Impact of HIV infection on overall survival among women with stage IV breast cancer in South Africa

• Published in: Breast cancer research and treatment Vol. 189; no. 1; pp. 285 - 296
• Main Authors: Pumpalova, Yoanna S., Ayeni, Oluwatosin A., Chen, Wenlong Carl, O’Neil, Daniel S., Nietz, Sarah, Phakathi, Boitumelo, Buccimazza, Ines, Čačala, Sharon, Stopforth, Laura W., Farrow, Hayley A., Joffe, Maureen, Mapanga, Witness, Jacobson, Judith S., Crew, Katherine D., Cubasch, Herbert, Ruff, Paul, Neugut, Alfred I.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2021; Springer Nature B.V
• Subjects: Breast cancer; Breast Neoplasms - epidemiology; Cancer research; Cohort Studies; Epidemiology; Female; HIV; HIV Infections - complications; HIV Infections - epidemiology; Hospitals; Human immunodeficiency virus; Humans; Medicine; Medicine & Public Health; Middle Aged; Oncology; Prospective Studies; Regression analysis; South Africa - epidemiology; Survival; United States; United States; South Africa; United States > US; sub-Saharan Africa; Breast cancer; Metastatic; HIV
• ISSN: 0167-6806; 1573-7217; 1573-7217
• DOI: 10.1007/s10549-021-06265-w

Purpose
Advanced breast cancer (BC) at diagnosis is common in sub-Saharan Africa (SSA), including among women living with HIV (WLWH). In public hospitals across South Africa (SA), 10–15% of women present with stage IV BC, compared to < 5% in the United States (US); 20% of new BC diagnoses in SA are in WLWH. We evaluated the impact of HIV on overall survival (OS) among women with stage IV BC.
Methods
We conducted a prospective cohort study of women diagnosed with stage IV BC between February 2, 2015 and September 18, 2019 at six public hospitals in SA. Multivariate Cox regression models were used to estimate the association between HIV status and OS.
Results
Among 550 eligible women, 147 (26.7%) were WLWH. Compared to HIV-negative BC patients, WLWH were younger (median age 45 vs. 60 years,
p
 < 0.001), predominantly black (95.9% vs. 77.9%,
p
 < 0.001), and more likely to have hormone receptor-negative (hormone-negative) BC (32.7% vs. 22.6%,
p
 = 0.016). Most women received systemic cancer-directed therapy (80.1%). HIV status was not associated with treatment or OS (Hazard Ratio (HR) 1.13 [95%CI 0.89–1.44]). On exploratory subgroup analysis, WLWH and hormone-negative BC had shorter OS compared to HIV-uninfected women (1-year OS: 27.1% vs. 48.8%,
p
 = 0.003; HR 1.94 [95%CI 1.27–2.94];
p
 = 0.002), which was not observed for hormone receptor-positive BC.
Conclusion
HIV status was not associated with worse OS in women with stage IV BC in SA and cannot account for the poor survival in this cohort. Subgroup analysis revealed that WLWH with hormone-negative BC had worse OS, which warrants further investigation.