Topical Diclofenac and Topical DFMO Chemoprevention Trial in Subjects With a History of Skin Cancer

There will be two groups to the study. Individuals, aged 18 years or older, who have extensive actinic damage, at least 8 AKs and a history of at least one non-melanoma skin cancer, but are in otherwise general good health, will be given topical diclofenac and topical DFMO. They will be compared to individuals, aged 18 years or older, who have extensive actinic damage, but are in otherwise general good health, will be given placebo. All participants must be at increased risk of non-melanoma skin cancer as evidenced by a history of prior squamous or basal cell skin cancer, ongoing or history of actinic keratoses, and the presence, at baseline, of at least eight actinic keratoses on the face, neck, scalp and arms. Subjects will be randomized to: 1. topical diclofenac once daily and topical DFMO once daily 2. placebo for the topical diclofenac once daily and placebo for the topical DFMO once daily