RESUMEN
<p><b>OBJECTIVE</b>To study the distribution and quantity of CD44+/CD24- cells in breast cancer tissue and the cell lines, and as well as its correlation with the expression of various breast cancer markers and molecular subtyping of breast carcinoma.</p><p><b>METHODS</b>The expression of CD44/CD24, estrogen receptor, progesterone receptor, HER2, human estrogen-induced protein PS2, bcl-2 and nm23 in 60 cases of invasive ductal carcinoma of breast were studied by either single or double immunohistochemical staining. The co-expression of CD44 and CD24 in 3 breast cancer cell lines (MCF-7, MDA-MB-468, and MDA-MB-231) was also examined.</p><p><b>RESULTS</b>The quantity and distribution of CD44+/CD24- cells varied greatly and no specific patterns were identified. The percentage of CD44+/CD24- in breast cancer was 65%. The amount of CD44+/CD24- cells did not correlate with the age of patients, lymph node metastasis, tumor size, molecular subtypes and expression of various breast cancer markers in breast carcinoma. The proportion of CD44+/CD24- cells in MCF-7, MDA-MB-468, and MDA-MB-231 cell lines was <1%, 5% and >80%, respectively.</p><p><b>CONCLUSIONS</b>CD44+/CD24- cells are demonstrated in certain breast cancer tissues and cell lines. However, there is no relationship obtained between the quantity or the distribution of these cells and the molecular subtyping or the clinicopathologic parameters in breast cancer.</p>