Expression of survivin in different stages of carcinogenesis and progression of breast cancer

BACKGROUND & OBJECTIVE: Survivin is one of the newly identified apoptosis inhibitor; it can block the cell apoptosis by inhibiting the function of the enzyme caspase-3 and caspase-7. Present studies indicate that survivin is overexpressed in malignant tumor. This current study was designed to investigate the effects of survivin in tumorigenesis and progression of breast carcinoma through observing the expression of survivin in the tissue of normal mammary, cystic hyperplasia mammary, atypical hyperplasia mammary and breast carcinoma. METHODS: The expression of survivin in the tissue of normal mammary (96 cases), cystic hyperplasia mammary (56 cases), atypical hyperplasia mammary (12 cases), and breast carcinoma (119 cases) were evaluated by SP immunohistochemistry. The relationship between survivin expression and the pathologically biological features of breast cancer was assessed. RESULTS: The positive rates of survivin were 4.2%(4/96),5.4% (3/56),42.7% (5/12), and 72.3%(86/119)in the tissue of normal mammary, cystic hyperplasia mammary, atypical hyperplasia mammary, and breast carcinoma, respectively. The positive rates in the last two groups were higher than those in the former two groups (P< 0.005). Survivin was more expressed in the infiltrative nonspecial breast carcinoma (82.0%, 73/89) than in the special and early stage infiltrative breast carcinoma (37.5%,3/8)(P< 0.05). Expression of survivin was correlated with lymph node metastasis although the difference is not significant (P >0.05). CONCLUSION: Overexpression of survivin is common in tumorigenesis and progression of breast carcinoma. Altered expression of survivin may contribute to tumorigenesis and progression of breast carcinoma by inhibiting cell apoptosis, its overexpression indicates worse prognosis.