Melanoma and keratinocyte skin cancer (KSC) are the most common types of cancer in White-skinned populations. Both tumor entities showed increasing incidence rates worldwide but stable or decreasing mortality rates. Rising incidence rates of cutaneous melanoma (CM) and KSC are largely attributed to increasing exposure to ultraviolet (UV) radiation, the main causal risk factor for skin cancer.Incidence rates of KSC, comprising of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are much higher than that of melanoma. BCC development is mainly the cause of an intensive UV exposure in childhood and adolescence, while SCC development is related to chronic, cumulative UV exposure over decades. Although mortality is relatively low, KSC is an increasing problem for health care services causing significant morbidity.Cutaneous melanoma is rapidly increasing in White populations, with an estimated annual increase of around 3-7% over the past decades. In contrast to SCC, melanoma risk is associated with intermittent and chronic exposure to sunlight. The frequency of its occurrence is closely associated with the constitutive color of the skin and the geographical zone. Changes in outdoor activities and exposure to sunlight during the past 70 years are an important factor for the increasing incidence of melanoma. Mortality rates of melanoma show stabilization in the USA, Australia, and in European countries. In the USA even dropping numbers of death cases were recently reported, probably reflecting efficacy of the new systemic treatments.Among younger cohorts in some populations (e.g., Australia and New Zealand,), stabilizing or declining incidence rates of CM are observed, potentially caused by primary prevention campaigns aimed at reducing UV exposure. In contrast, incidence rates of CM are still rising in most European countries and in the USA. Ongoing trends towards thinner melanoma are largely ascribed to earlier detection.
Keywords: Chronic or intermittent sunlight exposure; Decreasing or stable mortality; Increasing incidence; Keratinocyte skin cancer; Melanoma.