Is there a host immune response to melanoma?

Yes. Observations such as incomplete or complete regression of melanoma, occurrence of vitiligo and halo nevi in patients, as well as increased rates of melanoma in immune suppressed patients indicate that immunologic events appear to play a role in the clinical course of the melanoma and may occasionally cause clinical regressions. Tumor antigen (TA)–specific T cells have been shown to play an active role in eliminating tumors and metastases, as well as in inducing TA-specific T-cell memory responses in a wide range of animal tumor models. Similarly, in vitro studies employing human peripheral blood lymphocytes (PBL) isolated from patients with melanoma have been reported to contain TA-specific CD8+ and CD4+ T-cell precursors, as well as natural killer (NK) cells and macrophages that are capable of killing tumor cell targets after appropriate in vitro activation. CD8+ T cells are believed to play a major role in control of melanoma growth. It is thought that this immunosurveillance of melanoma often fails in patients. This has been the rationale for the development of immunotherapy of melanoma.

Parmiani G, Castelli C, Santinami M, Rivoltini L: Melanoma immunology: past, present and future, Curr Opin Oncol 19:121–127, 2007.