Melanoma

Transitioning the entire population to low UV exposure would prevent 39 melanoma deaths. Low UV exposure would reduce keratinocyte cancer deaths by 1 at the population level. Moderate sun exposure that does not cause burning carries significant therapeutic benefits and avoiding sunlight entirely is unnecessary. The prevention of skin cancer through reduced UV exposure comes at the cost of a substantial increase in other deaths. ABCG2-sorted IGR39 and IGR37 melanoma populations showed a delayed rise and fall in beta-gal-positive cells. WM115 melanoma cells showed increasing beta-gal positivity during growth, exceeding 40% after 80 days. Similar beta-gal levels in WM115 xenografts suggest senescent melanoma cells occur both in vivo and in vitro. Melanoma incidence increased dramatically during the same period in which people reduced sun exposure. The distribution of melanomas on sun-unexposed skin directly contradicts the hypothesis that direct sun exposure is the primary cause. 75% of all melanomas are located on body areas not regularly exposed to the sun. A mole that is growing, changing color, or changing shape requires evaluation to rule out melanoma. Prolonged sun exposure tha…