Retinoids for Chemoprophylaxis of Nonmelanoma Skin Cancer

The document reviews the effectiveness of retinoids in preventing nonmelanoma skin cancer (NMSC) in high-risk populations, including organ transplant recipients (OTRs) and individuals with certain medical conditions or genetic syndromes. It discusses the pharmacology and mechanisms of retinoids, such as isotretinoin and acitretin, and their role in inhibiting the promotion and progression of carcinogenesis. The review includes studies with varying results: one with 11 renal transplant recipients showed fewer NMSCs with etretinate, and a trial with 19 patients found a significant reduction in SCCs with acitretin. However, a study with 525 patients did not find a significant difference in BCC or SCC occurrence between those treated with retinoids and those given a placebo. Side effects of retinoid therapy are generally mild but dose-related, and include mucocutaneous effects and laboratory abnormalities. The document concludes that while systemic retinoids are effective in preventing NMSC in high-risk groups, their toxicity can be limiting, and more research is needed to determine optimal dosing and efficacy.