Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand.
Am J Surg Pathol. 2013 Mar;37(3):311-22. doi: 10.1097/PAS.0b013e318270f71c.
Grading of renal cell carcinoma (RCC) has prognostic significance, and there is recent consensus by the International Society of Urological Pathology (ISUP) that for clear cell and papillary RCC, grading should primarily be based on nucleolar prominence. Microscopic tumor necrosis also predicts outcome independent of tumor grading. This study was undertaken to assess whether the incorporation of microscopic tumor necrosis into the ISUP grading system provides survival information superior to ISUP grading alone. Data on 3017 patients treated surgically for clear cell RCC, 556 for papillary RCC, and 180 for chromophobe RCC were retrieved from the Mayo Clinic Registry. Median follow-up periods were 8.9, 9.7, and 8.5 years, respectively. Four proposed grades were defined: grade 1: ISUP grade 1+ISUP grade 2 without necrosis; grade 2: ISUP grade 2 with necrosis+ISUP grade 3 without necrosis; grade 3: ISUP grade 3 with necrosis+ISUP grade 4 without necrosis; grade 4: ISUP grade 4 with necrosis or sarcomatoid/rhabdoid tumors. There was a significant difference in survival between each of the grades for clear cell RCC, and the concordance index was superior to that of ISUP grading. The proposed grading system also outperformed the ISUP grading system when cases were stratified according to the TNM stage. Similar results were not obtained for papillary RCC or chromophobe RCC. We conclude that grading for clear cell RCC should be based on nucleolar prominence and necrosis, that ISUP grading should be used for papillary RCC, and that chromophobe RCC should not be graded.
肾细胞癌（RCC）的分级具有预后意义，国际泌尿病理学会（ISUP）最近达成共识，对于透明细胞和乳头状 RCC，分级应主要基于核仁突出。显微镜下肿瘤坏死也可独立于肿瘤分级预测预后。本研究旨在评估将显微镜下肿瘤坏死纳入 ISUP 分级系统是否提供优于 ISUP 分级的生存信息。从 Mayo 诊所登记处检索了 3017 例透明细胞 RCC、556 例乳头状 RCC 和 180 例嫌色细胞 RCC 患者的手术治疗数据。中位随访时间分别为 8.9、9.7 和 8.5 年。定义了四个拟议的等级：等级 1：ISUP 等级 1+ISUP 等级 2 无坏死；等级 2：ISUP 等级 2 有坏死+ISUP 等级 3 无坏死；等级 3：ISUP 等级 3 有坏死+ISUP 等级 4 无坏死；等级 4：ISUP 等级 4 有坏死或肉瘤样/横纹肌样肿瘤。对于透明细胞 RCC，每个等级之间的生存率存在显著差异，且一致性指数优于 ISUP 分级。当根据 TNM 分期对病例进行分层时，该分级系统也优于 ISUP 分级系统。对于乳头状 RCC 或嫌色细胞 RCC，则未获得类似结果。我们得出结论，透明细胞 RCC 的分级应基于核仁突出和坏死，乳头状 RCC 应采用 ISUP 分级，而嫌色细胞 RCC 不应分级。
