and Black women (OR 1.21, 95% CI 1.07-1.37, p=0.002) had a 20% greater crude odds of mastectomy. In Black women, this was attenuated by adjusting for deprivation and age (p=0.18). Mortality between ethnicities varied by breast surgery (p=0.0008). SA women had a lower mortality risk and this was attenuated by deprivation and age. SA women had the greatest mortality disparity by BCS/mastectomy.
Table 1: Mastectomy in South Asian compared to White women
Deprivation and age partially attenuate for surgical differences in Black women and mortality differences in SA women. Further work should explore ethnic inequalities across the cancer pathways and improve ethnicity-related data recording.
The receipt of breast cancer surgery varies by ethnicity and this may play a role in cancer mortality inequalities.