初回前立腺針生検にて癌の検出されなかった患者に対する再生検の検討

Abstract

前立腺針生検施行654例.1回目で癌が検出されたのは239例で, 陰性例のうち104例に2回目を行い, 16例に検出された.更に3回目が39例中4例, 4回目は10例中3例の検出であった.再検査で最終的に癌が検出された23例(A群)とされなかった81例(B群)において, 年齢, PSA, PSA density, PSA velocityに有意差はなかった.再検査時の所見で, MRIのT2強調像でlow intensityのあるものを陽性とすると, p=0.118, 感度79%, 特異度42%, 経直腸エコーでlow echoic areaのあるものを陽性とした場合はp=0.134, 感度74%, 特異度48%, 直腸診はp=0.027, 感度65%, 特異度59%で, 直腸診にのみ有意差を認めた.生検でatypical findings(AF)とされ再検査を施行した症例では, 9例中6例に癌が検出された.AFの内訳は「高分化腺癌を疑うが検体量少なく判別困難」3例, 「核異型があるが癌とは言い切れない」5例, 「ハイグレードprostatic intraepithelial neoplasia」1例であった

We retrospectively analyzed the results of 104 patients who underwent a second prostate needle biopsy. Between January 1993 and September 2000, 654 needle biopsies were performed and cancer was found in 239 patients. Among the other 415 patients, 104 patients underwent a second biopsy. The average prostate specific antigen (PSA) value was 9.6 ng/ml (2.0-30.9) (Tandem R conversion value). Cancer was detected in 16 out of 104 cases (15%) at the second biopsy, 4 out of 39 (10%) at the third biopsy, and 3 out of 10 (30%) at the fourth biopsy. The age, PSA value, digital examination, echography, and magnetic resonance imaging (MRI) were not helpful in distinguishing the patients with prostate cancer and atypical histological findings at the previous biopsy were the most important information. Among the 9 patients who showed atypical findings at the previous biopsy, 6 (67%) had cancer.