Yoshimura N, Takami N, Ogawa O, Kakehi Y, Okada Y, Fukui T, Yoshida O
Department of Urology, Faculty of Medicine, Kyoto University.
Jpn J Cancer Res. 1998 Jun;89(6):681-9. doi: 10.1111/j.1349-7006.1998.tb03271.x.
We performed a decision analysis to evaluate the usefulness of pretreatment prediction of clinically significant or insignificant tumor in patients with prostate-specific antigen (PSA)-detected stage T1c prostate cancer nonpalpable on rectal examination. Analysis was done for otherwise healthy subjects with 20 years of life expectancy. The prevalence of insignificant tumor among those with T1c prostate cancer was initially assumed to be 0.2. Quality-adjusted life expectancy was calculated and compared between 2 strategies; one with prediction-based selection of either radical prostatectomy or watchful waiting and the other with unselective assignment of one of the treatments. The selection strategy was superior when the sensitivity and specificity for detecting clinically significant tumor were 0.92 and 0.73, respectively, as reported by Epstein et al. (1994) using criteria of PSA density and Gleason score in a needle biopsy specimen. Sensitivity analysis revealed that the prediction-based selection strategy is preferred, with sensitivity and specificity constant, when the prevalence of insignificant tumor exceeds 0.16. On the other hand, when the prevalence of insignificant tumor is kept constant at 0.2, sensitivity should be 0.85 or higher for the prediction strategy to be preferred. As the prevalence of insignificant tumor among those with T1c prostate cancer increased, the prediction-based selection strategy is preferred with lower values of sensitivity and specificity for detecting significant tumor. These results suggest that a selective treatment strategy of either radical or conservative treatment based on pretreatment prediction for significant tumor is a beneficial alternative to radical prostatectomy unselectively assigned to all patients at the T1c stage, if a reasonable accuracy in prediction is attained.
我们进行了一项决策分析，以评估在前列腺特异性抗原（PSA）检测到的直肠指检未触及的T1c期前列腺癌患者中，术前预测临床显著或不显著肿瘤的有用性。对预期寿命为20年的其他健康受试者进行了分析。最初假设T1c期前列腺癌患者中不显著肿瘤的患病率为0.2。计算并比较了两种策略的质量调整预期寿命；一种是基于预测选择根治性前列腺切除术或观察等待，另一种是无选择地分配其中一种治疗方法。正如Epstein等人（1994年）在针吸活检标本中使用PSA密度和Gleason评分标准所报告的那样，当检测临床显著肿瘤的敏感性和特异性分别为0.92和0.73时，选择策略更具优势。敏感性分析表明，当不显著肿瘤的患病率超过0.16时，在敏感性和特异性不变的情况下，基于预测的选择策略更受青睐。另一方面，当不显著肿瘤的患病率保持在0.2不变时，预测策略要更受青睐，敏感性应达到0.85或更高。随着T1c期前列腺癌患者中不显著肿瘤患病率的增加，基于预测的选择策略更受青睐，此时检测显著肿瘤的敏感性和特异性值较低。这些结果表明，如果在预测中获得合理的准确性，基于术前预测显著肿瘤的选择性治疗策略（根治性或保守性治疗）是对所有T1c期患者无选择地进行根治性前列腺切除术的有益替代方案。
