前立腺検診と前立腺特異抗原

Abstract

1) RIA法とEIA法の二種類のPSA測定用キットを比較する目的では, 診断の明らかな前立腺癌または前立腺肥大症を有する51例を対象として, 76検体を検索した.2)高齢者前立腺重量と前記両法のPSA値との関連を検索する目的には前立腺集団検診受診者125名を対象とした.3)前立腺検診時の疾患検出率とPSA値との関係を検討する目的では, 前記125例を含む415例の前立腺検診受診者を対象として, EIA法によるPSA値を検討した.1)群の報告例より算出したRIA法のカットオフ値6.3 ng/mlをもってしても, 125例中16例に陽性例が検出された.前立腺検診の場合は, 要治療前立腺肥大症はスクリーニングの対象疾患となるため, さらに前立腺重量30グラム未満の群111例で検討したが11例に陽性例(6.4 ng/ml以上)がみられた.一方EIA法では非癌例の陽性例は要治療前立腺肥大症の1例のみであった.EIA法のみで検討した415例の結果では, 前立腺癌の陽性率は5例中4例であり, 非癌例で要治療前立腺肥大症を除いた372例では1例の偽陽性率で, 偽陽性率に関しては十分満足される結果があった

We examined the values of prostate specific antigen (PSA) with a RIA kit (Pros Check PSA) and an EIA kit (Market F PA), measuring prostate weights of 125 participants in a mass screening of the prostatic diseases. A mild positive correlation (r = 0.467) between values of PSA (RIA) and prostate weights was found in the participants in whom the prostate cancer was not detected. Since serum PSA levels measured by RIA of 45 normal subjects were 1.8 +/- 1.5 ng/ml (Mean +/- S.D), the upper limit of the normal range was set at 6.3 ng/ml. The participants whose PSA levels exceeded this upper normal range and also whose prostate weights were under 30 g were found in 11 of the 122 subjects (9%). On the contrary, the abnormal values (EIA) were found in only two subjects (one, a prostate cancer and the other, a benign prostate hypertrophy). We, further, examined the PSA values (EIA) in 415 subjects in whom the prostate cancer was detected in 5 (1.2%). The abnormal values were found in 8 (4 prostate cancer, 3 benign prostate hypertrophy and one without prostatic disease). As the false positive rate was very low, the use of PSA is recommended in the first screening of the check up program of the prostatic disease.