Chemopreventie van huidkanker

Despite an increased awareness of the importance of sun protection there still is a rise in the incidence of skin cancer. Patients at high risk of developing skin cancer can benefit from systemic chemoprevention to reduce the burden of skin tumors. Vitamin A derivates (beta-carotene, retinol and retinoid) have all been tested for their chemopreventive effect. Beta-carotene and retinol (topical and oral) have shown not to reduce keratinocyte cancers (KC) or melanoma. Use of oral retinoid has shown a reduction of the number of squamous cell carcinoma (SCC) in renal transplant recipients, but many patients withdrew because of side effects. In recent years studies have reported the effects of nicotinamide, the amide form of vitamin B3 in the prevention of KC. It appears to have a protective effect on SCC in immunocompetent patients and probably also in solid organ transplant recipients. Sunscreen is so far the best proven chemopreventive remedy for both KC and melanoma. More research is needed to show what can be added to the repertoire.