Watanabe H
Gan No Rinsho. 1984 May;30(6 Suppl):606-10.
We developed transrectal ultrasonotomography for practical use in 1967 and started a model trial mass screening program for prostatic diseases with the method in 1975. A mobile unit "Dolphin" for mass screening, in which two sets of special chair-type scanner for the method was loaded, was developed successfully in 1980. Up to March, 1983, 2394 males over the age of 55 were submitted to the primary study. Among them, 12 cases (0.5%) of prostatic cancer (PC) and 755 cases (31.5%) of benign prostatic hypertrophy (BPH) were finally detected in the secondary study. Thus the prevalence of BPH was significant and even the detection rate of PC was still remarkably higher than that in mass screening for other malignancies. The diagnostic accuracy in transrectal ultrasonotomography in PC was calculated from the results of patients visiting our out-patient clinic during 7 years until March, 1983. The sensitivity was 96.5% and the specificity was 84.6%. On the other hand, the sensitivity of digital examination in the same series was 80.7%. We concluded from this study that the efficacy of digital examination was thought to be insufficient for the screening of PC. The cost-benefit balance in our mass screening system was estimated from the above mentioned results. We needed yen 2,000,000 to find out each case of early PC in the system. In our clinic, patients with early PC paid yen 2,000,000 in average for treatments including radical surgery and were cured. On the contrary, patients with advanced PC paid yen 5,000,000 approximately yen 8,000,000 and died eventually. The minimum difference of treatment fee between early and advanced PC was yen 3,000,000, accordingly. Since the cost of detecting each early PC in mass screening was yen 2,000,000, we are contributing approximately yen 1,000,000 to the national finance on each time when we pick up one case of early PC. This doesn't include benefits from detecting BPH and from life prolongation. Thus the balance seems to be sufficiently positive. In conclusion, a mass screening program for prostatic diseases is promising because it can detect the diseases accurately by transrectal ultrasonotomography with a good cost-benefit balance. The only remaining problem is how to transfer this to national political measures.
1967年，我们研发了经直肠超声断层扫描技术以供实际应用，并于1975年开始用该方法开展前列腺疾病的大规模筛查模型试验项目。1980年，成功研制出用于大规模筛查的移动设备“海豚号”，其中装载了两套用于该方法的特殊椅式扫描仪。截至1983年3月，2394名55岁以上男性参与了初步研究。在二次研究中，最终检测出12例（0.5%）前列腺癌（PC）和755例（31.5%）良性前列腺增生（BPH）。因此，BPH的患病率很高，甚至PC的检出率仍显著高于其他恶性肿瘤的大规模筛查。经直肠超声断层扫描对PC的诊断准确性是根据1983年3月前7年期间到我们门诊就诊的患者结果计算得出的。敏感性为96.5%，特异性为84.6%。另一方面，同一系列中直肠指检的敏感性为80.7%。我们从这项研究中得出结论，直肠指检在筛查PC方面的效果被认为是不足的。根据上述结果估算了我们大规模筛查系统中的成本效益平衡。在该系统中，发现每一例早期PC需要200万日元。在我们诊所，早期PC患者平均支付200万日元用于包括根治性手术在内的治疗并被治愈。相反，晚期PC患者支付约500万日元至800万日元，最终死亡。因此，早期和晚期PC治疗费用的最小差额为300万日元。由于大规模筛查中检测每例早期PC的成本为200万日元，所以每次发现一例早期PC，我们大约为国家财政贡献100万日元。这还不包括检测BPH和延长寿命带来的益处。因此，这种平衡似乎是非常积极的。总之，前列腺疾病大规模筛查项目很有前景，因为它可以通过经直肠超声断层扫描准确检测疾病，且成本效益平衡良好。唯一剩下的问题是如何将其转化为国家政策措施。
