Lee W R, Hanlon A L, Hanks G E
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.
J Urol. 1996 Aug;156(2 Pt 1):450-3. doi: 10.1097/00005392-199608000-00033.
We determined whether the prostate specific antigen (PSA) nadir achieved following external beam radiation therapy alone predicts biochemical disease-free survival in a large cohort of men with clinically localized prostate cancer.
Between January 1986 and October 1993, 364 men with clinically localized, stages T1 to T3 adenocarcinoma of the prostate received definitive external beam radiation therapy with no prior, concomitant or adjuvant endocrine therapy. PSA was measured before treatment in 326 men (90%) and serial PSA was measured following treatment in all patients. All men were followed continuously for at least 24 months (median 44 months, range 24 to 90, mean 46). Biochemical failure after irradiation was defined as PSA of 1.5 ng./ml. or more and 2 consecutive serum PSA elevations.
The 5-year overall biochemical disease-free survival rate for the entire group was 56%. PSA nadir was predictive of subsequent biochemical disease-free survival. The biochemical disease-free survival rate at 3 years was 93, 49 and 16% for PSA nadirs of 0 to 0.99, 1 to 1.99 and 2 or more ng./ml., respectively (p = 0.0001). In a multivariate analysis PSA nadir (0 to 0.99 versus 1.0 to 1.99 versus 2 or more ng./ml.) was an independent predictor of biochemical disease-free survival along with pretreatment PSA, central axis dose, Gleason grade and T stage.
PSA nadir after radiation therapy is an indicator of subsequent biochemical disease-free survival. Patients who achieve a nadir of less than 1 ng./ml. following external beam radiation therapy have a favorable biochemical disease-free survival rate, while those with a nadir of greater than 1 ng./ml. have a high subsequent failure rate. Strategies to improve results should focus on techniques to increase the likelihood of achieving a PSA nadir of less than 1 ng./ml.
我们确定了单纯外照射放疗后达到的前列腺特异性抗原（PSA）最低点是否能预测一大群临床局限性前列腺癌男性患者的生化无病生存率。
1986年1月至1993年10月期间，364例临床局限性前列腺T1至T3期腺癌男性患者接受了确定性外照射放疗，之前未接受过、同时未接受或辅助内分泌治疗。326例（90%）男性患者在治疗前测量了PSA，所有患者在治疗后均进行了系列PSA测量。所有男性患者均连续随访至少24个月（中位数44个月，范围24至90个月，平均46个月）。放疗后的生化失败定义为PSA为1.5 ng/ml或更高且血清PSA连续两次升高。
整个组的5年总体生化无病生存率为56%。PSA最低点可预测随后的生化无病生存率。PSA最低点为0至0.99、1至1.99和2 ng/ml或更高时，3年生化无病生存率分别为93%、49%和16%（p = 0.0001）。在多变量分析中，PSA最低点（0至0.99与1.0至1.99与2 ng/ml或更高）与治疗前PSA、中心轴剂量、Gleason分级和T分期一起是生化无病生存的独立预测因素。
放疗后的PSA最低点是随后生化无病生存的一个指标。外照射放疗后最低点低于1 ng/ml的患者生化无病生存率良好，而最低点高于1 ng/ml的患者随后失败率较高。改善结果的策略应侧重于提高达到PSA最低点低于1 ng/ml可能性的技术。
