Skin Cancer - Causes

Causes

Ultraviolet radiation from sun exposure is the primary cause of skin cancer. Other factors that play a role include:

• Smoking tobacco

• HPV infections increase the risk of squamous cell carcinoma.

• Some genetic syndromes including congenital melanocytic nevi syndrome which is characterized by the presence of nevi (birthmarks or moles) of varying size which are either present at birth, or appear within 6 months of birth. Nevi larger than 20 mm (3/4") in size are at higher risk for becoming cancerous.

• Chronic non-healing wounds. These are called Marjolin's ulcers based on their appearance, and can develop into squamous cell carcinoma.

• Ionizing radiation, environmental carcinogens, artificial UV radiation (e.g. tanning beds), aging, and light skin color. It is believed that tanning beds are the cause of hundreds of thousands of basil and squamous cell carcinomas.

• The use of many immunosuppressive medication increase the risk of skin cancer. Cyclosporin A, a calcineurin inhibitor for example increases the risk approximately 200 times, and azathioprine about 60 times.