Abstract 4735: Stem cells like phenotype of inflammatory breast cancer and locally advanced breast cancer: increased expression of sox2 and oct3/4 contributes to poor response to treatment and reduced survival rates

Abstract

Abstract Background: Inflammatory breast cancer (IBC) is an aggressive form of locally advanced breast cancer (LABC) with poor response to treatment or metastasis in one-third of patients at presentation. The aggressive behavior of IBC was attributed to the cancer stem cell (CSC) component in these tumors. We assessed the correlation between CSC markers in IBC, LABC and the aggressive behavior of these tumors compared to invasive duct carcinoma (IDC-NOS). Methods: CD44, CD90, CD133, nestin, SOX2 and OCT4 RNA and proteins expression were assessed in 30 cases of IDC-NOS, IBC and LABC (each) using quantitative real time PCR (qPCR) and immunohistochemistry (IHC). Markers expression was correlated to patients' characteristics, response to treatment, 4 years- overall and progression free survival (OS& PFS) . Results: The expression levels in IBC and LABC was as follows: (CD44; 70%& 26.3%, p=0.003), (CD90; 49.2%& 28.1%, p=0.06), (CD133; 66.7%& 26.3%, p=0.006), (OCT4; 70%& 26.6%, p=0.004), (SOX2: 63.3%& 30%, p=0.02) and (Nestin; 53.3%& 31%, p=0.08). The difference in the expression levels of all studied markers between IDC-NOS and the other two groups was statistically significant (p.value: <0.05- <0.001). A significant relation was reported between the expression levels of SOX2, OCT-4 and the clinical response in IBC and LABC (p<0.01). PFS significantly correlated with SOX2 and OCT4 expression (p=0.045) in IBC, whereas OS correlated with OCT4 in IBC and LABC (0.034& 0.04) Conclusions: The aggressive phenotype of IBC and LABC could be attributed, at least partially, to the presence of CSC populations in these tumors. Therefore, CSC markers represent Interesting candidates for targeted therapy for this resistant type of breast tumors. Citation Format: Abdel-Rahman N. Zekri, Abeer Bahnassy, Ahmed E. El-Bastawisy, Hanan R. Nassar, Neveen M. Elhady, John Effat. Stem cells like phenotype of inflammatory breast cancer and locally advanced breast cancer: increased expression of sox2 and oct3/4 contributes to poor response to treatment and reduced survival rates. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4735. doi:10.1158/1538-7445.AM2014-4735