Sparsity of dendritic cells and cytotoxic T cells in tumor microenvironment may lead to recurrence in basal cell carcinoma.

Our results suggest the existence of an immunosuppressive microenvironment in BCC. Lower CD8+ T-cell numbers and sparsity of dendritic cells in primary tumors of recurrent patients suggest further immunosuppression in the tumor microenvironment and an increase in recurrence risk. This is the first study that evaluates and compares tumor immune microenvironments of primary and recurrent BCC lesions with several markers and investigates the role of antitumor immunity on BCC recurrence.