Whittemore A S, Lele C, Friedman G D, Stamey T, Vogelman J H, Orentreich N
Department of Health Research and Policy, Stanford University School of Medicine, Calif. 94305-5092.
J Natl Cancer Inst. 1995 Mar 1;87(5):354-60. doi: 10.1093/jnci/87.5.354.
The increasing incidence of prostate cancer creates complex issues in health care management and cost containment. There is a need to evaluate serial measurements of prostate-specific antigen (PSA) as a marker for long-term risk of clinically important prostate cancer (stages B through D).
We used a nested case-control design within a retrospective cohort study to evaluate serial PSA concentrations in relation to subsequent prostate cancer diagnoses.
Participants included 40 black and 96 white men with subsequent diagnoses of prostate cancer and 84 black and 100 white men without such diagnoses (control subjects) in a multiphasic health screening program conducted by the Kaiser Permanente Medical Care Program of Northern California. Serial serum samples were collected 1.5-23 years before prostate cancer diagnosis.
Median serum PSA concentrations, specific for age and subsequent cancer status, were similar in blacks and whites. Concentrations in control subjects increased exponentially with age, with a doubling time of 24.9 years. Concentrations in men with stage A cancer were similar to those in control subjects. Until about 13 years before diagnosis, PSA in men with subsequent cancer stages B through D increased exponentially with age, with a doubling time similar to that of control subjects. Thereafter, the PSA concentrations increased exponentially, with a doubling time of 4.3 years. Rapid increase in PSA concentration started about 1.5 years earlier for men with stage D cancer than for men with stage B or C cancer. The single PSA measurement drawn closest to diagnosis was a more sensitive marker of stages B through D cancer within the next 7 years than was any index of change that also took account of earlier PSA readings.
These data suggest that 1) age-specific PSA concentrations are similar in black men and white men and 2) current PSA concentration, specific for age, outperforms changes in past concentrations in identifying the man who will develop stage B, C, or D cancer within 7 years, albeit at the cost of a slightly higher rate of false-positive results. This interpretation needs confirmation in other data containing many serial PSA measurements within a few years of diagnosis.
前列腺癌发病率的不断上升给医疗保健管理和成本控制带来了复杂问题。有必要评估前列腺特异性抗原（PSA）的系列测量值，以此作为临床上重要前列腺癌（B至D期）长期风险的标志物。
我们在一项回顾性队列研究中采用巢式病例对照设计，以评估系列PSA浓度与后续前列腺癌诊断之间的关系。
参与者包括加利福尼亚州北部凯撒永久医疗计划开展的多阶段健康筛查项目中的40名黑人男性和96名白人男性，他们随后被诊断出患有前列腺癌，以及84名黑人男性和100名白人男性（对照对象）未被诊断出患有前列腺癌。在前列腺癌诊断前1.5至23年收集系列血清样本。
针对年龄和后续癌症状态的血清PSA浓度中位数在黑人和白人中相似。对照对象的浓度随年龄呈指数增长，倍增时间为24.9年。A期癌症男性的浓度与对照对象相似。在诊断前约13年之前，后续癌症分期为B至D期的男性的PSA随年龄呈指数增长，倍增时间与对照对象相似。此后，PSA浓度呈指数增长，倍增时间为4.3年。D期癌症男性的PSA浓度快速增长开始时间比B期或C期癌症男性早约1.5年。在接下来7年内，最接近诊断时进行的单次PSA测量比任何同时考虑早期PSA读数的变化指标更能敏感地检测出B至D期癌症。
这些数据表明：1）黑人和白人中按年龄分层的PSA浓度相似；2）针对年龄的当前PSA浓度在识别7年内将发展为B、C或D期癌症的男性方面优于过去浓度的变化，尽管代价是假阳性结果率略高。这一解释需要在其他包含诊断后几年内多次系列PSA测量数据中得到证实。
