New strategies in melanoma: Vaccines and chemoprevention

May 1, 2005

New Orleans — Two new strategies for treating melanoma are the use of vaccines and chemoprevention, according to Marie-France Demierre, M.D., from the Skin Oncology Program, Boston Medical Center.

Vaccine therapy "In oncology, active immunotherapy with specific vaccines has now become an accepted approach to targeting cancers," said Dr. Demierre at the 63rd Annual Meeting of the American Academy of Dermatology, here.

There is evidence that host defense mechanisms can influence the growth of cancer. Studies have found:

"T-cells play an important role in the in vivo rejection of melanoma" Dr. Demierre says. "T-cell infiltrates are present in regressing tumors after IL-2-based immunotherapy, and there is a correlation between the accumulation of injected T-cells in tumor sites and clinical response to tumor-infiltrating T lymphocytes."

New alternatives She notes that the identification of antigens recognized by cytotoxic T-cells has provided new immunotherapeutic alternatives, and cytotoxic T-cell clones identify three categories of melanoma antigens:

The three most extensively studied immunogenic peptides have been tyrosinase, gp100 and MART-1.

The immune system The immune system functions via two interdependent types of immune responses: innate immunity and adaptive immunity.

"In innate immunity, an immediate immune response is triggered that signals immune cells to attack and contain pathogens/tumor cell antigen until a long term and more specific response can be generated," she tells Dermatology Times.

"Adaptive immunity will fight the existing pathogen/antigen and enables the immune system to recognize and respond more rapidly to a subsequent encounter with the same antigen (immune memory)," she adds.