Relationship between CacyBP/SIP expression and prognosis in astrocytoma.

The aim of this study was to investigate the expression of calcyclin-binding protein (also known as Siah-1-interacting protein [CacyBP/SIP]) in astrocytoma and to determine its prognostic value in overall survival of patients with glioblastoma multiforme (GBM). Tissue specimens were obtained from 77 Chinese patients who had undergone surgery for astrocytoma. The expression of CacyBP/SIP was examined by immunohistochemistry. The relationship between CacyBP/SIP and proliferating cell nuclear antigen index (PCNA) expression was investigated, and the prognostic value of CacyBP/SIP expression in patients with astrocytomas was analyzed. Of 77 tumors, 49 (63.6%) were negative for CacyBP/SIP expression. Loss of CacyBP/SIP expression was significantly associated with a high histological grade and with poor survival in univariate and multivariate analyses. Cox multivariable analysis showed that loss of CacyBP/SIP expression correlated with poor prognosis in patients with astrocytomas and was an independent prognostic factor (p<0.05). The mean survival time of patients with tumors that had lost expression of CacyBP/SIP was 25.58months (95% confidence interval [CI], 15.36-25.81months), compared to a mean survival time of 36.37months (95% CI, 27.90-44.84months) for patients with CacyBP/SIP-expressing tumors. CacyBP/SIP expression was also negatively correlated with PCNA expression in astrocytoma tissue (p<0.05). Our findings suggest that CacyBP/SIP may have an important role as a negative regulator of astrocytoma development and progression, and that CacyBP/SIP might be a useful molecular marker for predicting the prognosis of astrocytoma.