Comparative study of the PD-L1 expression and CD8+ tumor-infiltrating lymphocyte between surgically resected and matched re-biopsy specimens in recurrent non-small cell lung cancer

Abstract

Introduction: Numerous studies conducted until date have reported that the chemotherapy regimen could affect the programmed cell death ligand 1 (PD-L1) expression status in patients with non-small cell lung cancer (NSCLC).

Materials and methods: A total of 36 NSCLC patients for whom both the surgically resected specimens of the primary tumors and re-biopsy specimens of the recurrent tumors were available were enrolled in this study. The PD-L1 expression status and tumor-infiltrating CD8-positive T lymphocytes (CD8+TILs) count were measured in paired samples by immunohistochemistry. The concordance rate in the tumor immune microenvironment (TIME) classification based on the PD-L1 expression status and CD8+TILs count was analyzed.

Results: While the PD-L1 expression levels were similar between the surgical and re-biopsy specimens in 77.8% of cases, in 16.7% of cases, the expression levels were higher in the re-biopsy specimens. When the analysis was confined to patients who had received platinum-based chemotherapy, the percentage increased to 42.9%. The TIME classification changed in the re-biopsy specimens as compared to the surgical specimens in one-third of the patients, especially in those who had received chemotherapy previously. The TIME classification in the re-biopsy specimens more closely resembled that in the metastatic lymph nodes as compared to that in the primary tumor.

Conclusion: In patients with recurrent NSCLC, especially those who have received chemotherapy previously, a recent re-biopsy sample is required to determine whether PD-1/PD-L1 inhibitors should be used for treatment or not.

Keywords:

• non-small cell lung cancer, NSCLC
• programmed cell death ligand 1 (PD-L1)
• tumor-infiltrating T lymphocytes
• tumor immunemicroenvironment (TIME)
• re-biopsy

Acknowledgments

We thank Ms. Keiko Isoda and the staff of the Tissue Culture & Immunology and the Tissue Biology & Electron Microscopy Research Centers (Kawasaki Medical School) for providing technical assistance.

Disclosure

The authors report no conflicts of interest in this work.