Correlation between immunotherapy biomarker PD-L1 expression and genetic alteration in patients with non-small cell lung cancer.

Programmed death-ligand 1 (PD-L1) has been widely used in immunotherapy evaluation of patients with non-small cell lung cancer (NSCLC). However, the effect is not particularly ideal, and the association between PD-L1 and genetic alterations requires more exploration. Here, we performed targeted next-generation sequencing and PD-L1 immunohistochemistry (IHC) testing for PD-L1 expression on both tumor cells (TCs) and tumor-infiltrating immune cells (ICs) in 1549 patients. Our studies showed that surgical method of resection was positively correlated with IC+, and a low tumor mutation burden (TMB) was negatively correlated with TC+. Furthermore, we found that EGFR was mutually exclusive with both ALK and STK11. In addition, the features between PD-L1 expression status and genomic alterations were characterized. These results suggest that clinical characteristics and molecular phenotypes are associated with PD-L1 expression signatures, which may provide novel insights for improving the efficiency of immune checkpoint inhibitors (ICIs) in immunotherapy.

Special issue "The advance of solid tumor research in China": FGFR4 alterations predict efficacy of immune checkpoint inhibitors in nonsmall cell lung cancer.

Immune checkpoint inhibitors (ICIs), which represent the new standard of care for advanced nonsmall cell lung cancer (NCSLC), are not effective in many patients. Biomarkers are needed to guide treatment. Sequencing data of an ICI-treated cohort were analyzed to identify genomic signatures predicting ICI efficacy, followed by validation using multiple independent cohorts. Their predictive mechanism was explored by evaluating the tumor immune microenvironment and tumor mutational burden (TMB). In the discovery cohort, patients carrying FGFR4 alterations (FGFR4altered ) had a better objective response rate (ORR) (50.0% vs 19.4%; P = .057) and improved median progression-free survival (mPFS) (13.17 vs 3.17 months; HR 0.37; 95% CI 0.14-1; P = .04) than wild-type patients (FGFR4wt ). In the publicly available validation cohorts, FGFR4 alterations correlated with higher ORR (100% vs 31%; P = .028), longer median overall survival (mOS) (not reached [NR] vs 11 months; HR 0.28, 95% CI 0.09-0.89, P = .02), and mPFS (NR vs 6.07 months; HR 0.05, 95% CI 0-3.94, P = .039). FGFR4 alterations were confirmed as an independent predictor of superior PFS (P = .014) and OS (P = .005). FGFR4altered patients also exhibited a significantly improved disease control rate (100% vs 60%, P = .045) and prolonged mPFS (9.70 vs 3.16 months; P = .095) compared to FGFR4wt patients in our Shanghai Pulmonary Hospital cohort. FGFR4 alterations associated with a higher TMB levels, more CD8+ T cells in the tumor stroma, and a higher M1/M2 ratio for tumor-associated macrophages in the tumor center and stroma. Thus, FGFR4 alterations may serve as a potential independent predictor of ICI efficacy in NSCLC.