We lack reports on the clinicopathological characteristics and prognostic value of serum sirtuin 1 (SIRT1) levels and their association with SIRT1 expression in tissues of patients with gastric cancer (GC). Thus, we investigated the pathological characteristics and prognostic values of SIRT1 tissue expression and its serum concentration in GC. Moreover, we investigated the correlation between these two factors.

A total of 78 patients with GC who underwent curative gastrectomy were evaluated in this study. The expression of SIRT1 in the surgical specimens was assessed using immunohistochemistry. Serum levels of SIRT1 were measured using an enzyme-linked immunosorbent assay. The association of tissue and serum SIRT1 with the clinicopathological features and prognosis were evaluated.

Positive SIRT1 tissue expression was significantly related to an advanced cancer stage (p=0.017). Furthermore, a significant relationship existed between a positive SIRT1 tissue expression and poorer overall survival (OS) and relapse-free survival (RFS) (p=0.033 and p=0.033, respectively). In contrast, serum SIRT1 levels showed no significant association with clinicopathological characteristics besides age. In addition, no significant correlation was observed between tissue SIRT1 expression and serum SIRT1 concentration.

Tissue SIRT1 expression may be a valuable novel prognostic biomarker; nonetheless, further studies are required to clarify the relationship between tissue SIRT1 expression and serum SIRT1 levels in GC.