Introduction Sub-Saharan African (SSA) women with breast cancer (BC) have low survival rates from this potentially treatable disease. An understanding of context-specific societal, health-systems and woman-level barriers to BC early detection, diagnosis and treatment are needed.

Methods The African Breast Cancer—Disparities in Outcomes (ABC-DO) is a prospective hospital-based study of overall survival, impact on quality of life (QOL) and delays along the journey to diagnosis and treatment of BC in SSA. ABC-DO is currently recruiting in Namibia, Nigeria, South Africa, Uganda and Zambia. Women aged 18 years or older who present at participating secondary and tertiary hospitals with a new clinical or histocytological diagnosis of primary BC are invited to participate. For consented women, tumour characteristics, specimen and treatment data are obtained. Over a 2-year enrolment period, we aim to recruit 2000 women who, in the first instance, will be followed for between 1 and 3 years. A face-to-face baseline interview obtains information on socioeconomic, cultural and demographic factors, QOL, health and BC attitudes/knowledge, and timing of all prediagnostic contacts with caregivers in orthodox health, traditional and spiritual systems. Responses are immediately captured on mobile devices that are fed into a tailored mobile health (mHealth) study management system. This system implements the study protocol, by prompting study researchers to phone women on her mobile phone every 3 months and, failing to reach her, prompts contact with her next-of-kin. At follow-up calls, women provide updated information on QOL, care received and disease impacts on family and working life; date of death is asked of her next-of-kin when relevant.

Ethics and dissemination The study was approved by ethics committees of all involved institutions. All participants provide written informed consent. The findings from the study will be published in peer-reviewed scientific journals, presented to funders and relevant local organisations and at scientific conferences.