Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY 10029, USA.
Int J Radiat Oncol Biol Phys. 2012 Jun 1;83(2):600-7. doi: 10.1016/j.ijrobp.2011.07.009. Epub 2011 Oct 8.
Because limited information exists regarding whether the rate or magnitude of PSA decline following brachytherapy predicts long-term clinical outcomes, we evaluated whether achieving a prostate-specific antigen (PSA) nadir (nPSA) <0.5 ng/mL following brachytherapy is associated with decreased PSA failure and/or distant metastasis.
We retrospectively analyzed our database of early-stage prostate adenocarcinoma patients who underwent brachytherapy, excluding those receiving androgen-deprivation therapy and those with <2 years follow-up. Median and mean pretreatment PSA were 6 ng/mL and 7.16 ng/mL, respectively. By clinical stage, 775 were low risk (≤ T2a), 126 were intermediate risk (T2b), and 20 were high risk (>T2b). By Gleason score, 840 were low risk (≤ 6), 71 were intermediate risk (7), and 10 were high risk (>7). Patients were treated with brachytherapy only (I-125, n = 779, or Pd-103, n = 47), or brachytherapy + external-beam radiation therapy (n = 95). Median follow-up was 6.3 years. We noted whether nPSA <0.5 ng/mL was achieved and the time to achieve this nadir and tested for associations with pretreatment risk factors. We also determined whether this PSA endpoint was associated with decreased PSA failure or distant metastasis.
Absence of high-risk factors in clinical stage (≤ T2b), Gleason score (≤ 7), and pretreatment PSA (≤ 20 ng/mL) was significantly associated with achieving nPSA <0.5 ng/mL. By Kaplan-Meier analysis, patients achieving nPSA <0.5 ng/mL had significantly higher long-term freedom from biochemical failure (FFBF) than nonresponders (5-year FFBF: 95.2 ± 0.8% vs. 71.5 ± 6.7%; p < 0.0005). Among responders, those who achieved nPSA <0.5 ng/mL in ≤ 5 years had higher FFBF than those requiring >5 years (5-year FFBF: 96.7 ± 0.7% vs. 80.8 ± 4.6%; p < 0.0005). On multivariate analysis, patients who achieved nPSA <0.5 ng/mL in ≤ 5 years had significantly higher FFBF than other patients.
Pretreatment risk factors (clinical tumor stage, Gleason score, pretreatment PSA) strongly predict for patients achieving nPSA <0.5 ng/mL following brachytherapy, and this cohort had significantly higher long-term FFBF.
由于关于接受近距离放射治疗后 PSA 下降的速度或幅度是否能预测长期临床结果的信息有限，我们评估了近距离放射治疗后是否达到前列腺特异性抗原（PSA）最低点（nPSA）<0.5ng/mL 是否与 PSA 失败和/或远处转移减少有关。
我们回顾性分析了接受近距离放射治疗的早期前列腺腺癌患者的数据库，排除了接受雄激素剥夺治疗和随访时间<2 年的患者。中位和平均预处理 PSA 分别为 6ng/mL 和 7.16ng/mL。按临床分期，775 例为低危（≤T2a），126 例为中危（T2b），20 例为高危（>T2b）。按 Gleason 评分，840 例为低危（≤6），71 例为中危（7），10 例为高危（>7）。患者接受单纯近距离放射治疗（I-125，n=779 或 Pd-103，n=47）或近距离放射治疗+外照射（n=95）。中位随访时间为 6.3 年。我们记录是否达到 nPSA<0.5ng/mL 以及达到该最低点的时间，并检测与预处理危险因素的相关性。我们还确定了该 PSA 终点是否与 PSA 失败或远处转移减少有关。
临床分期（≤T2b）、Gleason 评分（≤7）和预处理 PSA（≤20ng/mL）无高危因素与达到 nPSA<0.5ng/mL 显著相关。Kaplan-Meier 分析显示，达到 nPSA<0.5ng/mL 的患者具有显著更高的长期生化无复发生存率（FFBF）（5 年 FFBF：95.2%±0.8%比 71.5%±6.7%；p<0.0005）。在应答者中，在≤5 年内达到 nPSA<0.5ng/mL 的患者比需要>5 年的患者具有更高的 FFBF（5 年 FFBF：96.7%±0.7%比 80.8%±4.6%；p<0.0005）。多因素分析显示，在≤5 年内达到 nPSA<0.5ng/mL 的患者具有显著更高的 FFBF。
预处理危险因素（临床肿瘤分期、Gleason 评分、预处理 PSA）强烈预测接受近距离放射治疗后达到 nPSA<0.5ng/mL 的患者，该队列具有显著更高的长期 FFBF。
