Y-box binding protein-1 expression in diffuse large B-cell lymphoma: an impact on prognosis in the rituximab era

The expression of YB-1 has been reported to predict poor clinical outcome in many human malignancies, including hematopoietic malignancies. In this study, we investigated the correlations between YB-1 expression and the clinicopathological features of patients with diffuse large B-cell lymphoma (DLBCL) in a single institution. The expression of YB-1 was analyzed in 168 cases by immunohistochemistry. Fifteen out of 168 cases (8.9%) showed cytoplasmic expression of YB-1. The expression of YB-1 was significantly associated with 5-year overall survival (OS) (p = 0.023). Rituximab plus CHOP therapy (n = 94) improved the 5-year survival rate in both YB-1-positive and -negative patients. In conclusion, the data presented in this report provide evidence that the cytoplasmic expression of YB-1 is a poor prognosis factor in DLBCL treated with CHOP therapy, whereas rituximab improves the survival of both YB-1-positive and -negative patients with DLBCL.