Prognostic Impact of Programmed Death-ligand 1 and Surrounding Immune Status on Stage I Lung Cancer.

The programmed death 1/programmed death-ligand 1 (PD-L1) pathway reportedly is as an important factor determining effects of immunotherapy; however, its prognostic impact is controversial, and its association with the surrounding immune microenvironment has not yet been elucidated. We retrospectively analyzed 126 patients with pathologic stage I non-small-cell lung cancer. Patients with lepidic-dominant adenocarcinoma were excluded. PD-L1 expression was evaluated with immunohistochemistry correlated with clinicopathologic features and surrounding immune microenvironment status, including CD4, CD8, regulatory T cells, and human leukocyte antigen class I. Factors affecting prognosis were assessed by Kaplan-Meier and Cox regression analyses. Twenty-three (18.3%) patients were positive for PD-L1 expression. No significant correlation was observed between PD-L1 expression and the surrounding immune microenvironment status. The PD-L1-positive group had a worse prognosis than the PD-L1-negative group (5-year recurrence-free survival rates, 63.4% vs. 81.0%; P = .061). Among surrounding immune cells, intratumoral CD8 status had the strongest impact on prognosis (P = .12). In the intratumoral CD8-high group, PD-L1 expression demonstrated no significant prognostic impact, whereas in the intratumoral CD8-low group, patients positive for PD-L1 demonstrated a significantly worse prognosis than those negative for PD-L1 (5-year recurrence-free survival rates, 41.7% vs. 78.6%; P = .034). Multivariable Cox regression analysis revealed that 'PD-L1-positive and intratumoral CD8-low' status was an independent prognostic factor (hazard ratio, 3.80; 95% confidence interval, 1.22-10.5; P = .023). The prognostic impact of the PD-1/PD-L1 pathway may be distinct according to concurrent intratumoral CD8 status.

Handa Y ，Tsutani Y ，Shiroma N ，Kai Y ，Mimae T ，Miyata Y ，Takeshima Y ，Arihiro K ，Okada M ... -  《-》

Clinical significance of PD-L1-positive cancer-associated fibroblasts in pN0M0 non-small cell lung cancer.

Cancer-associated fibroblasts (CAFs) are a dominant cell type in tumor stroma and support the generation of pro-tumorigenic microenvironment. CAFs have frequent opportunities to interact with immune cells infiltrating the tumor stroma, but the process remains to be determined. In this study, we focused on immune checkpoint mechanism. We also examined the induction of programmed cell death-ligand 1 (PD-L1) on CAFs by immune cell, and the clinical significance of PD-L1-expressed CAFs in non-small cell lung cancer (NSCLC). CAFs were isolated from human NSCLC tissues, and PD-L1 expression levels in CAFs were analyzed by real-time polymerase chain reaction and flow-cytometry. Following immunohistochemical analysis of PD-L1 in surgically resected pN0M0 NSCLC (n = 125, including 88 invasive adenocarcinomas and 37 squamous cell carcinomas), the correlation of PD-L1-positive CAFs with clinicopathological features was investigated. PD-L1 mRNA and protein expression on CAFs was upregulated by exogenously supplemented interferon-gamma (IFN-γ) and downregulated through the depletion of IFN-γ. PD-L1 expression on CAFs was upregulated by co-culture with activated lymphocytes releasing IFN-γ. Immunohistochemistry revealed that PD-L1-positive CAFs were observed in 31 cases (24.8%). Postoperative relapse-free survival was significantly prolonged in patients with PD-L1-positive CAFs as compared with those with PD-L1-negative CAFs, with 5-year relapse-free probabilities of 84.5% and 66.3%, respectively (P = 0.031). Multivariate analysis revealed that PD-L1 expression on CAFs was an independent prognostic factor of longer relapse-free survival after surgery (hazard ratio: 3.225, P = 0.027). PD-L1 expression on CAFs is reversibly regulated by environmental stimuli including IFN-γ from activated lymphocytes. In the non-metastatic NSCLC, PD-L1 expression on CAFs suggests the induction of anti-tumor immune responses, contributing to better prognosis after surgery.

Teramoto K ，Igarashi T ，Kataoka Y ，Ishida M ，Hanaoka J ，Sumimoto H ，Daigo Y ... -  《-》

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 ... -  《-》

Alteration in tumoural PD-L1 expression and stromal CD8-positive tumour-infiltrating lymphocytes after concurrent chemo-radiotherapy for non-small cell lung cancer.

Yoneda K ，Kuwata T ，Kanayama M ，Mori M ，Kawanami T ，Yatera K ，Ohguri T ，Hisaoka M ，Nakayama T ，Tanaka F ... -  《-》

Assessing PDL-1 and PD-1 in Non-Small Cell Lung Cancer: A Novel Immunoscore Approach.

Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) or its ligand, PD-L1, have gained momentum in the treatment of non-small cell lung cancer (NSCLC). However, their prognostic significance remains controversial. The present study evaluated the expression of PD-L1 and PD-1 and their potential role in an Immunoscore, supplementing the TNM classification of NSCLC. Tissue microarrays constructed from tumor tissue samples from 2 cohorts of a total of 536 patients (University Hospital of North Norway, n = 285; Nordland Hospital, n = 251) with primary resected stage I to IIIA NSCLC. PD-L1 and PD-1 were evaluated by immunohistochemistry in the primary tumor and metastatic lymph node tissue. In univariate analysis, a high density of PD-L1+ immune cells in the stromal compartment (S-PD-L1) and PD-1+ intraepithelial tumor infiltrating lymphocytes (T-PD-1) was associated with favorable disease-specific survival (DSS; S-PD-L1, P = .004; T-PD-1, P = .012), both limited to the squamous cell carcinoma histologic subgroup (S-PD-L1, P = .002; T-PD-1, P = .034). A combined low S-PD-L1 and T-PD-1 was associated with poor survival in all patients (DSS: hazard ratio [HR], 1.81; 95% confidence interval [CI], 1.37-2.40; P < .001) at both centers and for all pathologic stages. In multivariate analysis, S-PD-L1 and T-PD-1 were independent positive prognostic factors, and combined low scores remained an independent prognosticator for poor survival (DSS: HR, 1.72; 95% CI, 1.29-2.28; P < .001; disease-free survival, P = .001; overall survival, P = .005). Our study identified S-PD-L1 and T-PD-1 as independent positive prognostic factors for NSCLC patients. Their combination added significant prognostic impact within each pathologic stage and hence are feasible to include in a TNM Immunoscore.

Paulsen EE ，Kilvaer TK ，Khanehkenari MR ，Al-Saad S ，Hald SM ，Andersen S ，Richardsen E ，Ness N ，Busund LT ，Bremnes RM ，Donnem T ... -  《-》