Does mountaineering increase the incidence of cutaneous melanoma? A hypothesis based on cancer registry data.

Exposure to ultraviolet radiation is considered a major risk factor for the development of cutaneous melanoma. In white populations in Australia or the USA, the melanoma incidence increases with the vicinity of residence to the equator. In Europe decreasing incidence rates towards southern countries may be due to the darker pigmentation of the Mediterranean population. The comparison of age-standardized incidence rates (world standard population) in Europe shows that Swiss cancer registries and the Austrian Tyrol registry have much higher incidence rates for cutaneous melanoma than other Central European cancer registries. The excess of Swiss/Austrian incidence rates is even more pronounced when head localization is analysed separately. Due to the altitude-related increase in UV radiation two possible explanations for the Swiss/Austrian excess rates may be considered: firstly, as a result of the altitude of residence, higher UV exposure is generally present in these countries; secondly, mountaineering activities may additionally increase UV exposure.