前列腺癌（PCa）活检中测量癌细胞范围的最佳方法尚不清楚。方法和结果：回顾管理保守的981名临床局部PCa患者并进行随访。计算阳性穿刺针的数量（NPC），穿刺针中最大癌细胞长度（MCL），总癌细胞长度（TCL）和阳性穿刺针的百分比（%+cores），并使用血清前列腺特异性抗原（PSA），T分期和Gleason评分进行单变量和多变量分析。记录间质缺口（SG）。在MCL受到SG影响的单变量模型有显著差异。在单变量模型中，所有变量都与PCa死亡有显著关联。在多变量模型中，仅有%+cores是预测结果的显著预测因子，每增加10%的%+cores结果为危险率（HR）1.07（LRT p > Χ2 = 0.01）。有120名患者MCL受到SG影响，该组共有20起事件。在包括SG的单变量分析中，中位数MCL为10毫米，HR为1.16（p = 0.007），未包括SG，中位数MCL为6毫米，HR为1.23（p = 6.3x10-4）。包括或不包括SG不会对TCL作为预测结果产生显著差异。癌细胞范围是PCa死亡的强预测因子，但只有%+cores对多元模型有贡献。作为NPC /总穿刺针数的分数表示，这是我们在非靶向活检中偏爱的最简单的评估方法。本文受版权保护。保留所有权利。

The Optimal method of measuring cancer extent in prostate cancer (PCa) biopsies is unknown METHODS AND RESULTS: 981 men with clinically localized PCa managed conservatively were reviewed with follow up. The number of positive cores (NPC), the Maximum Cancer Length in a core (MCL), Total Cancer Length (TCL) and percentage of positive cores (%+cores) was calculated and univariate and multivariate analysis performed using PSA, T-stage and Gleason score. The presence of stromal gaps (SG) was recorded. Univariate models were run where SG made a difference to the MCL. All variables showed significant association with PCa death in univariate models. In multivariate models, incorporating PSA, T-stage and Gleason score, only %+cores was a significant predictor of outcome with a 10% increase in %+cores resulting in a hazard ratio (HR) of 1.07 (LRT p > Χ2 = 0.01). There were 120 patients where SG made a difference to the MCL and a total of 20 events in this group. Including SG, on univariate analysis the median MCL was 10 mm and HR was 1.16 (p=0.007), not including SG the median MCL was 6 mm and HR was 1.23 (p=6.3x10-4). Inclusion or exclusion of SG made no significant difference to TCL as a predictor of outcome.Cancer extent is a strong predictor of PCa death but only %+cores adds to the multivariate model. Expressed as a fraction of NPC/total number of cores, this is the simplest method of assessment which we favour over more complicated methods in non-targeted biopsies.This article is protected by copyright. All rights reserved.