尿路上皮癌における尿中Tissue PolypeptideAntigen(TPA)濃度測定の臨床応用

Abstract

尿路上皮癌526例, 前立腺癌140例を含む2, 521例に対して, プロリフィゲンTPAキット"第一"2を用いて尿中TPA濃度の測定を行った.1)健常人486例の尿中TPA濃度の平均値±標準偏差は199±218 U/lであり, 95%が陰性となる600 U/lをcut off値とした.2)尿路上皮癌の陽性率は57.6%(143/248例), 前立腺再燃例45.5%(5/11例)と高い陽性率を得た.一方, 良性疾患では腎盂腎炎, 膀胱炎, 尿道炎の急性期および水腎症を有する上部尿路結石で62.5～76.5%の高い偽陽性率を示したが, 尿路感染症安定期を含む他の疾患では約20%の偽陽性率にすぎなかった.3)尿路上皮癌において, 尿中TPAと尿細胞診を比較検討したが, 両者の陽性率に差はなく, 併用することにより73.1%の高い陽性率を得た

We have investigated the clinical significance of urinary tissue polypeptide antigen (TPA) as a tumor marker for urothelial cancers. Urinary TPA levels were determined by the immunoradiometric assay of Prolifigen TPA Kit "Daiichi"-II in 486 healthy controls and 1835 patients with various diseases including 526 with urothelial cancers and 140 with prostatic cancer. The mean value of urinary TPA was 199 +/- 213 (1SD)U/1 in 486 healthy controls. 95% of them having a level below 600 U/l. Therefore, 600 U/l was applied as a cut-off level. Positive rates of urothelial cancers and reactivated prostatic cancer were 57.6% (148 of 248 cases) and 45.5% (5 of 11 cases) respectively. On the other hand, the false positive rate of most urological benign diseases was only about 20% except for the acute stage of urinary tract infections and upper urinary tract stones with hydronephrosis. There was no significant difference in the positive rate between urinary TPA level and urinary cytology in urothelial cancers. The combination of both tests raised the positive rate to 73.1%. Therefore, urinary TPA may be useful in the monitoring of urothelial cancers, and the combination of urinary TPA and urinary cytology may increase the diagnostic accuracy.