Upregulated tumor sirtuin 2 expression correlates with reduced TNM stage and better overall survival in surgical breast cancer patients

Abstract

This study is aimed at exploring the correlation of sirtuin 2 (SIRT2) with clinical characteristics as well as overall survival (OS) in breast cancer patients. Totally, 296 primary breast cancer patients who underwent surgical resection were retrospectively reviewed in this study, and SIRT2 expression in tumor and adjacent tissues was determined by immunohistochemistry (IHC) and scored by semiquantitative scoring (0-12). Clinicopathological features were retrieved, and OS was calculated. Both SIRT2 IHC semiquantitative score and percentage of SIRT2 high expression by IHC score > 3 were lower in tumor tissues compared with adjacent tissues. Additionally, tumor SIRT2 high expression was associated with lower T stage, decreased N stage, and reduced TNM stage. Kaplan-Meier curves displayed that tumor SIRT2 high expression predicted longer OS. Univariate Cox's regression analysis showed that tumor SIRT2 high expression was associated with prolonged OS, while multivariate Cox's regression analysis displayed that tumor SIRT2 high expression was not an independent predictive factor for OS, which implied that tumor SIRT2 might predict OS indirectly through the interaction of tumor features (such as TNM stage) in breast cancer patients. SIRT2 expression is lower in tumor tissues compared with adjacent tissues, and tumor SIRT2 high expression correlates with lower T stage, decreased N stage, reduced TNM stage, and longer OS in breast cancer patients.