Abstract

Chronic exposure to sunlight with its high proportion of high energy ultraviolet light is the main cause of the common cutaneous precancerous lesions and carcinomas of the head and neck. This causes a field cancerization effect frequently with multiple actinic keratoses (AKs), basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs). Although demonstrating the best cure rates and lowest recurrence rates, surgical excision rapidly progresses to its limits. Field cancerization requires field therapy. Non-specific caustic agents may remove superficial lesions, however, the modern therapeutic modalities such as topical cytotoxic treatment with 5-fluorouracil, photodynamic therapy with 5-aminolevulinic acid (ALA) or its methyl ester (MeALA), the topical immune response modifier imiquimod or the local application of the cyclooxygenase inhibitor diclofenac are more specific and effective. Intralesional and perilesional injections of cytotoxic agents and interferons as well as the new targeted anti-cancer drugs are further alternatives. The most important aspect, however, is the prophylaxis of chronic photodamage.