Breast cancer overall survival, annual risks of death, and survival gap apportionment in sub-Saharan Africa (ABC-DO): 7-year follow-up of a prospective cohort study

Researchers from the International Agency for Research on Cancer (IARC) and partner institutions across Africa have completed a 7-year follow-up of women diagnosed with breast cancer in five countries in sub-Saharan Africa and found that only 1 in 3 women survived for 7 years after diagnosis. This is the final follow-up of the prospective African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort study. The results were published in The Lancet Global Health.

The study team analysed data for 2153 women who were newly diagnosed with breast cancer between 8 September 2014 and 31 December 2017 and who were followed up until 1 January 2022, and for a further year in South Africa. Of these women, 1323 (61%) had died, 672 (31%) remained alive, and 158 (7%) were lost to follow-up. The crude survival was 51% at 3 years, 40% at 5 years, and 33% at 7 years. Estimates of net survival were slightly higher.

Large between-country variations in 5-year age-standardized net survival were observed, ranging from 35–42% in Zambia and Nigeria to 52–58% in Black women in Uganda, South Africa, and Namibia and more than 83% in non-Black women in Namibia.

The World Health Organization (WHO) Global Breast Cancer Initiative aims to reduce breast cancer mortality through health promotion for earlier diagnosis and increasing treatment completion rates. The study team estimated that if these goals could be achieved, approximately one third of breast cancer deaths among Black women in sub-Saharan Africa would be averted. Increasing awareness of breast cancer in women and in health providers, accelerating supported referral pathways to diagnosis, and ensuring that accessible multimodal treatment is completed would strengthen breast cancer control in this region.

Mo T, Joffe M, Cubasch H, Galukande M, Parham G, Pinder L, et al.
Breast cancer overall survival, annual risks of death, and survival gap apportionment in sub-Saharan Africa (ABC-DO): 7-year follow-up of a prospective cohort study
Lancet Glob Health. Published online 17 September 2025;
https://doi.org/10.1016/S2214-109X(25)00273-6

Read the article