前立腺集団検診における血中前立腺特異抗原(PSA)値の検討

Abstract

集団検診受診の55歳以上の男子647例で直腸診, 経直腸的超音波断層法, 及び血清PSA(前立腺特異抗原)測定を行った。前立腺癌7例及び要治療前立腺肥大症53例を発見した。癌患者中6例でPSA値は3.6ng/ml以上, 1例で2.6ng/mlであった。前立腺癌及び良性前立腺肥大症の臨床的徴候がない587例中564例でPSA値は2.6ng/ml以下であった。前立腺疾患がなく, PSA値が2.6ng/ml以上を示す症例の比率は全症例3.4%に過ぎなかった

While it is widely recognized that elevated prostate specific antigen (PSA) correlates with the presence of prostate cancer, little data exist on the use of PSA as the initial test in the mass screening for prostate diseases. Thus, digital rectal examination, transrectal ultrasonography of the prostate as well as measurements of serum PSA were performed in a series of 647 men 55 years old or older who participated in the mass screening. We found 7 patients with prostatic cancer (1.1%) and 53 with benign prostatic hypertrophy faced with the necessity of the therapy (8.2%). The PSA values of 6 cancer patients exceeded 3.6 ng/ml and that of one cancer patient was 2.6 ng/ml. While 587 subjects were judged to be without clinical evidence of prostate cancer and benign prostatic hypertrophy, 564 of them has PSA values under 2.6 ng/ml. The proportion of those who were free from prostatic diseases and had a PSA value of 2.6 ng/ml or more was only 3.4% of all participants. Since the proportion of the subjects falsely screened at a relatively lower cut-off point of PSA was quite low, the measurement of serum PSA is suggested to be useful as the initial test in the mass screening for prostatic diseases.