Prognostic value of the pretreatment serum level of cytokeratin fraction 21-1 in undifferentiated nasopharyngeal carcinoma: a study of 332 cases.

BACKGROUND Prognostic value of serum cytokeratin fraction 21-1 (CYFRA 21-1) has not been fully validated for nasopharyngeal carcinoma (NPC). METHODS Serum CYFRA 21-1 levels of 332 patients with NPC were measured before treatment, and their association with overall survival (OS), tumor-free survival (TFS), time to local recurrence (TLR), and time to distant recurrence (TDR) was studied. RESULTS Pretreatment serum CYFRA 21-1 level of patients with classification of T1+2 , N0 , stage I+II was significantly lower than that of those with T3+4 , N1+2+3 and III+IV, respectively. Multivariate analysis showed that a high pretreatment serum level of CYFRA 21-1 and T classification were independent predictors of poor OS and TDR. A high pretreatment level of CYFRA 21-1 was an independent predictor of shorter TFS and TLR. CONCLUSION The pretreatment serum level of CYFRA 21-1 would be a reliable biomarker to evaluate the long-term prognosis of patients with undifferentiated NPC.