Immunohistochemical expression of PTEN and survivin in ductal carcinoma of breast cancer and correlation with apoptotic index

Abstract

Backround Survivin is a recently identified inhibitor of apoptosis and PTEN plays an important role in arrangement of signals required for cell growing and apoptosis. In case of absence or mutations of PTEN, tumour cells can protect themselves against apoptosis by the way of lipid signal transduction. Methods In this study, the relationship of PTEN and survivin expression with apoptosis was investigated by the means of immunohistochemical method in 39 patients with invasive breast cancer (IBC) and ductal carcinoma in situ (DCIS) within the same breast tissue. Results A decrease or loss in PTEN expression was observed in an important portion in DCIS (46.7%) and IBC (71.8%). In cases with invasive ductal carcinomas, strong staining with survivin was observed in 33.3% of cases, while there was weak staining in 61.6% and no staining in 5.1% of cases. All of the DCIS tumour cells were positive with survivin but staining was weak. Apoptotic index was higher in IBC than in DCIS, but there was no significant difference. No relationship was found between apoptosis and PTEN or survivin expression in breast carcinoma. Conclusion Our results suggest that a decrease in PTEN expression and increase in apoptosis is important in progression of IBC.