Coley C M, Barry M J, Fleming C, Mulley A G
Massachusetis General Hospital, Boston, USA.
Ann Intern Med. 1997 Mar 1;126(5):394-406. doi: 10.7326/0003-4819-126-5-199703010-00010.
To estimate the prevalence of clinically important prostate cancer and to evaluate the effectiveness of digital rectal examination and measurement of prostate-specific antigen (PSA) in early detection of prostate cancer.
Relevant studies were identified from a structured MEDLINE search (1966 to 1995), reviews, bibliographies of retrieved articles, author files, and abstracts.
Articles selected for analysis of test effectiveness were prospective cohort studies of early detection that did not have obvious selection bias.
Likelihood ratios for digital rectal examination and PSA measurement were estimated from studies that specified the age distribution of participants.
In patients who have abnormalities on digital rectal examination, the risk for a large intracapsular tumor is increased twofold but the risk for extracapsular disease is increased threefold to ninefold. An elevation in PSA level greater than 4 ng/mL increases the odds of intracapsular tumors by as much as threefold and the odds of extracapsular tumors by threefold to fivefold. For studies in which biopsies were done if results of either test were abnormal, 18% to 26% of screened patients had suspicious results, cancer detection rates were approximately 4%, and the positive predictive value of the tests combined was 15% to 21%. Men who have lower urinary tract symptoms that are consistent with benign prostatic hyperplasia are not more likely to harbor prostate cancer; the specificity of PSA measurement is considerably lower among these men.
Larger-volume tumors of the prostate are common among older men. Available tests for the early detection of cancer have limited specificity, which necessitates a relatively high biopsy rate. The positive predictive value of combined digital rectal examination and PSA measurement has been defined, but the negative predictive value is less clear. Measurement of PSA is the most sensitive noninvasive test for prostate cancer. However, digital rectal examination detects cancer that would otherwise be missed by PSA measurement.
评估具有临床意义的前列腺癌的患病率，并评价直肠指检和前列腺特异性抗原（PSA）检测在前列腺癌早期诊断中的有效性。
通过对MEDLINE数据库（1966年至1995年）进行结构化检索、综述、检索文章的参考文献、作者档案以及摘要，确定相关研究。
入选用于分析检测有效性的文章为无明显选择偏倚的早期诊断前瞻性队列研究。
根据明确参与者年龄分布的研究估算直肠指检和PSA检测的似然比。
直肠指检异常的患者，包膜内大肿瘤的风险增加两倍，但包膜外疾病的风险增加三倍至九倍。PSA水平高于4 ng/mL会使包膜内肿瘤的几率增加多达三倍，包膜外肿瘤的几率增加三倍至五倍。对于两项检测结果任一项异常即进行活检的研究，18%至26%的筛查患者有可疑结果，癌症检出率约为4%，两项检测联合的阳性预测值为15%至21%。有与良性前列腺增生相符的下尿路症状的男性患前列腺癌的可能性并不更高；在这些男性中，PSA检测的特异性相当低。
老年男性中较大体积的前列腺肿瘤很常见。现有的癌症早期检测方法特异性有限，这就需要相对较高的活检率。直肠指检和PSA检测联合的阳性预测值已明确，但阴性预测值尚不清楚。PSA检测是前列腺癌最敏感的非侵入性检测方法。然而，直肠指检能检测出PSA检测可能遗漏的癌症。
