Beta Blockers and Melanoma.

Understanding the mechanisms of cancer immune-tolerance is one of the most important challenges. Several studies have demonstrated the potential anticarcinogenic effects of beta-blockers, in patients with prostate cancer, breast cancer, and melanoma. At the other side variety of dermatoses may be caused or aggravated by β-blockers-psoriasis, lichen planus-like drug eruptions (LDE), acrocyanosis, alopecia etc. Beta-blockers have been shown to improve the prognosis of melanoma patients significantly. Propranolol inhibits melanoma by downregulating the tumour angiogenesis but also tumour cell proliferation, invasiveness and local immune suppression. Studies showed that only β3-but, not β2-adrenoceptors, were up-regulated under hypoxia in peripheral blood mononuclear cells and selectively expressed in immune cell sub-populations including Treg, MDSC, and NK. They increased NK and CD8 number and cytotoxicity. Catecholamines may retard melanoma progression and that β-blockers may have unrecognised potential as a therapeutic intervention for melanoma, in the prevention of the growth of melanoma in all stages and as adjuvant therapy with other targeted and immune therapies for melanoma.