Zagars G K, Pollack A, Kavadi V S, von Eschenbach A C
Department of Clinical Radiotherapy, University of Texas, M. D. Anderson Cancer Center, Houston 77030, USA.
Int J Radiat Oncol Biol Phys. 1995 May 15;32(2):293-306. doi: 10.1016/0360-3016(95)00077-C.
This study was undertaken to: (a) define the prognostic significance of pretreatment serum prostate-specific antigen (PSA) levels in localized prostate cancer treated with radiation; (b) define the prognostic usefulness of postradiation PSA levels; (c) evaluate the outcome of radiation using PSA as an endpoint.
Disease outcome in 707 patients with Stages T1 (205 men), T2 (256 men), T3 (239 men), and T4 (7 men), receiving definitive external radiation as sole therapy, was evaluated using univariate and multivariate techniques.
At a mean follow-up of 31 months, 157 patients (22%) developed relapse or a rising PSA. Multivariate analysis revealed pretreatment PSA level to be the most significant prognostic factor, with lesser though significant contributions due to Gleason grade (2-6 vs. 7-10) and transurethral resection in T3/T4 disease. The following four prognostic groupings were defined: group I, PSA < or = 4 ng/ml, any grade; group II, 4 < PSA < or = 20, grades 2-6; group III, 4 < PSA < or = 20, grades 7-10; group IV, PSA > 20, any grade. Five-year actuarial relapse rates in these groups were: I, 12%; II, 34%; III, 40%; and IV, 81%. Posttreatment nadir PSA was an independent determinant of outcome and only patients with nadir values < 1 ng/ml fared well (5-year relapse rate 20%). Using rising PSA as an endpoint the 461 patients with T1/T2 disease had an actuarial freedom from disease rate of 70% at 5 years, which appeared to plateau, suggesting that many were cured. No plateau was evident for T3/T4 disease.
Pretreatment serum PSA is the single most important predictor of disease outcome after radiation for local prostate cancer. Tumor grade has a lesser though significant prognostic role. Postirradiation nadir PSA value during the first year is a sensitive indicator of response to treatment. Only nadir values < 1 ng/ml are associated with a favorable outlook. A significant fraction of men with T1/T2 disease may be cured with radiation. There was no evidence for a cured fraction among patients with T3/T4 disease.
本研究旨在：（a）确定放疗治疗局限性前列腺癌时，治疗前血清前列腺特异性抗原（PSA）水平的预后意义；（b）确定放疗后PSA水平的预后价值；（c）以PSA为终点评估放疗效果。
采用单因素和多因素分析技术，评估707例接受根治性外照射作为唯一治疗的T1期（205例）、T2期（256例）、T3期（239例）和T4期（7例）患者的疾病转归。
平均随访31个月时，157例患者（22%）出现复发或PSA升高。多因素分析显示，治疗前PSA水平是最重要的预后因素，Gleason分级（2 - 6级与7 - 10级）以及T3/T4期疾病中的经尿道切除术也有较小但显著的影响。定义了以下四个预后分组：I组，PSA≤4 ng/ml，任何分级；II组，4＜PSA≤20，2 - 6级；III组，4＜PSA≤20，7 - 10级；IV组，PSA＞20，任何分级。这些组的5年精算复发率分别为：I组，12%；II组，34%；III组，40%；IV组，81%。治疗后PSA最低点是转归的独立决定因素，只有最低点值＜1 ng/ml的患者预后良好（5年复发率20%）。以PSA升高为终点，461例T1/T2期疾病患者5年时的精算无病生存率为70%，似乎趋于平稳，提示许多患者已治愈。T3/T4期疾病未出现明显的平稳期。
治疗前血清PSA是局部前列腺癌放疗后疾病转归的最重要单一预测指标。肿瘤分级的预后作用较小但显著。放疗后第一年的PSA最低点值是治疗反应的敏感指标。只有最低点值＜1 ng/ml与良好预后相关。相当一部分T1/T2期疾病患者可能通过放疗治愈。没有证据表明T3/T4期疾病患者中有治愈的比例。
