The distribution of CD44+/CD24- cancer stem cells in breast cancer and its relationship with prognostic factors.

PURPOSE The purpose of this study was to investigate the correlation between the percentages of CD44+/CD24- cancer stem cells (CSCs) and the clinicopathological and prognostic factors in breast cancer patients. METHODS Twenty three women who underwent surgery for breast cancer were enrolled in this study. The mean age of the patients was 46.65 years and 52% had early-stage disease. Tumor tissues obtained during surgery were digested enzymatically. CD44+/CD24- cell phenotype was identified by using surface marker antibodies and percentages were determined by surface marker expression of the cells. RESULTS Sixty five percent of the tumors were positive for estrogen (ER)/ progesterone receptors (PR) and 38% of the tumors were positive for HER-2. All of the patients with hormone receptor positive tumors had ER positive tumors, while only 11 patients had PR positive breast cancer. CD44+/CD24- cells were present in all tumor tissues. The mean proportion of the CD44+/CD24- cells was 1.43±1.6. The mean percentages of CD18+ cells and MUC1+ were 27.9±26.5% and 6.07±11.34%, respectively. The percentage of CD18+ cells was significantly higher in PR positive tumors (p=0.042). There was no significant correlation between the percentage of CD44+/CD24- cells and clinicopathological features. CONCLUSION This study showed that CD44+/CD24- cells were present in all tumor tissues. The percentage of CD44+/CD24- cells was higher in early-stage disease, yet without statistical significance. No correlation was found between prognostic factors and the percentage of the CD44+/CD24- cells.