前立腺癌における腫瘍マーカーの臨床的検計

Abstract

未治療前立腺癌52例, 前立腺肥大症44例に対しPAP, γ-Sm, PSAを同時に測定した.1)前立腺癌における各腫瘍マーカー単独での陽性率はPSAが最も高く, 特に早期癌で顕著であり, 診断効率でもPSAが最も優れていた.2)PAP, γ-Sm, PSAを組み合わせても, PSA単独に比べさほど陽性率は上昇せず, また診断効率では2種あるいは3種のどの組み合わせよりもPSA単独の方が優れており, 組み合わせの意義はあまりみられなかった.3)前立腺癌の細胞分化度と各腫瘍マーカーの値および陽性率との間には一定の関係はみられなかった.4)前立腺癌においてPAPとγ-Sm, PAPとPSAの間には有意な相関があるものの, γ-SmとPSAとの間には相関はなかった

We measured prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm) and prostatic specific antigen (PSA) levels simultaneously in the serum of 52 patients with untreated prostatic cancer and 44 patients with benign prostatic hypertrophy to assess the clinical usefulness of these tumor markers. PAP and PSA were measured by radioimmunoassay and gamma-Sm by enzyme immunoassay. The positive rates of PAP, gamma-Sm and PSA in patients with prostatic cancer were 50.0, 61.5 and 69.2%, respectively, and those in patients with benign prostatic hypertrophy were 11.4, 13.6 and 13.6%, respectively. In patients with early stage prostatic cancer (stage A and B), the positive rates of PAP, gamma-Sm and PSA were 20.8, 41.7 and 54.2%. The efficiency of PSA was the highest among the three markers. The positive rate of the combination assay of PAP and PSA, that of gamma-Sm and PSA and that of PAP, gamma-Sm and PSA were slightly higher than that of the PSA assay alone. However, the efficiency of the PSA assay alone was higher than that of any combination. No significant correlation was found between histopathological grade and the level of each tumor marker. A significant correlation was found between PAP and gamma-Sm (r = 0.68, P less than 0.001), and between PAP and PSA (r = 0.61, P less than 0.001), but there was no correlation between gamma-Sm and PSA. These results suggest that PSA is the most useful marker and the combination assay of multiple markers is not so advantageous, at least for screening of prostatic cancer.