Clinical evaluation of soluble cytokeratin 19 fragments (CYFRA 21-1) in serum and urine of patients with bladder cancer

Abstract

Objectives: CYFRA 21-1 is a new tumor marker that measures cytokeratin 19 (CK-19) fragments by a sandwich enzyme-linked immunosorbent assay (ELISA). In this study, we evaluated the usefulness of serum and urine CYFRA 21-1 as a tumor marker for bladder cancers.

Methods: We measured serum and urine CYFRA 21-1 levels in a group of patients with bladder cancer (n = 58) and a group without bladder cancer (n = 220). The latter group was divided into five subgroups of patients (those with cystitis, benign prostatic hyperplasia (BPH), urolithiasis, or renal dysfunction, and a group of healthy, controls). In the bladder cancer group, we measured CYFRA 21-1 levels after transurethral resection of bladder tumor (TUR-Bt), and we also analyzed the relationship between serum and urine CYFRA 21-1 levels and tumor-related factors.

Results: Serum and urine CYFRA 21-1 levels were significantly higher in the bladder cancer group than in each of the non-bladder cancer subgroups. However, urine CYFRA 21-1 levels did not differ significantly between the bladder cancer group and the cystitis subgroup. In the bladder cancer group, serum CYFRA 21-1 levels were significantly higher in patients with local advanced-stage tumors and in those who had metastases. Urine CYFRA 21-1 levels decreased as a function of time after TUR-Bt. These levels were strongly correlated with tumor volume and were significantly better than urine cytology for the detection of bladder cancers of grades 1 and 2.

Conclusions: These results suggest that urine CYFRA 21-1 is a useful tumor marker in screening for bladder cancer, and that serum CYFRA 21-1 may be a tumor marker for advanced bladder cancers.