Zagars G K, von Eschenbach A C
Department of Clinical Radiotherapy, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Cancer. 1993 Jul 15;72(2):538-48. doi: 10.1002/1097-0142(19930715)72:2<538::aid-cncr2820720234>3.0.co;2-s.
Prostate-specific antigen (PSA) is a valuable serum marker for prostate cancer. However, the prognostic importance of baseline PSA values in relation to other prognostic factors has not been elucidated. The incidence of postradiation rising PSA values has not been documented, and the extent to which PSA influences the assessment of radiation therapy is unclear. This study was designed to address these issues.
Three hundred and fourteen consecutive patients with baseline PSA values who were treated between 1987 and 1991 with external beam radiation alone were reviewed for disease outcome and posttreatment PSA levels.
Clinical stages at diagnosis were: Stage A2, 87 (28%); Stage B, 108 (34%); and Stage C, 119 (38%). At a mean follow-up of 21 months, 25 patients had relapsed, 53 had developed rising PSA profiles, and 58 had either relapsed or had rising PSA profiles. The actuarial relapse rate was 20% at 4 years, the incidence of rising PSA profiles was 38% at 4 years, and the incidence of either relapse or rising PSA was 40% at 4 years. In multivariate analysis, baseline PSA value was the single most important factor predicting for local relapse, metastatic relapse, any disease relapse, and posttreatment rising PSA values. Using relapse or rising PSA as endpoints, the following four prognostic groupings based on baseline PSA and M.D. Anderson (MDA) grade were delineated: I, PSA less than or equal to 4 ng/ml, any grade; II, PSA greater than 4 but less than or equal to 10 ng/ml, Grades 1 and 2; III, PSA greater than 4 but less than or equal to 10 ng/ml, Grades 3 and 4 or PSA greater than 10 but less than or equal to 30 ng/ml, Grades 1 and 2; and IV, PSA greater than 10 but less than or equal to 30 ng/ml, Grades 3 and 4 or PSA greater than 30 ng/ml, any grade. The actuarial incidence of relapse or rising PSA in these groups was: I, less than 10% at 3 years; II, 20% at 3 years; III, 55% at 3 years; and IV, 90% at 30 months. When using traditional endpoints of disease outcome, the patients in this series had an outcome equivalent to that in 799 patients treated in our institution in the pre-PSA era; when using rising PSA profiles as endpoints, treatment was significantly less effective.
Pretreatment serum PSA level is the single most significant predictor of disease outcome after radiation therapy for local-regional prostate cancer. Moreover, postirradiation PSA values may potentially serve as an early endpoint to evaluate treatment efficacy. Using a rising posttreatment PSA profile as an index of treatment failure reveals that total and permanent eradication of prostate cancer with radiation therapy alone is not achieved as often as previously believed and that multimodal treatment approaches to prognostically unfavorable early stage disease need investigation.
前列腺特异性抗原（PSA）是前列腺癌的一种重要血清标志物。然而，基线PSA值与其他预后因素相关的预后重要性尚未阐明。放疗后PSA值升高的发生率尚未有文献记载，且PSA对放疗评估的影响程度尚不清楚。本研究旨在解决这些问题。
回顾了1987年至1991年间仅接受外照射放疗的314例有基线PSA值的连续患者的疾病转归和治疗后PSA水平。
诊断时的临床分期为：A2期，87例（28%）；B期，108例（34%）；C期，119例（38%）。平均随访21个月时，25例患者复发，53例患者PSA水平升高，58例患者复发或PSA水平升高。4年时的精算复发率为20%，4年时PSA水平升高的发生率为38%，4年时复发或PSA升高的发生率为40%。多因素分析中，基线PSA值是预测局部复发、远处转移复发、任何疾病复发及治疗后PSA值升高的唯一最重要因素。以复发或PSA升高为终点，根据基线PSA和MD安德森（MDA）分级划定了以下四个预后分组：I组，PSA小于或等于4 ng/ml，任何分级；II组，PSA大于4但小于或等于10 ng/ml，1级和2级；III组，PSA大于4但小于或等于10 ng/ml，3级和4级或PSA大于10但小于或等于30 ng/ml，1级和2级；IV组，PSA大于10但小于或等于30 ng/ml，3级和4级或PSA大于30 ng/ml，任何分级。这些组中复发或PSA升高的精算发生率为：I组，3年时小于10%；II组，3年时20%；III组，3年时55%；IV组，30个月时90%。当使用传统的疾病转归终点时，本系列患者的转归与我院PSA时代之前治疗的799例患者相当；当以PSA水平升高为终点时，治疗效果明显较差。
治疗前血清PSA水平是局部区域性前列腺癌放疗后疾病转归的唯一最重要预测因素。此外，放疗后PSA值可能作为评估治疗疗效的早期终点。将治疗后PSA水平升高作为治疗失败的指标显示，单纯放疗并不能像以前认为的那样经常实现前列腺癌的完全和永久性根除，对于预后不良的早期疾病，多模式治疗方法需要研究。
