前立腺癌のスクリーニング検査としての血清中前立腺特異的抗原の測定

Measurement of Prostate-Specific Antigen in Serum as a Screening Test for Prostate Cancer

　背景：前立腺特異抗原（PSA）は前立腺表皮細胞によって特異的に分泌され，その血中濃度は癌を含めた前立腺疾患において上昇する．われわれは前立腺癌の検出および病期分類におけるPSA測定の有用性を検討した．

　方法：50歳以上の健常男性1,653名の血中前立腺特異抗原を測定した．血中PSA値が4μg/l以上のものはさらに直腸診と超音波検査を受けた．直腸診，超音波診断ないしこの両方で異常が認められた場合にはさらに超音波下での前立腺針生検を行った．ここで得られた結果は，症状的に異常があったためないし直腸診で異常を認めたために超音波下生検を行った50歳以上の男性300症例の連続して検討した結果と比較した．

　Background. Prostate-specific antigen (PSA) is secreted exclusively by prostatic epithelial cells, and its serum concentration is increased in men with prostatic disease, including cancer. We evaluated its usefulness in the detection and staging of prostate cancer.

　Methods. We measured serum PSA concentrations in 1653 healthy men 50 or more years old. Those with PSA values≧4.0 μg per liter then underwent rectal examination and prostatic ultrasonography. Ultrasound-directed prostatic needle biopsies were performed in the men with abnormal findings on rectal examination, ultrasonography, or both. The results were compared with those in 300 consecutivelystudied men 50 or more years old who underwent ultrasound-directed biopsy because of symptoms or abnormal findings on rectal examination.