[Pancreatic secretory trypsin inhibitor in urothelial cancer]

Pancreatic secretory trypsin inhibitor (PSTI) levels are known to increase in some kinds of cancer. We determined the PSTI levels in patients with urothelial cancer to evaluate its usefulness as a tumor marker. The subjects were 101 patients who had bladder cancer (n = 81) or renal pelvis and ureter cancer (n = 20). Twenty-six healthy volunteers were used as controls. PSTI was measured by an RI kit using the double antibody method, and levels above 20 ng/ml were taken as positive. Serum tissue polypeptide antigen (TPA) levels were also measured in 32 cases. None of the controls, 65% of the patients with renal pelvis and ureter cancer, and 30.9% of bladder cancer had positive levels of PSTI. The positive rate for each stage was 22.3% for Tis, Taand T1, 38.5% for T2, 73.3% for T3 and 100% for T4. The rate tended to increase with the progress of tumor infiltration. All subjects with positive readings above 30 ng/ml had progressive cancer. The usefulness of PSTI as a tumor marker was similar to that of TPA. PSTI is not a specific marker of urothelial cancer, but it showed an association with the progression of cancer. Therefore, it is considered to be a useful marker to determine postoperative metastasis, recurrence, and disease progression.