前列腺穿刺对根治性前列腺切除术后标本ISUP升级预测列线图模型的建立及其应用

Establishment and application of prostate biopsy on ISUP upgradation prediction profile model after radical prostatectomy

目的:构建一个从前列腺穿刺组织到根治性前列腺切除术(RP)后标本ISUP分级升高(ISUP grade upgrading,IGU)风险的预测列线图模型并进行内部验证。方法:对2019年05月至2020年05月我院泌尿外科收治的166例前列腺癌患者临床和病理学资料进行回顾性分析。采用单因素及多因素Logistic回归分析得到IGU的独立危险因素,后根据这些因素构建列线图预测模型。通过校准图进行模型校准,C-指数评估模型的预测能力,决策曲线分析用于检验临床效用,采用Bootstrap resampling对模型进行诊断效能内部验证。结果:该研究中ISUP升级组有47例(28.3%)患者,未升级组有119例(71.7%)患者。多因素logistic回归分析发现前列腺穿刺活检组织Gleason评分(P=0.001)、前列腺穿刺活检方法(P=0.03)和穿刺阳性针数(P=0.04)是IGU的独立危险因素。IGU列线图模型是基于上述独立因素而构建,模型的ROC曲线下面积为0.802,C-指数为0.798,校准图显示预测曲线与实际曲线有较好的相符度。列线图模型在内部验证中C-指数达到0.772。决策曲线分析表明,RP-ISUP升级风险的区间阈值为3%~67%。结论:该研究构建了一个准确性相对较高的列线图模型,有助于临床医生评估RP术后标本ISUP分级升高(特别是经直肠穿刺活检诊断的低风险前列腺癌)的风险。

Objective:To develop and internally validate a nomogram for risk of upgrade of ISUP grade group from biopsy tissue to RP final histology.Methods:166 patients by biopsy and RP in our hospital from May 2019 to May 2020 were analyzed retrospectively.Logistic regression analysis was used to predict the significant independent factors for ISUP upgrade.A nomogram was then developed based on these independent factors.The C-index,calibration plot,and decision curve analysis were used to assess the discrimination,calibration,and clinical usefulness of the pre-dicting model.Internal validation was evaluated by using the bootstrapping validation.Results:There were 47 patients(29.3%)in the ISUP upgrade group and 119 patients(71.7%)in the no ISUP upgrade group respectively.Multiva-riate logistic regression analysis showed that Gleason scores(P=0.001),prostate biopsy approach(P=0.03)and number of positive cores(P=0.04)were the independent risk factors for ISUP upgrade.A prediction nomogram mod-el of ISUP upgrade was built based on these significant factors above,the AUC of which was 0.802.The C-index for the prediction nomogram was 0.798 and the nomogram showed good calibration.High C-index value of 0.772 could still be reached in the interval validation.Decision curve analysis also demonstrated that the threshold value of RP-ISUP upgrade risk was 3%to 67%.Conclusion:A novel nomogram was built with a relatively good accuracy to assist clinicians to evaluate the risk of ISUP upgrade in the RP specimen,especially for the low-risk prostate cancer diag-nosed by transrectal prostate biopsy.