Cystatin SN has been considered to be involved in human
cancer, but its clinical significance in
non-small cell lung cancer (NSCLC) has not been elucidated. The aim of this study was to evaluate the clinical value of
Cystatin SN expression in patients with surgically resected NSCLCs. A retrospective analysis of 174 patients with surgically resected NSCLCs from April 2002 to March 2005 was performed with immunohistochemistry and fluorescence in situ hybridization to analyze the
protein expression and amplification of
Cystatin SN. The associations between
Cystatin SN expression and recurrence,
metastasis, and survival were investigated. In recurrence and
metastasis analysis, compared with low-
Cystatin SN expression NSCLCs, high expression
tumors were more likely to recur and metastasize (P < 0.001). Disease-free survival (DFS) and overall survival (OS) were significantly prolonged in the low-
Cystatin SN expression subgroup compared with the high-
Cystatin SN expression subgroup (DFS, P < 0.001; OS, P = 0.001). A multivariate analysis confirmed that high expression of
Cystatin SN was associated with poor survival (DFS, P = 0.001; OS, P = 0.006) and was an independent prognostic
indicator. The present study indicates that high expression of
Cystatin SN is a significant prognostic
indicator of a higher rate of recurrence, metastatic risk, and poor survival in patients with surgically resected NSCLCs.