Cell-mediated immunity in patients with basal and squamous cell skin cancer

T and B lymphocyte levels were normal in fifty patients with basal and squamous cell skin cancer. Patients with basal cell carcinomas and small squamous cell carcinomas reacted normally to intradermal antigens and to dinitrochlorobenzene (DNCB). However, patients with large (greater than 3 cm) squamous cell carcinomas appeared to have defective systemic cell-mediated immunity because only 33% of them reacted to at least one intradermal antigen, and only 67% could be sensitized to DNCB. Presently, it is unknown whether this defect is related to the occurrence or behavior of squamous cell carcinoma.