Department of Histopathology, Royal Brompton & Harefield NHS Foundation Trust, London, UK.
National Heart and Lung Institute, Imperial College London, London, UK.
Histopathology. 2018 May;72(6):1024-1032. doi: 10.1111/his.13466. Epub 2018 Mar 5.
As immunomodulatory therapy is being integrated into treatment regimens for non-small-cell lung carcinoma, we aimed to prospectively collect data on the immunohistochemical profile of tumours assessed in our institution and to correlate this with morphological tumour features.
Immunohistochemistry for programmed death-ligand 1 (PD-L1) was considered to be adequate when >100 tumour cells were seen microscopically. When adequate, PD-L1 staining was scored as <1%, ≥1-49% or ≥50% positive membrane staining within tumour cells only. There were 197 assessable cases, of which 87% of those with pleomorphic features (n = 39) showed ≥50% positivity for PD-L1 expression, as compared with only 33% of cases without pleomorphic features (P < 0.05) (90% versus 25% in resected cases). Further correlation of PD-L1 expression with architectural patterns within the tumours was performed in 74 adenocarcinoma resections. All invasive mucinous adenocarcinomas scored <1%. All lepidic components in non-mucinous adenocarcinoma resections scored <1%. Thirty-five per cent of the acinar/papillary components and 53% of the solid/micropapillary components were positive for PD-L1 expression.
There are significant differences in PD-L1 expression in relation to histological patterns, with particularly high levels in those with pleomorphic features and low/undetectable levels in invasive mucinous adenocarcinomas and the lepidic components of non-mucinous adenocarcinomas. Assessment of PD-L1 expression in a resected adenocarcinoma with a lepidic component may therefore not be reliable when immumodulatory therapy for recurrent disease is being considered, and either re-biopsy or limiting assessment to the invasive component may be more appropriate.
随着免疫调节疗法被纳入非小细胞肺癌的治疗方案，我们旨在前瞻性地收集我们机构评估的肿瘤免疫组化特征数据，并将其与形态学肿瘤特征相关联。
当显微镜下观察到>100 个肿瘤细胞时，被认为程序性死亡配体 1（PD-L1）的免疫组化是充分的。当充分时，PD-L1 染色评分<1%、≥1-49%或仅肿瘤细胞内的≥50%阳性膜染色。共有 197 例可评估病例，其中具有多形性特征的病例（n=39）中≥50%的 PD-L1 表达阳性，而无多形性特征的病例中仅为 33%（P<0.05）（切除病例中为 90%对 25%）。在 74 例腺癌切除病例中进一步进行了 PD-L1 表达与肿瘤内结构模式的相关性分析。所有侵袭性黏液腺癌评分<1%。非黏液腺癌切除标本中所有贴壁成分评分<1%。35%的腺泡/乳头成分和 53%的实体/微乳头成分 PD-L1 表达阳性。
PD-L1 表达与组织学模式存在显著差异，多形性特征的表达水平特别高，而侵袭性黏液腺癌和非黏液腺癌的贴壁成分中表达水平低/无法检测。当考虑复发性疾病的免疫调节治疗时，在具有贴壁成分的切除腺癌中评估 PD-L1 表达可能不可靠，因此可能需要重新活检或仅评估侵袭性成分。
