Programmed Death-ligand 1 Expression With Clone 22C3 in Non-small Cell Lung Cancer: A Single Institution Experience

Factors correlating the expression of PD-L1

OBJECTIVE

PD-L1 was an important biomarker in lung adenocarcinoma. The study was to confirm the most important factor affecting the expression of PD-L1 remains undetermined.

METHODS

The clinical records of 1045 lung adenocarcinoma patients were retrospectively reviewed. The High-Resolution Computed Tomography (HRCT) scanning images of all the participants were analyzed, and based on the CT characteristics, the adenocarcinomas were categorized according to CT textures. Furthermore, PD-L1 expression and Ki67 index were detected by immunohistochemistry. All patients underwent EGFR mutation detection.

RESULTS

Multivariate logistic regression analysis revealed that smoking (OR: 1.73, 95% CI: 1.04-2.89, p = 0.004), EGFR wild (OR: 1.52, 95% CI: 1.11-2.07, p = 0.009), micropapillary subtypes (OR: 2.05, 95% CI: 1.46-2.89, p < 0.0001), and high expression of Ki67 (OR: 2.02, 95% CI: 1.44-2.82, p < 0.0001) were independent factors which influence PD-L1 expression. In univariate analysis, tumor size > 3 cm and CT textures of pSD showed a correlation with high expression of PD-L1. Further analysis revealed that smoking, micropapillary subtype, and EGFR wild type were also associated with high Ki67 expression. Moreover, high Ki67 expression was observed more frequently in tumors of size > 3 cm than in tumors with ≤ 3 cm size as well as in CT texture of pSD than lesions with GGO components. In addition, multivariate logistic regression analysis revealed that only lesions with micropapillary components correlated with pSD (OR: 3.96, 95% CI: 2.52-5.37, p < 0.0001).

CONCLUSION

This study revealed that in lung adenocarcinoma high Ki67 expression significantly influenced PD-L1 expression, an important biomarker for immune checkpoint treatment.

Recent Advancement of PD-L1 Detection Technologies and Clinical Applications in the Era of Precision Cancer Therapy

Programmed death-1 is a protein found on the surface of immune cells that can interact with its ligand, programmed death-ligand 1 (PD-L1), which is expressed on the plasma membrane, the surface of secreted cellular exosomes, in cell nuclei, or as a circulating soluble protein. This interaction can lead to immune escape in cancer patients. In clinical settings, PD-L1 plays an important role in tumor disease diagnosis, determining therapeutic effectiveness, and predicting patient prognosis. PD-L1 inhibitors are also essential components of tumor immunotherapy. Thus, the detection of PD-L1 levels is crucial, especially in the era of precision cancer therapy. In recent years, innovations have been made in traditional immunoassay methods and the development of new immunoassays for PD-L1 detection. This review aims to summarize recent research progress in tumor PD-L1 detection technology and highlight the clinical applications of PD-L1.

Impact of cancer cachexia on the therapeutic outcome of combined chemoimmunotherapy in patients with non-small cell lung cancer: a retrospective study

Although previous studies suggest that cancer cachexia is a poor prognostic factor for immune checkpoint inhibitor monotherapy, the impact of cancer cachexia on chemoimmunotherapy is unclear. We investigated the impact of cancer cachexia on the therapeutic outcomes of chemoimmunotherapy for non-small cell lung cancer (NSCLC). We retrospectively analyzed patients' medical records with NSCLC who received chemoimmunotherapy in 12 institutions in Japan between January and November 2019. We defined cancer cachexia as weight loss exceeding 5% of the total body weight or a body mass index of < 20 kg/m2 and weight loss of more than 2% of the total body weight within 6 months before chemoimmunotherapy initiation, with laboratory results exceeding reference values. This study enrolled 235 patients with NSCLC, among whom 196 were eligible for analysis, and 50 (25.5%) met the criteria for cachexia diagnosis. Patients with cancer cachexia had a significantly higher frequency of a programmed death-ligand 1 (PD-L1) expression of ≥ 50% (48%, p = .01) and shorter progression-free survival (PFS; log-rank test: p = .04) than patients without cachexia. There was no significant difference in overall survival (OS) between the cachexia and no-cachexia groups (log-rank test: p = .14). In the PD-L1 ≥ 50% population, there was no significant difference in PFS and OS (log-rank test: p = .19 and p = .79, respectively) between patients with NSCLC in the cachexia or no-cachexia groups. Cancer cachexia might be a poor prognostic factor in patients with NSCLC receiving chemoimmunotherapy.

