Retrospective comparison of the clinical effects of programmed death protein 1 inhibitors to treat melanoma versus nonmelanoma skin cancer

Background: Programmed death protein (PD) 1 inhibitors have revolutionized treatment for cancers such as melanoma. However, clinical benefits and risks of PD-1 inhibitors among nonmelanoma skin cancers (NMSCs) are less well known, although off-label usage has been reported in the medical literature.