Diagnostic Value of Cytokeratin-18 as a Tumor Marker in Bladder Cancer

Abstract

Objectives: The aim of the study was to compare serum levels of cytokeratin-18 of patients with bladder cancer with those of the healthy controls, and to investigate the relation between cytokeratin level and the tumor stage. Design and methods: Serum cytokeratin-18 levels of 38 patients with bladder cancer and of 25 healthy people were determined. Tumor stage was T-1 in 12 patients, T-2 in 9 patients, T-3 in 10 patients and T-4 in 7 patients. The serum cytokeratin-18 levels in these cases were analyzed with respect to the stage of the tumor. Results: Cytokeratin- 18 level in the patient group was found to be significantly higher than that of the control group (p < 0.010) when the groups were totally compared. However, when the levels in patients with different tumor stages were compared with that of the controls, the difference was not significant in patients with stage I and 2 tumors (p > 0.05). Regarding the cut off value as 4.0 ng/mL, sensitivity and specificity for serum cytokeratin-18 were found to be 53% and 72% respectively. When sensitivity was calculated with respect to tumor stages, it was 8% for T-1, 33% for T-2, 90% for T-3 and 100% for T-4. On the other hand, considering higher stage (T-3 and T-4) tumors only, the sensitivity was calculated as 94%, but the sensitivity for lower stage (T-1 and T-2) tumors was 19%. Conclusions: It is clear that serum cytokeratin- 18 level increases in patients with bladder cancer. However, it can only be useful as a tumor marker in the diagnosis of T-3 and higher staged tumors. This study indicated that cytokeratin- 18 does not have any diagnostic value in lower stage bladder cancers. (C) 2002 The Canadian Society of Clinical Chemists. All rights reserved.