Ethnicity and breast cancer incidence in over 329,500 women in England in 2011-2019.

[INTRODUCTION] Previous studies have reported an overall lower breast cancer incidence in women from Asian and Black backgrounds compared with white women. Age standardised and age specific incidence rates in the largest specific ethnicities within Asian and Black groups are not reported.

[MATERIALS AND METHODS] Data on population size and the age distribution of women in five ethnic groups of interest (white British, Black African, Black Caribbean, Indian and Pakistani) were extracted from the Office for National Statistics 2001, 2011 and 2021 census data for England.Cancer registrations for invasive breast cancer (ICD-10 C50) in women in England aged ≥25 years during 2011-2019 with a recorded ethnicity were extracted from the National Cancer Registration and Analysis Service.Age standardised (ASIRs) and age specific (ASRs) incidence rates in five ethnic groups of interest were calculated.

[RESULTS] 329,655 women who were aged ≥25 years and in one of the five ethnic groups of interest had a record of an incident C50 cancer registration during 2011-2019. The ASIR was highest for white women (199.6 (95% CI 198.9-200.3)), and lowest for Black African women (118.2 (95% CI 111.6-125.1)). The ASRs for invasive breast cancer were generally lower in women from minority ethnic groups compared to white women in all age groups examined except for younger Black Caribbean women.

[CONCLUSIONS] There are significant differences in breast cancer incidence rates between women from specific ethnicities. This requires further investigation in large scale prospective studies considering potential differences by ethnicity in known risk factors for breast cancer.