The comparison of SOX2 expression with pathologic and clinic parameters in breast carcinomas: Immunuhistochemical and molecular study

Aim: Breast cancer is the most common cancer among women and is one of the most common causes of cancer mortality worldwide and also in our country. Cancer stem cells are involved in breast carcinomas as well as in various tumors and have ability to self-renew, proliferation and differentiate into multiple cell lineages. Recently, studies about stem cell markers and cancer tumorogenesis have been increased owing to clinical benefits of targeted treatments. SOX2 is a transcription factor which is present in pluripotent stem cells during development, and responsible from self-renewal and precursor differentiation. In tumorogenesis, SOX2 is involved in cell proliferation and migration, apoptosis, tumor metastasis, invasion and drug resistance. In many studies it is shown that SOX2 is associated with poor clinicopathological factors in breast carcinomas such as increased tumor size, lymph node metastasis, high nuclear grade and has an effect in early stage of breast tumorigenesis, early recurrence and poor disease-free survival. In our study, we investigated SOX2 expression in invasive breast cancer patients and aimed to search the obtained data with clinicopathological parameters. Materials and Methods: SOX2 expression was investigated in paraffin sections of 99 invasive breast carcinoma cases by performing immunohistochemistry and RT-PCR methods. Results: SOX2 expression was detected in 78,8 % of invasive breast carcinomas. SOX2 expression was statistically correlated with larger tumor size (p=0,011), subtype (p=0,018), high ki 67 proliferation index (p=0,0001), lymphovascular invasion (p=0,039), lymph node metastasis (P=0,038), distant metastasis (p=0,038), advanced stage (p=0,030) and poor disease free survival (p=0,049). There was no significant correlation between SOX2 expression and age, histologic grade, hormone receptor status. Conclusions: In present study, SOX2 expression was correlated with poor prognostic factors such as tumor size, lymphovascular invasion, lymph node metastasis, distant metastasis, advanced clinical stage, high ki 67 proliferation indices and shorter disease-free survival time. It is thought that SOX2 can be a useful prognostic marker in routine practice for management of individual treatments and clinical follow up of breast cancer patients. Forward studies including larger series with clinical treatment choices are needed to improve these results. Keywords: breast cancer, cancer stem cell markers, PCR, immunohistochemistry, SOX2.