What Causes Skin Cancer? continued...
Ultraviolet (UV) radiation from the sun is the number-one cause of skin cancer, but UV light from tanning beds is just as harmful. Exposure to sunlight during the winter months puts you at the same risk as exposure during the summertime because UVA rays are present in daylight.
Cumulative sun exposure causes mainly basal cell and squamous cell skin cancer, while episodes of severe sunburns, usually before age 18, can contribute to developing melanoma. Other less common causes are repeated X-ray exposure and occupational exposure to certain chemicals.
Who Is at Risk for Skin Cancer?
Although anyone can get skin cancer, the risk is greatest for people who have fair or freckled skin that burns easily, light eyes and blond or red hair. Darker skinned individuals are also susceptible to all types of skin cancer, although their risk is substantially lower.
Aside from complexion, other risk factors include having a family history or personal history of skin cancer, having an outdoor job and living in a sunny climate. A history of severe sunburns and an abundance (greater than 30) of large and irregularly-shaped moles are risk factors unique to melanoma.
What Are the Symptoms of Skin Cancer?
The most common warning sign of skin cancer is a change on the skin, typically a new mole or skin lesion or a change in an existing mole.
- Basal cell carcinoma may appear as a small, smooth, pearly or waxy bump on the face, ears or neck, or as a flat pink, red or brown lesion on the trunk or arms and legs.
- Squamous cell carcinoma can appear as a firm, red nodule, or as a rough, scaly flat lesion that may bleed and become crusty. Both basal cell and squamous cell cancers mainly occur on areas of the skin frequently exposed to the sun, but can occur anywhere.
- Melanoma usually appears as a pigmented patch or bump but can also be red or white. It may resemble a normal mole, but usually has a more irregular appearance.
When looking for melanoma, think of the ABCDE rule that tells you the signs to watch for:
- Asymmetry - the shape of one half doesn't match the other
- Border - edges are ragged or blurred
- Color - uneven shades of brown, black, tan, red, white or blue
- Diameter - A significant change in size (greater than 6mm)- although any mole that begins enlarging should be brought to the attention of your dermatologist. Many melanomas are being diagnosed at much smaller diameters.
- Evolving - any new spot of mole changing in color, shape or size