[238] Expression of CD44⁺/CD24^- Cells in Breast Cancer

XQ Lu, ZH Suo, CL Ma, KJ Xu, YS Liu, HX Li. Zhengzhou University School of Medicine, Zhengzhou, Henan, China; Rikshospitalet University Hospital, University of Oslo, Oslo, Norway

Background: The cancer stem cells have been found recently to associate with tumor's development, drug resistance, and recurrence and have also become potential targets for cancer treatment. Two lineages of stem-like cell, side-population and CD44⁺/CD24^-/low cells, have been identified in breast cancer cells lines, but there is little research on tumor tissue.
Design: Sixty-four cases of breast cancer tissues with invasive ductal carcinoma were examined with immunohistochemical stains for expression of CD44⁺/CD24^- cells. The correlation between the CD44⁺/CD24^- expression and other conventional biomarkers including ER, PR, HER-2, PS2, Bcl-2, and nm23 were analyzed. The association of the distribution and number of CD44⁺/CD24^- cells with clinicopathological factors like tumour size, lymph node status and metastasis were explored. Expression of CD44 and/or CD24 was defined as over 1% of tumor cells positive for CD44 and/or CD24 staining while 5% was used as the cutoff for other markers.
Results: CD44⁺/CD24^- cells were randomly distributed in breast cancer tissues. The expression of CD44⁺/CD24^- cells were identified in 43 of 64 (67.2%) cases of the invasive ductal breast cancer, significantly higher than that of CD44^-/CD24^- (p=0.001) or CD44^-/CD24⁺ (p=0.007) cells but similar to that of CD44⁺/CD24⁺ cells. The expression of CD44⁺/CD24^- cells in breast cancers was neither correlated to that of other biomarkers of breast cancer nor to the clinicopathological factors examined.
Conclusions: CD44⁺/CD24^- cells are randomly distributed in breast cancer tissue and not peripherally concentrated as predicted. The expression of CD44⁺/CD24^- is significantly higher than that of CD44^-/CD24^- or CD44^-/CD24⁺ in invasive ductal breast cancer. Similar expression of CD44⁺/CD24^- and CD44+^-/CD24⁺ suggest the stem-like cells may be diversified in breast cancer. Expression of CD44⁺/CD24^- was not associated with that of ER, PR, HER-2, PS2, Bcl-2, nm23 or with the clinical factors including patients' age, tumor size and lymph node metastasis.
Category: Breast

Monday, March 9, 2009 1:00 PM

Poster Session II # 37, Monday Afternoon