Background The human Y-box-binding protein 1 (YB-1) is a member of the DNA/RNA-binding family of proteins that regulates transcription and translation of genes. Previous studies suggest that YB-1 may have an oncogenic role in various cancers. In this study, we evaluate the prognostic value of cytoplasmic YB-1 with respect to breast cancer. Methods Immunohistochemical staining study was performed with YB-1 using tissue block from 233 patients with invasive ductal carcinoma. Patients were divided into two groups according to expression of cytoplasmic YB-1 in tumor cell (high versus low). The relationship between the expression of YB-1, clinicopathological characteristics and breast cancer prognosis was analyzed. Results Hormone receptor negativity, worse histologic and nuclear grade, high tumor stage, lymphovascular invasion and high Ki67 (≥14 %) were related with the increased expression of cytoplasmic YB-1 in tumor cell (p
