A systematic review 1 including about 17 studies for primary prevention and 30 studies for secondary prevention was abstracted in DARE.
Primary prevention: One RCT (588 adults during one summer) has shown the effectiveness of sunscreens in the prevention of solar keratoses (mean difference 1.53 keratoses, 95% CI 0.81 to 2.25). Evidence that sun exposure behaviour can be altered is very weak. Beta carotene and isotretinoin were not effective in RCTs (one RCT for each) in the prevention of non-melanoma skin cancer and basalioma respectively.
Secondary prevention: The effectiveness of screening for skin cancer is incomplete.
Comment: The quality of evidence is downgraded by study quality (very limited information about the original study in the review) and by imprecise results (few patients and wide confidence intervals).
Primary/Secondary Keywords