当院における経直腸的前立腺生検の臨床的検討 : 系統的12ヶ所生検の有用性について

Abstract

系統的12ヶ所生検の有用性を検討する目的で, 過去8年間に経直腸的前立腺生検を行った978例(平均年齢71.2±7.6歳)を系統的6ヶ所生検例213例(平均年齢72.1±7.7歳;A群), 系統的12ヶ所生検例(平均年齢71.0±7.5歳;B群)に分け, 癌検出率, 癌検出部位などを比較検討した。その結果, 癌検出率は全体で54.3%で, B群はA群より検出率が有意に高く, grey zoneでは差が拡大していた。また, 部位別癌検出率はapexを含むPZで検出率が高い傾向を認め, 追加部位であるapexとTZからのみの癌検出率は14.4%で, その内, 尖部のみからの検出率は2.0%であった。B群の合併症は一時的尿閉1.05%, 38度以上の発熱0.92%, クリッピングを要した直腸出血0.26%であったが, 重篤な症例は認めなかった。以上より, 系統的12ヶ所生検は比較的安全で, 前立腺癌の診断に有用である。

A total of 978 of transrectal prostate biopsies performed between January 1998 and December 2005 at Ikeda Municipal Hospital were reviewed to determine the usefulness of the systematic 12 core biopsy including the apex and transition zone (TZ). Prostate cancer was detected in 531 of the 978 cases (54.3%). The systematic 6 core biopsy was performed between 1998 and 2000. In this group the cancer detection rate was 40.8% (87 out of 213 cases). In the systematic 12 core biopsy group since 2001 the cancer detection rate was 58.0% (444 out of 765 cases). The cancer detection ratio in the systematic 12 core biopsy group was significantly higher than that in the 6 core group (p<0.0001). In the subgroup whose prostate-specific antigen (PSA) value was in the gray zone (4. 1-10.0 ng/ml), the cancer detection rate was 22.9% (25 of 109 cases) in the systematic 6 core biopsy group and 45.7% (186 of 407 cases) in the systematic 12 core biopsy group. Of the 444 cases diagnosed as having prostate cancer by the systematic 12 core biopsy, 64 cases (14.4%) had positive cores only in additional cores from the apex and TZ. Our study revealed that the systematic 12 core prostate biopsy including the apex and TZ was useful for improving the cancer detection ratio of the prostate.