前立腺特異抗原(PSA)高値患者への低脂肪高大豆蛋白介入後のPSA変化と前立腺癌発生頻度

Abstract

2000年9月～2002年3月までの31ヵ月間に164例(50～80歳)に対して食生活介入を行った.PSA値は3.9～44.9ng/ml(平均7.4ng/ml), 経過観察期間は3～30ヵ月(平均18ヵ月)であった.2001年2月に検査法をEquimolarタイプの試薬に変更したため, それ以前に採血した58例はPSAの変化を観察する対象から除外した.また, 経過観察中にTUR-Pを施行したり, drop outした症例を除外すると, 3, 6ヵ月, 1年後のPSAの変化が評価できる症例は63, 34, 25例であった.低脂肪高大豆蛋白食の食事介入によりPSAはそれぞれ平均で3ヵ月後0.5ng/ml下降, 6ヵ月後で0.3ng/ml下降, 1年後で0.1ng/ml上昇した.統計上3ヵ月後の値にのみ有意な差であった.これは食生活介入によりPSAは一時的に下降することを意味する.食事介入症例の平均PSA倍加時間は444ヵ月であった.164例中9例に前立腺癌が発生した

A total of 164 patients with a high serum prostate specific antigen (PSA) level were enrolled in a supervised program of dietary intervention with a low-fat and high-soybean-protein diet. The primary endpoints were the evaluation of PSA change and morbidity of prostate cancer in this population. In the evaluable cases, the average serum PSA level had decreased 0.5 ng/ml after 3 months, 0.3 ng/ml after 6 months, and increased 0.1 ng/ml after 1 year. The change after 3 months was statistically significant (p=0.018, paired t-test). The average PSA doubling time was 444 months. During this study period, 9 of the patients developed prostate cancer. These findings indicate that this dietary intervention method was temporarily able to decrease serum PSA level, and indicates the possibility of prevention of prostate cancer by dietary intervention. However, more detailed analysis is necessary to determine why PSA did not keep decreasing.