A pan-cancer analysis of PD-L1 immunohistochemistry and gene amplification, tumor mutation burden and microsatellite instability in 48,782 cases

PD-L1 immunohistochemistry (IHC) currently has the most Food and Drug Administration (FDA) approvals as a companion diagnostic (CDx) for immunotherapies in specific tumor types; however, multiple other immunotherapy biomarkers exist. We performed this study to examine and report the prevalence of PD-L1 expression in a wide variety of tumor types and examine its relationship to microsatellite instability (MSI), tumor mutational burden (TMB), and CD274 (PD-L1) gene amplification. We performed a retrospective analysis of all cases in which both PD-L1 IHC (using the DAKO 22C3 IHC assay with either tumor proportion score (TPS) or combined positive score (CPS); or the VENTANA SP142 assay with infiltrating immune cell score (IC)) and comprehensive genomic profiling (CGP) were tested at Foundation Medicine between January 2016 and November 2019. Of note, PD-L1 positivity is defined per the CDx indication and tumor proportion score (TPS ≥ 1) for indications without a CDx claim; and TMB positivity is defined as ≥10 mutations/Mb. A total of 48,782 cases were tested for PD-L1 IHC and CGP. Immune cell expression of PD-L1 was more frequently identified than tumor cell expression of PD-L1. We saw a high correlation between PD-L1 expression and CD274 gene amplification (p < 0.0001), MSI and TMB (p < 0.0001), and PD-L1 and TMB (p < 0.0001). In addition, the combination of PD-L1 and TMB identified four unique disease subsets PD-L1^-/TMB^-, PD-L1⁺/TMB^-, PD-L1^-/TMB⁺, and PD-L1⁺/TMB⁺ with varying prevalence dependent on tumor type. Lastly, 50.3% (24527/48782) of the overall cohort was positive for at least one of the CDx or exploratory biomarkers described above. This is the largest pan-cancer analysis of relevant biomarkers associated with response to checkpoint inhibitors to date, including more than 48,000 cases. Additional clinical trials with treatment outcome data in individual tumor types are needed to determine whether the double positive PD-L1⁺/TMB⁺ disease subset would respond best to immunotherapy.

The B7-H4 gene induces immune escape partly via upregulating the PD-1/Stat3 pathway in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is associated with high mortality rates worldwide. The costimulatory molecule, B7-H4, a member of the B7 family, plays an important role in immune regulation, mainly by inhibiting the proliferation of T cells to achieve a negative regulatory T cell immune response. The mechanism of action of B7-H4 in non-small cell lung cancer is unknown at present. Tumor tissues from 71 patients subjected to radical pneumonectomy were examined, along with NSCLC cells and BALB/c mice. Among the 71 NSCLC cases, overall and recurrence-free survival rates were significantly lower in those displaying high B7-H4 expression. Mechanistic analyses showed that B7-H4 promoted the growth and metastasis of non-small cell lung cancer tumor tissues in mice through effects on CD8⁺ T cell apoptosis. Data from western blot experiments further suggested that B7-H4 induced CD8⁺ T cell death, both in vitro and in vivo, and affecting the PD-1/Stat3 pathway and promoting immune escape of tumor cells. Our collective findings support the potential utility of B7-H4 gene expression as a marker of NSCLC prognosis and provide a novel strategy for targeted therapy.