Molecular Biology of Breast Cancer in the Horn of Africa: Case Series—A Pilot Study of Breast Cancer from Eritrea

Background. Recently, gene expression profiling and its surrogate immunohistochemistry (IHC) markers classified breast cancer into four distinct molecular subtypes, which have different prognoses, targeted therapies, and/or clinical outcomes. Objective. To conduct a preliminary study, to correlate the clinical pathological profiles and taxonomy of molecular subtypes of breast cancer in Eritrea, in the Horn of Africa. Design. Review of pathology reports from Jan. 1 to Nov. 30, 2009, provided 22 cases of microscopically confirmed invasive breast carcinoma that were evaluable for histology and IHC (ER, PR, HER2, and Cytokeratin 5/6). Result. Twenty patients were female and most of them (68%) were under 50 years at presentation. 90% were invasive invasive carcinoma of no special type and were histological grade 3. The molecular subtypes were luminal A (55%), luminal B (5%), HER2 (5%), basal-like (10%), and unclassified (25%). Triple negative carcinoma (basal-like and unclassified combined) was 35%, mostly (71%) in women under 50 years with grade 3 tumours. Conclusion. Breast carcinoma in Eritrean women presents at a younger age and with a high histologic grade. The two predominant molecular subtypes are luminal A and triple negative. Determining the molecular subtype using surrogate IHC markers has important treatment and prognostic implications for Eritrean women with breast cancer.