Objective: To determine the total and age-specific cut-off values of total prostate specific antigen (tPSA) and the ratio of free PSA divided total PSA (fPSA/tPSA) for screening prostate cancer in China. Methods: Based on the Chinese Colorectal, Breast, Lung, Liver, and Stomach cancer Screening Trial (C-BLAST) and the Tianjin Common Cancer Case Cohort (TJ4C), males who were not diagnosed with any cancers at baseline since 2017 and received both tPSA and fPSA testes were selected. Based on Cox regression, the overall and age-specific (＜60, 60-＜70, and ≥70 years) accuracy and optimal cut-off values of tPSA and fPSA/tPSA ratio for screening prostate cancer were evaluated with time-dependent receiver operating characteristic curve (tdROC) and area under curve (AUC). Bootstrap resampling was used to internally validate the stability of the optimal cut-off value, and the PLCO study was used to externally validate the accuracy under different cut-off values. Results: A total of 5 180 participants were included in the study, and after a median follow-up of 1.48 years, a total of 332 prostate cancer patients were included. In the total population, the tdAUC of tPSA and fPSA/tPSA screening for prostate cancer were 0.852 and 0.748, respectively, with the optimal cut-off values of 5.08 ng/ml and 0.173, respectively. After age stratification, the age specific cut-off values of tPSA in the <60, 60-<70, and ≥70 age groups were 3.13, 4.82, and 11.54 ng/ml, respectively, while the age-specific cut-off values of fPSA/tPSA were 0.153, 0.135, and 0.130, respectively. Under the age-specific cut-off values, the sensitivities of tPSA screening for prostate cancer in males <60, 60-70, and ≥70 years old were 92.3%, 82.0%, and 77.6%, respectively, while the specificities were 84.7%, 81.3%, and 75.4%, respectively. The age-specific sensitivities of fPSA/tPSA for screening prostate cancer were 74.4%, 53.3%, and 55.9%, respectively, while the specificities were 83.8%, 83.7%, and 83.7%, respectively. Both bootstrap's internal validation and PLCO external validation provided similar results. The combination of tPSA and fPSA/tPSA could further improve the accuracy of screening. Conclusion: To improve the screening effects, it is recommended that age-specific cut-off values of tPSA and fPSA/tPSA should be used to screen for prostate cancer in the general risk population.
目的： 探讨总人群及不同年龄下总前列腺特异性抗原（tPSA）和游离前列腺特异性抗原（fPSA）与tPSA比值（fPSA/tPSA）筛查前列腺癌的最佳切点值及筛查准确性。 方法： 基于天津市常见恶性肿瘤联合筛查项目人群及同期天津市常见恶性肿瘤队列人群，选取2017年以来基线未患癌且接受tPSA及fPSA检测的男性，基于Cox回归采用时间依赖的受试者工作特征曲线（tdROC）及曲线下面积（tdAUC）评价tPSA和fPSA/tPSA比值筛查2年内总体人群及年龄特异性（＜60岁、60～＜70岁及≥70岁）新发前列腺癌的准确性及最佳切点值。采用Bootstrap重抽样内部验证最佳切点值的稳定性，并采用前列腺、肺、结肠和卵巢癌筛查试验（PLCO）人群外部验证不同切点值下的筛查准确性。 结果： 共5 180名参与者纳入研究，中位随访1.48年后，共发现332例前列腺癌患者。总人群中（n=5 180），tPSA和fPSA/tPSA筛查2年内新发前列腺癌的tdAUC分别为0.852和0.748，最佳切点值分别为5.08 ng/ml和0.173。按年龄分层后，＜60岁、60～＜70岁和≥70岁年龄组tPSA年龄特异性切点值分别为3.13、4.82、11.54 ng/ml，年龄别特异性fPSA/tPSA最佳切点值分别为0.153、0.135、0.130。相应年龄别特异性切点值下，＜60岁、60～＜70岁和≥70岁男性tPSA筛查前列腺癌的灵敏度分别为92.3%、82.0%和77.6%，特异度分别为84.7%、81.3%和75.4%；fPSA/tPSA 筛查前列腺癌的灵敏度分别为74.4%、53.3%和55.9%，特异度分别为83.8%、83.7%和83.7%。Bootstrap内部验证及PLCO外部验证均得到类似的结果，tPSA及fPSA/tPSA联合后可进一步改善筛查的准确性。 结论： 为提高筛查准确性，推荐在一般风险人群中，采用年龄别特异性的tPSA和fPSA/tPSA筛查切点值来筛查前列腺癌。.