Abstract A075: Hypofractionated radiotherapy for metastatic breast cancer: A 5-year single-institution experience in sub-Saharan Africa.

Abstract

Hypofractionation has documented comparable outcomes to conventional treatment, with potential advantages of reduced strain on providers, patients, and the healthcare system. Various studies have aimed to validate this experience in countries with different resource availability. This study contributes to the literature on hypofractionated radiotherapy (HFRT) in sub-Saharan Africa (SSA) by reporting our 5-year experience using HFRT in the treatment of patients with metastatic breast cancer (mBC). We conducted a retrospective study of patients with mBC treated with HFRT at the Medserve-LUTH Cancer Centre, Lagos, Nigeria, between May 2019 and April 2024. Of 2,048 patient records reviewed, 562 had metastatic disease, and 214 received HFRT. Data were extracted from electronic medical records and analyzed using descriptive statistics. The mean age was 49.34 ± 11.7 years, 211 were female, and 3 were male. The peak age group was 51-60 years (29.4%), and the most common histology was ductal carcinoma (71.5%). The most frequently documented presenting complaint was breast lump (58.9%), and laterality showed right breast cancer in 50.5% and left breast cancer in 47.2%. Immunohistochemistry was reported for 75.2% of patients. Metastatic sites included the brain (65.4%), bone (65.9%), lung (37.4%), and liver (18.7%). Radiotherapy intent was curative in 13.1% and palliative in 86.9% of cases. Overall, 61.7% of patients were treated with three-dimensional conformal radiotherapy (3DCRT), while 38.3% received intensity-modulated radiotherapy (IMRT). Spinal irradiation was administered to 76 patients (35.5%), predominantly with palliative intent (96.1%). The most frequently used technique for spinal irradiation was 3DCRT (60.5%), and the most common dose schedule was 20 Gy in 5 fractions (65.8%). Chest wall HFRT was delivered to 61 patients (28.5%), mainly for palliative purposes (82.0%). IMRT was more commonly used (54.1%), and the most frequently utilized dose was 30 Gy in 10 fractions (47.5%). Breast HFRT was administered to 24 patients (11.2%), with curative intent in 54.2%. Treatment techniques were evenly distributed between 3DCRT and IMRT (50% each). The most common breast dose schedule was 42 Gy in 15 fractions (41.7%). Brain HFRT was administered to 137 patients (64.0%). Most treatments were palliative (88.3%) and delivered using 3DCRT (64.2%). The most common brain dose schedule was 20 Gy in 5 fractions (54.7%). This study presents a five-year experience with HFRT for metastatic breast cancer at a cancer centre in SSA. Hypofractionated radiotherapy was predominantly used for palliative management, particularly for brain metastases, and proved to be a feasible treatment option in a resource-limited setting. The findings support the broader use of HFRT in similar environments and support the need for further research on long-term outcomes. Emmanuel T. Andero, Anthonia C. Sowunmi, Adedayo Joseph, Bolanle Adegboyega, Ayodeji O. Ojetunde, Oluwadara A. Ojediran. Hypofractionated radiotherapy for metastatic breast cancer: A 5-year single-institution experience in sub-Saharan Africa [abstract]. In: Proceedings of the 19th AACR Conference on the Science of Cancer Health Disparities; 2026 Oct 18-21; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2026;35(10 Suppl):Abstract nr A075.