Disparities in breast cancer survival between women with and without HIV across sub-Saharan Africa (ABC-DO): a prospective, cohort study

Researchers from the International Agency for Research on Cancer (IARC) and partner institutions conducting the African Breast Cancer–Disparities in Outcomes (ABC-DO) study have compared survival rates of HIV-negative women with breast cancer with survival rates of HIV-positive women with breast cancer in a new study published in The Lancet HIV.

Previous studies have shown increased mortality in women living with HIV diagnosed with breast cancer compared with HIV-negative women with breast cancer. The ABC-DO team followed up more than 1600 women with and without HIV in five countries in sub-Saharan Africa to explore how this HIV-related survival differential varies by patient or breast tumour characteristics at diagnosis.

At diagnosis of breast cancer, women with HIV were younger and had lower body mass index (BMI) than their HIV-negative counterparts, but had similar tumour stage, grade, and receptor subtypes. At the end of the follow-up, a higher proportion of women with HIV had died than had HIV-negative women, and crude 3-year survival was lower for women with HIV than for HIV-negative women. The HIV survival differential did not differ by age, BMI, tumour subtype, or tumour grade, but was stronger in women with non-metastatic disease. Women with metastatic cancer had low survival, regardless of HIV status.

The larger survival deficit in women with HIV with non-metastatic breast cancer highlights the need for a better understanding of the reasons underlying this differential (e.g. biological mechanisms, health behaviours, detrimental interactions between HIV and breast cancer treatment, or higher background mortality associated with HIV), to inform strategies to reduce mortality in this group of patients.

Chasimpha S, McCormack V, Cubasch H, Joffe M, Zietsman A, Galukande M, et al.
Disparities in breast cancer survival between women with and without HIV across sub-Saharan Africa (ABC-DO): a prospective, cohort study
Lancet HIV, Published online 2 March 2022;
https://doi.org/10.1016/S2352-3018(21)00326-X

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