Usefulness of tissue polypeptide antigen in the follow-up of bladder cancer

To evaluate the sensitivity and specificity of serum tissue polypeptide antigen (TPA) as a tumor marker for monitoring tumor recurrence in a prospective Phase II study.

This study consisted of 421 subjects allocated to three groups: 241 patients treated for bladder cancer between 1991 and 1995, 126 subjects with a previous history of bladder tumor but with no recurrence at the time of study enrollment, and 54 healthy volunteers. Soluble TPA concentrations were measured by radioimmunoassay.

On the basis of receiver operating characteristic plot analysis, the normal test threshold was set at 63 U/L. For bladder cancer detection, the TPA specificity was 73% and sensitivity was 45%. TPA levels correlated with tumor stage (P <0.01), histologic grade, nodal stage, and metastatic stage and with urinary cytology in univariate analysis. In the subsets of patients with a history of bladder cancer and normal TPA levels, 34.9% experienced a relapse compared with 37.5% of patients with elevated TPA levels (no statistically significant difference). Among the patients with normal TPA levels who experienced recurrence, the mean disease-free interval was 30.6 months compared with 25.1 months in patients with elevated TPA levels (no statistically significant difference). Multivariate analysis showed that TPA was not an independent prognostic biomarker for tumor relapse.

In patients with bladder cancer, the TPA serum level correlated with initial tumor stage and grade, but it was not useful for detecting or monitoring relapses.