Skin Cancer

Skin Cancer Causes

Ultraviolet (UV) light exposure, most commonly from sunlight, is overwhelmingly the most frequent cause of skin cancer.

Other important causes of skin cancer include the following:

• Use of tanning booths
• Immunosuppression-impairment of the immune system, which protects the body from foreign entities, such as germs or substances that cause an allergic reaction. This may occur as a consequence of some diseases or can be due to medications prescribed to combat autoimmune diseases or prevent organ transplant rejection.
• Exposure to unusually high levels of x-rays
• Contact with certain chemicals-arsenic(miners, sheep shearers, and farmers), hydrocarbons in tar, oils, and soot (may cause squamous cell carcinoma)

The following people are at the greatest risk:

• People with fair skin, especially types thatfreckle, sunburn easily, or become painful in the sun
• People with light (blond or red) hair and blue or green eyes
• Those with certain genetic disorders that deplete skin pigment such as albinism,xeroderma pigmentosum
• People who have already been treated for skin cancer
• People with numerous moles, unusual moles, or large moles that were present at birth
• People with close family members who have developed skin cancer
• People who had at least one severe sunburn early in life

Basal cell carcinomas and squamous cell carcinomas are more common in older people. Melanomas are more common in younger people. For example, melanoma is the most common cancer in people 25-29 years of age.

Skin Cancer Symptoms

A basal cell carcinoma (BCC) usually looks like a raised, smooth, pearly bump on the sun-exposed skin of the head, neck, or shoulders.

• Small blood vessels may be visible within the tumor.
• A central depression with crusting and bleeding (ulceration) frequently develops.
• A BCC is often mistaken for a sore that does not heal.

A squamous cell carcinoma (SCC) is commonly a well-defined, red, scaling, thickened patch on sun-exposed skin.

• Like BCCs, SCCs may ulcerate and bleed.
• Left untreated, SCC may develop into a large mass.

The majority of malignant melanomas are brown to black pigmented lesions.

• Warning signs include change in size, shape, color, or elevation of a mole.
• The appearance of a new mole during adulthood, or new pain, itching, ulceration, or bleeding of an existing mole should all be checked by a health-care provider.

The following easy-to-remember guideline, "ABCD," is useful for identifying malignant melanoma:

• Asymmetry-One side of the lesion does not look like the other.
• Border irregularity-Margins may be notched or irregular.
• Color-Melanomas are often a mixture of black, tan, brown, blue, red, or white.
• Diameter-Cancerous lesions are usually larger than 6 mm across (about the size of a pencil eraser), but any change in size may be significant.

When to Seek Medical Care

Many people, especially those who have fair coloring or have had extensive sun exposure, should periodically check their entire body for suggestive moles and lesions.

Have your primary health-care provider or a skin specialist (dermatologist) check any moles or spots that concern you.

See your health-care provider to check your skin if you notice any changes in the size, shape, color, or texture of pigmented areas (such as darker areas of skin or moles).

If you have skin cancer, your skin specialist (dermatologist) or cancer specialist (oncologist) will talk to you about symptoms of metastatic disease that might require care in a hospital.