Correlation and survival analysis of SIRT1 expression level and clinicopathological features of breast cancer patients

Abstract

Objective To detect the expression of silent information regulator 1 (SIRT1) in breast cancer and adjacent paracancerous tissues, and to analyze the correlation between its expression level and other clinical features of breast cancer and its significance in prognosis. Methods The expression of SIRT1 was detected by immunohistochemistry in 120 breast cancer tissues and 53 adjacent paracancerous tissues. The difference between the two groups and the relationship between SIRT1 expression and other clinical features were tested by chi-square test. Survival analysis was calculated by Kaplan-Meier method, and the survival rate was compared by Log-rank test. Results The expression of SIRT1 in breast cancer group was significantly higher than adjacent paracancerous tissues group (53.3% vs 34.0%, χ2=5.533, P=0.02). SIRT1 expression level showed positive correlation with tumor size and expresion of Ki-67 (χ2=6.790, 21.316, P=0.009, 0.000), but no statistical correlation with lymph node metastasis, clinical stage, histological grade, ER, PR and Her-2 expression. Statistical analysis showed that compared with low SIRT1 expression, patients with high SIRT1 expression level had significantly poorer prognosis (χ2=9.320, P<0.05). Conclusions The expression of SIRT1 is obviously increased in breast cancer patients than that in adjacent paracancerous tissues, and its expression is correlated with tumor size and expression of Ki-67. These results may implicate that SIRT1 will improve the development of breast cancer and the high-er expression of SIRT1 indicates the activated proliferation and poor survival rate. Key words: Breast neoplasms; Silent information regulaltor 1; Immuneohistochemistry