Comparison of PD-L1 Expression Status between Pure-Solid Versus Part-Solid Lung Adenocarcinomas

Abstract

Although lung adenocarcinomas (LADs) with ground-glass opacity (GGO; part-solid tumors) have been shown to differ from those without GGO (pure-solid tumors) in clinicopathological features and prognoses, whether programmed death ligand-1 (PD-L1) protein expression differs between these two tumor types is unclear. This study included 124 patients with clinical T1a–c LAD who received pulmonary resections during 2007–2009. The E1L3N antibody was used to stain for PD-L1 in primary LAD specimens. The specimens were considered PD-L1+ if ≥1% of tumor cells showed membrane staining, and were classified as having a high PD-L1+ tumor proportion score (TPS) if ≥50% of the tumor cells did so. Among the 124 patients, 45 had part-solid tumors and 79 had pure-solid tumors. These two groups did not significantly differ in terms of clinical factors. However, the rates for PD-L1 positivity (4% vs. 25%, p < 0.01) and high PD-L1+ TPS (2% vs. 16%, p = 0.02) were significantly higher in the pure-solid tumors. The multivariate analyses (logistic regression model) showed that the odds ratios for PD-L1 positivity and high PD-L1+ TPS in pure-solid LADs were 5.9 (95% CI; 1.2–29.7) and 8.0 (95% CI; 1.0–63.8), respectively. In conclusion, LADs with GGO were correlated with a lower incidence of PD-L1 expression than pure-solid tumors.

Tailing effect of PD-1 antibody results in the eradication of unresectable multiple primary lung cancer presenting as ground-glass opacities: a case report

“…Nelson et al observed differential immune cell infiltration and PD-L1 expression in adenocarcinoma presenting as GGOs compared with solid lesions in a CT scan (8). Lung adenocarcinoma with GGO was correlated with a lower incidence of PD-L1 expression than pure-solid tumors (9). In our case, following a complete reduction in the size and density of almost all the remaining GGOs 12 months after pneumonitis, we presumed that all the GGOs had a similar TMB or TIME.…”

Molecular Alterations in Lung Adenocarcinoma With Ground-Glass Nodules: A Systematic Review and Meta-Analysis

“…We clearly showed that the incidence of PD-L1 expression was much lower in GGOs than pure-solid tumors in several articles, which was verified by Suda et al. in a clinical experiment including 124 qualified patients (4% vs. 25%, p < 0.01) ( 32 ). Wu et al.…”

“…There was only one article (33) that provided details in the subgroups, so a meta-analysis could not be performed on the subgroups. Still, it was shown in the articles that the rate of PD-L1 expression was significantly lower in GGOs (4.44%-14.16%) than solid nodules (18.36%-35.04%) in the same cohorts (9,(31)(32)(33).…”

Recent Advances in Cancer Immunotherapy

“…This study reveals the immunological differences between these two types of lung adenocarcinomas. Additionally, the results of this report provided an important speculation regarding the prognostic impact of PD-L1 expression in lung adenocarcinomas, which had been controversial in previous studies [ 5 ]; the ratio of tumors with GGO, which are associated with favorable prognosis, will determine the apparent prognostic implication of PD-L1 expression in a cohort [ 4 ]. The second paper on this topic is a review article written by Fujimura et al [ 6 ].…”

“…Among these six papers, three are classified into topic (i) evaluating the immunological status of cancer/the tumor microenvironment. The first study is from our group, which reported that PD-L1 expression is significantly lower in lung adenocarcinomas with ground-glass opacity (GGO) compared with those without GGO (pure-solid tumors) [ 4 ]. This study reveals the immunological differences between these two types of lung adenocarcinomas.…”