The TNM 8th edition: Validation of the proposal for organ - confined (pT2) prostate cancer

ABSTRACT Purpose: The 8th edition of the TNM has been updated and improved in order to ensure a high degree of clinical relevance. A major change in prostate includes pathologically organ - confined disease to be considered pT2 and no longer subclassified by extent of involvement or laterality. The aim of this study was to validate this major change. Materials and Methods: Prostates were step - sectioned from 196 patients submitted to radical prostatectomy with organ confined disease (pT2) and negative surgical margins. Tumor extent was evaluated by a semiquantitative point count method. The dominant nodule extent was recorded as the maximal number of positive points of the largest single focus of cancer from the quadrants. Laterality was considered as either total tumor extent (Group 1) or index tumor extent (Group 2). Time to biochemical recurrence was analyzed with the Kaplan - Meier product limit analysis and prediction of shorter time to biochemical recurrence with Cox proportional hazards model. Results: In Group 1, 43 / 196 (21.9%) tumors were unilateral and 153 / 196 (78.1%) bilateral and in Group 2, 156 / 196 (79.6%) tumors were unilateral and 40 / 196 (20.4%) bilateral. In both groups, comparing unilateral vs bilateral tumors, there was no significant clinicopathological difference, and no significant association with time as well as prediction of shorter time to biochemical recurrence following surgery. Conclusions: Pathologic sub - staging of organ confined disease does not convey prognostic information either considering laterality as total tumor extent or index tumor extent. Furthermore, no correlation exists between digital rectal examination and pathologic stage.**摘要** **目的**：第8版TNM分期系统（TNM staging system）已完成更新与优化，以保障其具备高度临床相关性。前列腺癌分类的一项核心调整为：将病理器官局限性疾病归为pT2分期，不再依据肿瘤受累范围或侧别进行亚分期。本研究旨在验证该项重大调整的临床价值。 **材料与方法**：纳入196例接受根治性前列腺切除术的患者，其术后病理证实为器官局限性疾病（pT2）且手术切缘阴性，对其前列腺标本进行连续切片检查。采用半定量点数法评估肿瘤范围，记录各象限中最大单个癌灶的阳性点数最大值作为主结节的肿瘤范围。侧别界定分为两组：组1以总肿瘤范围作为侧别判定依据，组2以指数癌灶范围作为侧别判定依据。采用Kaplan-Meier乘积限法分析患者的生化复发时间，采用Cox比例风险模型预测较短生化复发时间的发生风险。 **结果**：组1中，43/196（21.9%）的肿瘤为单侧性，153/196（78.1%）为双侧性；组2中，156/196（79.6%）的肿瘤为单侧性，40/196（20.4%）为双侧性。两组内，单侧与双侧肿瘤的临床病理特征均无显著差异，且与术后生化复发时间及较短复发时间的预测均无显著关联。 **结论**：无论是以总肿瘤范围还是指数癌灶范围来界定侧别，器官局限性疾病的病理亚分期均无法提供有效的预后信息。此外，直肠指检结果与病理分期之间不存在相关性。