Chondroitin sulfate proteoglycan 4 (CSPG4), a transmembrane proteoglycan originally identified in melanoma cells, has been reported to be expressed in breast cancer cells. This study was performed to examine the expression and significance of CSPG4 in a cohort of breast cancer patients. Immunohistochemical analysis of CSPG4 was performed on tissue microarrays constructed from tissue specimens from 240 breast cancer patients. CSPG4 staining was correlated with clinical and pathological characteristics, overall survival (OS), and disease recurrence. Contradicting to a previous report, our results showed that high CSPG4 expression was not related to triple-negative status of breast cancer patients. The Kaplan-Meier method showed that high CSPG4 expression was significantly associated with shorter time to recurrence (TTR). Patients with high CSPG4 expression had poorer OS and shorter TTR in a multivariate survival analysis after adjustment for stage, tumor grade, expression of estrogen receptor and progesterone receptor, and HER2 overexpression. This study showed that high CSPG4 expression correlates with disease recurrence and OS in breast cancers. (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved.