Showing posts with label Mucosal Melanoma. Show all posts
Showing posts with label Mucosal Melanoma. Show all posts

Mucosal Melanoma

Mucosal melanoma is considered an epidemic cancer as its worldwide incidence has increased 697% between 1950 and 2000, faster than that of any other cancer subtype; although, recent evidence suggests that this rise many have peaked. The American Cancer Society noe estimates thet the lifetime risk of developing melanoma is approximately 1 in 50 for Caucasians, 1 in 200 for African Americans. In the United States, invasive melanoma is the 6th most common cancer in men and the 7th in women; the lifetime probability of developing this tumor is 1 in 37 for males and 1 in 56 for females. An estimated 68,130 new cases of cutaneous melanoma were diagnosed in 2010, with 8,700 estimated deaths from this disease. While representing <7% of all skin malignancies, melanoma is the most lethal cutaneous malignancy and accounts for 75% of all deaths from skin tumors.

Melanoma tumors can demonstrate spontaneous immune-mediated regression. In addition, tumor-specific cytotoxic T-cells and antibodies may be found in the peripheral blood of patients with melanoma. Therefore, immunotheray is a potentially effective treatment strategy for individuals with the disease. One approach is the enhancement of anti-melanoma immune responses through the optimization of T-cell activation. The latter involves interactions between the T-cell receptor (TCR), the co-stimulatory receptor CD28, and the ligands CD80 and CD86.

T-cell inhibition is mediated by the inhibitory receptor, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a molecule that shares 30% structural homology with CD28, and is expressed by activated T-cells and T-regulatory cells (Tregs). CLTA-4 binds CD80/CD86 with greather affinity than CD28 does, theraby inhibiting CD28-mediated T-cell activation and IL-2 production. CTLA-4 is critical in maintaining immune tolerance to self-antigens, but may also limit host responses to tumor antigens and the efficacy of vaccine therapy.