Background: Tissue polypeptide antigen (TPA) is a differentiation and a proliferation tissue marker of non-squamous epithelia. Increased urinary and serum TPA (S-TPA) levels were found in some patients with invasive bladder cancer. The authors report the results of a prospective study evaluating the role of serum TPA (S-TPA) in bladder carcinoma.
Methods: S-TPA concentrations were measured by radioimmunoassay in 53 patients with invasive bladder tumor before treatment, at the end of treatment, and during follow-up. The upper normal limit of the test was set at 80 UI/ml.
Results: With a specificity of 100%, the diagnostic sensitivity of the test was 54.7%. S-TPA was increased in 88% of patients with N1 + N2 disease compared with 38.8% of the patients with N0 disease (P = 0.01) and in 100% of patients with metastatic disease and 48% of patients with nonmetastatic disease (P = 0.01). S-TPA was increased in 23% of patients with total macroscopic debulking and in 68% of patients with persistent macroscopic disease (P = 0.004). For patients staged N0 M0, no statistical correlation between S-TPA level and debulking by transurethral resection (TUR) was found (P = 0.15). In the subset of patients with normal pretherapeutic S-TPA levels, 75% achieved a complete response, compared with 44.8% of the patients with initial elevated S-TPA levels (P = 0.04). However, there was no statistically significant relationship between pretherapeutic S-TPA levels and immediate response to treatment according to the stratification for tumor volume after initial debulking by TUR. For a mean follow-up of 15 months +/- 7 months, median survival time and 1-year survival rates were studied in the subset of patients with limited disease (N0 M0) according to the pretherapeutic S-TPA levels. The median survival time was not reached, and the 1-year survival rate was 80% when the initial S-TPA level was normal; these were 10 months and 44%, respectively, when the S-TPA level was high (P < 0.01). Among the 31 patients who achieved a complete response, 9 experienced a relapse, with an increase of the S-TPA level in 8 patients.
Conclusions: The S-TPA level is correlated with initial tumor volume. It appears to be a prognostic factor and a valuable parameter for follow-up.