Aldehyde dehydrogenase 1 expression predicts poor prognosis in triple‐negative breast cancer

Ohi Y, Umekita Y, Yoshioka T, Souda M, Rai Y, Sagara Y, Sagara Y, Sagara Y & Tanimoto A (2011) Histopathology59, 776–780 Aldehyde dehydrogenase 1 expression predicts poor prognosis in triple‐negative breast cancer Aims: Aldehyde dehydrogenase 1 (ALDH1) has been identified as a reliable marker of breast cancer stem cells, and its clinical significance as a prognostic indicator of breast cancer has been reported by several investigators. However, the clinical significance of ALDH1 expression in triple‐negative (TN) breast cancer, a high‐risk breast cancer lacking the benefit of specific therapy, remains to be solved. Methods and results: We performed immunohistochemical analyses of 106 TN breast cancers, using paraffin‐embedded sections. The basal‐like phenotype was also investigated with the use of basal cytokeratin 5/6 and epidermal growth factor receptor. ALDH1 expression in carcinoma cells was found in 59% of cases and was correlated with high histological grade alone (P