Melanoma is the most dangerous type of skin cancer. It is a cancer that develops in melanocytes, cells which produce a skin pigment called melanin. Skin and hair colour are due to melanin. Melanoma is the leading cause of death from skin disease. In rare cases malignant melanoma may also begin in the eyes, the respiratory passage, the intestine, or the brain. Melanoma occurs in areas of the body that have the melanocyte cells.
Melanin is normally a protective pigment that protects the skin by absorbing the ultraviolet (UV) radiation. Melanocytes cells distribution in the skin is similar in both the black and in white skin, however in black skin the melanocytes produce more melanin. Hence people with dark brown or black skin are very much less likely to be damaged by UV radiation than those with white skin. Moles and freckles are non-cancerous growth of melanocytes.
Major risk factors for the incidence of Melanoma include:
- Life in sunny climates or at high altitudes
- Long-term exposure to high levels of strong sunlight. Slow daily sun exposure may considerably raise your risk of skin cancer.
- One or more blistering sunburns during childhood
- Use of tanning devices
Other risk factors include -
(1) Having a family history of malignant melanoma, i.e. if you have someone in the family diagnosed with the cancer.
(2) Exposure to carcinogenic chemicals, i.e. those which can cause cancer, such as arsenic, coal tar, and creosote
Presence of certain types of moles (atypical dysplastic) or multiple birthmarks
(3) A weak immune system. This may be due to a number of causes like AIDS, some types of blood cancer (leukemias), side effect of drugs etc.