Different prognostic significance of CD24 and CD44 expression in breast cancer according to hormone receptor status

Abstract Objective CD44+ CD24−/low -expressing tumor cells have been studied as tumorigenic stem cells in vitro study. This study was designed to determine the clinical implication of the CD44 and CD24 expression in breast cancer. Methods Tissue microarray blocks containing 643 consecutive cases of invasive breast carcinomas from 1993 to 1998 were immunostained for CD44 and CD24. The median follow-up period was 127 months. Results CD44− CD24+ phenotype was associated with frequent hormone receptor positivity and Her2/neu positivity ( P = 0.000; Both). The CD44+ CD24− phenotype was inversely associated with lymph node metastasis ( P = 0.002), and it showed positive associations with prolonged disease-free survival (DFS; P = 0.003) and overall survival (OS; P = 0.002). 10-year DFS and OS were 68.9% and 74.6% for CD24 negative group, 55.6% and 60.9% for CD24 positive group ( P = 0.001; Both). 10-year DFS and OS were 62.2% and 68.1% for CD44 negative group, 73% and 77.7% for CD44 positive group ( P = 0.012, P = 0.013, respectively). In a multivariate analysis, CD24 expression was negatively related to OS only in the receptor positive group (Hazard ratio = 2.03; P = 0.003; 95% CI: 1.27–3.24) and CD44 expression was positively related to OS only in the hormone receptor negative group (hazard ratio = 0.58; P = 0.022; 95% CI: 0.36–0.92). Conclusions The CD44+ CD24− group is considered a favorable prognostic subgroup in breast cancer. CD24 expression was a poor prognosis marker in hormone receptor positive breast cancer, and CD44 expression was a good prognostic marker in the receptor negative group.