KA showed significantly higher numbers of CD4+ and FOXp3+ cells as well as lower numbers of CD8+ cells in comparison with invasive cSCC. cSCC expressed significantly more PD-L1 in comparison with AK and KA.
PD-L1 expression of tumour cells as well as tumour-infiltrating cells (TILs) was significantly higher in KA and cSCC when compared to AK and BD (P = 0.00028 and P = 0.00033, respectively).