Biostatistics, Yale University School of Public Health, New Haven, Connecticut, USA.
Department of Veterans Affairs Connecticut Healthcare System, Clinical Epidemiology Research Center, Veterans Affairs Medical Center (VAMC), West Haven, Connecticut, USA.
J Investig Med. 2018 Apr;66(4):768-772. doi: 10.1136/jim-2017-000627. Epub 2017 Nov 22.
Prostate-specific antigen (PSA) measurements after primary treatment reflect residual tumor burden among men with prostate cancer. Using a mixture model analysis, we identified distinct trajectories of post-treatment PSA measurements and evaluated their associations with prostate cancer mortality. The study sample included 623 US Veterans treated for prostate cancer with curative intent during 1991-1995; 225 men received surgery and 398 men received radiation therapy. Post-treatment PSA measurements over a 2-year period for each patient were evaluated in latent class mixture models using the SAS TRAJ procedure, and groups of men with distinct trajectories of PSA were identified. These groups were then assessed for associations with 10-year prostate cancer mortality using proportional hazards analysis. Analyses identified three distinct groups-representing patterns of both initial values and changes in PSA over time-after surgery (n=172/31/14) and radiation therapy (n=253/103/22). Men in groups with patterns of higher (compared with the group with lowest) PSA values tended to have worse survival experience: HRs for prostate cancer mortality were 3.45 (P=0.18) and 22.7 (P<0.001) for surgery, and 2.70 (P=0.005) and 18.1 (P<0.001) for radiation therapy. The results indicate that PSA measurements after surgery or radiation therapy with curative intent include groups of men with a diverse spectrum of prognosis for prostate cancer mortality. Although contemporary PSA levels are lower than those observed in the study sample, the corresponding trajectory patterns may become evident shortly after the time of diagnosis and treatment.
前列腺特异性抗原（PSA）在初次治疗后的测量结果反映了前列腺癌患者的残留肿瘤负担。通过混合模型分析，我们确定了治疗后 PSA 测量的不同轨迹，并评估了它们与前列腺癌死亡率的关系。研究样本包括 1991-1995 年期间接受根治性治疗的 623 名美国退伍军人；225 名男性接受手术治疗，398 名男性接受放射治疗。使用 SAS TRAJ 程序对每位患者在 2 年内的治疗后 PSA 测量值进行潜在类别混合模型评估，并确定具有不同 PSA 轨迹的男性群体。然后使用比例风险分析评估这些群体与 10 年前列腺癌死亡率的关系。分析确定了三个不同的群体-代表手术后（n=172/31/14）和放射治疗（n=253/103/22）PSA 初始值和随时间变化的模式。与 PSA 值最低的组相比，PSA 值较高（与最低组相比）的男性模式往往生存体验较差：前列腺癌死亡率的 HRs 分别为 3.45（P=0.18）和 22.7（P<0.001）手术，2.70（P=0.005）和 18.1（P<0.001）放射治疗。结果表明，具有根治性意图的手术或放射治疗后的 PSA 测量结果包括一组具有不同前列腺癌死亡率预后的男性。尽管当代 PSA 水平低于研究样本中观察到的水平，但相应的轨迹模式可能在诊断和治疗后不久就变得明显。
