Department of Pathology, University of Virginia, Charlottesville, VA.
Am J Surg Pathol. 2018 Aug;42(8):1090-1094. doi: 10.1097/PAS.0000000000001085.
The heterogeneity of programmed death ligand 1 (PD-L1) expression in non-small cell lung carcinomas (NSCLCs) is well studied; however, the method of tissue sampling needed to obtain adequate diagnostic material has not been established. This study aimed to determine whether core needle biopsy provides sufficient tissue for accurate PD-L1 evaluation despite tumor heterogeneity. A retrospective analysis comparing tumoral expression of PD-L1 in 51 lung core biopsies to subsequent resection specimens was performed. Scoring of membranous staining was categorized as 0%, 1% to 49%, and ≥50% of tumor cells. Staining ≥50% tumoral PD-L1 expression was detected in 8/51 (15.7%) of core biopsies and 8/51 (15.7%) of resection specimens. Core biopsy and resection results were concordant in 92.2% of cases (κ, 0.70; 95% confidence interval, 0.43-0.98). Therefore, despite tumor heterogeneity, detection of tumoral PD-L1 expression in NSCLC appears to be largely concordant between core biopsies and resection specimens, with the caveat that it may be helpful to reassess resection specimens for low-level staining. These findings suggest that core biopsy may be adequate for determining PD-L1 expression in NSCLC.
程序性死亡配体 1（PD-L1）在非小细胞肺癌（NSCLC）中的表达异质性已得到充分研究；然而，为了获得足够的诊断材料，需要进行何种组织取样方法尚未确定。本研究旨在确定即使存在肿瘤异质性，肺核心活检是否能够提供足够的组织来进行准确的 PD-L1 评估。对 51 例肺核心活检标本与后续切除标本的 PD-L1 肿瘤表达进行了回顾性分析。膜染色评分分为 0%、1%至 49%和≥50%肿瘤细胞。在 8/51（15.7%）例核心活检和 8/51（15.7%）例切除标本中检测到肿瘤 PD-L1 表达≥50%。核心活检和切除结果在 92.2%的病例中具有一致性（κ，0.70；95%置信区间，0.43-0.98）。因此，尽管存在肿瘤异质性，但在 NSCLC 中检测肿瘤 PD-L1 表达在核心活检和切除标本之间似乎具有很大的一致性，但需要注意的是，对于低水平染色，重新评估切除标本可能会有所帮助。这些发现表明，核心活检可能足以确定 NSCLC 中的 PD-L1 表达。
