СD44+/CD24− markers of cancer stem cells in patients with breast cancer of different molecular subtypes

Abstract

Aim: To determine frequency of tumors with immunohistochemical markers of cancer stem cells (CSC) CD44+/CD24− in patients with breast cancer (BC) of different molecular subtype and to evaluate their prognostic value. Object: Surgical material of 132 patients with BC stage I–II, age from 23 to 75 years, mean age — 50.2 ± 3.1 years was studied. Methods: Clinical, immunohistochemical (expression CD44+/CD24−), morphological, statistical. Results: BC is characterized by heterogeneity of molecular subtypes and expression of markers (CD44+/CD24−). Immunohistochemical study of expression of CSC markers in surgical material has detected their expression in 34 (25.4%) patients with BC of different molecular subtypes. The highest frequency of cells with expression of CSC marker was observed in patients with basal molecular subtype (44.8% patients). Most of BC patients with phenotype CD44+/CD24 had stage I of tumor process (34.3%). Statistical processing of data has showen that Yule colligation coefficient equaled 0.28 (р > 0.05) that argues poor correlation between stage of tumor process and number of tumors with positive expression of CSC markers. Statistical processing of data has showen high correlation between presence of cells with expression of CSC markers and metastases of BC in regional lymph nodes (Yule colligation coefficient equals 0.943; р < 0.5). Difference in overall survival of patients with BC of basal molecular subtype depending on expression of CSC CD44+/CD24− markers was detected. Survival of patients with basal BC was reliably higher at lack in tumors of cells with CSC markers CD44+/CD24− and, correspondingly, lower at presence of such cells (р < 0.05). In patients with BC of luminal (A and B), HER-2-positive subtypes, significant change in survival of patients depending on expression of CSC markers was not determined (р > 0.05). Conclusion: Significance of tumor cells with markers CD44+/CD24− within the limits of molecular subtype of BC may be additional criterion for advanced biological characteristic of BC, and in patients with BC of basal molecular subtype — for predictive evaluation of individual potential of tumor to aggressive clinical course. Key Words: breast cancer, cancer stem cells, СD44+/CD24−, molecular subtype.