Characterization of PD-L1 expression in Chinese non-small cell lung cancer patients with PTEN expression as a means for tissue quality screening.

The goal of this study is to evaluate PD-L1 prevalence and its association with major clinical characteristics in Chinese non-small cell lung cancer (NSCLC) patients to inform the clinical development of anti-PD1/PD-L1 agents in this population. We used phosphatase and tensin homolog (PTEN) expression through IHC as a surrogate tissue quality marker to screen surgical NSCLC samples in tissue microarray (TMA; 172 cases) or whole-section (268 cases) format. The samples were then analyzed with a clinically validated PD-L1 IHC assay. The results were correlated with baseline characteristics and clinical outcomes. PTEN IHC showed that 108 TMA samples and 105 whole-section samples qualified for PD-L1 IHC. With a clinically relevant cutoff, 41.7% of the TMA samples were PD-L1 positive. PD-L1 level was much lower in EGFR-mutant patients and seemed to be a favorable prognostic factor for both overall survival (OS) and recurrence-free survival (RFS). These findings were confirmed in the whole-section samples except that their survival data were not mature enough for correlation analysis. In summary, PD-L1 expression was detected in approximately 40% of PTEN-qualified Chinese NSCLC samples, negatively correlated with EGFR mutation and seemed to be a favorable prognostic factor for both OS and RFS. Notably, the different results from PTEN-qualified and PTEN-disqualified samples underscore the importance of tissue quality control prior to biomarker testing.

Immune Characteristics of Chinese Diffuse Large B-Cell Lymphoma Patients: Implications for Cancer Immunotherapies.

Immunotherapeutic agents have demonstrated encouraging signs of clinical utility in non-Hodgkin lymphoma. The goal of this study is to analyze the immune characteristics of Chinese patients with diffuse large B-cell lymphoma (DLBCL) to inform the development of immunotherapies in this patient population. Tumor samples from 211 DLBCL patients were analyzed for cell of origin (COO) and immune characteristics using the NanoString platform as well as MYC protein expression through immunohistochemistry. Lower incidence of the germinal center B-cell (GCB) subtype (93/211, 44.1%) was observed in this cohort. Compared to the GCB subtype, the activated B-cell (ABC) subtype was associated with significantly increased expression of multiple pro-inflammatory gene signatures and decreased expression of anti-inflammatory gene signatures. Instead of affecting the pro-inflammatory genes, MYC protein overexpression showed a negative correlation with the expression of T-cell receptor (TCR) and T regulatory genes as well as the OX40 gene. Regardless of COO, higher PD-L1 or IDO1 gene expression correlated with increased expression of T effector and Interferon-γ gene signatures while the expression of multiple oncogenes including ACTR3B, ERBB2, AKT2 and SMARCD1 was down-regulated. Our findings may thus be helpful in guiding further development of immunotherapies for the different subsets of Chinese DLBCL patients.