Feigenberg Steven J, Hanlon Alexandra L, Horwitz Eric M, Uzzo Robert G, Eisenberg Debra, Pollack Alan
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111-2497, USA.
Am J Clin Oncol. 2006 Oct;29(5):458-62. doi: 10.1097/01.coc.0000225410.37469.58.
The purpose of this report is to determine whether any specific magnitude in the prostate specific antigen (PSA) bounce predicted for a clinically poorer outcome.
Between May 1989 and August 1999, 568 prostate cancer patients were treated with 3-dimensional conformal radiotherapy (RT). All patients had at least 5 years of follow up, 6 post-RT PSA measurements and received no hormonal therapy as part of their initial management. The median follow up was 85 months. The median RT dose was 74 Gy. A bounce was defined by a minimum rise in PSA of 0.4 ng/mL over a 6-month period, followed by a drop of PSA of any magnitude. The analysis of the optimal PSA bounce cut-point was based upon a recursive partitioning approach (RPA) for censored data using the log-rank test for nodal separation of freedom from biochemical failure (FFBF) as defined by the American Society for Therapeutic Radiology and Oncology (ASTRO) definition. Cox multivariate regression analysis (MVA) was used to confirm independent predictors of outcome among clinical and treatment related factors: PSA bounce as defined by the RPA, pretreatment PSA (continuous), Gleason score (2-6 versus 7-10), T stage (T1c/T2ab versus T2c/T3), and total radiation dose (continuous).
There were 154 patients (27%) experienced a bounce with a median magnitude of 0.6. The RPA resulted in an optimal PSA bounce cut-point of 1.4 ng/mL such that 5-year Kaplan-Meier estimates of FFBF were 71%, 59%, and 38% for nonbouncers, a bounce < or =1.4 ng/mL and >1.4 ng/mL, respectively. Twenty-one (14%) of the 154 patients who experienced a bounce had a PSA bounce magnitude >1.4 ng/mL. Stepwise MVA demonstrated that the PSA bounce grouped as above was an independent predictor of FFBF (P = 0.0013), freedom from distant metastases (P = 0.0028) and cause specific survival (P = 0.0266). Lower RT dose (P < 0.0001) was the only independent predictor of a PSA bounce >1.4 ng/mL.
Using recursive partitioning techniques, a clinically significant PSA bounce occurred when the magnitude of the bounce was >1.4 ng/mL. This is important information to aid clinicians in determining management after RT.
本报告旨在确定前列腺特异性抗原（PSA）反弹的任何特定幅度是否预示着临床预后较差。
1989年5月至1999年8月期间，568例前列腺癌患者接受了三维适形放疗（RT）。所有患者至少随访5年，放疗后进行6次PSA测量，且在初始治疗中未接受激素治疗。中位随访时间为85个月。中位放疗剂量为74 Gy。反弹定义为PSA在6个月内至少升高0.4 ng/mL，随后PSA出现任何幅度的下降。基于递归划分方法（RPA）对删失数据进行分析，采用对数秩检验来确定按照美国放射肿瘤学会（ASTRO）定义的生化无复发生存（FFBF）的节点分离自由度。采用Cox多变量回归分析（MVA）来确认临床和治疗相关因素中预后的独立预测因素：由RPA定义的PSA反弹、治疗前PSA（连续变量）、Gleason评分（2 - 6与7 - 10）、T分期（T1c/T2ab与T2c/T3）以及总放射剂量（连续变量）。
154例患者（27%）出现反弹，中位幅度为0.6。RPA得出最佳PSA反弹切点为1.4 ng/mL，使得非反弹者、反弹幅度≤1.4 ng/mL和>1.4 ng/mL的患者5年FFBF的Kaplan - Meier估计值分别为71%、59%和38%。154例出现反弹的患者中有21例（14%）的PSA反弹幅度>1.4 ng/mL。逐步MVA表明，如上分组的PSA反弹是FFBF（P = 0.0013）、无远处转移生存（P = 0.00
