Department of Pathology.
Department of Urology, University of California Los Angeles, Los Angeles, CA.
Am J Surg Pathol. 2020 May;44(5):582-593. doi: 10.1097/PAS.0000000000001455.
Conflicting data have been published on the prognostic significance of histologic parameters in papillary renal cell carcinoma (PRCC). We conducted a comprehensive evaluation of clinical and histologic parameters in PRCC in nephrectomies and their impact on prognosis, with an emphasis on World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grade, tumor architecture (solid, micropapillary, and hobnail), and PRCC type. A total of 185 PRCC cases were evaluated, 117 (63.2%) type 1, 45 (24.3%) type 2, and 11 (5.9%) mixed type 1 and type 2. Using WHO/ISUP grading criteria, PRCCs were graded as follows: 6 (3.2%) grade 1; 116 (62.7%) grade 2; 61 (33.0%) grade 3; and 2 (1.1%) grade 4. The solid architecture was present in 3 cases (1.6%) and comprised 10%, 10%, and 30% of the tumor area. Micropapillary architecture was present in 10 cases (5.4%), ranging from 5% to 30% of the tumor (mean=11%; median=10%). Hobnail architecture was seen in 9 cases (4.9%), with mean percentage of 23% (median=15%; range: 5% to 50%) involvement of tumor area. Parameters associated with worse disease-free survival (DFS) and overall survival (OS) in the univariate analysis included WHO/ISUP grade, pathologic stage, tumor size, and solid, micropapillary, or hobnail architecture (P<0.05). The pathologic stage and WHO/ISUP grade were significantly associated with both DFS and OS in stepwise multivariate Cox regression analysis (P<0.05). In addition, micropapillary architecture and type 1 histology were linked with an adverse impact on OS (P<0.05). We found no difference in DFS (P=0.8237) and OS (P=0.8222) for type 1 versus type 2 PRCC in our patient cohort. In addition, we performed a meta-analysis with data from studies with reported hazard ratios (HRs) on PRCC type in relation to DFS and OS. We identified 5 studies that reported DFS and found no significant effect for type 2 PRCC (P=0.30; HR=1.43; 95% confidence interval: 0.73-2.80). We identified 7 studies that reported OS and found no significant association between type 2 PRCC and worse OS (P=0.41; HR: 1.21; 95% confidence interval: 0.77-1.91). Our findings suggest that high WHO/ISUP grade and unfavorable architecture (solid, micropapillary, or hobnail), rather than typing of PRCC, are associated with worse outcomes.
关于乳头状肾细胞癌（PRCC）中组织学参数的预后意义，已有相互矛盾的数据发表。我们对肾切除术的 PRCC 的临床和组织学参数进行了全面评估，并强调了世界卫生组织（WHO）/国际泌尿病理学会（ISUP）分级、肿瘤结构（实性、微乳头状和钉突状）和 PRCC 类型对预后的影响。共评估了 185 例 PRCC 病例，其中 117 例（63.2%）为 1 型，45 例（24.3%）为 2 型，11 例（5.9%）为 1 型和 2 型混合。根据 WHO/ISUP 分级标准，PRCC 分级如下：6 例（3.2%）为 1 级；116 例（62.7%）为 2 级；61 例（33.0%）为 3 级；2 例（1.1%）为 4 级。3 例（1.6%）存在实性结构，占肿瘤面积的 10%、10%和 30%。10 例（5.4%）存在微乳头状结构，占肿瘤的 5%至 30%（平均 11%；中位数 10%）。9 例（4.9%）存在钉突状结构，肿瘤面积的平均百分比为 23%（中位数 15%；范围：5%至 50%）。单因素分析中，与无病生存（DFS）和总生存（OS）较差相关的参数包括 WHO/ISUP 分级、病理分期、肿瘤大小以及实性、微乳头状或钉突状结构（P<0.05）。多因素逐步 Cox 回归分析显示，病理分期和 WHO/ISUP 分级与 DFS 和 OS 均显著相关（P<0.05）。此外，微乳头状结构和 1 型组织学与 OS 不良预后相关（P<0.05）。在我们的患者队列中，我们未发现 1 型与 2 型 PRCC 之间 DFS（P=0.8237）和 OS（P=0.8222）存在差异。此外，我们进行了荟萃分析，纳入了报道与 DFS 和 OS 相关的 PRCC 类型的风险比（HR）的研究数据。我们确定了 5 项报道 DFS 的研究，发现 2 型 PRCC 无显著影响（P=0.30；HR=1.43；95%置信区间：0.73-2.80）。我们确定了 7 项报道 OS 的研究，发现 2 型 PRCC 与 OS 较差之间无显著相关性（P=0.41；HR：1.21；95%置信区间：0.77-1.91）。我们的研究结果表明，高 WHO/ISUP 分级和不良结构（实性、微乳头状或钉突状）而非 PRCC 分型与预后较差相关。
