Immune microenvironment of basal cell carcinoma and tumor regression following combined PD-1/LAG-3 blockade.

Systemic treatment options for patients with locally advanced or metastatic basal cell carcinoma (BCC) are limited, particularly when tumors are refractory to anti-programmed cell death protein-1 (PD-1). A better understanding of immune checkpoint expression within the BCC tumor microenvironment may inform combinatorial treatment strategies to optimize response rates. CD3, PD-1, programmed death ligand-1 (PD-L1), lymphocyte activation gene 3 (LAG-3), and T-cell immunoglobulin domain and mucin domain 3 (TIM-3)+ cell densities within the tumor microenvironment of 34 archival, histologically aggressive BCCs were assessed.