[Correlation of pretreatment serum level of endostatin to posttreatment distant metastasis in patients with advanced nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Distant metastasis is the main failure of advanced nasopharyngeal carcinoma (NPC) after treatment. Endostatin is a strong prognostic factor of many tumors. This study was to evaluate the correlation of pretreatment serum endostatin level to posttreatment distant metastasis in patients with advanced NPC.

METHODS: The serum concentration of endostatin in 218 advanced NPC patients (122 at stage III and 96 at stage IV) before and after treatment, and in 20 healthy subjects was detected by ELISA. The correlations of serum endostatin level to patients' sex, T stage, N stage, distant metastasis and local relapse after treatment were analyzed.

RESULTS: The median serum concentration of endostatin was significantly higher in NPC patients than in controls (149.75 microg/L vs. 31.00 microg/L, P<0.05). Using the concentration of 187.50 microg/L as a break point, the patients were divided into low concentration group (< or =187.50 microg/L) and high concentration group (>187.50 microg/L). No significant differences were detected in 2-year local relapse-free survival rate (P=0.963), progression-free survival rate (P=0.063) and overall survival rate (P=0.381) between low concentration group and high concentration group, while the 2-year distant metastasis-free survival rate was significantly lower in low concentration group than in high concentration group (79.0% vs. 85.8%,P=0.034). Multivariate analysis revealed that serum endostatin concentration of more than 187.50 mug/L before treatment may predict the distant metastasis of local advanced NPC after treatment (95% confidence interval = 1.039-3.696, P=0.03).

CONCLUSION: High level of serum endostatin before treatment may predict distant metastasis of advanced NPC patients after treatment.