Cutaneous malignant melanoma: facts about sunbeds and sunscreen. 
The incidence of cutaneous malignant melanoma is still increasing in most light-skinned populations.  Sunscreen use has been proposed for the primary prevention of melanoma.  However, sunscreen use may increase time spent in the sun when users are willing to acquire a tan or to stay in the sun for a long time, which may increase melanoma risk.  When sun exposure is not associated with the desire to acquire a tan or stay in the sun for a long time, sunscreen use may prevent squamous cell skin carcinoma.  Sun protection should give priority to clothing and sun exposure reduction.  Over the last 20 years, tan acquisition through exposure to artificial sources of ultraviolet radiation has become frequent among fair-skinned adolescents and young adults.  There is accumulating evidence that sunbed use is associated with melanoma when started before approximately 30 years of age.