Jacobsen S J, Bergstralh E J, Guess H A, Katusic S K, Klee G G, Oesterling J E, Lieber M M
Section of Clinical Epidemiology, Mayo Clinic, Rochester, Minn, USA.
Arch Intern Med. 1996 Nov 25;156(21):2462-8.
Most studies that have described the sensitivity and specificity of prostate-specific antigen (PSA) as a screening test have been conducted in urology practice settings or in media-based screening programs. The control patients from these settings may have a higher prevalence of urologic disorders that increase serum PSA levels than that of the general population in which screening efforts might take place, leading to biased estimates of sensitivity and specificity.
To determine the sensitivity and specificity of serum PSA levels for the early detection of prostate cancer in a population-based setting.
This population-based case-control study was conducted in Olmsted County, Minnesota, where the Rochester Epidemiology Project could identify all incident cases of prostate cancer through passive surveillance of medical care provided to local residents. Case patients were all 177 men (age range, 50-79 years) who were newly diagnosed as having prostate cancer from 1990 through 1992 and had a prediagnostic serum PSA determination (90% of all incident cases). Control patients were randomly selected from the Olmsted County population and had undergone a clinical examination to exclude prostate cancer.
The median (25th and 75th percentiles) of serum PSA levels was 9.4 ng/mL (5.4 and 18.6 ng/mL, respectively) for case patients and 1.2 ng/mL (0.7 and 2.1 ng/mL, respectively) for control patients (P < .001). When sensitivity was plotted against 1-specificity, the area under the receiver operating characteristic curve was 0.94 (SE, 0.01). The predictive power declined somewhat with age, with areas under the curve of 0.96, 0.94, and 0.90 for men in their 50s, 60s, and 70s, respectively. When cases were restricted to the 155 men with clinically localized disease, the area under the curve was essentially unchanged (0.94; SE, 0.01) and still much greater than the estimates of 0.75 that were reported from urology practice- and media-based settings.
In a community-based setting, serum PSA levels provide better discrimination between men with and without clinically localized prostate cancer than has been observed in studies that were conducted in urologic practices. These results suggest that previous decision analyses may have underestimated the predictive value of PSA for the detection of prostate cancer in a primary care or community-wide screening program.
大多数描述前列腺特异性抗原（PSA）作为筛查试验的敏感性和特异性的研究是在泌尿外科临床环境或基于媒体的筛查项目中进行的。这些环境中的对照患者可能比可能进行筛查的普通人群有更高的泌尿系统疾病患病率，而这些疾病会使血清PSA水平升高，从而导致对敏感性和特异性的估计有偏差。
确定在基于人群的环境中血清PSA水平对早期检测前列腺癌的敏感性和特异性。
这项基于人群的病例对照研究在明尼苏达州的奥尔姆斯特德县进行，在那里罗切斯特流行病学项目可以通过对当地居民提供的医疗服务进行被动监测来识别所有前列腺癌新发病例。病例患者为1990年至1992年新诊断为前列腺癌且在诊断前进行过血清PSA测定的所有177名男性（年龄范围50 - 79岁）（占所有新发病例的90%）。对照患者从奥尔姆斯特德县人群中随机选取，并经过临床检查以排除前列腺癌。
病例患者血清PSA水平的中位数（第25和第75百分位数）分别为9.4 ng/mL（5.4和18.6 ng/mL），对照患者为1.2 ng/mL（0.7和2.1 ng/mL）（P <.001）。当绘制敏感性与1 - 特异性的关系图时，受试者操作特征曲线下面积为0.94（标准误，0.01）。预测能力随年龄略有下降，50多岁、60多岁和70多岁男性的曲线下面积分别为0.96、0.94和0.90。当病例仅限于155名临床局限性疾病患者时，曲线下面积基本不变（0.94；标准误，0.01），仍远高于泌尿外科临床和基于媒体的研究中报道的0.75的估计值。
在基于社区的环境中，血清PSA水平在区分有临床局限性前列腺癌和无临床局限性前列腺癌的男性方面比在泌尿外科临床研究中观察到的情况更好。这些结果表明，先前的决策分析可能低估了PSA在初级保健或社区范围筛查项目中检测前列腺癌的预测价值。
