Tandem PSAによる前立腺癌の診断

Abstract

前立腺疾患が疑われる81症例でTandem PSAをMarkit-M PA, γ-seminoproteinと同時に測定し, Tandem PSAの前立腺癌の診断における有用性について検討した.81症例の診断は前立腺癌16例, 前立腺肥大症56例, その他9例であった.前立腺癌16例中にはTlC症例が2例含まれていた.Tandem PSA, Markit-M PA及びγ-seminoproteinの感度はそれぞれ81.3%, 62.5%, 68.8%であり, 特異度はそれぞれ67.7%, 81.5%, 72.3%であった.又, Tandem PSAとγ-seminoproteinの比を比較検討すると, Tandem PSAが4.0ng/mlより大きい前立腺肥大症と前立腺癌症例において, この比は, それぞれ1.53±0.966, 3.21±1.811(平均±標準偏差)であり, 有意差を認めた

The Tandem PSA test was performed simultaneously with assay of Markit-M PA and gamma-seminoprotein to determine its usefulness for the diagnosis of prostate cancer in a total of 81 patients with prostate diseases. The diagnosis was untreated prostate cancer in 16 patients including 2 with T1c tumor, benign prostatic hyperplasia in 56 patients, and other diseases in 9 patients. Tandem PSA, Markit-M PA, and gamma-seminoprotein showed a sensitivity of 81.3, 62.5, and 68.8%, respectively, while the specificity was 67.7, 81.5, and 72.3%, respectively. Tandem PSA had the highest sensitivity, although the specificity and accuracy were the lowest. These results were considered to be due to the fact that the PSA level becomes significantly higher with an increase in the weight of benign prostatic hyperplasia. This indicates that the PSA density should be considered to improve the specificity of Tandem PSA. Use of the Tandem PSA/gamma-seminoprotein ratio was also examined as a possible method which might improve the specificity. Patients with benign prostatic hyperplasia and prostate cancer had a ratio of 1.53 +/- 0.966 and 3.21 +/- 1.811 (mean plus standard deviation), respectively, and these 2 groups showed a significant difference (p = 0.0008). This indicates that calculation of the Tandem PSA/gamma-seminoprotein ratio may be useful to improve the specificity of Tandem PSA for the diagnosis of prostate cancer.