Programmed Death-Ligand 1 Expression Predicts Tyrosine Kinase Inhibitor Response and Better Prognosis in a Cohort of Patients With Epidermal Growth Factor Receptor Mutation-Positive Lung Adenocarcinoma.

The immune checkpoint proteins programmed death-1/ligand (PD-1/PD-L1) play a critical role in immune escape of tumor cells. In models of epidermal growth factor receptor (EGFR)-driven non-small-cell lung cancer (NSCLC), EGFR signal upregulates PD-1/PD-L1. However, data on the clinical significance of PD1/PD-L1 expression in patients with the subtype of NSCLC carrying EGFR mutations remain limited. Immunohistochemistry was performed to evaluate the expression of PD-1, PD-L1, and CD4+ and CD8+ tumor-infiltrating T lymphocytes (TILs). In a cohort of 56 patients, PD-L1 and PD-1 was positive in 53.6% and 32.1% of tumor specimens, respectively. PD-L1(+) patients had a significantly greater disease-control rate (P = .004), in association with longer progression-free survival (P = .001) after EGFR-tyrosine kinase inhibitor (TKI) therapy and overall survival (P = .004), and no correlation between PD-1 positivity and clinical outcomes was observed. PD-L1 expression was not significantly associated with either clinicopathologic features or TILs. These findings suggest that this subtype of EGFR mutation-positive NSCLC is highly eligible for PD-1/PD-L1 immunotherapy. PD-L1 might represent a favorable biomarker candidate for the response to EGFR-TKIs and outcomes of these patients with NSCLC.

Lin C ，Chen X ，Li M ，Liu J ，Qi X ，Yang W ，Zhang H ，Cai Z ，Dai Y ，Ouyang X ... -  《-》

Changes in programmed death ligand 1 expression in non-small cell lung cancer patients who received anticancer treatments.

Omori S ，Kenmotsu H ，Abe M ，Watanabe R ，Sugino T ，Kobayashi H ，Nakashima K ，Wakuda K ，Ono A ，Taira T ，Naito T ，Murakami H ，Ohde Y ，Endo M ，Akiyama Y ，Nakajima T ，Takahashi T ... -  《-》

[Correlation Study on Expression of PD-1 and PD-L1 in Non-small Cell Lung Cancer and Epidermal Growth Factor Receptor Mutations].

Jiang L ，Lin Z ，Li N ，Jiang J ，Lu C ，Du S ，Zhang J ，Wang Y ，Chen J ，Gong P ... -  《-》

PD-L1 expression and T cells infiltration in patients with uncommon EGFR-mutant non-small cell lung cancer and the response to immunotherapy.

The efficacy of immunotherapy in epidermal growth factor receptor (EGFR)-activating non-small cell lung cancer (NSCLC) is limited. However, a series of patients with uncommon EGFR alterations was reported to derive clinical benefit from PD-1 blockade. To characterize the tumor immune microenvironment, we retrospectively evaluated tumor PD-L1 expression and T cells infiltration among NSCLC patients with uncommon EGFR mutations. Immunohistochemistry was used to analyze the expression of PD-L1 and the abundance of CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs). Chi-square test and Cox proportional hazards regression were conducted to investigate the correlations between the immune microenvironment features and clinicopathological variables and survival, as well as to explore the potential of immunotherapy in this patient population. Among 600 NSCLC patients with EGFR alterations, we identified 49 (8.2 %) bearing uncommon mutations, including G719X, L861Q, S768I, and Ex20 ins. In total, 49.0 % (24/49) of these patients showed positive PD-L1 expression in tumor cells, markedly higher than the proportion in patients with classic sensitive mutations (19del and L858R, 12.2 % [67/551], P < 0.05). Furthermore, PD-L1 expression was associated with relatively short overall survival (OS; 15.2 vs 29.3 months, P = 0.006) and was identified as an independent predictor of OS (hazard ratio=2.57, 95 % confidence interval: 1.03-7.12, P = 0.045). Additionally, PD-L1 positivity was predominantly observed among tumors with CD8+ TILs infiltration (P = 0.001). Uncommon EGFR-mutant tumors had a high frequency (36.7 %) of concurrent PD-L1 expression and abundant CD8 + TILs infiltration. Moreover, this dual-positive group exhibited the most unfavorable prognosis (P = 0.023). Notably, patients with PD-L1 and CD8 dual positivity showed a favorable response to PD-1 inhibitors. High rates of concomitant PD-L1 expression and CD8 + TILs within the tumor microenvironment were observed in NSCLC patients with uncommon EGFR mutations. Further investigations are needed to confirm the therapeutic sensitivity to PD-1 blockade in this subgroup.

Chen K ，Cheng G ，Zhang F ，Zhu G ，Xu Y ，Yu X ，Huang Z ，Fan Y ... -  《-》

Tumor immune microenvironment and nivolumab efficacy in EGFR mutation-positive non-small-cell lung cancer based on T790M status after disease progression during EGFR-TKI treatment.

The efficacy of programmed death-1 blockade in epidermal growth factor receptor gene (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) patients with different mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) is unknown. We retrospectively evaluated nivolumab efficacy and immune-related factors in such patients according to their status for the T790M resistance mutation of EGFR. We identified 25 patients with EGFR mutation-positive NSCLC who were treated with nivolumab after disease progression during EGFR-TKI treatment (cohort A). Programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocyte (TIL) density in tumor specimens obtained after acquisition of EGFR-TKI resistance were determined by immunohistochemistry. Whole-exome sequencing of tumor DNA was carried out to identify gene alterations. The relation of T790M status to PD-L1 expression or TIL density was also examined in an independent cohort of 60 patients (cohort B). In cohort A, median progression-free survival (PFS) was 2.1 and 1.3 months for T790M-negative and T790M-positive patients, respectively (P = 0.099; hazard ratio of 0.48 with a 95% confidence interval of 0.20-1.24). Median PFS was 2.1 and 1.3 months for patients with a PD-L1 expression level of ≥1% or <1%, respectively (P = 0.084; hazard ratio of 0.37, 95% confidence interval of 0.10-1.21). PFS tended to increase as the PD-L1 expression level increased with cutoff values of ≥10% and ≥50%. The proportion of tumors with a PD-L1 level of ≥10% or ≥50% was higher among T790M-negative patients than among T790M-positive patients of both cohorts A and B. Nivolumab responders had a significantly higher CD8+ TIL density and nonsynonymous mutation burden. T790M-negative patients with EGFR mutation-positive NSCLC are more likely to benefit from nivolumab after EGFR-TKI treatment, possibly as a result of a higher PD-L1 expression level, than are T790M-positive patients.

Haratani K ，Hayashi H ，Tanaka T ，Kaneda H ，Togashi Y ，Sakai K ，Hayashi K ，Tomida S ，Chiba Y ，Yonesaka K ，Nonagase Y ，Takahama T ，Tanizaki J ，Tanaka K ，Yoshida T ，Tanimura K ，Takeda M ，Yoshioka H ，Ishida T ，Mitsudomi T ，Nishio K ，Nakagawa K ... -  《-》