Ciezki Jay P, Reddy Chandana A, Garcia Jorge, Angermeier Kenneth, Ulchaker James, Mahadevan Arul, Chehade Nabil, Altman Andrew, Klein Eric A
Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Int J Radiat Oncol Biol Phys. 2006 Feb 1;64(2):512-7. doi: 10.1016/j.ijrobp.2005.07.960. Epub 2005 Oct 6.
To analyze prostate-specific antigen (PSA) kinetics in patients treated with prostate brachytherapy (PI) with a minimum of 5 years of PSA follow-up.
The records of 162 patients treated with PI for localized prostate cancer with a minimum of 5 years of PSA follow-up were reviewed. A variety of pretreatment and posttreatment variables were examined. Patients were coded as having a PSA bounce if their PSA achieved a nadir, elevated at least 0.2 ng/mL greater than that nadir, and decreased to, or below, the initial nadir. Two definitions of biochemical failure (bF) or biochemical relapse-free survival (bRFS) were used: the classic American Society for Therapeutic Radiology and Oncology consensus definition of three consecutive rises (bF3) and the nadir plus 2 ng/mL definition (bFn+2). Associations between a PSA bounce and the various pre- and posttreatment factors were assessed with logistic regression analysis, and the association between a PSA bounce and bF was examined with the log-rank test. The Mann-Whitney U test was applied to test for differences in the PSA doubling time (PSADT) and the time to a PSA rise between the PSA bounce patients and the bF patients. PSADT was calculated from the nadir to the time of the first PSA rise, because this point is known first in the clinical setting.
The 5-year overall bRFS rate was 87% for the bF3 definition and 96% for the bFn+2 definition. A PSA bounce was experienced by 75 patients (46.3%). Patients who experienced a PSA bounce were less likely to have a bF, regardless of the bRFS definition used (bF3: p=0.0015; bFn+2: p=0.0040). Among the pre- and posttreatment factors, only younger age predicted for a PSA bounce on multivariate analysis (p=0.0018). The use of androgen deprivation had no effect on PSA bounce. No difference was found in the PSADT between patients who had a PSA bounce and those with bF. The median PSADT for those with a PSA bounce was 8.3 months vs. 10.3 months using the bF3 definition and 8.8 months using the bFn+2 definition. However, a significant difference was found in the time to the first rise in PSA after PI for patients with a PSA bounce vs. patients with bF. The median time to the first rise in PSA after nadir for those with a PSA bounce was 15.1 months vs. 30.0 months using the bF3 definition (p=0.001) and 22.3 months using the bFn+2 definition (p=0.013).
Patients experiencing a PSA bounce are more likely to be younger and will have a better bRFS. The PSADT cannot differentiate a PSA bounce from bF. The time to the initial PSA rise after nadir is an excellent discriminator of bF from PSA bounce. The time of the PSA rise after nadir occurs far sooner for a PSA bounce than for bF. This factor should be considered when assessing a patient with a rising PSA level after PI before a patient is administered salvage therapy.
分析接受前列腺近距离放射治疗（PI）且前列腺特异性抗原（PSA）随访至少5年的患者的PSA动力学。
回顾了162例接受PI治疗局限性前列腺癌且PSA随访至少5年的患者的记录。检查了各种治疗前和治疗后的变量。如果患者的PSA达到最低点，升高至少0.2 ng/mL高于该最低点，并降至或低于初始最低点，则将其编码为发生PSA反弹。使用了两种生化失败（bF）或生化无复发生存（bRFS）的定义：美国放射肿瘤学会经典的连续三次升高的共识定义（bF3）和最低点加2 ng/mL的定义（bFn+2）。通过逻辑回归分析评估PSA反弹与各种治疗前和治疗后因素之间的关联，并使用对数秩检验检查PSA反弹与bF之间的关联。应用曼-惠特尼U检验来检验PSA反弹患者和bF患者之间PSA倍增时间（PSADT）以及PSA升高时间的差异。PSADT是从最低点到首次PSA升高的时间计算得出的，因为这一点在临床环境中是首先知道的。
对于bF3定义，5年总体bRFS率为87%，对于bFn+2定义为96%。75例患者（46.3%）经历了PSA反弹。无论使用哪种bRFS定义，经历PSA反弹的患者发生bF的可能性较小（bF3：p=0.0015；bFn+2：p=0.0040）。在治疗前和治疗后的因素中，多变量分析中只有较年轻的年龄预测会发生PSA反弹（p=0.0018）。使用雄激素剥夺对PSA反弹没有影响。发生PSA反弹的患者与发生bF的患者之间的PSADT没有差异。发生PSA反弹的患者的中位PSADT为8.3个月，使用bF3定义时为10.3个月，使用bFn+2定义时为8.8个月。然而，对于发生PSA反弹的患者与发生bF的患者，PI后首次PSA升高的时间存在显著差异。最低点后首次PSA升高的中位时间，发生PSA反弹的患者为15.1个月，使用bF3定义时为30.0个月（p=0.001），使用bFn+2定义时为
