The Study On CK5/6 And EGFR As Poor Prognostic Factors In The Triple Negative Breast Cancer

Objective:Triple negative breast cancer is defined by a lack of expression of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2, which is considered to be a disease with young patients, aggressive behaviors, early recurrence, short survival, and not sensitive to endocrine therapy and anti HER-2 and poor prognosis.Cytokeratin 5/6 are considered to be the CKs expressed by basal cells of the mammary, which are mainly used in the identification and diagnosis of squamous cell carcinoma, basal cell carcinoma, basal papilloma, lymph cell carcinoma of nasopharynx and other parts, adenocarcinoma and mesothelial cells.Epidermal growth factor receptor is a intersection of G protein, cytokines, integrins and other signaling pathways, which plays an important role during the development of body. The expression of EGFR is associated with differentiation, metastasis, prognosis of cancer. If EGFR are activated, the receptor autophosphorylation and tyrosine kinase activation will be priminged, which will activate intracellular signal transduction pathway, promote cell proliferation, inhibit apoptosis, and promote the invasion and metastasis of tumor cell.In this study, the expression of CK5/6 and EGFR in triple negative breast cancer were detected by immunohistochemistry. Cinical pathology data were collected. The expression characteristics and correlation of these two proteins in the triple negative breast cancer were analyzed, which revealed the biological characteristics of triple negative breast cancer, and provided new ideas to research on breast cancer, and also provided the basis on that the two proteins were poor prognostic factors of triple negative breast cancer.Methods: Histopathological examination and immunohistochemical staining identified 48 patients with triple negative breast cancer and 274 cases with non-triple negative breast cancer in the First Affiliated Hospital of Dalian Medical University from October 2008 to October 2010. All patients were female, median age was 52 years(32～82), and pathological types were infiltrating ductal carcinoma grade I-III. All the breast cancer tumor tissue specimens were fixed by routine 10% neutral formalin, embedded by paraffin, stained by HE and detected by immunohistochemistry.Results:1.62.50% of triple negative breast cancer were positive CK5/6, and 4.74% of non-triple negative breast cancer were positive CK5/6. EGFR were 31.25% and 8.1%, respectively (P <0.05). 2.CK5/6 was correlated with EGFR in the triple negative breast cancer (P <0.05).Conclusion:1.Positive CK5/6 in the triple negative breast cancer was significantly higher than that in the non-triple negative breast cancer, which can be considered as a poor prognostic factor of triple negative breast cancer. 2.Positive EGFR in the triple negative breast cancer was significantly higher than that in the non-triple negative breast cancer, which can be also considered as a poor prognostic factor of triple negative breast cancer. 3.About 16.7% of the triple negative breast cancer were both positive CK5/6 and positive EGFR.