Thoracic Oncology Unit, Instituto Nacional de Cancerología, Mexico City, Mexico.
Laboratory of Personalized Medicine, Instituto Nacional de Cancerología, Mexico City, Mexico.
Pathol Oncol Res. 2021 Apr 8;27:597499. doi: 10.3389/pore.2021.597499. eCollection 2021.
Programmed cell death-ligand 1 (PD-L1) protein expression is one of the most extensively studied biomarkers in patients with non-small cell lung cancer (NSCLC). However, there is scarce information regarding its association with distinct adenocarcinoma subtypes. This study evaluated the frequency of PD-L1 expression according to the IASLC/ATS/ERS classification and other relevant histological and clinical features. PD-L1 expression was assessed by immunohistochemistry (IHC). According to its positivity in tumor cells membrane, we stratified patients in three different tumor proportions score (TPS) cut-off points: a) <1% (negative), b) between 1 and 49%, and c) ≥50%; afterward, we analyzed the association among PD-L1 expression and lung adenocarcinoma (LADC) predominant subtypes, as well as other clinical features. As an exploratory outcome we evaluated if a PD-L1 TPS score ≥15% was useful as a biomarker for determining survival. A total of 240 patients were included to our final analysis. Median age at diagnosis was 65 years (range 23-94 years). A PD-L1 TPS ≥1% was observed in 52.5% of the entire cohort; regarding specific predominant histological patterns, a PD-L1 TPS ≥1 was documented in 31.2% of patients with predominant-lepidic pattern, 46.2% of patients with predominant-acinar pattern, 42.8% of patients with a predominant-papillary pattern, and 68.7% of patients with predominant-solid pattern ( = 0.002). On the other hand, proportion of tumors with PD-L1 TPS ≥50% was not significantly different among adenocarcinoma subtypes. At the univariate survival analysis, a PD-L1 TPS cut-off value of ≥15% was associated with a worse PFS and OS. According to IASLC/ATS/ERS lung adenocarcinoma classification, the predominant-solid pattern is associated with a higher proportion of PD-L1 positive samples, no subtype was identified to be associated with a high (≥50%) TPS PD-L1.
程序性死亡配体 1（PD-L1）蛋白表达是研究非小细胞肺癌（NSCLC）患者的最广泛的生物标志物之一。然而，关于其与不同腺癌亚型的关联的信息却很少。本研究根据 IASLC/ATS/ERS 分类以及其他相关组织学和临床特征评估了 PD-L1 表达的频率。通过免疫组织化学（IHC）评估 PD-L1 表达。根据肿瘤细胞膜的阳性程度，我们将患者分为三个不同的肿瘤比例评分（TPS）截断点：a）<1%（阴性），b）1%至 49%，c）≥50%；之后，我们分析了 PD-L1 表达与肺腺癌（LADC）主要亚型以及其他临床特征之间的关联。作为探索性结果，我们评估了 PD-L1 TPS 评分≥15%是否可作为确定生存的生物标志物。共有 240 例患者纳入最终分析。诊断时的中位年龄为 65 岁（范围 23-94 岁）。整个队列中观察到 52.5%的患者存在 PD-L1 TPS≥1%；关于特定的主要组织学模式，在主要表现为贴壁型的患者中，有 31.2%的患者 PD-L1 TPS≥1%，在主要表现为腺泡型的患者中，有 46.2%的患者 PD-L1 TPS≥1%，在主要表现为乳头型的患者中，有 42.8%的患者 PD-L1 TPS≥1%，在主要表现为实体型的患者中，有 68.7%的患者 PD-L1 TPS≥1%（=0.002）。另一方面，在腺癌亚型中，PD-L1 TPS≥50%的肿瘤比例无显著差异。在单变量生存分析中，PD-L1 TPS 截断值≥15%与较差的 PFS 和 OS 相关。根据 IASLC/ATS/ERS 肺腺癌分类，主要实体型与更高比例的 PD-L1 阳性样本相关，没有一个亚型与高（≥50%）TPS PD-L1 相关。
