Originally Posted by Alaska Gator

What Is Melanoma?

Melanoma is the most serious type of skin cancer.

Melanoma is the most serious type of skin cancer. It begins in skin cells called melanocytes.
Melanocytes are the cells that make melanin, which gives skin its color. Melanin also protects the deeper layers of the skin from the sun's harmful ultraviolet (UV) rays.
When people spend time in the sunlight, the melanocytes make more melanin and cause the skin to tan. This also happens when skin is exposed to other forms of ultraviolet light (such as in a tanning booth). If the skin receives too much ultraviolet light, the melanocytes may begin to grow abnormally and become cancerous. This condition is called melanoma.

Melanoma rate among commercial airline pilots is about 3 times the rate of the general population. However, day vs. night, pax vs. freight does not change the rates. I believe that is why the current scientific thought leans toward circadian disruptions as the cause of this increased rate.