摘要
Breast cancer is a complex and heterogeneous disease with different clinical outcomes. The investigations of new biomolecular markers are essential to know the prognosis and improve the clinical management of patients. The SIRT-1 （sirtuin- 1） is a histone deacetylase implicated in various epigenetic critical functions for the cells and the maintenance of genomic stability. The objective of this study is to investigate the grade of expression of the SIRT-I （sirtuin-1） and the prognostic value in overall survival of women with breast cancer. Retrospective cohort of 457 women with breast cancer has been researched, undergoing treatment in Erechim-RS from 2003 to 2013 and followed until July 2015. The degree of SIRT-1 expression was investigated by immunohistochemistry in 123 patients （26.9%） of the cohort. The OS （overall survival） from specific disease and risk of death from breast cancer were estimated by Kaplan-Meier and Cox＇s proportional risks. The median age of 57.4 years cohort with OS of 79.6% in 5 years and 69.1% at 10 years, with follow-up time of 61.9 months are revealed in this work. The SIRT-1 overexpression was found in 6.5% of cases and characterized a subgroup of women with shorter survival and increased risk of death from breast cancer （HR = 2.66; 95% CI 1.03 to 6.86; p = 0.043） and adjusted by age （HR = 2.86; 95% CI 1.11 to 7.38; p = 0.030）, histology （HR = 2.79; 95% CI 1.07 to 7.28; p = 0.036）, lymph nodes （HR = 2.73; 95% CI 1.06 to 7.04; p = 0.037）, Her-2 （HR = 2.82; 95% CI 1.07 to 7.44; p = 0.036）; chemotherapy （HR = 2.90; 95% CI 1.11 to 7.60; p = 0.030） and radiotherapy （HR = 2.71; 95% CI 1.05 to 7.01; p = 0.040）. In regressive multivariate models adjusted for age, status of axillary lymph nodes, Her-2 expression and proliferation index （Ki-67）, the grade of expression of the SIRT-1 maintained association with poor prognosis. From the study, it can be concluded that the assessment of the SIRT-1 expression is an independent prognostic biomarker in breast cancer.
