目的： 自建评分法评估前列腺特异性抗原（prostate specific antigen,PSA）值处在灰区（PSA值灰区）的前列腺疾病患者为前列腺癌的风险度,并验证其诊断价值。方法： 2017年4月至2019年11月期间,回顾性分析在我院行超声引导下经会阴前列腺穿刺活检的412例PSA值处于灰区（4~10 μg/L）前列腺疾病患者的资料,应用U检验及卡方检验比较良、恶性前列腺疾病组间的年龄、前列腺体积、血清学指标 、PSA密度（prostate specific antigen density, PSAD）及直肠腔内超声（transrectal ultrasonography, TRUS）影像学表现差异,绘制受试者操作特征（receiver operating characteristic,ROC）曲线,确定有效参数曲线下面积最大时的临界值,建立PSA值灰区前列腺疾病患者恶性风险度评分,以前列腺穿刺活检为标准,绘制ROC曲线评估其诊断效能。结果： 良、恶性前列腺疾病组间,年龄、前列腺体积、游离/总前列腺特异性抗原比值（free/total prostate specific antigen ratio,f/t PSA）、PSAD及TRUS检出可疑结节方面差异均有统计学意义（P均<0.05）。应用年龄、前列腺体积、f/t PSA、PSAD及TRUS影像表现建立PSA值灰区前列腺疾病患者恶性风险度评分,总分0~5分患者的前列腺癌风险分别为3.12%、9.57%、18.02%、30.48%、53.45%及100%,采用该评分法（>2.5分）在PSA值灰区患者中诊断前列腺癌的ROC曲线下面积为0.759,灵敏度为71.41%,特异度为67.39%,优于其他单项指标。结论： 本研究新建立的前列腺疾病恶性风险度评分能有效评估PSA值处于灰区患者的前列腺癌风险。

Objective: To establish a scoring method for assessing the risk of prostate cancer in subjects with prostate specific antigen（PSA） in gray zone, and evaluate its diagnostic value. Methods: A total of 412 cases with gray zone PSA (4~10 μg/L) were enrolled from April 2017 to November 2019, and all had transperineal prostate biopsy performed under ultrasound guidance. Patients were divided into benign and malignant groups based on biopsy. Differences in age, prostate volume, serological indicators, PSA density (PSAD) and transrectal ultrasonography （TRUS） imaging between benign and malignant groups were compared with U test and Chi-square test. Receiver operator characteristic (ROC) curve was used to screen for the valid parameters and determine the cutoff values. The risk scoring method using valid parameters was then established for differentiating benign from malignant lesions in patients with gray zone PSA. The capability of the risk scoring method was assessed by ROC curve. Results: The age, prostate volume, free/total PSA ratio（f/t PSA） and PSAD between benign and malignant groups were statistically different (P<0.05). The detection rates of suspicious -looking nodules by TRUS between benign and malignant groups were also statistically different (P<0.05). The above mentioned indice including age, prostate volume, f/t PSA, PSAD and TRUS imaging findings were accepted to establish the risk scoring method. As scores of the scoring method increased from 0 to 5, the malignancy rates of prostate lesions assessed were 3.12%, 9.57%, 18.02%, 30.48%, 53.45% and 100%, respectively. The area under the ROC curve of the risk scoring method(cut off value >2.5) for diagnosing prostate cancer was 0.759, and the sensitivity and specificity were 71.41%, 67.39%, respectively. The performance of the established risk scoring method was superior to any other single index. Conclusions: The self-established scoring method could be used to assess malignant risk of prostate cancer in patients with gray zone PSA, which might facilitate the diagnosis of prostate cancer.