Urine tissue-polypeptide-specific antigen (TPS) as a marker for bladder cancer

To determine the sensitivity and specificity of urine tissue-polypeptide-specific antigen (TPS) for bladder carcinomas and to evaluate whether urine TPS is influenced by tumour size, number, grade and stage.

A total of 260 patients entered the study, one group (n = 151) with known bladder cancer disease (79 with recurrent tumour and 72 with no tumour at cystoscopy). The other group (n = 109) consisted of patients without previously known bladder tumour disease, 55 with newly detected bladder tumour(s) and 54 investigated for microhematuria found to be idiopathic. TPS in urine was measured using an ELISA-kit, a solid phase two-site immunosorbent assay with polyclonal antibodies against cytokeratin 18.

Urine TPS was significantly higher in patients with bladder tumours (p < 0.001). There was a significant correlation between TPS and tumour size (p = 0.004), grade (p = 0.001) and stage (p = 0.001). Tumour number was not significantly correlated to urine TPS (p = 0.75). With TPS 42 as a cut-off level, the sensitivity was 73% for newly detected tumours and 50% for recurrences; the specificity was 70% and 63% respectively. With a 95% specificity, the sensitivity for newly detected tumours was 33% and for recurrences 18%. The lower sensitivity and specificity for recurrences was mainly explained by differences in tumour size, grade and stage between the recurrences and the newly detected tumours.

Urine TPS is a marker for bladder carcinoma correlated to size, grade and stage. The sensitivity and specificity for newly detected tumours are quite comparable with other markers. Its clinical usefulness is however not established and it appears less useful in the follow-up of patients with known bladder tumour disease.