The role of spatial interplay patterns between PD-L1-positive tumor cell and T cell in recurrence of locally advanced non-small cell lung cancer.

PURPOSE

To explore the relationship between the spatial interaction of programmed death-ligand 1(PD-L1)-positive tumor cell and T cell with specific functions and the recurrence of non-small cell lung cancer (NSCLC) and optimize prognostic stratification.

MATERIALS AND METHODS

This study retrospectively included 104 patients with locally advanced NSCLC who underwent radical surgery. Tissue microarrays were constructed including tumor center (TC) and invasion margin (IM), and CK/CD4/CD8/PD-L1/programmed death-1 (PD-1) was labeled using multiplex immunofluorescence to decipher the counts and spatial distribution of tumor cells and T cells. The immune microenvironment and recurrence stratification were characterized using the Mann-Whitney U test and Cox proportional hazards model.

RESULT

Compared with the IM, the proportion of tumor cells (especially PD-L1) was increased in the TC, while T cells (especially PD-1) were decreased. An increase in TC PD-1 CD8 T cells promoted relapse (HR = 2.183), while PD-L1 tumor cells alone or in combination with T cells had no predictive value for relapse. In addition, in both TC and IM, CD8 were on average closer to PD-L1 tumor cells than CD4, especially exhausted CD8. The effective density and percentage of PD-1 CD4 T cells interacting with PD-L1 tumor cells in the IM were both associated with recurrence, and the HRs increased sequentially (HRs were 2.809 and 4.063, respectively). Patients with low PD-1CD4 count combined high PD-1CD4 effective density showed significantly poorer RFS compared to those with high PD-1CD4 count combined low PD-1CD4 effective density, in both the TC and IM regions (HRs were 5.810 and 8.709, respectively).

CONCLUSION

Assessing the relative spatial proximity of PD-1/PD-L1 contributes to a deeper understanding of tumor immune escape and generates prognostic information in locally advanced NSCLC patients.