Association of CD44 and CD24 phenotype with lymph node metastasis and survival in triple-negative breast cancer

Background: CD44*CD24(-/low) phenotypes are associated with poor outcome of triple-negative breast cancer (TNBC); however, the role of the CD44*CD24(-/low) phenotype in lymph node metastasis and survival has not been fully understood in TNBC. Methods: A total of 51 TNBC patients were included. CD44 and CD24 expression was determined using immunohistochemistry by which CD44 and CD24 were double-immunostained. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Results: The proportion of the CD44*CD24(-/low) phenotype was 33.3% in TNBC specimens without lymph node metastases and 69.0% in those with lymph node metastases. In addition, the CD44*CD24(-/low) phenotype correlated significantly with tumor size, histologic classification, TNM stage, and lymph node metastasis (P < 0.05). The CD44*CD24(-/low) phenotype was detected in 69.0% of TNBC patients with lymph node metastases, and 51.7% of TNBC patients without lymph node metastases. In TNBC patients without lymph node metastases, the median DFS and OS were 18.2 and 28 months in cases with a CD44*CD24(-/low) phenotype and 26.5 and 42.5 months in those without a CD44*CD24(-/low) phenotype (P < 0.05), and in TNBC patients with lymph node metastases, the median DFS and OS were 17.2 and 25.7 months in cases with a CD44*CD24(-/low) phenotype and 24.5 and 39.3 months in those without a CD44*CD24(-/low )phenotype, respectively (P < 0.05). Conclusions: CD44 and CD24 are independent prognostic markers for patients with TNBC. The CD44*CD24(-/low) phenotype correlates with more aggressive clinicopathologic features and is strongly associated with poor prognosis in patients with TNBC.