Expression of Cyr61 in primary salivary adenoid cystic carcinoma and its relation to Ki-67 and prognosis

Cysteine-rich protein 61 (Cyr61) selectively binds heparin and insulin-like growth factors and mediates a variety of biological actions, including cell adhesion, differentiation, proliferation, migration, angiogenesis, and tumorigenesis. Cyr61 is also a prognostic factor for tumor progression and survival of individuals with various types of tumors. This study investigated the relationship between the expression level of Cyr61 and clinicopathological features, as well as the prognostic significance of Cyr61 expression in human salivary adenoid cystic carcinoma (SACC). The expression of Cyr61 and Ki-67, a cell-proliferation marker, was examined immunohistochemically in paraffin embedded tissue specimens from 60 SACC patients who underwent radical surgery between 1995 and 2004. A chi-square test was used to investigate the relationship between Cyr61 and Ki-67 expression and clinicopathological features. Survival analysis was performed to determine the prognostic significance of Cyr61 expression. Cyr61 expression was observed in 39 cases (39/60, 65%) of SACC, and Cyr61 expression was positively correlated with Ki-67 expression (P = 0.002). A high expression of Cyr61 was significantly associated with solid subtype, perineural invasion, vascular invasion or cancer embolus, advanced stage, recurrence, and metastasis (P < 0.05). The survival rate of patients with high expression of Cyr61 or Ki67 was significantly lower than that of patients with low expression. Multivariate Cox's proportional hazards analysis showed that vascular invasion, TNM stage, recurrence, distant metastasis, Ki-67 expression, and Cyr61 expression were independent prognostic factors of overall survival (P < 0.05). Cyr61 expression is significantly correlated with Ki-67 expression and may have potential value in screening high-risk cases for recurrence and metastasis, as well as identifying poor prognosis in SACC patients.