We know that ultra-violet radiation (UV) is a carcinogen and that sun exposure or indoor tanning are risk factors for melanoma. However we also know that not all melanomas are due to UV exposure. In a recent study from the American Cancer Society investigators tried to qualify the amount of melanoma that is related to UV exposure vs other causes. Their conclusion is not completely surprising. The researchers found that during 2011 to 2015, the estimated number of melanoma cases attributable to UV exposure in the United States was 338,701, that is 91% of the total cases. The effect of UV exposures causing melanoma was most prevalent in sunny climates. So the highest association was in Hawaii where they estimated over 97% of melanomas were UV induced. This contrasts with the District of Columbia where only about 88% of melanomas where thought to be UV induced. This just goes to emphasis the need for good UV avoidance / protection especially if you are living in a sunny environment. It also though reminds us that melanomas can occur in none sun exposed areas too. So remember to check all of you skin not just the exposed parts.

Article Citation

Cutaneous melanomas attributable to ultraviolet radiation exposure by state.
Farhad Islami et al
Int. J. Cancer: 00, 00–00 (2020)