初回前立腺生検陰性症例の臨床経過

Abstract

前立腺の疑いで針生検を行ったが陰性で, 再生検等, その後の経過を観察できた高齢者99例を検討した.経過観察中(中央値:76ヵ月)において, 血清前立腺特異抗原(PSA)値が持続的に高値, PSA velocity(PSAV)が0.75ng/ml/年以上, 直腸診・超音波上の持続する異常所見を再検査基準とした.再検査は43例に適応された.再検査例のPSAVは0.991で, 再検査非施行例の-0.012よりも高値であった.再検査施行例中, 前立腺癌18例(41.9%)を検出した.PSAVは1.950で, 癌陰性例の0.990よりも有意に高値であった.初回検査時に75歳以上であったのは19例で, 経過観察中に脳梗塞1例, 虚血性心疾患7例, 多臓器癌5例の発症がみられ, 4例が死亡した.10例に再検査を行い, 4例で限局性前立腺癌を検出した.PSAVは前立腺癌検出の指標として有用であった.しかし, 高齢者の余命, 癌検出までの期間, 他疾患発症の可能性を考慮すると, 高齢者への積極的な再検査の意義は限られていると考えられた

Of 227 men with a negative initial biopsy, the clinical course of 99 men who could be regularly followed using prostate specific antigen (PSA) determination was retrospectively analyzed. A repeat biopsy was recommended if the men showed persistent elevation of PSA > 10 ng/ml, PSA velocity (PSAV) > 0.75 ng/ml/year, or persistent abnormality on digital rectal examination and/or transrectal ultrasonography. A repeat biopsy was performed on 43 men. Because of the indication for a repeat biopsy, the PSAV of the 43 men who received a repeat biopsy was higher than that of the 56 men who did not. Clinically organ-confined cancer was detected in 18 patients (detection rate 41.9%). The patients having cancer had a higher PSAV (median 1.950) than those without the disease (median 0.900). Of 19 men aged 75 years and older at the initial biopsy, a repeat biopsy revealed organ-confined cancers in 4 out of 10 men. During follow-up of the 19 elderly men, 11 developed co-morbid illnesses such as cerebral infarction, ischemic heart diseases and other malignancies, and 4 died of the diseases. Thus, PSAV seems to be the best parameter for a repeat biopsy. Elderly men may not benefit from a repeat biopsy because they are unlikely to have lethal prostate cancer and highly likely to develop co-morbid illness that would affect their life-span.