Imai K, Fukabori Y, Yamanaka H
Dept. of Urology, Gunma University School of Medicine, Japan.
Gan To Kagaku Ryoho. 1996 Mar;23(4):403-6.
The incidence and mortality rate of prostate cancer in Japan are lower than in Western countries. Though studies of migrating populations would suggest that dietary or environmental factors may influence the etiology of the disease. The Westernized lifestyle after the Second World War may have influenced the increasing incidence of this disease in Japan. The screening by prostate specific antigen (PSA) on an asymptomatic healthy population can detect early prostate cancer. It is expected that the mortality may be decreased through such a system. However, some scientists hesitate to perform an aggressive program of early detection because of the possibility of latent cancer detection, the difficulty of distinguishing between clinically important and unimportant cancer, a high false positive rate to detect early stage cancer, and the lack of well-executed randomized prospective studies. Current clinical studies of the prostate cancer have demonstrated that the unimportant cancer detection rate by PSA was less than 10%. When a 4.0 ng/ml PSA cut-off value is applied for early detection, the false positive rate is approximately 80%. It is important to make subjects examined by the screening program aware of its the meaning. However, there is not a complete and cost-effective diagnostic modality to detect early prostate cancer. Moreover, it is confirmed that radical prostatectomy improves survival, but it has not been confirmed to improve the mortality based on population. We propose that well-executed randomized studies by the end point of the survival, cancer death rate, cost effective, QOL and etc. are urgently needed.
日本前列腺癌的发病率和死亡率低于西方国家。尽管对移民人群的研究表明，饮食或环境因素可能会影响该疾病的病因。第二次世界大战后的西方化生活方式可能影响了日本这种疾病发病率的上升。对无症状健康人群进行前列腺特异性抗原（PSA）筛查可以检测出早期前列腺癌。预计通过这样的系统死亡率可能会降低。然而，一些科学家由于存在检测到潜在癌症的可能性、区分临床重要和不重要癌症的困难、检测早期癌症的高假阳性率以及缺乏精心实施的随机前瞻性研究，而对积极开展早期检测计划持犹豫态度。目前前列腺癌的临床研究表明，PSA检测出不重要癌症的比率低于10%。当将4.0 ng/ml的PSA临界值用于早期检测时，假阳性率约为80%。让参与筛查项目的受试者了解其意义很重要。然而，目前尚无完整且具有成本效益的早期前列腺癌诊断方法。此外，已证实根治性前列腺切除术可提高生存率，但尚未证实基于人群的死亡率会因此降低。我们建议迫切需要开展以生存率、癌症死亡率、成本效益、生活质量等为终点的精心实施的随机研究。
