The Distribution of CD8- and Foxp3-positive T Cells in Skin Squamous Cell Tumors and Basal Cell Carcinomas

Abstract

Cancer is subject to dynamic interactions between contrary immune reactions that drive both tumor growth and suppression. Forkhead box p3 positive T cells (Foxp3 positive T cells) might support tumor promotion, while CD8 positive T cells might protect the host. The present study examined the distributions of CD8-and Foxp3-positive T cells and CD8 positive T cells/ Foxp3 positive T cells ratio in skin squamous cell carcinoma (SCC) and its precancerous lesions; it also compared this with data for basal cell carcinoma (BCC). Iimmunohistochemical staining for CD8 and Foxp3 was conducted in 20 cases of SCC, Bowen's disease (BD), actinic keratosis (AK) and BCC. The BD and SCC cases exhibited significantly increased numbers of both CD8-and Foxp3-positive T cells in their advancing regions compared with the AK and BCC cases, and the BD cases exhibited significantly lower CD8 positive T cells / Foxp3 positive T cells ratio in these regions than did the AK and BCC cases. There was no significant difference in both T cells and the ratio between BD and SCC. The degree of both T cells infiltration differed between the advancing and central areas in SCC and BCC. Immune microenvironments differ between cutaneous squamous cell tumors and BCC and differ as well among tumor compartments.